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By Jon F. Hunter, David P. Seaton, William M. Lively, Gerald E. Miller, and David L. Stoner . . . 5 Thin Layer Chromatography of Nitrogen Heterocycles on a Modified Silica Gel Support. By W. E. Rudzinski . . . . .37 Some Structural Aspects of a Western Cross Timbers Forest in North Central Texas. By Glenn C. Kroh and James Nisbet . . . . . 41 Heavy Metal Pollution in El Paso During Selected Time Periods. By Howard G. Applegate and Keith Redetzke . 47 The Commercial Production of Mudminnows ( Fundulus grandis ) for Live Bait: A Preliminary Economic Analysis. By Benita P. Waas, Kirk Strawn, Michael Johns, and Wade Griffin . . . 51 Effects of a High Potassium Diet and Prostaglandin on Induced Gastric Ulceration in Rats. By Marshall J. Mann and David P. Shepherd . 61 Biological Form Representation by Techniques Developed for Airfoils. By W. M. Heffington and K. L. Eaves . . . 67 Circulating Corticosteroid and Leucocyte Dynamics in Channel Catfish during Net Confinement. By J. R. Tomasso, Bill A. Simco, and Kenneth B. Davis . 83 Comparative Digestive Efficiency of White-tailed and Sika Deer. By Christopher Wheaton and Robert D. Brown . . . . . 89 Summer Diet of Finfish from Nearshore Habitats of West Bay, Texas. By Steve K. Alexander . 93 THE TEXAS JOURNAL OF SCIENCE Volume XXXV, No. 2 July 1983 CONTENTS Instructions to Authors . . . . . . . .99 Observation of Episodic Sedimentation in a Tidal Inlet (Sabine Pass, Texas and Louisiana). By George H. Ward, Jr . . . . . 101 Midwater Fishes of the Gulf of Mexico Collected from the R/V Alaminos, 1965-1973. By Edward O. Murdy, Richard E. Matheson, Jr., Janice D. Fechhelm, and Michael J. McCoid . 109 In Vitro Analysis of Transfer Factor Activity in Guinea Pig Leukocyte Extracts by the Agarose Drop Assay. By Andrew Paquet, Jr., George B. Olson, and C. G. Drube . 129 Variation in Transplantable Tumor Growth-parameters Can Be Reduced. By David G. Morrison, Mary Pat Moyer, Jay C. Daniel, Waid Rogers, and Rex C. Moyer . HI Paleoenvironmental Significance of a Nonmarine Pleistocene Molluscan Fauna from Southern Texas. By Raymond W. Neck . H7 Caloric Value of the Liver Fluke, Fasciola hepatica. By Jeremy M. Jay and Norman O. Dronen . 155 Status of Bighorn Sheep in Texas. By Bruce D. Leopold and Paul R. Krausman . . . 167 Eggs and Young of Schott’s Whipsnake, Masticophis taeniatus schotti. By Hugh K. McCrystal and James R. Dixon . 161 Observations on Host Selection by Lysathia ludoviciana (Chrysomelidae), a Beetle with Potential for Biological Control of Certain Aquatic Weeds. By John M. Campbell and William J. Clark . 165 Characterization of Erythrocyte Esterases on Electrophoretic Gels. By John P. Cherry . . . 169 THE TEXAS JOURNAL OF SCIENCE Volume XXXV, No. 3 September 1983 CONTENTS Instructions to Authors . 179 Geology’s Heritage and Promise. By Michel T. Halbouty . . 181 Translation of C Shell Scripts to C for Faster Execution of UNIX Computer Programs. By Grady Early, Jane Gambill and Teresa Thomas . 189 Vegetational Analysis of a Post Oak-Black Hickory Community in Eastern Texas. By K. L. Marietta and E. S. Nixon . 197 Woody, Streamside Vegetation of Prairie Creek in East Texas. By E. S. Nixon, R. L. Ehrhart, S. A. Jasper, J. S. Neck and J. R. Ward . 205 Global Inverse Function Theorem. By John D. Miller . 215 New Records of Invertebrate Saprovores from Barn Owl Pellets. By Kirk L. Hamilton and Annemarie B. Hamilton . . . 219 A New Edgeworth-type Expansion. By James G. Galloway and E. D. McCune . 221 Relationships of Sugar Maples (Acer saccharum and A. grandidentatum ) in Texas and Oklahoma with Special Reference to Relict Populations. By Frederick R. Gehlbach and Robert C. Gardner . 231 Recent Population Trends of Cormorants (Aves: Pelicaniformes) in Texas. By Michael L. Morrison, Brenda S. Hale and R. Douglas Slack . 239 Occurrence of the Caddisfly Atopsyche erigia in Texas’ Guadalupe River below Canyon Reservoir. By Robert A. Short . 243 Herpetofauna of the Pedro Armendariz Lava Field, New Mexico. By Troy L. Best, Herman C. James, and Frank H. Best . 245 Taxonomic Status of the Brazilian Colubrid Snake, Xenodon suspectus Cope. By James R. Dixon . 257 Viscometric Measurement of the Cellulase Activity of a Soil Fungus. By J. Ortega and E. J. Baca . . . . . 261 New Records of the Freshwater Ectoproct Pectinatella magnifica in Eastern Texas. By Raymond W. Neck and Richard W. Fullington . . .269 THE TEXAS JOURNAL OF SCIENCE Volume XXXV, No. 4 January 1984 CONTENTS Instructions to Authors . . . . . . .275 Toric Sections. By Ali R. Amir-Moez and Gregory A. Fredricks . 277 Use of Fissiogenic Stable Ruthenium Versus Xenon Isotopes in the Determination of Induced Fission in Uranium Ores. By Moses Attrep, Jr., and Kung Hsing-Tung . 283 The Death Dip Among Ordinary Folks: A Study of the Dip/Peak Phenomenon for Texans Dying in 1979. By Rollo K. Newsom, Alvin P. Short, Louis M. Tanner, and T. C. Borelli . . . 293 Cattle Egrets ( Ardeola ibis = Bubulcus ibis ) in Texas. By Raymond C. Telfair II and Larry E. Marcy . . . 303 Swim Bladder Stress Syndrome in Largemouth Bass. By Gary J. Carmichael and J. R. Tomasso . 315 Distributional Records and Notes for Nine Species of Mammals in Eastern Texas. By Arthur G. Cleveland, John T. Baccus, and Earl G. Zimmerman . 323 Development of Tensile Strength in Compatible Autografts of Eggplant ( Solanum pennellii) and Tomato ( Lycopersicon esculentum). By Mary T. McGarry and Randy Moore . . . 327 Abstracts of the Ninth North American Physarum Conference . 333 Index to Volume XXXV . . . 349 Reviewers 362 SECTION I MATHEMATICAL SCIENCES Mathematics, Statistics, Operations Research SECTION X AQUATIC SCIENCES SECTION IX COMPUTER SCIENCES The Texas Academy of Science SECTION II PHYSICS SECTION III EARTH SCIENCES Geography Geology SECTION VIII SCIENCE EDUCATION SECTION VII CHEMISTRY SECTION VI ENVIRONMENTAL SCIENCES SECTION IV BIOLOGICAL SCIENCES Agriculture, Botany, Medical Science, Zoology SECTION V SOCIAL SCIENCES Anthropology, Education, Economics, History, Psychology, Sociology AFFILIATED ORGANIZATIONS Texas Section, American Association of Physics Teachers Texas Section, Mathematical Association of America Texas Section, National Association of Geology Teachers GENERAL INFORMATION MEMBERSHIP. Any person or group engaged in scientific work or interested in the pro¬ motion of science is eligible for membership in The Texas Academy of Science. Dues for members are $20.00 annually; student members, $12.00 annually; sustaining members, at least $30.00 in addition to annual dues; life members, at least $400.00 in one payment; patrons, at least $500.00 in one payment; corporate members, $250.00 annually; corporate life members, $2000.00 in one payment. Library subscription rate is $45.00 annually. Pay¬ ments should be sent to the Secretary-Treasurer, Box 2176, Huntsville, TX 77341. The Journal is a quarterly publication of The Texas Academy of Science and is sent to all members and subscribers. Inquiries regarding back issues should be sent to Dr. Fred S. Hendricks, Dept. Wildlife 8c Fisheries Sciences, Texas A8cM University, College Station, TX 77843. Manuscripts submitted for publication in the Journal should be sent to Dr. W. H. Neill, Dept. Wildlife 8c Fisheries Sci., Texas A8cM Univ., College Station, TX 77843. The Texas Journal of Science (USPS 616740) is published quarterly at Huntsville, Texas U.S.A. (Second class postage paid at Post Office, Huntsville, TX 77341, and at additional mailing office at Lubbock, TX 79401.) Please send form 3579 and returned copies to Texas Tech Press, Box 4240, Lubbock, TX 79409.) THE TEXAS JOURNAL OF SCIENCE Volume XXXV, No. 1 March 1983 CONTENTS Instructions to Authors . . . . . 3 Modeling Systolic Mitral Valve Motion: A Tool for Clarifying Mitral Valve Prolapse. By Jon F. Hunter, David P. Seaton, William M. Lively, Gerald E. Miller, and David L. Stoner . 5 Thin Layer Chromatography of Nitrogen Heterocycles on a Modified Silica Gel Support. By W. E. Rudzinski . 37 Some Structural Aspects of a Western Cross Timbers Forest in North Central Texas. By Glenn C. Kroh and James Nisbet . . . . . 41 Heavy Metal Pollution in El Paso During Selected Time Periods. By Howard G. Applegate and Keith Redetzke . . . 47 The Commercial Production of Mudminnows ( Fundulus grandis) for Live Bait: A Preliminary Economic Analysis. By Benita P. Waas, Kirk Strawn, Michael Johns, and Wade Griffin . . . . . 51 Effects of a High Potassium Diet and Prostaglandin on Induced Gastric Ulceration in Rats. By Marshall J. Mann and David P. Shepherd . 61 Biological Form Representation by Techniques Developed for Airfoils. By W. M. Heffington and K. L. Eaves . . . . . 67 Circulating Corticosteroid and Leucocyte Dynamics in Channel Catfish During Net Confinement. By J. R. Tomasso, Bill A. Simco, and Kenneth B. Davis . . . . . . . . . . . . 83 Comparative Digestive Efficiency of White-tailed and Sika Deer. By Christopher Wheaton and Robert D. Brown . . . . . 89 Summer Diet of Finfish from Nearshore Habitats of West Bay, Texas. By Steve K. Alexander . . . 93 \ \\ \r NOTE: Authors with funds for page contributions are expected to make such payments. The contribution of $35.00 per page is encouraged to defray printing costs, and authors of articles exceeding ten printed pages are expected to make some contribution to the publication fund. How¬ ever, payment of printing costs is not a condition for publication in The Texas Journal of Science, and NO AUTHOR, WHO WOULD OTHER¬ WISE SUBMIT A MANUSCRIPT, SHOULD HESITATE TO DO SO BECAUSE OF LACK OF SUCH FUNDS. Members without funds may apply to the Texas Academy of Science for a grant to cover some or all costs of publication. This becomes effective January 23, 1982. INSTRUCTIONS TO AUTHORS Papers intended for publication in The Texas Journal of Science are to be submitted to Dr. William H. Neill, Dept. Wildlife & Fisheries Sciences, Texas A&M University, College Station, TX 77843. The manuscript is not to have been published elsewhere. Triplicate typewritten copies (the original and 2 reproduced copies) must be sub¬ mitted. Typing of both text and references should be double-spaced with 2-3 cm margins on standard 8V2 X 11 -inch typing paper. The title of the article should be followed by the name and business or institutional address of the author(s). Be sure to include zip code with the address. If the paper has been presented at a meeting, a footnote giving the name of the society, date, and occasion should be included but should not be numbered. Include a brief ABSTRACT at the beginning of the text (abstracting services pick this up directly) followed by an INTRODUC¬ TION (understandable to any scientist) and then whatever paragraph headings are desired. The usual editorial customs, as exemplified in the most recent issue of the Journal, are to be followed as closely as possible. In the text, cite all references by author and date in chronological order , i.e., Jones (1971); Jones (1971, 1972); (Jones 1971); (Jones 1971, 1972); Jones and Smith (1971); (Jones and Smith 1971); (Jones 1971; Smith 1972; Beacon 1973). If there are more than 2 authors, use: Jones et al. (1971); (Jones et al. 1971). References are then to be assembled, arranged ALPHABETICALLY, and placed at the end of the article under the heading LITERATURE CITED. For a PERIODICAL ARTICLE use: Jones, A. P., and R. J. Wilson. 1971. Effects of chlorinated hydrocarbons. J. Comp. Chem. 37:116-123. For a PAPER PRESENTED at a symposium, etc., use the form: Jones, A. P. 1971. Effects of chlorinated hydrocarbons. WMO Symposium on Organic Chemistry, New York, N.Y. For a PRINTED PAPER use: Jones, A. P. 1971. Effects of chlorinated hydrocar¬ bons. Univ. of Tex., Dallas, or Jones, A. P. 1971. Effects of chlorinated hydrocarbons. Univ. of Tex. Paper No. 14, 46 p. A MASTERS OR Ph D. THESIS should appear as: Jones, A. P. 1971. Effects of chlorinated hydro¬ carbons. M.S. Thesis, Tex. A&M Univ., College Station. For a BOOK, NO EDITORS, use: Jones, A. P. 1971. Effects of chlorinated hydrocarbons. Academic Press, New York, N.Y., 439 p. For a CHAPTER IN A BOOK WITH EDITORS: Jones, A. P. 1971. Structure of chlorinated hydrocarbons, p. 13-39. In A. P. Jones, B. R. Smith, Jr. and T. S. Gibbs (Eds.), Effects of chlorinated hydrocarbons. Academic Press, New York, N.Y. For a BOOK WITH EDITORS: Jones, A. P. 1971. Effects of chlorinated hydrocarbons. J. Doe (Ed.). Academic Press, New York, N.Y., p. 3-12. For an IN PRESS PERIODICAL reference, use: Jones, A. P. In Press. Effects of chlorinated hydrocarbons. J. Org. Chem. For an in PRESS BOOK reference, use: Jones, 4 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 A. P. In Press. Effects of chlorinated hydrocarbons. Academic Press, New York, N.Y. References must include article title and page numbers. References such as unpublished data or personal communications should not be listed in the LITERATURE CITED section. However, within the text they should be presented as: (unpubl. data from C. J. Jones, Dept. Zoology, Univ. Texas, Austin) or (pers. comm, from R. C. Smith, P.O. Box 133, Mexia, TX). All tables are to be typed with a carbon ribbon, free of error, without handwritten notations, and ready for photographic reproduction. Tables should be placed on separate sheets with a marginal notation on the manuscript to indicate preferred locations. Tables must have a text refer¬ ence, i.e., Table 2 shows. . .or (Table 2). Figures are to be original inked drawings or glossy photographs no larger than 6% X 4% inches and mounted on standard 8% X 11-inch paper. Legends for figures are to be typed separately. Figures must have a text reference, i.e., Figure 3 illustrates. . .or (Fig. 3). All photographs, line drawings, and tables are to be provided with self-explanatory titles or legends. Each illustration should be marked on the back with the name of the principle author, the figure number, and the title of the manuscript of which it is a part. Authors will receive galley proofs plus the original typescript along with information concerning reprints and page charges. Proofs must be corrected (using ink) and returned to the Editor within 3 days. Payment (check or purchase voucher) for page charges (or the publication grant request) must accompany the return of the corrected proofs or a delay in the printing of the manuscript could occur. Reprint orders should be returned directly to Texas Tech Press, Box 4240, Lubbock, TX 79409 NOTICE: IF YOUR ADDRESS OR TELEPHONE NUMBER CHANGES, NOTIFY US IMMEDIATELY SO WE CAN SEND YOUR GALLEY PROOFS TO YOU WITH¬ OUT LOSS OR DELAY. MODELING SYSTOLIC MITRAL VALVE MOTION: A TOOL FOR CLARIFYING MITRAL VALVE PROLAPSE' by JON F. HUNTER/" DAVID P. SEATON/ WILLIAM M. LIVELY/ GERALD E. MILLER," and DAVID L. STONER" 1 Department of Veterinary Physiology and Pharmacology, b Bioengineering Program, and c Computing Science Division Texas A&M University College Station, TX 77843 ABSTRACT A dynamic model of the human heart’s mitral valve motion during systole is presented. This model includes a description of the geometrical interrelationships between compo¬ nents of the mitral apparatus, namely mitral valve leaflets, annulus, chordae tendineae, papillary muscles, and left ventricle. The biomechanical properties of the mitral valve leaflets and chordae tendineae and the contractile nature of the annulus, papillary mus¬ cles and left ventricle are considered. Mitral valve profile/position is described for selected properties of model components. INTRODUCTION Mitral valve prolapse (also referred to as floppy or billowing mitral valve, systolic-click/late-systolic-murmur syndrome, Barlow’s or Reid- Barlow’s syndrome, or idiopathic mitral valve prolapse) has been des¬ cribed as the most common cardiac valve disorder (Jeresaty 1979). The exact prevalence of mitral valve prolapse is unknown, but results of various surveys indicate that approximately 4% of the general popula¬ tion may be affected (Brown et al. 1975; Procacci et al. 1976; Jeresaty 1979). Numerous articles describing this syndrome have been published during the past fifteen years and recent advances in ultrasound instru¬ mentation have greatly aided in its detection. However, considerable controversy still remains regarding the etiology, criteria for diagnosis, and significance of mitral valve prolapse. Normal function of the mitral apparatus depends upon the coordi¬ nated interaction of mitral valve leaflets, annulus, chordae tendineae, papillary muscles, the left ventricle, and the left atrium (Devereux et al. 1976). Mitral valve prolapse has been associated with alterations in all of these components except the left atrium. This model is a computer simulation of the anatomical and physiological interrelationships of •This investigation was supported under United States Air Force Contract F33615-78-D- 0629. The Texas Journal of Science, Vol. XXXV, No. 1, March 1983 6 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 those components of the mitral apparatus which have been implicated as contributing to prolapse. It is based on published anatomical and physiological data and is limited, as are other models of the mitral valve, by the assumption of quasi-static forces in the system (Burch and DePasquale 1965; Burch and Giles 1972; Ghista and Rao 1972; Clark and Sutera 1973). Large excursions of the mitral valve occur during five phases of the cardiac cycle — (1) rapid ventricular filling, (2) slow ventricular filling, (3) atrial systole, (4) isovolumetric systole (aortic valve closed), and (5) ventricular ejection (aortic valve open) (Karas and Elkins 1970). Valve motion during diastole is particularly complex. It is influenced by pressure differences across the mitral valve, geometry of the mitral opening and surrounding structures, transient vortices adjacent to the valve, and possibly active contraction of the muscle fibers in the leaflets (Zaky et al. 1969; Priola et al. 1970; Bellhouse 1972a, b; Hwang 1977). Diastolic valve motion has been excluded from this model due to the lack of quantitative information on the effects of pressure, flow, and active contraction during diastole. The effects of flow through the mitral valve opening can be neg¬ lected during systole provided regurgitation is not occurring. This sim¬ plifies the mathematical description of valve motion and since the intent of this model is to provide a better understanding of mitral valve prolapse, a systolic event, it seems logical to concentrate on this phase of the cardiac cycle. A computer program has been developed that accepts clinically obtained data, data based on published reports, and/or modeling assumptions and predicts mitral valve position/profile during systole. This approach was taken so that model verification and possibly diag¬ nostic screening could easily be achieved without major alteration of the program. Thus, input parameters were selected so that clinical measurements could be obtained using non-invasive instrumentation — electrocardiography, apexcardiography, carotid pulse pressures, indirect blood pressure, and cardiac imaging techniques (cineangiography or real-time ultrasound). DESCRIPTION OF THE MODEL Coordinate System Understanding the geometry of the mitral apparatus is essential for appreciating the interrelationships that exist between the various com¬ ponents of this model. An orthogonal coordinate system was devised to simplify the three dimensional description of the anatomy and dynamic motion associated with the various cardiac structures. This coordinate system is formed by the intersection of three planes (Fig. 1): (1) an x-y MODELING MITRAL VALVE MOTION 7 Figure 1. Coordinate system for the mitral apparatus. The origin is located at the cen¬ ter of attachment of the anterior leaflet to the annulus. plane that contains the mitral valve annulus and remains perpendicu¬ lar to the long axis of the ventricle throughout the cardiac cycle (Tsaki- ris et al. 1971), (2) an x-z plane that passes perpendicular to a line of coaptation and through the middle portions of the anterior and poste¬ rior mitral valve leaflets, and (3) a y-z plane passing through the ante¬ rior leaflet-annulus attachment. 8 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Pressure and Timing Considerations Systole has been classically defined as the period of ventricular con¬ traction beginning with the rise of the left ventricular pressure and ending at the time of the incisural notch of the aortic pressure pulse (Wiggers 1921). For purposes of this simulation, ventricular systole is considered to be the interval between the Q-wave of the electrocardio¬ gram and the incisural notch. To assist in properly sequencing the var¬ ious active contractions and pressure related events that are described in this model, systole is subdivided into three time periods— (1) electrome¬ chanical delay time (EDT), (2) isovolumetric contraction time (IVCT), and (3) ejection time (ET). The duration of these various phases of sys¬ tole is influenced by a number of factors, including stroke volume, aor¬ tic pressure, heart rate, and end diastolic volume (Wiggers 1921; Braunwald et al. 1958; Wallace et al. 1963). Electromechanical delay time (EDT) is the interval between electrical stimulation and mechanical contraction of the myocardium. It proba¬ bly represents the delay associated with the excitation-contraction cou¬ pling of individual muscle fibers (Spodick and Kumar 1968a). This phase of ventricular systole begins with the onset of the Q-wave of the EGG; however, the exact time of termination of this phase is poorly defined. Some researchers consider the mitral component of the first heart sound as defining the end of EDT (Frank and Kinlaw 1962). Other investigators believe that the kinetocardiograph provides an accurate indication of the termination of EDT (Harrison et al. 1964). Spodick and Kumar (1968a) report that the endpoint of EDT more appropriately corresponds to a distinctive portion of the apexcardio- gram, the apexcardiogram upstroke (ACGU). They have shown that ACGU coincides with the onset of intramural myocardial tension and therefore appears to be the best indicator of the initiation of ventricular contraction. Model assumptions: 1. During the period corresponding to the electromechanical delay time (EDT), the only component of the mitral apparatus that is actively contracting is the annulus (Tsakiris et al. 1971). 2. The mitral valves are in equilibrium and the leaflets are coapted during EDT. (This assumption is contradictory to published reports that valve closure does not occur until ventricular pressure rises, approximately 20 msec following the end of the EDT phase (Kostis et al. 1969; Fabian et al. 1972); however, this assumption is defensible based upon the fact that valve motion is negligible immediately following closure and therefore previous movements will have minimal influence on subsequent valve positions (Upton et al. 1976).) MODELING MITRAL VALVE MOTION 9 100 Transvalvular Pressure 50 (Hypothetical) 0 Carotid Pressure Profile Apexcardiogram Electrocardiogram M-IVCTHh - ET - H EOT i i i i i i Time (msec) 0 100 200 300 400 500 Figure 2. Diagrammatic representation of pressure and timing events during systole — electromechanical delay (EDT), isovolumetric contraction time (IVCT), ejection time (ET), apexcardiogram upstroke (ACGU), pulse transmission delay (PTT), carotid pulse upstroke (CARU), and carotid pulse incisura (GARIN). Input data (Fig. 2): Hypothetical— Electromechanical delay time (EDT) equals 22 msec (Spodick and Kumar 1968a). Clinical-Electromechanical delay time (EDT) as determined by measuring the interval between the onset of the Q-wave and the upstroke of the apexcardiogram (EDT = QWAVE— ACGU). Isovolumetric contraction time (IVCT) is the period of the caardiac cycle extending from the end of EDT to the opening of the aortic valve. IVCT changes from beat to beat and has been shown to be affected by heart rate, contractile state of the myocardium, ventricular end-diastolic volume, aortic diastolic pressure, and stroke volume (Wallace et ah 1963; Harrison et al. 1964; Kumar and Spodick 1970; Fabian et al. 1972; Hirschfeld et al. 1976). For purposes of this model the onset of this 10 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 phase is associated with the upstroke of the apexcardiogram (ACGU). The three most commonly used indicators for the end of IVCT are (1) the carotid pulse upstroke (CARU), (2) the carotid pulse upstroke cor¬ rected for pulse transmission delay (CARUC), and (3) the E point of the apexcardiogram (Spodick and Kumar 1968b; Kumar and Spodick 1970; Oreshkov 1972; Fabian et al. 1972). For purposes of this model, the carotid pulse upstroke corrected for pulse transmission delay is the most accurate timing index. Pulse transmission delay (PTT) may be determined by simultaneously recording carotid pulse profile and pho- nocardiograms; the time between the aortic component of the second heart sound and the nadir of the carotid incisura provides an accurate estimate of PTT. The average PTT for the right carotid artery is approximately 23 msec (Fabian et al. 1972). Model assumptions: 1. Left ventricular wall and papillary muscle contractions begin with the onset of IVCT (Spodick and Kumar 1968b; Hirakawa et al. 1977). 2. Transvalvular pressure increases linearly during this phase of the cardiac cycle. Input data (Fig. 2): Hypothetical — Isovolumetric contraction time (IVCT) equals 71 msec (Kumar and Spodick 1970). Transvalvular pressure (TP) at the end of IVCT equals 80 mm Hg. Clinical — Isovolumetric contraction time (IVCT) as determined from apexcardiogram and carotic pulse recordings corrected for pulse transmission delay (IVCT = ACGU— CARUC). Transvalvu¬ lar pressure (TP) at the time of aortic valve opening may be esti¬ mated using standard indirect sphygmomanometric techniques to determine peripheral diastolic pressures (Krausman 1975). Ejection time (ET) is defined as the period between the onset of the aortic pressure rise and the incisural notch. This can be clinically mea¬ sured from the beginning of the carotid pulse upstroke (CARU) to the nadir of the carotid pulse incisura (CARIN) (Fabian et al. 1972). Close agreement exists between ET measured in this manner and direct mea¬ surements obtained within the aorta (Weissler et al. 1961; Van de Werf et al. 1975). Kumar and Spodick (1970) and Fabian et al. (1972) have experimentally derived equations relating heart rate to ET; however, other parameters that affect ET, namely stroke volume, aortic pressure, and myocardial contractility, have not been mathematically character¬ ized. During ejection the carotid pulse profile is closely related to the aor¬ tic pressure waveform (Robinson 1963) and thus may serve as an approximation of transvalvular pressure profile. MODELING MITRAL VALVE MOTION 11 Model assumptions: 1. Annulus, left ventricular wall, and papillary muscle contractions continue throughout this phase of systole. Input data (Fig. 2): Hypothetical— Ejection time (ET) equals 292 msec (Kumar and Spodick 1970). Transvalvular pressure (mm Hg) is expressed by the following equation: TP = 80 + 40 • sin(K • ETT) (1) where ETT (msec) is the time measured from the start of the ejec¬ tion phase and K is a constant (0.009) selected so that peak trans¬ valvular pressure occurs at approximately 175 msec. Clinical— Ejection time (ET) as determined by carotid pulse recordings (ET = CARU— CARIN) (Fabian et al. 1972; Van de Werf et al. 1975) or by echocardiography (Hirschfeld et al. 1975). Transvalvular pressure throughout the ejection phase may be estimated from carotid pulse recordings and peripheral systolic and diastolic blood pressure determinations using sphygmoman- ometric techniques (Krausman 1975). Mitral Valve Leaflets The mitral valve has been described by Chiechi et al. (1956) as a con¬ tinuous veil of tissue attached around the entire circumference of the mitral orifice. The valve consists of fibrous, elastic, and muscular ele¬ ments covered by an endocardial coat. The muscular elements are con¬ centrated in the basal portion of the valve and appear to be anatomi¬ cally and possibly functionally continuous with the left atrium (Fenoglio et al. 1972; Wit et al. 1973). Collagen fibers extend from the annulus through the leaflet to form chordae tendineae and thus form a continuous fibrous tissue from the annulus to the papillary muscles (Fenoglio et al. 1972). The free edge of the veil of tissue is interrupted by indentations which divide the valvular tissue into two major leaflets (Fig. 3). The anterior leaflet (also referred to as the aortic, septal, greater, or ante¬ romedial leaflet) has been described as semicircular or triangular in shape (Fig. 4) (Chiechi et al. 1956; Ranganathan et al. 1976). The pos¬ terior leaflet is rectangular in shape (Fig. 4). Indentations along the free edge of the posterior leaflet give it a scalloped appearance. In 92% of the normal human hearts studied by Ranganathan et al. (1976), the posterior leaflet was triscalloped with a large middle scallop. Along the free edge of both leaflets is a zone of tissue that appears roughened (Fig. 4). This opaque portion of the mitral valve receives the insertion of chordae tendineae on its ventricular surface. This rough 12 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 y (top view of closed valve) Figure 3. Anatomy of the mitral valve. Infinitesimal strip of leaflet extending along the x-axis represents the mitral valve position and profile (modified from Davila and Palmer 1962). zone has been described as an area of coaptation for leaflet apposition (Carpender et al. 1976; Ranganathan et al. 1976). The ratio of rough zone to smooth leaflet tissue in the anterior leaflet is 0.6 and for the posterior leaflet 1.4 (Ranganathan et al. 1976). Based on these ratios and anatomical data for leaflet heights (Table 1), the leaflets would contact each other along a strip approximately 0.8 cm wide at the cen¬ ter of the leaflets. However, this is not compatible with measurements of annulus dimensions since the portions of the leaflets that are not opposed would not physically reach from the anterior to the posterior MODELING MITRAL VALVE MOTION 13 Anterior Leaflet Posterior Leaflet Figure 4. Schematic representation of mitral valve leaflets illustrating the shape of the leaflets and extent of the rough zone (modified from Ranganathan et al. 1970). The mechanical properties of mitral valve leaflets have been studied by several investigators (Clark and Butterworth 1971; Ghista and Rao 1972; Clark 1973). There is an initial stretching of the leaflet at very low (pre-transition) stresses (Fig. 5A). With additional stress, the modu¬ lus of elasticity changes abruptly at the transition stress (Fig. 5B) to a larger post-transition modulus of elasticity characteristic of a stiffer material (Fig. 5C). Typical values for pre- and post-transition moduli, transition stress, and transition strain are listed in Table 2. The strain at transition is approximately 15% of the original unstretched leaflet height. From this curve and values for the elastic moduli, it is apparent edge of the annulus. The extent of coaptation probably varies from a single line to a plane of coaptation depending upon the degree of annulus narrowing, leaflet dimensions, and positions of the leaflets rel¬ ative to the annulus. Table 1. Selected anatomical data for mitral valve leaflets (from autopsy of normal human subjects). Parameter Average Value Number Subjects Sex Reference Anterior Leaflet Height 23 mm 50 ? Carpentier et al. 1976 Anterior Leaflet Height 24 mm 26 M Ranganathan et al. 1970 Anterior Leaflet Height 22 mm 24 F Ranganathan et al. 1970 Anterior Leaflet Height 24 mm 60 M Chiechi et al. 1956 Anterior Leaflet Height 22 mm 45 F Chiechi et al. 1956 Anterior Leaflet Height 23 mm 25 M Rusted et al. 1952 Anterior Leaflet Height 21 mm 25 F Rusted et al. 1952 Posterior Leaflet Height 14 mm 50 p Carpentier et al. 1976 Posterior Leaflet Height 14 mm 26 M Ranganathan et al. 1970 Posterior Leaflet Height 12 mm 24 F Ranganathan et al. 1970 Posterior Leaflet Height 14 mm 60 M Chiechi et al. 1956 Posterior Leaflet Height 12 mm 45 F Chiechi et al. 1956 Posterior Leaflet Height 13 mm 25 M Rusted et al. 1952 Posterior Leaflet Height 12 mm 25 F Rusted et al. 1952 14 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Figure 5. Typical stress-strain characteristics of mitral valve leaflets. Pre-transition (A), transition (B), and post-transition (C) properties. that most of the total leaflet stretch is associated with the relative elastic properties of the leaflet prior to reaching transition. Based on studies of Ghista and Rao (1972) and Miller et al. (1981), transition for the leaflets is reached at low transvalvular pressure (between 2 and 13 mm Hg). Lack of apparent leaflet stretch in angio¬ graphic and ultrasound imaging studies support the conclusion of Rushmer et al. (1956) and Miller et al. (1981) that the valve leaflets and chordae tendineae are normally under tension throughout the cardiac cycle and that this tension is sufficient to cause the leaflets to operate in the post-transitional region at all times. Model assumptions: 1. The presystolic leaflet heights, which represent pre-stressed dimen¬ sions, are anterior leaflet height (AMVIL) = 2.4 cm, and posterior leaflet height (PMVIL) = 1.4 cm. Table 2. Biomechanical properties of mitral valve leaflets ex situ. Pre-Transition Modulus dyne /cm2- Post-Transition Modulus dyne /cm2 Transition Stress dyne /cm2 Transition Strain % Reference 1 • 105 5 • 107 3 • 104 Ghista and Rao 1972 1.1 • 105 2.9’ 107 3.4- 104 14.3 Clark 1973 NO oo 8.3 • 107 3.8- 104 15.0 Clark and Butterworth 1971 MODELING MITRAL VALVE MOTION 15 Anterior Leaflet Figure 6. Elliptically shaped leaflets. Major axes drawn between annulus attachment and leaflet free edges. 2. The leaflets are uniform, thin membranes which are only capable of supporting internal stress in tension (Clark and Sutera 1973). 3. An infinitesimal strip of leaflet selected from the middle portion of each leaflet will represent the position and profile of the mitral leaflets and that this leaflet strip can only move in the x-z plane (Clark and Sutera 1973) (Fig. 3). 4. The leaflet assumes an elliptical shape which has as its major axis an imaginary line joining the free edge of the leaflet to the point of attachment of the leaflet to the annulus (Fig. 6). 5. The extent of coaptation is determined by the natural intersection of elliptical segments drawn to represent the anterior and poste¬ rior leaflets (Fig. 7). 6. The forces exerted by the chordae tendineae on the free edges of the leaflets can be represented as a distributed tension along the entire free edges (Clark and Sutera 1973). 7. The attachments between the annulus and the leaflets and between the chordae tendineae and the leaflets can be regarded as ideal hinges which offer no resistance to rotation (Clark and Sutera 1973). 16 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 z Figure 7. Zone of leaflet coaptation as determined by the natural intersection of ellip- tically shaped leaflets. 8. The inertial forces are neglected throughout the analysis and the mechanical forces generated by transvalvular pressure are treated in a quasi-static manner. 9. The mitral valve leaflets are pre-stressed and can be characterized by their post-transition modulus (MVE = 5 • 107 dyne/cm2) (Ghista and Rao 1972). 10. The tension or stress in the leaflet (MVT) can be calculated by the following equation (Miller et al. 1981): MVT = 666 • TP • ANL ^2) HL where MVT is leaflet tension (dyne/cm2), TP is transvalvular pres¬ sure (mm Hg), ANL is annulus diameter measured along x-axis (cm), and HL is leaflet thickness (assumed to be 0.05 cm). 11. The strain of the leaflets (MVSTR) is: MVSTR = MVT (3) MVE 12. The height of each leaflet is: AMVL = AMVIL • (1 + MVSTR), (4) where AMVL is the anterior mitral valve leaflet height (cm), and AMVIL is the anterior mitral valve leaflet height initially (assumed to be 2.4 cm). A similar expression applies for calculat¬ ing the height of the posterior mitral valve: MODELING MITRAL VALVE MOTION 17 Z Z Figure 8. Diagrammatic representation of the initial geometry of the mitral apparatus. Point Q is located at the leaflet free edges. A is the angle between the chordae tendi- neae and a line parallel to the z-axis. PM VL = PMVIL • ( 1 + MVSTR). (5) Input data: Hypothetical — The initial position (Figs. 8A and B) of the leaflet free edges (Q) is QX = 2.0, QY = 0.0, and QZ = —0.9. Clinical — The initial position of the leaflets may be determined using real-time, two-dimensional ultrasound imaging techniques; however, translation of axes from a transducer-centered coordinate system to that used in this model must be performed to insure appropriateness of the data. Mitral Valve Annulus The annulus consists of dense collagenous tissue with scattered thin elastic fibers and serves as a framework for attachment of the mitral valve leaflets (Davila and Palmer 1962). Viewed from above with the atria removed (Fig. 9), the annulus consists of (1) a fibrous trigone sit¬ uated between the anterior leaflet and the aortic and tricuspid valves, 18 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Left Fibrous Trigone Figure 9. Anatomy of the mitral valve annulus (modified from Silverman and Hurst 1968). and (2) a rather poorly defined band of fibroelastic tissue which forms the attachment site for the posterior leaflet (Silverman and Hurst 1968). Besides serving as a base for leaflet attachment, the annulus may be involved in insuring competence of the mitral valve (Perloff 1976). Tsakiris et al. (1971) have demonstrated, using anesthetized dogs, that the annulus undergoes active contraction. After reaching a maximum size in late diastole, the area of the annulus decreases by 19 to 34% dur¬ ing atrial and ventricular systole. One-half to two-thirds of this decrease in area apparently occurs during atrial contraction. This nar¬ rowing of the annulus is eccentric: The portion of the annulus forming the attachment for the posterior leaflet moves toward a relatively fixed site of anterior leaflet attachment, the fibrous trigone. The degree of Table 3. Selected anatomical data for mitral annulus (from autopsy of normal human subjects). Parameter Average Number of Value Subjects Sex Reference Circumference 9 cm 24 11M, 13F Bulkley and Roberts 1975 Circumference 11.6 cm 60 p Carpentier et al. 1976 Circumference 9 cm 26 M Ranganathan et al. 1970 Circumference 7.5 cm 24 F Ranganathan et al. 1970 Circumference 10.0 cm 60 M Chiechi et al. 1956 Circumference 9.0 cm 45 F Chiechi et al. 1956 Circumference 9.9 cm 25 M Rusted et al. 1952 Circumference 8.5 cm 25 F Rusted et al. 1952 Intercommissural Diameter 2.5 cm 25 M Rusted et al. 1952 Intercommissural Diameter 2.1 cm 25 F Rusted et al. 1952 Area of Annulus 7.93 cm2 8 M Chiechi et al. 1956 Area of Annulus 6.42 cm2 8 F Chiechi et al. 1956 MODELING MITRAL VALVE MOTION 19 narrowing of the annulus is a function of several factors, including duration of the P-R interval, duration of the ventricular systole, ven¬ tricular volume during diastole, and degree of emptying during systole. Table 3 is a compilation of published reports regarding dimensions of the human mitral valve annulus. Model assumptions: 1. The annulus remains at right angles to the long axis of the ven¬ tricle during systole (Tsakiris et al. 1971). 2. The annulus does not rotate relative to the ventricle during systole (Tsakiris et al. 1971). 3. The orthogonal coordinate system used in this simulation is cen¬ tered at the annular attachment of the mid-point of the anterior leaflet (Fig. 1). 4. The annulus narrows at a constant rate throughout systole. Input data: Hypothetical — Annulus diameter (ANEDL) at the start of systole — 2.90 cm. Annulus diameter (ANESL) at the end of ventricular ejection = 2.73 cm. (These dimensions are based on assuming a circular annulus with a maximal diastolic circumference — 10 cm, a total reduction in annulus area of 26.5% which corresponds to a decrease in diameter of 14.3%, and contraction during atrial systole accounting for 63% of the total narrowing.) Clinical— Annulus measurements, obtained using cineangio¬ graphy or ultrasound imaging, may be substituted for hypotheti¬ cal data. Chordae Tendineae Chordae tendineae radiate from the tips of both papillary muscles to attach to the ventricular border of the mitral valve leaflets (Fig. 10). Chordae arising from the anterolateral papillary muscle connect to the anterolateral commissure and the adjoining halves of the anterior and posterior leaflets. Similarly, chordae arising from the posteromedial papillary muscle pass to the respective commissure and portions of the leaflets (Davila and Palmer 1962; Silverman and Hurst 1968). Ranganathan et al. (1976) have categorized chordae tendineae on the basis of their size and location of attachment to the mitral valve. Chor¬ dae attaching to the anterior leaflet are classified as either (1) rough- zone chordae which branch before inserting on or near the free edge of the leaflet, or (2) strut chordae which are relatively large chordae and insert directly on the edge of the leaflet near its mid-portion. Posterior leaflet chordae are either (1) rough-zone chordae, (2) cleft chordae which attach between leaflet scallops, or (3) basal chordae which attach near the annulus and may arise directly from the wall of the left ventri¬ cle. An average of 25 primary chordae tendineae is associated with the 20 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 z Figure 10. Anatomy of the chordae tendineae (modified from Davila and Palmer 1962). mitral valve; 9 attach to the anterior leaflet (7 rough-zone and 2 strut types), 14 attach to the posterior leaflet (10 rough-zone, 2 cleft, and 2 basal), and 2 attach to the commissures separating the anterior and pos¬ terior leaflets (Lam et al. 1970; Ranganathan et al. 1976). The lengths of chordae attaching to the leaflets are summarized in Table 4. Chordae tendineae are composed of three layers— (1) an outer layer of endocardial cells, (2) an intermediate layer of loosely meshed collagen and elastic fibers, and (3) an inner core of dense collagen (Fenoglio et al. 1972; Lim and Boughner 1977). The mechanical properties of chor¬ dae are similar to those of the mitral valve leaflets, in that these struc¬ tures exhibit a non-linear stress-strain characteristic (Fig. 11) (Lim and Boughner 1975). Salisbury et al. (1963) measured tension along chordae tendineae throughout the cardiac cycle and reported that (1) presystolic chordae tendineae tension can be as high as 12 g; (2) during the isovo- lumetric contraction phase, tension in the chordae tendineae rises simultaneously with left ventricular pressure; and (3) during ejection, tension either drops or levels off and does not appear to be directly related to left ventricular pressure. Model Assumptions: 1. Chordae tendineae insert on the free edges of the mitral valve leaf¬ lets. 2. Chordae tendineae are freely hinged at the sites of attachment to the leaflets and papillary muscles. MODELING MITRAL VALVE MOTION 21 Table 4. Selected anatomical data for chordae tendineae (from autopsy of normal human subjects). Parameter Average Number of Value Subjects Sex Reference Chordae Tendineae Length Anterolateral P.M. to Anterior Leaflet 1.5 cm 50 ? Carpentier et al. 1976 Chordae Tendineae Length Posteromedial P.M. to Anterior Leaflet 1.7 cm 50 p Carpemier et al. 1976 Chordae Tendineae Length Anterior Leaflet 1.75 cm 50 27M, 23F Lam et al. 1970 Chordae Tendineae Length Posterior Leaflet 1.4 cm 50 ? Carpentier et al. 1976 Posterior Leaflet 1.4 cm 50 27M, 23F Lam et al. 1970 STRAIN (%) Figure 11. Biomechanical properties of the chordae tendineae. Cross-sectional area = 0.004 - 0.006 cm2; strain-rate = 12.7 cm /min (from Lim and Boughner 1975). 22 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 3. Chordae tendineae operate in a pre-stressed condition at the start of systole (Salisbury et al. 1963) and thus may be characterized by their post-transition elastic modulus throughout systole (CTE = 2 • 109 dyne/cm2) (Lim and Boughner 1975). 4. Chordae tendineae lengths reported in Table 4 represent pre¬ stressed measurements. The initial length for all chordae (CTIL) equals 1.5 cm. 5. Chordae tendineae tension (CTT) is a function of two parameters — transvalvular pressure (TP) and ventricular geometry. The chordae exert tension on the free edges of the leaflets to res¬ train their atrial-ward movement. Ventricular geometry influences the angle that the chordae make with respect to the z-axis and thus the tension within the chordae counteracting atrial-ward movement of the leaflets (Fig. 8D). Based on a study by Salisbury et al. (1963) and considerations for ventricular geometry, an empirical formula relating CTT to TP has been derived: CTT = 650 • _ _ (6) COSA • CTA where CTT is chordae tendineae tension (dyne/cm2), TP is trans¬ valvular pressure (mm Hg), COSA is the cosine of angle A, and CTA is the area of an average chordae tendineae (assumed to be .004 cm2). 6. Chordae tendineae strain (CTSTR) may be calculated as follows: CTSTR = CTT ; (7) CTE and the length of the chordae tendineae may be expressed by the following equation: CTL = CTIL ( 1 + CTSTR) (8) where CTL is the chordae length (cm), and CTIL is the initial chordae length (assumed to be 1.5 cm). Papillary Muscles The two groups of papillary muscles, the anterolateral and poste¬ romedial, are located immediately below the respective commissures of the leaflets. The antereolateral papillary muscle usually has a single muscle belly and is continuous with the ventricle along the anterolat¬ eral free wall; the posteromedial papillary muscle typically consists of two or three distinct muscle bellies and is located at the junction of the MODELING MITRAL VALVE MOTION 23 posterior free wall and the ventricular septum (Rusted et al. 1952; Chie- chi et al. 1956; Estes et al. 1966; Silverman and Hurst 1968; Roberts and Cohen 1972). Papillary muscles may also be classified on the basis of their morphology as follows: (1) Completely tethered, the papillary muscle is fully adherent to the ventricular myocardium; (2) Free and fingerlike, with one-third or more of the papillary muscle protruding freely into the ventricular cavity; and (3) Mixed or intermediate, with considerable trabecular attachments and tethering between the papillary muscle and ventricular wall (Ranganathan and Burch 1969). The papillary muscles normally arise from the left ventricular wall at the apical and middle thirds (Silverman and Hurst 1968; Perloff 1976). They are oriented parallel to the left ventricular wall to which they are attached. The attachment usually extends almost the full length of the muscle and consists of crossing muscle bundles and threadlike bands (Estes et al. 1966; Silverman and Hurst 1968). There is considerable disagreement among investigators regarding the timing and extent of papillary muscle contraction. Cronin et al. (1969) indicate that ventricular wall contraction precedes papillary muscle contraction. According to Semafuko and Bowie (1975), the anterolateral papillary muscle lengthens during isovolumetric contrac¬ tion and the early ejection phase of the cardiac cycle. This study sug¬ gests that papillary muscle shortening may occur only when the force of muscle contraction exceeds the forces that tend to elongate the papil¬ lary muscle, i.e. chordae tendineae tension resisting atrial-ward leaflet excursion. Other investigators report that the papillary muscles shorten throughout systole (Burch and DePasquale 1965; Hirakawa et al. 1977). The total shortening, measured in dogs, varies in published data from 10% to 22.8% of the total length (Grimm et al. 1975; Hirakawa et al. 1977; Huntsman et al. 1977). Model assumptions: 1. The papillary muscles are symmetrically oriented relative to the x- z plane and attach to the ventricular wall at points two-thirds of the distance from the annulus to the apex (Fig. 8D). 2. The papillary muscles are tethered along their entire lengths to the ventricular wall and maintain a longitudinal orientation, parallel to the x-axis, throughout systole. 3. The presystolic lengths of the papillary muscles are determined from geometric considerations following specifications of the pre¬ systolic position of the mitral valve, chordae tendineae lengths, and left ventricular dimensions. 4. A total contraction of 16.4% of the presystolic papillary muscle length occurs linearly with respect to time during the isovolumet¬ ric contraction and ejection phases of systole. 24 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Table 5. Selected anatomical data for the left ventricle (normal human subjects). Average Number of Parameter Value Subjects Sex Method3 Reference Annulus to Apex Length at End-Diastole (AAEDL) 7.0 cm 24 11M, 13F A Bulkley and Roberts 1975 AAEDL 7.3 cm 25 M A Rusted et al. 1952 AAEDL 6.7 cm 25 F A Rusted et al. 1952 Minor Axis Length at End-Diastole (MAEDL) 5.0 cm 10 ? E Fortuin et al. 1972 MAEDL 4.40 cm 20 11M, 9F E McDonald et al. 1972 MAEDL 5.18 cm 37 M E Gerstenblith et al. 1977 Minor Axis Length at End-Systole (MAESL) 3.8 cm 10 p E Fortuin et al. 1972 MAESL 2.83 cm 20 1 1M,9F E McDonald et al. 1972 MAESL 3.44 cm 37 M E Gerstenblith et al. 1977 aA — autopsy; E = echocardiography Left Ventricle Cardiac performance traditionally has been defined according to hemodynamic determinants and only recently have attemps been made to correlate these with muscle function and geometric considerations (Liedtke et al. 1972). The left ventricle has a particularly important role in the anatomy and physiology of the mitral apparatus. Ventricular shape and contraction patterns influence value motion directly through changes in transvalular pressure and indirectly through alternations in geometric relationships between the papillary muscles and the valve leaflets. Major dimensional changes of the left ventricle are associated with the ejection phase of systole. During ejection, there is marked contrac¬ tion of the left ventricle which results in continuous repositioning of the papillary muscles relative to the leaflets /annulus. Altered left ven¬ tricular shape will affect the overall operation of the mitral apparatus due to the complex geometric interrelationships among components of the mitral apparatus. Table 5 summarizes published data regarding ventricular dimensions. Table 6 lists results of various studies that have attemped to measure the extent of ventricular contraction. Model assumptions: 1. The left ventricle is a truncated ellipsoid of revolution (Koushan- pour and Codings 1966; Hutchins et al. 1978) that both shortens and contracts symmetrically about its major axis throughout the ejection phase of systole (McDonald 1970). MODELING MITRAL VALVE MOTION 25 Table 6. Selected physiological data for the left ventricle. Parameter Average Value Subjects Number of Subjects Sex Method3 Reference Annulus to Apex % Shortening 6.9-8. 1% Canine 5 ? S Hirakawa et al. 1977 Annulus to Apex % Shortening 8% Canine 5 p c Liedtke et al. 1972 Annulus to Apex % Shorteing 4.6% Canine 13 ? A Ross et al. 1967 Minor Axis Length % Shortening 25% Human ? ? R Daughters et al. 1977 Minor Axis Length % Shortening 35.5% Human 20 11M E McDonald et al. 1972 Minor Axis Length % Shortening 61% Canine 5 9F ? C Liedtke et al. 1972 Minor Axis Length % Shortening 26% Canine 13 ? A Ross et al. 1967 Minor Axis Length % Shortening 34% Human 37 M E Gerstenblith et al. 1977 Minor Axis Length % Shortening 24%b Human 10 p E Fortuin et al. 1972 aA = autopsy (special fixation); C = cineangiocardiography; E = echocardiography; R = radiopaque markers; S = sonomicrometry. b Computed from anatomical data. 2. The contractions along the major and minor axes are linear func¬ tions of time (i.e. constant rate of contraction) (Bishop et al. 1969; Hinds et al. 1969; Bishop and Horwitz 1970). Input data: Hypothetical — Mitral annulus to apex dimensions (AAL) are end- diastole (AAEDL) — 7.30 cm, and end-systole (AAESL) = 6.75 cm — resulting in an overall 7.5% shortening. Minor axis dimen¬ sions (MAL) are end-diastole (MAEDL) = 4.86 cm, and end-systole (MAESL) = 3.34 cm — resulting in an overall 31% shortening. Extent of truncation (TRUNC): The annulus is located at 60% of the total eliptical major axis; major axis end-diastole = 12.17 cm, and major axis end-systole = 1 1.25 cm. Clinical — Actual dimensional measurements of annulus-to-apex and minor axis may be obtained using cineangiography or ultra¬ sound imaging and degree of truncation estimated from these measurements. MODEL OPERATION Mitral value motion is predicted by a computer program that de¬ scribes the dynamic alterations in the various components of the mitral 26 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Table 7. Input values for the model. Abbreviation i Parameter Assumed Value EDT Electromechanical Delay Time 22 msec IVCT Isovolumetric Contraction Time 71 msec ET Ejection Time 292 msec TP Transvalvular Pressure (Refer to Fig. 2) AMVIL Anterior Leaflet Height (Initial) 2.4 cm PMVIL Posterior Leaflet Height (Initial) 1.4 cm MVE Mitral Valve Leaflet Elastic Modulus 5 • 107 dyne/ cm2 QX X — Coordinate of Leaflet Free Edge (Initial) 2.0 cm QY Y — Coordinate of Leaflet Free Edge (Initial) 0.0 cm Qz Z — Coordinate of Leaflet Free Edge (Initial) —0.9 cm ANEDL Annulus Diameter at End-Diastole 2.70 cm ANESL Annulus Diameter at End- Systole 2.56 cm CTIL Chordae Tendineae Length (Initial) 1.5 cm CTE Chordae Tendineae Elastic Modulus 2 • 109 dyne /cm2 PMPER Papillary Muscles-Percent Shortening 16.4% AAEDL Annulus to Apex — End-Diastolic Length 7.3 cm AAESL Annulus to Apex — End-Systolic Length 6.75 cm MAEDL Minor Axis — End-Diastolic Length 4.86 cm MAESL Minor Axis — End-Systolic Length 3.34 cm TRUNC Truncation — Percent (annulus to apex /major axis length) 60% GAPIL Distance Between the Point of Annular Attachment of the Posterior Leaflet and the Ventricular Wall (Initial) 0.0 cm INCRT Time Increment to Step Through Program 10 msec apparatus. Following input of clinically obtained and/or hypothetical data (Table 7), the computer program initializes the geometry of the model using the coordinate system previously described (Fig. 1). The anterior portion of the annulus is located at x=0, y=0, and z=0 (Fig. 8A). The leaflets are represented by elliptical segments in the x-z plane, extending from the annulus to the point of coaptation (Q) at the leaflet free edges (Fig. 8A). In a y-z plane (x=Qx), the leaflets are represented as single point, Q (Fig. 8B). As previously described, a truncated ellipse is used to model the left ventricle. Its major axis is parallel to the z-axis and located within the x-z plane; the minor axis is parallel to the x-y plane and separated from this plane by a distance specified by the extent of truncation (Fig. 8C). The ellipse representing the ventricle is assumed to pass through the posterior portion of the annulus (x= ANEDL, y=0, z=0), but can be positioned anywhere along the x-axis by specifying a separation between the annulus and ventricle wall (GAPIL) as an input condition. The papillary muscles are represented as straight lines oriented parallel to the z-axis in a y-z plane (x=Qx), and attaching to the ventricular wall at a point two-thrids the distance from annulus to apex. The lengths of the papillary muscles are deter¬ mined by geometric considerations — specifically, the intersection of MODELING MITRAL VALVE MOTION 27 lines representing chordae tendineae with vertical lines projecting from the papillary muscle attachment sites toward the annulus (Fig. 8D). The computer program is designed so that this initial geometry can be easily altered to describe a wide range of clinical or hypothetical con¬ figurations of the mitral apparatus. The model is “set in motion” by performing a series of subroutines that describe the dynamic alterations in the various components of the mitral apparatus. These alterations include (1) contractility of the annulus, papillary muscles, and the left ventricle (linear functions of time); (2) mechanical deformation of the mitral value leaflets (linearly related to transvalvular pressure); and, (3) lengthening of the chordae tendinease (a function of transvalvular pressure and ventricular geome¬ try). Calculations are performed to describe the geometry of the mitral apparatus at specific time intervals (INCRT) throughout systole. Sub¬ routines are executed in the following sequence: (1) annulus contrac¬ tion; (2) ventricular contraction (determines the x,y, and z coordinates of the sites for attachment of papillary muscles); (3) papillary muscle contraction (specifies the z coordinate of the papillary muscles-chordae tendineae junctions); (4) chordae tendineae length, Eq. (8) (determines point Q); and , (5) mitral value leaflet heights, Eqs. (4) and (5). Note: During the electromechanical delay (EDT) phase of systole, only the annulus contraction subroutine is utilized; during the isovolumetric contraction (IVCT) phase, all subroutines except ventricular contrac¬ tion are performed. The output of the program is a time-series description of the mitral value components throughout systole. The following numerical output is listed at time intervals (INCRT) specified in the input data set: (1) anterior and posterior coordinates of the annular ring, (2) annulus to apex distance, (3) ventricular minor axis length, (4) papillary muscle length, (5) chordae tendineae length, (6) coordinates of point Q, (7) anterior and posterior leaflet heights, (8) major and minor axes for leaf¬ let ellipses, and (9) maximum leaflet deflection in the z-direction for each leaflet. RESULTS Normal Model The output of this model, using the hypothetical input data indicated in Table 7, is summarized in Fig. 12. Point Q moves slightly down¬ ward (0.02 cm) from its initial position during the isovolumetric con¬ traction phase and then moves upward approximately 0.1 cm during the ejection phase. The anterior leaflet elongates approximately 0.05 cm and the posterior leaflet elongates approximately 0.02 cm. The 28 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Z Figure 12. Mitral valve position /profile at selected times during systole. Input data as specified in Table 7. AA is the anterior portion of the annulus, AP is the posterior portion of the annulus, and point Q is located at the leaflet free edges. maximum leaflet deflection in the z-direction is less than 0.1 cm above the plane of the annulus. Fig. 12 illustrates, in a graphical way, the motion of the leaflets and demonstrates the relatively small displace¬ ments throughout systole. Sensitivity Analysis Perturbation of the model may be performed by altering any of the input parameters. In terms of mitral valve prolapse, the model is insen¬ sitive to changes in the annulus diameter, chordae tendineae length, time of onset of papillary muscle contraction, time of onset of ventricu¬ lar contraction, ventricular minor axis dimension, and annulus to apex distance. The model is moderately sensitive to changes in the percent of papillary muscle contraction and changes in the papillary muscle att¬ achment point. The model is extremely sensitive to change in leaflet and chordae tendineae properties. Three selected perturbations are illustrated in Figs. 13-15. Increasing the elasticity of the leaflets (MVE = 5T06 dyne/cm2, —1/10 the stiff¬ ness of normal valvular tissue) produces a rapid ballooning of the ante¬ rior leaflet (Fig. 13). Increasing the elasticity of the chordae tendineae (CTE = 1 TO8 dyne/cm2, —1/20 the stiffness of normal chordae tendi¬ neae) results in an early prolapse of both leaflets (Fig. 14). Eliminating MODELING MITRAL VALVE MOTION 29 Figure 13. Mitral valve position /profile at selected times during systole. Input data as specified in Table 7, except the leaflets have increased elasticity (MVE = 5 • 106 dyne/cm2). AA is the anterior portion of the annulus, AP is the posterior portion of the annulus, and point Q is located at the leaflet free edges. papillary muscle contraction produces a late prolapse, which is most noticeable in the posterior leaflet (Fig. 15). DISCUSSION Biological models are, by necessity, limited in scope and subjective in nature (Yates 1978). They represent an attempt to mathematically express anatomical, physiological, and/or pathological concepts that quite often, are not fully defined. Despite these inherent limitations in biological models, they are extremely useful tools for (1) identifying the essential components of a system, (2) quantifying information about a subject, (3) exposing contradictions or incompleteness in data sets, (4) examining major implications regarding a system, and (5) determining the effects of selected perturbations upon the performance of a system (Yates 1978). This model will hopefully provide a better overall understanding of the functioning of the mitral value and associated structures in relation to prolapse. The model has established that the basic components that must be included in any model of the mitral valve prolapse are mitral value leaflets, annulus, chordae tendineae, papillary muscles, and the left ventricle. Alteration in the physical dimensions, mechanical prop- 30 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Figure 14. Mitral valve position /profile at selected times during systole. Input data as specified in Table 7, except the chordae tendineae have increased elasticity (CTE = 1 • 108 dyne/cm2). AA is the anteior portion of the annulus, AP is the posterior portion of the annulus, and Q is located at the leaflet free edges. erties, or contractile properties of these elements can markedly influ¬ ence the performance of the mitral value itself. Construction of this model represents a compilation of published anatomical and physiological information regarding the mitral appara¬ tus. Review of the literature indicates that an adequate, quantitiative description of dynamic cardiac anatomy and physiology does not exist. Published data regarding the mitral apparatus are fragmentary and occasionally contradictory. Unfortunately, this rather tenuous data base has been used to support various hypotheses for mitral valve prolapse. The primary abnormalities producing mitral valve prolapse still elude description. Prolapse has been associated with (1) myxomatous degeneration of the valve leaflets (Read et al. 1965; Pomerance 1969; Kern and Tucker 1972; Marshall and Shappell 1974; Silver 1976), (2) anomalous arrangement of chordae tendineae (Edward 1971; Silver 1976), (2) anomalous arrangement of chordae tendineae (Edwards 1971; Silver 1976), (3) coronary artery disease (Aranda et al. 1976), (4) left ven¬ tricular asynergies (Pisano et al. 1977), (5) annulus dilatation (Bulkley and Roberts 1975), (6) papillary muscle dysfunction (Nutter et al. 1975; Cobb's and King 1977), and (7) postural changes in left ventricular geometry (Fontana et al. 1975). Results of this modeling effort support the belief of Barlow et al. (1968), who claim that there is obviously more than one etiology for mitral valve prolapse. MODELING MITRAL VALVE MOTION 31 Figure 15. Mitral valve position /profile at selected times during systole. Input data as specified in Table 7, except the papillary muscles are non-contractile (PMPER = 0%). AA is the anterior position of the annulus, AP is the posterior portion of the annulus, and point Q is located at the leaflet free edges. Perhaps the greatest value of this model is in predicting mitral valve profile /position under various conditions. Perturbation studies indi¬ cate that prolapse can either result from or be accentuated by (1) reduc¬ ing the degree of annulus contraction (annular calcification), (2) increasing the elasticity of the leaflets (myxomatous degeneration), (3) increasing the elasticity of the chordae tendineae, (4) decreasing the contractility of the papillary muscles (coronary artery disease), (5) decreasing end-systolic ventricular volume, and (6) increasing preload /afterload. Particularly dramatic changes occur with alterations in either leaflet properties, chordae tendineae properties, or papillary muscle contractility. One exciting potential application of this model is its use as a clini¬ cal tool in determining the underlying pathological alteration(s) con¬ tributing to a particular pattern of mitral valve prolapse. Mitral valve profiles obtained in patients using either biplane cineagiography or ultrasound imaging could be compared to profiles based on selected model perturbations and therby establish relationships between mitral valve profiles and specific pathological conditions. It is apparent in Figures 13-15 that a particular perturbation may result in a distinctive time sequence of mitral profiles. This potentially provides the cardiol¬ ogist with an extremely valuable diagnostic and prognostic tool. 32 THE TEXAS JOURNAL OF SCIENCE— VOL. 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The duration of the consecutive phases of the cardiac cycle and the criteria for their precise determination. Am. J. Physiol. 56:415-438. Wit, A.L., J.J. Fenoglio, Jr., B.M. Wagner, and A.L. Bassett. 1973. Electrophysiological properties of cardiac muscle in the anterior mitral valve leaflet and the adjacent atrium in the dog. Circ. Res. 32:731-745. Yates, F.E. 1978. Good manners in good modeling: Mathematical models and computer simulations of physiological systems. Am. J. Physiol. 3.R159-R160. Zaky, A., E. Steinmetz, and H. Feigenbaum. 1969. Role of atrium in closure of mitral valve in man. Am. J. Physiol. 217:1652-1659. THIN LAYER CHROMATOGRAPHY OF NITROGEN HETEROCYCLES ON A MODIFIED SILICA GEL SUPPORT by W. E. RUDZINSKI Department of Chemistry Southwest Texas State University San Marcos , TX 78666 ABSTRACT Square planar dialkylphosphorodithioate complexes of nickel have been sorbed onto a silica gel surface, and the extent of adduct formation with nitrogen heterocyclic bases has been evaluated and explained in terms of steric hindrance between the nickel complex and associating base. INTRODUCTION The neutral square planar dialkylphosphorodithioate complexes of nickel have a tendency to form tetragonal adducts in the presence of Lewis bases (Coucouvanis 1979). If the Lewis base is a heterocyclic ni¬ trogen compound, the structure of the heterocycle plays a dominant role in the extent of adduct formation (Rudzinski 1977). In order to study the coordination chemistry of bis(0,0’-dimethylphosphoro- dithioate) nickel (II), Ni (DMPDT>2, the nickel complexes are sorbed onto a silica gel plate forming a surface available for adduct formation. Nitrogen heterocyclic bases then are spotted on the plate and their affinity for the surface evaluated. Bulky or sterically-hindered bases are not expected to have a high retentivity on the surface. If the dialkyl¬ phosphorodithioate ligand had large alkoxy groups bonded to the phosphorus, then these also will affect the extent of adduct formation. MATERIALS AND METHODS Bis(0,0’-dimethylphosphorodithioate) nickel (II) was synthesized as described elsewhere (Rudzinski et al. 1977). Bis(0,0’-diethylphos- phorodithioate) nickel (II) was synthesized in the same manner as above by using ethanol instead of methanol. The chelate was dissovlved in reagent grade benzene, and the solution was sprayed on a thin layer silica gel plate (Eastman Chromagram Sheet 6061) using a dichlorofluoromethane aerosol. Three coats were sufficient to cover the silica gel plate. The plates then were allowed to air dry for ten minutes. The Texas Journal of Science, Vol. XXXV, No. 1, March 1983 38 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Table 1. Thin layer chromatography results. Heterocycle # of Samples Rr Standard Deviation isoquinoline Ni(DEPDT)2 with 1-propanol as 9 the solvent .83 2 X 10"2 quinoline 3 .76 2 X 10~2 8-aminoquinoline 3 .75 3 X 10"2 6-methoxyquinoline 3 .77 5 X 10“2 aridine Ni(DMPDT)2 with 2-propanol as 4 the solvent .68 6.2 X 10~2 isoquinoline 4 .33 1.7 X 10~2 isoquinoline Ni(DMPDT)2 with 1 -propanol as the solvent 10 .04 1.2 X 10"2 pridine 7 0 0 1 , 1 0-phenanthroline 2 .005 quinoline 12 .74 7.1 X 10“2 2-methoxyquinoline 3 .65 9.1 X 10“2 The nitrogen heterocycles used for the study were the following: (1) pyridine (Mallinckrodt), (2) quinoline (Aldrich Chemical Co.), (3) iso¬ quinoline (J. T. Baker Chemical Co.), (4) 2-methoxy quinoline (Aldrich Chemical Co.), (5) 6-methoxyquinoline (K and K Laboratories), (6) 8- aminoquinoline (G. Frederick Smith Chemical Co.), (7) acridine (Aldrich Chemical Co.), (8) phenazine (Aldrich Chemical Co.), and (9) 1,10-phenanthroline (J. T. Baker Chemical Co.). Isoquinoline, quino¬ line, and pyridine were redistilled. The remaining compounds were used as received from the manufacturer. The developing solvents (ethanol, 1 -propanol, 2-propanol) were redis¬ tilled. Liquid samples were spotted at one end of the plate and then developed by an ascending technique in a closed container saturated with developer vapor. The plate then was dried and the Rf values mea¬ sured. No reagent was needed for the detection of the components since they were self-indicating. Solids were dissolved in the minimum amount of developing solvent, and then spotted and developed as above. RESULTS AND DISCUSSION The results of the thin layer chromatography are summarized in Table 1. The Rf values obtained with Ni(DEPDT)2 as the stationary phase and 1 -propanol as the mobile phase indicate that there is little variation in the Rf value with a variation in heterocycle. This is ascribed to the steric hindrance provided by the ethoxy group bonded to the phosphorus atom. In this case, the alkyl group of the phosphorodi- thioate is the primary regulator in adduct formation. The silica gel support does not seem to influence significantly the retention of the CHROMATOGRAPHY OF NITROGEN HETEROCYCLES 39 heterocycles (all Rf > 0.75). When Ni (DMPDTJa is the stationary phase and 1 -propanol is the solvent, the nature of the heterocyclic base is a primary regulator in adduct formation. As an example, quinoline has an Rf value of 0.74 while isoquinoline essentially does not move (Rf = 0.04). This is attributed to the fact that quinoline is sterically hindered in aligning itself for proper coordination: x\ /K /N / / Ks/NVs/P\; X = -0CH3, ^ 0CH2CH3 Isoquinoline on the other hand can coordinate with a minimum of steric interaction: X = -0CH3, - 0CH2CH3 The adducts of pyridine (Ooi and Fernando 1967), and 1,10- phenanthroline (Shetty and Fernando 1970) with dialkylphosphorodi- thioate nickel (II) are known to exist and have been characterized by single crystal X-ray structure determinations, and the low Rf values support the interpretation of adduct formation. Finally, there appears to be a correlation between the solvent and the extent of adduct formation. The longer the carbon chain in the alkyl group of the developing solvent the stronger the adduct formed between the nigrogen heterocycle and Ni(DMPDT)2. In analyzing the compara¬ tive Rf values of quinoline and isoquinoline in ethanol, 2-propanol, and 1 -propanol, quinoline retains essentially the same Rf value, while 40 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 that of isoquinoline decreases (Rf = 0.59 in ethanol, Rf = 0.33 in 2- propanol, Rf = 0.04 in 1 -propanol). This decrease in Rf with develop¬ ing solvent correlates well with the solvent strength of the alcohols (Snyder and Kirdland 1979). LITERATURE CITED Coucouvanis, D. 1979. The chemistry of the dithioacid and 1,1-dithiolate complexes, 1968-1977, p. 301-469. In S. J. Lippard (Ed.), Progress in Inorganic Chemistry, v. 26. John Wiley and Sons, New York, NY. Ooi, S., and Fernando, Q. 1967. The crystal and molecular structure of the adduct of bis(0,0’-diethyldithiophosphato) nickel (II) with pyridine. Inorg. Chem. 6:1558-1562. Rudzinski, W.E. 1977. Stability of transition metal complexes of 0,0’-dialkyldithiophos- phates and their adducts. Ph.D. Dissertion, University of Arizona, Tucson, AZ. Rudzinski, W.E., Behnke, G.T., and Fernando, Q. 1977. A normal coordinate analysis of bis(0,0’-dialkyldithiophosphate) nickel (II) complexes. Inorg. Chem. 16:1206-1210. Shetty, P.S., and Fernando, Q. 1970. Structures of five and six-coordinated mixed- ligand chelates of nickel (II) containing sulfur and nitrogen donor atoms. J. Am. Chem. Soc. 92:3964-3969. Snyder, L. R., and Kirkland, J. J. 1979. Introduction to Modern Liquid Chromato¬ graphy, 2 Ed. John Wiley and Sons, Inc., New York, NY., 246-268. SOME STRUCTURAL ASPECTS OF A WESTERN CROSS TIMBERS FOREST IN NORTH CENTRAL TEXAS1 by GLENN C. KROH and JAMES NISBET Department of Biology Texas Christian University Fort Worth, TX 16129 ABSTRACT Structural aspects of a north-central Texas tract of the cross timbers forest were deter¬ mined. The one-hectare study area was located within the Fort Worth, Texas, Nature Center and Refuge. Specifically, average basal area, frequency distribution of height and size classes, diversity, importance values and taxonomic composition of the forest were determined. Mean basal area by species indicated post oak ( Quercus stellata) is dominant (80%), followed by blackjack oak ( Quercus marilandica) (9%). Mean basal area for all tree species combined was 24.6 m2/ha, indicating that the forest is mature. Tree diversity, cal¬ culated by the Shannon- Weiner method, is 1.03. INTRODUCTION The cross timbers, as described by Dyksterhuis (1948), occurs from the Arkansas River in Oklahoma to approximately 150 miles south of the Red River. At the Red River, the forest splits into two bands, the western cross timbers and eastern cross timbers. Rice and Penfound (1955) evaluated different methods of sampling upland oak forests based on the cross timbers of Oklahoma, and later (Rice and Penfound 1959) did a descriptive study of the area. Risser and Rice (1971a) used an ordination technique to determine upland tree species associations of the Oklahoma cross timbers and then (Risser and Rice 1971b) com¬ pared diversity indices with the mixed mesophytic and oak hickory forest in the southern Appalachian region. The oak upland forest was significantly less diverse than those in the eastern United States. The objectives of the present study were to determine structural parameters of a north Texas post-oak forest and contrast some aspects of this community with similar oak forest communities in Oklahoma. STUDY AREA The study area is located in the western cross timbers community at the Fort Worth, Texas, Nature Center and Refuge. Principal trees in the undisturbed forest are Quercus stellata (post oak), Quercus mari¬ landica (blackjack oak), Celtis laevigata (hackberry) and Ulmus crassi- 1 Funded by Texas Christian University Research Foundation Grant #B7986. Presented at the 1978 Texas Academy of Science Meeting At Texas Tech University, Lubbock, TX. The Texas Journal of Science, Vol. XXXV, No. 1, March 1983 42 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 NO. OF 100 m2 samples Figure 1. Performance curve. Only trees greater than 2.5 cm in diameter were considered. Vertical bars represent ± two standard errors. folia (cedar elm). The climate is humid subtropical with hot summers. It is also continential, characterized by a wide range in annual tempera¬ ture extremes. Precipitation averages about 81 cm annually, but varies considerably from year to year, ranging from less than 51 to more than 127 cm. Greatest amount of rain occurs during April and May. The soil is a yellow-brown podsolic derived from Cretaceous strata. The study area was selected within the forest on the basis of accessibility and gen¬ eral representativeness of the stand. Table 1. Density, dominance, frequency, and importance of woody species with DBH of 2.5 cm or greater.3 Species Relative Density % Relative Dominance % Relative Frequency % Importance Value5 Post Oak 54 80.0 82.0 216.0 Blackjack Oak 24 9.0 13.0 46.0 Hackberry 14 7.0 4.0 25.0 Cedar Elm 5 3.0 1.0 9.0 Red Mulberry 3 0.4 0.06 3.46 TOTAL 100 99.4 100.06 299.46 aWoody species with DBH less than 2.5 cm were Acer negundo, Bumelia lanuginosa, Cornus drummondii, Crataegus sp., Forestiera acuminata, Fraxinus pennsylvanica, Gleditsia tria- canthos, Ilex decidua, Viburnum rufidulum. bImportance value is the sum of relative density, relative dominance and relative frequency. CROSS TIMBERS FOREST STRUCTURE 43 DIAMETER CLASSES CD OtC DBH CLASS CM Figure 2. Frequency distribution of post oak and blackjack oak by diameter at breast height (DBH). MATERIALS AND METHODS A 1-ha area was measured and ten 100-m transects, 10 m apart, were established with permanent numbered stakes placed at 25-m intervals. Sampling sites were randomly selected with the aid of a random numbers table. A circular sample of 100 m2 was taken at each site. The number of sites sampled was determined with a performance curve 44 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 15 <—> LT\ CsJ A| oo 10 2 5 75% POST OAK 18% BLACKJACK 8% HACKBERRY 5b7o POST OAK 8% BLACKJACK 2% HACKBERRY 4% CEDAR ELM 77% POST OAK 6% BLACKJACK 14% HACKBERRY 2% CEDAR ELM 1% MULBERRY l 10 y 20 30 % OF TREES — r~ 40 ~r~ 50 Figure 3. Frequency distribution of trees by height. Only trees with DBH greater than 2.5 cm were considered. (Greig-Smith 1957), with total basal area used as the criterion (Fig. 1). Twenty sites were sampled. Only trees with diameters at breast height (DBH) greater than 2.5 cm were measured. Heights were determined using a Haga altimeter. Total basal area, basal area per species, density, frequency, tree diversity using the Shannon-Weiner index (H’ = — T plog2pi; Cox 1980), size and height class frequencies were determined. RESULTS AND DISCUSSION A total of 14 species of trees was noted at the study site (Table 1). The four dominant trees were post oak, blackjack oak, hackberry, and cedar elm. Post oak had the greatest importance value (Cox 1980), fol¬ lowed by blackjack oak, hackberry, cedar elm and red mulberry ( Moms rubra). Importance values have been used as a measure of niche size (Whittaker 1970) and may indicate the proportion of site resources used by each species (Kroh and Stephenson 1980). CROSS TIMBERS FOREST STRUCTURE 45 Post oak and blackjack oak together account for approximately 70% of the total basal area in the upland forests of Oklahoma (Rice and Penfound 1959). In our forest, 80% of the basal area was comprised by post oak and 9% by blackjack oak. Rice and Penfound (1959) indicated that upland forest stands rarely exceed a total basal area of 25 m2/ha. The oak stand in which Johnson and Risser (1974) measured biomass and net primary production had a basal area of 18 m2 /ha. With a mean basal area of 24.6 m2/ha (Fig. 1), the forest we studied seems cer¬ tain to be an old-growth forest and is quite possibly a climax commun¬ ity. The Shannon- Weiner index was 1.03, a value similar to that (0.94) found by Risser and Rice (1971a) in Oklahoma upland forest areas. Frequency distributions of size classes (Fig. 2) show that blackjack oak may be declining in the study area; its replacement rate seems to be less than one. Post oak, however, appears to be maintaining its popula¬ tion. There may be a dynamic equilibrium between post oak and black¬ jack oak as a function of the availiability of moisture and nutrients. Johnson and Risser (1974) showed that post oak required a higher level of moisture and nutrients than blackjack oak. Replacement rates may decrease in post oak populations during years of drought, releasing blackjack oak seedlings from competition. Height-class frequency distributions show that about 50% of the trees sampled were between 5 and 10 m tall, with only 14% taller than 10 m (Fig. 3). Red mulberry was restricted to the lower understory; cedar elm was not greater than 10 m tall; and post oak, blackjack oak, and hack- berry were found in all three layers. LITERATURE CITED Cox, G. 1980. Laboratory Manual of General Ecology. 4th ed. W. C. Brown Co., Dubuque, Iowa. Dyksterhuis, E. J. 1948. The vegetation of the western cross timbers. Ecol. Monogr. 18:325-376. Greig-Smith, P. 1957. Quantitative Plant Ecology. Butterworths, London. Johnson, F. L., and P. G. Risser. 1974. Biomass, annual net primary production, and dynamics of six mineral elements in a post oak-blackjack oak forest. Ecology 55:1246- 1258. Kroh, G. C., and S. N. Stephenson. 1980. Effects of diversity and pattern on relative yields of four Michigan first-year fallow-field plant species. Oecologia 45:366-371. Rice, E.L., and W.T. Penfound. 1955. An evaluation of the variable-radius and paired- tree methods in the blackjack- post oak forest. Ecology 36:315-320. Rice, E. L., and W. T. Penfound. 1959. The upland forests of Oklahoma. Ecology 40:593-608. Risser, P. G., and E. L. Rice. 1971a. Diversity in tree species in Oklahoma upland forest. Ecology 52:876-880. Risser, P. G., and E. L. Rice. 1971b. Phytosociological analysis of Oklahoma upland forest species. Ecology 52:940-945. Whittaker, R. H. 1970. Communities and Ecosystems. Macmillan, London. HEAVY METAL POLLUTION IN EL PASO DURING SELECTED TIME PERIODS by HOWARD G. APPLEGATE Center for Inter-American and Border Studies University of Texas at El Paso El Paso, TX 79968 and KEITH REDETZKE Department of Biology University of Texas at El Paso El Paso, TX 79968 ABSTRACT Ambient concentrations of lead, zinc, cadmium and arsenic were measured in El Paso, Texas. Data collected before, during and after strike periods at a local copper smelter were compared. Lowest values were obtained during the strike period. This suggests the smelter was a source of a portion of the heavy metals. INTRODUCTION A previous article in this journal detailed the use of a scanning elec¬ tron microscope and ion-probe to identify sources of particulates in ambient air (Gray et al. 1980). By means of morphology and chemical composition, individual particles were related to processing steps at a local smelter. This equipment is not available to all investigators inter¬ ested in identifying point sources of particulates. Another way to iden¬ tify these sources is to monitor the atmosphere when the suspected source is and is not in operation. This is difficult to do if the plant operates 24-hours a day, seven days a week. In such a case, one way to gather data is when the plant is on strike. METHODS Suspended particulates were collected by the El Paso City-County Air Polllution Control Unit using hi-vol samplers according to Environ¬ mental Protection Agency-approved methodology (40 CFR 50.1, 1978). The samples were analyzed by atomic absorption spectroscopy for lead, zinc, cadmium and arsenic (Hubert et al. 1980). Sampling sites were shown in a previous publication (Hubert et al 1981a). The Texas Journal of Science, Vol. XXXV, No. 1, March 1983 48 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 RESULTS AND DISCUSSION Data are presented in Table 1. Pre-and post-strike data were collected for the same length of time as the duration of the strike. Exceptional operating conditions can be expected when a plant is preparing to shut down prior to a strike and again when the plant is starting up produc¬ tion subsequent to the strike. Accordingly, data for the last week prior to the shut down and the first week of the start up are shown separ¬ ately. Each time period thus has five sets of data: normal pre-strike emissions, shutting-down emissions, strike emissions, starting-up emis¬ sions and normal post-strike emissions. These data were analyzed statistically using a t-test. A one-tailed test was used with a probability value of 0.05, since lowered ambient levels were expected during the strike period. Each metal was tested separ¬ ately, pairing strike levels versus normal levels by site and year. Normal operating levels were calculated as the average of pre- and post-strike emissions. Ambient levels of lead, cadmium, and arsenic were signifi¬ cantly reduced (P = 0.05) during the strike periods, and the reduction in zinc levels was nearly significant (P = 0.1). These results indicate that the smelter is a significant source of lead, cadmium and arsenic. Zinc showed consistent declines during strike periods, but the relationship is less certain and may involve other sour¬ ces. Only for cadmium and arsenic were zero amounts recorded during strikes. This probably reflects the low concentrations of these two com¬ pounds during normal pre- and post-strike conditions. Usually, they are found in concentrations of less than one microgram per cubic meter of air. Several times during the abnormal conditions associated with shutting down and starting up, concentrations of cadmium and arsenic were found to be greater than one microgram per cubic meter of air. The relatively high concentrations of lead and zinc in ambient air even during the longest strike (5 months) are probably due to blowing residual dust. Also, ores are stockpiled in the open. Particulates blown from these stocks could be deposited on hi-vol filters and thus detected in atomic-absorption spectroscopic analysis. Cadmium and arsenic were not present in the ores in high enough concentrations to be detected on a routine basis during strikes. Abnormal ambient concentrations of the metal can be expected in the process of shutting down and staring up an industry. A comparison was made between the values found the week prior to and the week fol¬ lowing the strike with their respective “normal” values. A greater per¬ centage of abnormally high ambient concentrations was found prior to the strike than following the strike— -i.e., 58 percent vs 37 percent in 1974; 75 percent vs 17 percent in 1977; 31 precent vs zero percent in Table 1. Ambient concentrations of heavy metals in the atmosphere of El Paso, Texas, before, during, and after smelter strikes. All values are micrograms per cubic meter of air. ND indicates no data. HEAVY METAL POLLUTION IN EL PASO 49 © CM on on © © !>■ © © © < o © © © © © © © © © © © © © i— i © © © © © © © © © © © © © © © CM © © oo © © © © © © CM u o © © © © © © © © © © © © © © © © © © © © © © © © © © © © © qj .ts C/3 on © on on on 00 © on © on © CM oo c N CM —1 CM >— < CM © © CM © on X © © © © © © © © © © © © © © © © oo © © © © on E^ © CM X in CM © on on CM ■—i © on © CM o © © © © © © © © © © © © © As on t © on on © l Q © , CM © © © o © © © © ■ — i © © •—> © © © CM © © © © © © © © Z © © © © © © © © © © CM on © Q M"1 oo © © © E'' T3 u o © © © © © © © © © © © © © on © © © © © © © © Z © © © © © © Qj .£2 c n 00 © — CM 00 © Q on © © CM 00 X c N 1—1 CM >—< © CM © © <—> © © © on ■— i © © © © © © © © Z © © © © © — © © 00 © CM © © Q © © o- © X 00 © © CM 00 © © © CD E>- oo on oo if) © © © © © © Z ~l © © on As © ■'f 00 on oo CM CM © © CM © 00 © © oo ©■ © rt< 00 © i— i on CM © CM © cc © © © © © © © © on © © © E" © on CM ■'f © © © oo on CM © X u © © CM © © CM CM ■— < © © © X CM © X © © © © © © © © © X © © © oj c/3 CM on CM CM on on © © © — CM © 00 © C m © !>■ CM CM CM t" ■— i © © © © on X N © © © on 05 on © © CM X X X © Tf! r— ' © 00 CM on © © OO © on CM r^ X Xi © CM CM © oo © © © E-' © CM © oo Oh © X X on © © © on X © X r~l —■ ' As , Q © CM i>- on on © © © on © © Q X © © © © CM ■— i © © ■— i >— i © © ■— i © Z © © © © © © © © © © © Z © r- Q © © © on © © CM oo © © Q X u © © © © © © © © © © © © © — ! © Z © © © © © © © © © © C5 Z © qj X C/3 CM Q © CM on © !>• © © © © © Q © £ N F—l CM on © •— i © © 1— 1 © Z © © © © © © © © © © © Z © Q E oo on © on on on Q 00 £ © © in o © on E"> E'~ CM 00 © © Z CD © © © © “ © © Z ubc ^bo 3 "a 3 JO c "> ■e 3 0 Cl 3 JO 3 3 < < QJ co 3 •—5 3 “a ‘°a QJ 0 Z 3 i 3 >— 5 °> O £ < © •—5 on © v-~ CM on CM © on c/3 (X on ^f CM CM © on © CM X c 3 *— j 3 3 bo 3 < bo 3 < t" a < C 3 © 3 a QJ a QJ C/3 © 00 © X X c 3 ►—5 3 > O Z > 0 03 ►— j ■'f © 00 © s>- ■M" >—> C/3 TF © on ^5 © 00 »— i r-^ <—* CM CM ■—i <—> CM i— i — i i— i CM CM CM X 3 • i-i c n O, 03 i § O X C 03 cstrike dabnormal post-strike 'normal post-strike 50 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 1980. This suggests the process of shutting down is inherently more dirty than the processes involved in starting up. Thermal inversions start in the fall, peak during the winter and are least during the summer in El Paso. These affect the quantities of heavy metals measured in the area (Hubert et al. 1981a, b). Compari¬ sons cannot be made among the three data sets for 1974, 1977 and 1980 since they cover different time spans and different inversion conditions. Meteorological conditions at the smelter are not known. Official meteorological data from the El Paso International Airport were com¬ pared with data from the Cd. Juarez Airport and two continuous air monitoring stations. Wind speeds and directions at the four stations could not be correlated. None of the stations was near the smelter. LITERATURE CITED 40 CFR 50.1. 1978. Code of Federal Regulations: “Protection of the Environment.” Parts 50-59. Gray, R. W., H. G. Applegate and W. R. Roser. 1980. Analysis of particulates by scan¬ ning electron microscopy and ion probe. Texas J. Sci. 32 (3): 259-264. Hubert, J. S., R. M. Candelaria and H. G. Applegate. 1980. Determination of lead, zinc, cadmium and arsenic in environmental samples. Atomic Spectroscopy, 1 (4):90-93. Hubert, J. S., R. M. Candelaria, B. F. Rosenblum and H. G. Applegate. 1981a. A survey of ambient air levels of lead in El Paso, Texas, from 1972-1979. Air Pollution Control Association Jour. 3 1 (3):259-261 . Hubert, J. S., R. M. Candelaria, B. F. Rosenblum, R. Munoz and H. G. Applegate. 1981b. A survey of ambient air levels of arsenic and cadmium in El Paso, Texas, from 1972-1979. Air Pollution Control Association Jour. 31(3):262-263. THE COMMERCIAL PRODUCTION OF MUDMINNOWS (. FUNDULUS GRANDIS) FOR LIVE BAIT: A PRELIMINARY ECONOMIC ANALYSIS by BENITA P. WAAS and KIRK STRAWN Department of Wildlife and Fisheries Sciences Texas A&M University College Station, TX 77843 and MICHAEL JOHNS and WADE GRIFFIN Department of Agricultural Economics Texas A&M University College Station, TX 77843 ABSTRACT The economic feasibiltiy of operating a commercial mudminnow farm was determined using the Generalized Budget Simulation Model for Aquaculture developed at Texas A&M University. A 10-yr planning horizon was used for the study. Initial investment costs, annual budgets and cash flows were estimated to determine cost, returns and profit. Economic profit, break-even analysis and net present value were used to evaluate the eco¬ nomic feasibility. Based on a grow-out stocking density of 400,000 /ha, 85% projected sur¬ vival, 2 crops per year and achieved production at 80% of capacity, the 24-ha facility showed an economic profit of $41,160 for the 6th year of operation. The break-even price of $0.40 /dozen was $0.25 less than the market price of $0.65. The break-even production of 278,705 dozen /yr is 174,629 dozen less than the assumed annual production of 453,334 dozen. INTRODUCTION In recent years there has been an increased interest not only in devel¬ oping biological and technological aspects of aquaculture systems but also in looking into their economic relationships. Economic, investi- ment and feasibility studies have been undertaken for a number of aquacultural systems including catfish (Griffin and Lacewell 1978; Ekstrom 1979), penaeid shrimp (Anderson and Tabb 1970; Williams 1973; Aquacop 1975; Adams et al. 1979; Johns et al. 1981a, b), fresh¬ water prawn (Gibson and Wang 1977; Shang and Fujimura 1977; Roberts and Baur 1978) pompano (Cuevas 1978) and oysters (Im et al. 1976; Lipschultz and Krantz 1978, 1980). Although commercial baitfish farming has proved to be a rapidly growing, high-profit business, very few economic studies on baitfish production have been documented in scientific literture (Shang and Iversen 1971; Herrick and Baldwin 1975). The Texas Journal of Science, Vol. XXXV, No. 1, March 1983 52 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Fundulus grandis (Cyprinodontidae), regionally called “bullmin- now”, “chub”, “mudfish” or “mudminnow”, is in popular demand as live bait for sport fishes such as southern flounder, spotted seatrout and red drum along the coastal Gulf of Mexico and South Atlantic states. Local suppliers of mudminnows rely exclusively on catches from the wild. Fish are either seined from tidal marshes or trapped using min¬ now traps baited with cracked crabs. Since these methods are not relia¬ ble, supply is irregular and has continued to fall short of demand since 1970. As a result, there is much interest in raising this fish as a com¬ mercial enterprise. Initial research efforts on the culture of mudminnows were con¬ ducted at Claude Peteet Mariculture Center in Alabama. Studies focused on the maintenance, spawning and harvesting techniques of broodstock and young, and rearing of juveniles to bait size utilizing commercial feeds (Tatum and Helton 1977; Tatum et al. 1979). Mcll- wain (1977) reared mudminnows in a closed system and concluded that it would not be a commercially feasible venture because of the high cost of rearing systems. Our studies at Houston Lighting 8c Power Company’s Cedar Bayou Generating Station research facility east of Baytown, Texas, have shown positive technological feasibility for mudminnow farming along the Texas Gulf coast (Waas 1982). How¬ ever, commercial baitfish production is a highly specialized industry due to the nature of transportation and sales facilities needed, the res¬ tricted areas in which production can occur economically, and the sea¬ sonal nature of the market. Thus, it is important not only to know the biological and technological aspects of production but also to be able to establish and demonstrate the economic feasibility of such an opera¬ tion before prospective investors commit substantial resources to pro¬ duction. METHODS AND DATA The economic feasibility of a mudminnow hatchery /grow-out opera¬ tion was examined using the Generalized Budget Simulation Model for Aquaculture developed at the Department of Agricultural Economics, Texas A8cM University (Griffin et al. 1980). The model is designed to produce itemized fixed and variable costs, annual and monthly budge¬ tary outputs, cash flows, break-even quantities and prices for a specified aquaculture system. These values are then presented to reveal produc¬ tion and net revenue for a venture. The proposed 24-ha (60 acre) facility would consist of a system of 40 0.2-ha spawning/hatching ponds and 10 1.0-ha grow-out ponds cover¬ ing a total area of 18 hectares. The facility design (Fig. 1) is based on data relative to growth and reproductive biology of mudminnows ECONOMICS OF MUDMINNOW PRODUCTION 53 E3 3 £ - 1 l - - - 1 I - l : i _ _ _ r i 1 I _ s t . . 3 I - 1 t - — \ i - — i : r r I 33 i — 1 i _ i 7 partitioning levee 3333 r . . . . ■}] X 1 I _ 1 l 3 l _ 3 roaded 1 ~ levee * i - 1 i _ i L. } Cl 3 . 1 - 1 1*0 ha f 0-2 ha 1 i — . 33 i . . - i T . . T :: : 13 3 r . 3 C _ .33 I _ _ _ j : I . 3 i i X _ I i - 1 t - r r . i i - 1 rl - L t - J I 1 l _ J C - 1 £ _ I I - 1 I _ _ 1 33 3 I - 1 X _ I I - - - 1 1 _ I I - 1 I _ I £ - 1 I _ I i - 1 . t _ j i x .3 f . x 1 food silos storaqe office* - J oo 3 3 Figure 1. Design of the proposed 3-phase pond production facility (spawning/hatching/ grow-out) for mudminnow farming. Ponds marked X are equipped with wooden piers. obtained from studies at Cedar Bayou as well as from previous work in Alabama (Tatum et al. 1979; Trimble et al. unpubl. data). Several bio¬ logical parameters, discussed below, are assumed to be of importance for optimal production of mudminnows. 54 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Climatic Conditions The designed facility can be adapted for production anywhere along the Texas Gulf coast where a sufficient water supply is available and outdoor temperatures are suitable for continued spawning (approxi¬ mately 22-28°C) from March to October (Fivizzani 1977; Waas 1982). Production of Fry During the spawning season 20 0.2-ha ponds would function as spawning ponds while the other 20 would function as hatching ponds. Eggs laid on spawing mats will be hatched in the latter and the fry grown to an average size of 0.5 g (28-30 mm). Stocked at 65,000 brood fish /ha, production for each spawning pond is assumed to be 400,000 fry (at 75% survival from egg to fry) during the spawning season (late February to October). Fry produced from late February to May and May to August would be raised as crops I and II, respectively. Fry resulting from spawning activities after August would be overwintered and used for broodstock the following year. The recommended size for spaw¬ ning/hatching ponds is 0.2 ha as it would be necessary to keep them small to facilitate efficient egg collection and fry harvest. Two of the 0.2 ha ponds would be equipped with wooden piers and would serve as holding facilities for fish during harvest (Fig. 1). Fish would be held in large net cages and sold to bait dealers at the facility. Grow-out Ponds The 10 1.0-ha grow-out ponds would be stocked at a density of 400,000 fish /ha. Fry would be graded prior to stocking to ensure size uniformity. Although this stocking density has not been tested, work in Alabama has demonstrated that fish stocked at 370,000 /ha grew only a little slower than those stocked at 250,000 /ha (Trimble et al. 1981). Current studies show sufficient growth rates can be maintained at stocking densities as high as 500,000 /ha (P. Perschbacher, pers. comm.). A grow-out season of 55-65 days and 85% survival is based on Cedar Bayou and Alabama data (Tatum et al. 1979). Food and Feeding Fish would be fed commercial minnow feed (33% protein; particle size 0.5 mm) at the rate of 3% of body weight /day for brood fish. Food comsumption values for grow-out fish were based on an average food conversion ratio of 2.0. Average weight of brood fish and of fish sold is considered to be 7 and 3 g, respectively. RESULTS OF ECONOMIC ANALYSIS The analysis first calculates capital investment for the designed facil¬ ity followed by yearly gross revenue and operating costs. It also pro- ECONOMICS OF MUDMINNOW PRODUCTION 55 Table 1. Estimate of capital cost for year 6 in the 10-year planning horizon of the mud- minnow hatchery /grow-out operation, 1982. 1. Land (60 acres @ $2,000 /acre) $120,000 2. Pond Construction a. Levees: excavation, caliche, grass seed $101,768 b. Pipes, Drains, Water Supply System 28,646 Subtotal $130,414 3. Buildings a. Storage and Shop (1,800 sq. ft.) $36,000 b. Office Building (750 sq. ft.) 15,000 c. Architecture and Engineering Fee 13,457 Subtotal $64,457 4. Machinery and Equipment a. Pumps $1,100 b. Stand Pipe Screen, Filter Bags 755 c. Transport Tank and Agitators 1,060 d. Feed Blower /Trailer 3,610 e. Feed Silos (2) 8,000 f. Spawning Mats (2,400 @ $5.00 per mat) 12,000 g- Minnow Graders, Holding Baskets, Seines etc. 2,146 h. Refrigerator 950 i. Miscellaneous Lab Equipment (microscope, scale, refractometer, etc.) 4,031 j- Shop Tools 1,290 k. Office Equipment 1,518 Subtotal $36,460 5. Vehicles a. Tractor $8,762 b. Pick-up 10,000 Subtotal $18,762 6. Broodstock Establishment (21,666 doz. @ $0.85 /doz.) $18,417 TOTAL CAPITAL COSTS $388,510 vides a detailed annual budget for the sixth year of operation. All input and output prices are assumed to remain constant over the planning horizon. Break-even analysis, economic profit and net present value are then examined to evaluate the feasibility of the facility. Revenue and cost are in 1982 dollars. Capital Investment Included in this category are funds initially committed to the project (Table 1). All equipment and construction prices were obtained during the spring of 1982 and are representative of the upper Texas coastal area. A 10-yr planning horizon is used for the facility. The total capital cost (CC) of the facility is $388,510. Pond construction and land value are the two major expenses, accounting for 33.6 and 30.9% of the total investment. Building cost constitutes 16.6% of CC; buildings consist of 56 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Table 2. Schedule of activities for a 2-crop mudminnow farming enterprise. Total Spawning Hatching to Grow-out Grow-out Phase Juveniles Phase Harvest Days Crop I Feb. 15-Apr. 30 Feb. 22-May 25 June 1-Aug. 5 Aug. 5-Aug. 20 65 Crop II Mayl-July30 May 8-Aug. 20 Sept. 1 -Nov. 5 Nov. 5-Nov. 20 65 Aug. 1-Oct. 10 Fry resulting from this spawning activity would be raised, wintered and used for broodstock the following year. a storage facility for spawning mats and equipment and an office. Cost of machinery and equipment is 9.4%. The useful life of all facilities is estimated at 10 years, and salvage value of buildings and pond facility are estimated by the straight-line depreciation method. Adult brood- stock would be initially purchased from trappers for 85 C per dozen, which amounts to only 4.7% of CC. Annual Production and Revenue A suggested schedule of activities for the 2-crop operation is pre¬ sented in Table 2. This operation is based on a production rate of 80% of the total capacity of the facility, allowing for problems such as occa¬ sional outbreaks of disease, equipment failures, adverse weather condi¬ tions, bird predation, or other production problems. Also, based on the stocking density of 400,000 /ha and projected survival of 85%, a total of 453,333 dozen mudminnows would be produced on an 8-9 month pro¬ duction schedule (crop I in August; crop II in November). At $0.65 per dozen of baitfish, sales would generate an annual revenue of $294,667 (Table 3). Operating Costs Estimated annual operating costs (OC) (Table 4) are considered in two categories, variable costs (VC) and fixed costs (FC). Feed is the Table 3. Summarized annual budget for year 6 in 10-year planning horizon for baitfish hatchery /grow-out operation. Gross revenue from baitfish production $294,667.00 Total variable cost (VC) $ 31,795.00 Total fixed cost (FC) $149,363.00 Total cost (FC + VC) $181,158.00 Net revenue $113,509.00 Income tax $ 52,214.00 Net after-tax revenue $ 61,295.00 Required return to equity capital $ 20,135.00 Economic profit $ 41,160.00 Break-even price $ .40 Break-even quantity 278,705 dozen Total capital investment $388,510.00 Net present value based on 25% initial investment in capital costs $341,866.00 ECONOMICS OF MUDMINNOW PRODUCTION 57 Table 4. Estimated annual opeating costs for year 6 in the 10-year planning horizon of the mudminnow hatchery /grow-out opeation, 1982. Variable Costs 1. Feed (52.6 metric tons) $12,185 2. Fuel $ 2,134 3. Part-time labor $ 9,240 4. Utilities a. Electricity $ 4,898 b. Telephone $ 600 c. Water $ 400 5. Repair and Maintenance a. Equipment $ 232 b. Machinery $ 663 6. Payroll taxes $ 1,443 Total Variable Costs $31,795 Fixed Costs 1. Salary — full time personnel $60,000 2. Interest $32,999 3. Depreciation $42,016 4. Taxes $ 6,126 5. Insurance $ 8,222 Total of Fixed Costs $149,363 TOTAL OPERATION COSTS $181,158 major VC item, representing 38.3%. Feed costs are calculated at 10.232/ kg. Part-time labor is 29.1% of VC. This labor would be utilized during harvest of fry for stocking and adults for marketing. Salaries of full-time personnel (manager and 6 laborers) represent 40.2% of FC. Depreciation is 28.1% of FC. Interest calculated at 21% per year is the third highest FC item (22.1%). Total annual operating cost of the facil¬ ity is $181,158. The annual budget for year 6 of the planning horizon is given in Table 3. Net revenue above total OC is $113,509. Income tax calculated on a corporate basis is $52,214, resulting in a net after-tax return of $61,295. Break-even Analysis Break-even analysis is useful in studying the relationship between FC, VC, and profit. Break-even price (BEP) and break-even production (BEQ) are considered in the analysis (Table 3). BEP of $0.40 represents the lease price required for the yield to equal OC for year 6 of opera¬ tion assuming the projected yearly production rate of 453,334 dozen baitfish. This is $0.25 less than the market price of $0.65 /doz. BEQ of 278,705 dozen at the current unit price of $0.65 indicates the lowest level of production needed to prevent losses. This BEQ is 61% of the production capacity assumed in the analysis. 58 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Economic Profit Economic profit helps to evaluate the investment potential of the baitfish operation as opposed to an alternative investment. This is done by estimating returns the owner can expect for his equity capital from the alternative investment. Equity capital is taken as 25% down pay¬ ment of the total investment of the facility. The alternative investment in this study is taken as corporate bonds which have a return rate of 15.73% per year, with an added 5% per year as adjustment for risk and uncertainty associated with the baitfish operation. That is, mudmin- now farming, being a new venture, can be considered a high risk in comparison to corporate bonds. Changes in demand for baitfish, deple¬ tion of sportfish stocks, discovery of additional or alternative bait sour¬ ces are some additional factors that contribute to the risk. The required return to equity capital (Table 3) is $20,135 and economic profit is $41,160. Positive value of economic profit implies that investment of equity capital in the baitfish operation results in higher returns than the next best alternative. Net Present Value By taking into account the time value of expenditures and earnings, the net present value (NPV) method allows one to make a realistic comparison of future returns with initial expenditures. This is done by discounting the expected future returns by an appropriate discount rate over the planning horizon of the project. Discount rate used for the analysis is 19.75%. A NPV value greater than zero means the investment is economically profitable. In the present analysis NPV was estimated considering the owner’s investment as 25% of the capital investment and remaining 75% financed at 17% interest rate for the life of the investment. A net present value of $341,866 (Table 3) indicates the investor would receive a rate of return greater than 21.7%. CONCLUSION Based on the assumptions incorporated into the framework of the model, a commercial mudminnow operation of the assumed design, located along the Texas coast would be economically profitable. Some of the assumptions that have major impact on its feasibility are fry production levels, stocking densities in grow-out ponds, timing of the production cycle to take advantage of peak periods, and a ready market. As previously mentioned, biological assumptions are based on experi¬ mental data and work is presently being carried out to further optimize stocking densities and increase fry production. Use of a higher ratio of females in spawning ponds has been shown to increase fry production (Waas unpubl. data). Timing of crop harvest with peak demand peri¬ ods may be the key element in success of the operation, as demand for mudminnows is seasonal. Along the Texas coast demand is low during ECONOMICS OF MUDMINNOW PRODUCTION 59 the first 6 months of the year. It increases steadily from late July to a November peak during the flounder season. Even if all possible steps are taken to market the crop during high-demand periods, oversupply or shortages of baitfish are not always forseeable. Climatic conditions that curtail fishing can cause a temporary decline in sales of bait. Since mudminnows have not been raised commercially, a thorough market survey is necessary before large-scale production is undertaken. Prospective producers should visit fish camps and other bait selling areas and determine the scope of the market. Although there will be initial competition from the wild catch, bait dealers have clearly shown a preference for pond raised mudminnows because of their higher qual¬ ity, uniform size, and most of all, because of the assurance of a reliable and adequate supply during high-demand periods. Supply of fish for bio-assay work and the sale of fingerlings as food for predatory aqua¬ rium fish are additional marketing channels that should be explored. Economies of size were not investigated in this study. It would be useful to determine the facility size that captures most of the available economies, as it aids in the reduction of fixed costs per unit of output. Since production of mudminnows for bait is a relatively new venture it would be wise initially to start with a smaller-sized production facility. Possibly 4-6 hectares (10-15 acres) in a one-man or family operation would help minimize investment per unit. ACKNOWLEDGEMENTS This research was funded by the Houston Lighting 8c Power Com¬ pany through the Department of Wildlife and fisheries Sciences and Texas Agricultural Experiment Station Project 6462-3790. We thank Ron Biever, Mark Byford, Mark Hardin, Pete Perschbacher, Celeste Rees and Dr. Larry Wiesepape for their help in data collection. The economic analysis was supported through a research project sponsored (in part) by the Texas A8cM University Sea Grant College Program, supported by the National Oceanic and Atmospheric Administration’s Office of Sea Grant, Department of Commerce, under grant number NA81AA-D-00092. This paper represents contribution number TA- 18031 of the Texas Agricultural Experiment Station. LITERATURE CITED Adams, C. M., W. L. Griffin, J. P. Nichols, and R. W. Brick. 1979. Bioengineering- economic-model for shrimp mariculture systems, 1979. TAMU-SG-80-203, Texas A&M University, College Station, TX. Anderson, L. G., and D. C. Tabb. 1970. Some economic aspects of pink shrimp farming. Gulf Carr. Fish Ins. 23:113-124. Aquacop. 1975. Maturation and spawning in captivity of penaeid shrimp Penaeus mer- guiensis de Man, Penaeus japonicus Bate, Penaeus aztecus Ives, Metapenaeus ensis de Hann, and Penaeus semisulcatus de Hann. Proc. World Mar. Soc. 6:123-132. 60 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Cuevas, H. Jr. 1978. Economic feasibility study of Florida pompano ( Trachinotus caro- linus) and rainbow trout ( Salmo gairdneri ) production in brackish water ponds. M.S. Thesis, Auburn Univ., Auburn, AL. Ekstrom, J. P. 1979. A computerized budget simulator for use in catfish farming. M.S. Thesis, Texas A8cM University, College Station, TX. Fivizzani, A. J., Jr. 1977. Environmental and hormonal regulation of seasonal conditions of the Gulf killifish ( Fundulus grandis). Ph.D. Dissertation, Louisiana State Univer¬ sity, Baton Rouge, LA. Gibson, R. T., and J. Wang. 1977. An alternative prawn production system design in Hawaii. UNIHI-Sea Grant TR-77-05. HAES J. Ser. paper no. 2142. Griffin, W. L., and R. D. Lacewell. 1978. Estimated cost of producting catfish in Texas, 1977-1978. Proc. 1978 Fish Farm. Conf., Ann. Conv. Fish Farmers TX. p. 35-61. Griffin, W. L., C. M. Adams, and L. A. Jensen. 1980. A generalized simulation model for aquaculture. Texas A&M University, Sea Grant Programs. Sea Grant 04-8- Mol- 133. Herrick, S. F., and W. J. Baldwin. 1975. The commercial production of top minnows — A preliminary economic analysis. Sea Grant Advisory Report. Unviersity of Hawaii. UNIHI-SG-AR-75-02. HIMB Contirb. no. 464. Im, K. H., R. H. Johnson, and R. D. Langmo. 1976. The economics of hatchery produc¬ tion of Pacific oyster seed — a research report. Proc. Nat. Shellfish Assoc. 66:81-94. Johns, M., W. Griffin, A. Lawrence, and D. Hutchins. 1981a. Budget analysis of shrimp maturation facility. J. World Mar. Soc. 12:104-109. Johns, M., W. Griffin, A. Lawrence, D. Hutchins, and J. Fox. 1981b. Budget analysis of shrimp hatchery facilities. J. World Mar. Soc. 12(2). In press. Lipschultz, F., and G. E. Krantz. 1978. An analysis of oyster hatchery production of cultched and cultchless oysters utilizing linear programming techniques. Proc. Nat. Shellfish. Assoc. 68:5-10. Lipschultz, F., and G. E. Krantz. 1980. Production optimization and economic analysis of an oyster ( Crassostrea virginica) hatchery in the Chesapeake Bay, Maryland, USA. Proc. World Mar. Soc. 11:580-591. Mcllwain, T. D. 1977. Bait fish rearing. Project GR-76-005, Mississippi Mar. Res. Coun¬ cil., Long Beach, MS. Roberts, K. J., and L. C. Bauer. 1978. Costs and returns for Macrobrachium grow-out in South Carolina, USA. Aquaculture 15:383-390. Shang, Y. C., and T. Fujimura. 1977. Production economics of fresh water prawn (Macrobrachium rosenbergii ) farming in Hawaii. Aquaculture 11:99-110. Shang, Y. C., and R. T. B. Iversen. 1971. The production of threadfin shad as live bait for Hawaii’s skipjack tuna fishery: an economic feasibility study. Economic Research Center, Univ. of Hawaii, Honolulu, HI. Tatum, W. M., and R. F. Helton, Jr. 1977. Preliminary results of experiments on the feasibility of producing bullminnows (Fundulus grandis ) for the live bait industry. Proc. World Mar. Soc. 8:49-54. Tatum, W. M., W. C. Trimble, and R. F. Helton, Jr. 1979. Production of Gulf killfish in brackish water ponds. Proc. An. Conf. Southeast. Assoc. Fish. Wildlife Agencies 32:502-508. Trimble, W. C., W. M. Tatum, and S. A. Styron. 1981. Pond studies on Gulf killifish (Fundulus grandis) mariculture. J. World Mar. Soc. 12(2). In press. Waas, P. B. 1982. Development and evaluation of a culture system suitable for the pro¬ duction of Gulf killifish (Fundulus grandis Baird and Girard) for live bait in the thermal effluent of a power plant. Ph.D. Dissertation, Texas A&M University, College Station, TX. Williams, R. J. 1973. Economic feasibility of commercial shrimp farming in Texas. M. S. Thesis, Texas A&M Unviersity, College Station, TX. EFFECTS OF A HIGH POTASSIUM DIET AND PROSTAGLANDIN ON INDUCED GASTRIC ULCERATION IN RATS1 by MARSHALL J. MANN and DAVID P. SHEPHERD Department of Biology Southeastern Louisiana University P.O. Box 791 Hammond, LA 70402 ABSTRACT Forty (40) Sprague-Dawley rats were placed on a high potassium (K), low sodium diet for 23 days while another 40 received standard rat chow. All animals received an IP injec¬ tion of 20mg/kg indomethacin to induce gastric ulcers. Twenty (20) animals from each of the above groups received a 0. 15mg/kg oral dose of prostaglandin (PGE2).. The high K diet alone reduced the number and severity of indomethacin-induced gastric ulcers and it enhanced the anti-ulcer effect of PGE2. INTRODUCTION Prostaglandin E2 (PGE2) has been shown to have a cytoprotective effect upon the gastric mucosa of rats exposed to various ulcer-inducing compounds, including the drug indomethacin (Lippman 1974; Robert 1976). Shepherd et al. (1973) reported that 65% of rats they fed a special diet high in potassium survived exposure to 1000R whole-body gamma irradiation. This amount of radiation typically results in the death of all animals, and the primary cause of death is damage to the gastroin¬ testinal tract (Quastler 1956; Casarett 1968). Therefore, a high- potassium diet may protect the gastrointestinal tract from radiation damage. The purpose of this study was to evaluate potassium as a potential protecting agent for the gastric mucosa of rats given the ulcer-inducing compound indomethacin. The approach was to use a high-potassium diet and standard laboratory chow to form two experimental groups. Half of each experimental group was given oral doses of PGE2. All animals were injected with indomethacin. MATERIALS AND METHODS Eighty (80) Sprague-Dawley rats, mixed sexes and weighing 100-125 g each, were divided into equal groups (A and B). Group A was placed Paper presented at 84th Annual Meeting of the Texas Academy of Science, Austin, TX, March 1981. The Texas Journal of Science, Vol. XXXV, No. 1, March 1983 62 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 on a standard laboratory chow (Purina Rat Chow), while Group B as given a special diet high in potassium (0.73%) and low in sodium (0.019%) (ICN Life Science Group, Cleveland, Ohio). This is half the sodium and four times more potassium than the minimum require¬ ments of these ions. Other data related to consumption of the high- potassium diet — including food intake, duration of the diet, weight gain and serum Na and K levels — have been previously reported (She¬ pherd et al. 1973). Animals of Group B were maintained on the diet for 23 days. All animals received distilled water ad libitum. After 23 days, Groups A and B were subdivided into groups of twenty animals each (Al, A2, Bl, B2). All animals were fasted 24 h with dis¬ tilled water ad libitum. Then, groups A2 and B2 were given Prosta¬ glandin E2 (PGE2) (Sigma Chemical Company, St. Louis, Mo.) orally at a dose of 0.15mg/kg (Main and Whittle 1975). PGE2 was combined with absolute ethanol (0. lml/mg) and added to 1% methyl cellulose and mixed five minutes with a magnetic stirrer. Oral administration of PGE2 was accomplished via a 76-mm intubation needle. Immediately following oral PGE2, all animals were injected (IP) with 20mg/kg indomethacin (Djahanguiri 1969). Preparation of the indomethacin fol¬ lowed the method of Main and Whittle (1975). Five hours later (Lip- pman 1974) all animals were etherized; the stomach was removed and opened along the greater curvature. The stomach was inverted on the index finger, washed under tap water and examined by an observer to whom the treatment was not known. The necrohemmorrhagic areas were counted, and graded on a severity scale of one to three (1 = less than 1mm; 2 = l-2mm; 3 = greater than 3mm) (Main and Whittle 1975). RESULTS The effects of a high potassium diet and synthetic prostaglandin (PGE2) on the incidence of indomethacin-induced acute gastric ulcers are indicated in Table 1. The most striking datum in Table 1 is the 80% reduction in the number of animals experiencing ulcers in the experimental group B2. These animals were on the high potassium diet and received oral PGE2 before indomethacin injection. The 80% reduc¬ tion is by comparison with group Bl. Group A2 which was on stand¬ ard lab chow also received oral PGE2 but only had a 30% reduction in incidence of ulcers, compared with Al. The difference in incidence of ulcers between groups Al and Bl was not significant, but there was a significant difference in the total number of ulcers (Table 2). The data from Table 2 demonstrates that diet was significantly involved in reducing the total number of indomethacin-induced ulcers. Group Bl, on the high-potassium diet, GASTRIC ULCERS IN RATS 63 Table 1. Effect of high-potassium diet and PGE2 on incidence of gastric ulcers in rats. Group3 Diet Dose of pge2 # of Animals with Ulcers per group (20) % Incidence % Reduction15 Al Lab Chow 18/20 90% A2 Lab Chow 0.15mg/kg 12/20 60% 30% Bl High K+ 20/20 100% B2 High K+ 0.15mg/kg 4/20 20% 80%c a All groups received 20mg/kg indoemthacin. b Reduction is based on comparison of A2 to A1 and B2 to Bl. Significant at 0.005 probability level. had 184 ulcers as compared to 328 ulcers for the lab-chow Group Al. Those animals that were on the high-potassium diet and given PGE2 (Group B2) had only 5 ulcers as compared to those animals on lab chow and receiving PGE2 (Group A2), which had 73 ulcers. Both prostaglandin treatment and the high potassium diet, when used alone, reduced the total number of ulcers; however, when used together, not only was the total number of ulcers reduced but also the severity was reduced (Table 3). Because ulcers of severity 3 had areas ranging from (2mm)2 to approximately total glandular surface, it is very significant that all the ulcers in Group B2 were less than 1mm. Of the four B2 animals with ulcers, three had only one (#1 severity) and the fourth had two (#1 severity). The sole difference between this group (B2) and Group A2 was the high potassium diet. Therefore, the syner¬ gism of PGE2 and a high potassium diet resulted in a smaller surface area of the stomach having necrohemmorrhagic lesions. DISCUSSION The fact that potassium is an essential requirement for protein syn¬ thesis and growth is well established (Eagle 1955; Lubin 1964, 1967; Ledbetter and Lubin 1977). When cells are damaged by irradiation, potassium moves out of the cells (Ting and Zirkle 1940; Harrison et al. 1958; Portela et al. 1963); but when animals are provided with optimal availability of potassium in the diet, they are somewhat protected from Table 2. Effect of high-potassium diet and PGE2 on the number of gastric ulcers in rats. Group3 Diet Dose of pge2 Total # Ulcers Average # Per Rat Al Lab Chow 328 16.4 A2 Lab Chow 0. 15mg/kg 73 3.6 Bl High K+ 184 9.2 Bw High K+ 0.15mg/kg 5 0.25 a All groups received 20mg/kg indoemthacin. 64 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Table 3. Effect of high-potassium diet and PGE2 on the severity of gastric ulcers in rats. Dose of Number of Ulcers with Severity = Group2 Diet pge2 1 2 3 Al Lab Chow 267 48 13 A2 Lab Chow 0.15mg/kg 57 12 4 B1 High K+ 158 (85.8%) 20 (10.8%) 6 (3.2%) B2 High K+ 0.15mg/kg 5 (100%) 0 0 a All groups received 20mg/kg indoemthacin. the radiation as shown by a reduction in the number of deaths (She¬ pherd et al 1973). Therefore, the primary objective of the present inves¬ tigation was to determine whether optimal availability of potassium would protect gastrointestinal cells from a potentially damaging agent, indomethacin. The results show that rats placed on a diet high in potassium and low in sodium enjoyed some degree of protection: the total number of experimental ulcers was reduced by almost half. But when oral admin¬ istration of prostaglandin (PGE2) accompanied the special diet, the effects were synergistic. PGE2 treatment alone resulted in a 30% reduc¬ tion in animals with ulcers. When PGE2 was combined with the high potassium diet, there was an 80% reduction in animals with ulcers. Most evidence suggests that the initial action of some damaging agents on the gastric mucosa is the inhibition of active ion transport (Kuo et al. 1974; Sernka et al. 1974; Kuo and Shanbour 1976a, b). Specif¬ ically, studies have shown that indomethacin inhibits active transport of sodium (Chaudhury and Jacobson 1978) while prostaglandin stimu¬ lates active transport of sodium (Bowen et al. 1975), and these results have been used to postulate a mechanism of PGE2 cytoprotection (Chaudhury and Jacobson 1978). There are no significant data concern¬ ing potassium in relation to this phenomenon. There is some evidence to suggest that there may exist a separate transfer mechanism resonsible for accumulating intracellular potassium and that this mechanism is not directly coupled to active sodium trans¬ port (Delong and Civan 1978). This could provide the basis for potas¬ sium acting as an independent protecting agent against the number and severity of indomethacin-induced ulcers. This could also explain why potassium acts synergistically with, or independent of, PGE2 in protecting the mucosa against indomethacin. Consistent with potassium being involved in cellular protection is the hypothesis that intracellular potassium controls the rate of macro- molecular synthesis. The latter hypothesis is based on the observation that when cells are induced to leak potassium, there is a parallel GASTRIC ULCERS IN RATS 65 depression in the rate of protein and DNA synthesis. When the potas¬ sium level in the medium around the cells is increased, near normal levels of cellular K can be sustained and macromolecular synthesis con¬ tinues (Ledbetter and Lubin 1977). This implies the possibility that a high-potassium medium may provide the cell with a means of “recov¬ ery” from various damaging agents. The specific role of dietary potas¬ sium in the apparent protection of the gastric mucosa against damag¬ ing agents such as indomethacin and radiation needs further investigation. LITERATURE CITED v Bowen, J. C., Y-J. Kuo, W. Pawlik, D. Williams, L. L. Shanbour, E. D. Jacobson. 1975. Electrophysiological effects of burimamide and 16, 16-dimethyl prostaglandin E2 on the canine gastric mucosa. Gastroenterology 68: 1480-1484. Casarett, A. P. 1978. Radiation Biology. Prentice-Hall, Englewood Cliffs, NJ. Chaudhury, T. K., and E. D. Jacobson. 1978. Prostaglandin cytoprotection of gastric mucosa. Gastroenterology 74:59-64. DeLong, J. and M.M. Civan. 1978. Dissociation of cellular K^~ accumulation from net Na-^ transport by toad urinary bladder. J. Membr. Biol. 42:19-31. Djahanguiri, B. 1969. The production of acute gastric ulceration by indomethacin in the rat. Scand. J. Gastroent. 4:265-268. Eagle, H. 1955. Nutrition needs of mammalian cells in tissue culture. Science 122:501- 502. Harrison, A. P., A. K. Bruce, and G. E. Stapleton. 1958. Influence of X-irradiation on potassium retentivity by Escherichia coli. Proc. Soc. Exp. Biol. Med. 98:740-746. Kuo, Y-J., L. L. Shanbour, and T. J. Sernka. 1974. Effect of ethanol on permeability and ion transport in the isolated dog stomach. Am. J. Dig. Dis. 19:818-819. Kuo, Y-J., and L. L. Shanbour. 1976a. Mechanism of action of aspirin on canine gastric mucosa. Am. J. Physiol. 230:762-768. Kuo, Y-J., and L. L. Shanbour. 1976b. Inhibition of ion transport by bile salts in canine gastric mucosa. Am. J. Physiol. 231:1433-1436. Leadbetter, M. L. S., and M. Lubin. 1977. Control of protein synthesis in human fibro¬ blasts in intracellular potassium. Exp. Cell Res. 105:223-227. Lippman, W. 1974. Inhibition of indomethancin induced gastric ulceration in the rat by perorally administered synthetic and natural prostaglandin analogues. Prostaglandins 7:1010-1023. Lubin, M. 1964. Intracellular potassium and control of protein synthesis. Fed. Proc. 23:994-999. Lubin, M. 1967. Intracellular potassium and macromolecular synthesis in mammalian cells. Nature (Lond.) 213:451-458. Main, I. H. M., and B. J. R. Whittle. 1975. Investigation of the vasodialator and antise- cretory role of prostaglandins in the rat gastric mucosa by use of non-steroidal anti¬ inflammatory drugs. Br. J. Pharmac. 53:217-226. Portela, A., J. C. Perez, P. Stewart, M. Hines, and V. Reddy. 1963. Radiation damage in muscle cell membranes and regulation of cell metabolism. Exp. Cell Res. 29:527-531. Quastler, H. 1956. The nature of intestinal radiation death. Radiat. Res. 4:303-307. Robert, A. 1976. Antisecretory, antiulcer, cytoprotective and diarrheogenic properties of prostglandins. Advances in Prostaglandin and Thromboxane Research 2:507-516. Sernka, T. J., C. W. Gilleland, and L. L. Shanbour. 1974. Effect of ethanol on active transport in the dog stomach. Am. J. Physiol. 226:397-399. 66 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Shepherd, D. P., S. O. Brown, G. M. Krise, and H. R. Crookshank. 1973. Dietary protec¬ tion against ionizing radiation. Radiat. Res. 56:282-289. Ting, T. P., and R. C. Zirkle. 1940. The kinetics of the diffusion of salts into and out of X-irradiated erythrocytes. J. Cell Comp. Physiol. 16:197-201. BIOLOGICAL FORM REPRESENTATION BY TECHNIQUES DEVELOPED FOR AIRFOILS1 by W. M. HEFFINGTON Department of Mechanical Engineering Texas A&M University College Station, TX 77843 and K. L. EAVES Department of Biochemistry Texas A&M University College Station, TX 77843 ABSTRACT Representation of biological forms that are approximately teardrop-shaped is possible by use of systems developed for describing airfoils. Such approaches include the Jou- kowski transformation (a conformal transformation which changes a circle in one com¬ plex plane into a teardrop shape in another complex plane) and the empirical NACA four-digit system. Both techniques require little data to represent the original object, unlike anthropological and biological methods which use large numbers of linear mea¬ surements and descriptive terms to describe shapes. Length, thickness and curvature angle are the only data required to represent a teardrop shape using the Joukowski transforma¬ tion, and four digits and the length are all that are required when using the NACA four¬ digit system. In this work, both the Joukowski tranformation and the NACA four-digit system are applied to incisors of olive baboons ( Papio cynocephalus anubis ), and the resulting shapes are compared to outlines of the original teeth. Shapes symmetrical about a central axis and unsymmetrical shapes are treated. Other transformations are discussed, and the use of microcomputers for obtaining outline drawings from photographs of bio¬ logical specimens is described. Possible uses and applications of these techniques are dis¬ cussed. INTRODUCTION Biological forms such as teeth are presently described in anthropo¬ logical and biological literature by photographs, drawings, or a series of linear measurements such as labial and lingual height and breadth, anterior-posterior crown length, and breadth of each molar cusp (Ash¬ ton and Zuckerman 1950). Descriptive terms used include biscuspid, sectorial, molariform, D-Y-5 cusp pattern, and bunodont-cusped (Zeisz and Nuckolls 1949; Krogman 1969). Problems with popular tooth- description methods are due in part to the quantity of data required to accurately describe a tooth. 'Presented at the Eighty-fourth Annual Meeting of the Texas Academy of Science, Austin, Texas, March, 1981. The Texas Journal of Science, Vol. XXXV, No. 1, March 1983 68 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Acquisition of a completely faithful quantitative representation of a biological form would require storage and manipulation of a infinite number of data points. Even to reproduce a two-dimensional outline of a tooth as viewed from a particular aspect (buccal or distal, for instance) would require an infinite number of data points for complete fidelity. In order to avoid this complexity, resort is made to approxi¬ mate systems in which the forms are represented by a finite number of points, and the features near the points are obtained by interpolation or extrapolation. As many as seventy points may be used to represent an object as simple as a tooth (Ashton and Zuckerman 1950). Another way of circumventing this difficulty is to provide a likeness of the original specimen such as a physical model, x-ray film, or a photograph (Zeisz and Nuckolls 1949). Lacking sufficient quantitative data from which an outline shape may be obtained, sources report only selected data deemed to be impor¬ tant. Often little data is required to represent individual shapes. Simply giving the length and thickness of the buccal aspect of an olive bab- boon’s ( Papio cynocephalus anubis) lateral incisor may be sufficient data for an anthropologist to construct a suitable representation for the task at hand. Since subsonic airfoils and some teardrop-shaped biological forms have similar outlines, systems developed by aerodynamicists for describ¬ ing these airfoil shapes should apply to teardrop-shaped teeth. Two such systems, the Joukowski conformal transformation and the NACA2 four-digit series, are used here to describe incisors from an olive baboon. Transformations of biological shapes into related biological shapes often have been accomplished by reliance upon empirical formulations of the type used by Thompson (1917). Later works, such as those by Bookstein (1977) and Rosen (1978), have attempted more mathematically-based transformations; or, as Bookstein (1977) observed, they have used methods less geometrically precise than those of Thompson but more arithmetically tractable. The present effort belongs to the latter category. Aerodynamicists have long known of conformal transformations using complex variables which transform simple circles into teardrop¬ shaped forms similar to the shapes of symmetrical and unsymmetrical subsonic airfoils. Many older text books — including those by Piercy (1937), von Karman and Burgers (1943), von Mises (1945), Pope (1951), and Rauscher (1953) — deal with this subject. These tranformations are perhaps less valuable to aerodynamicists for the shapes they transform 2NACA is an acronym for National Advisory Committee for Aeronautics, which has been replaced by NASA (National Aeronautics and Space Administration). BIOLOGICAL FORM REPRESENTATION 69 than for the characteristics of the related fluid-flow fields about the cylinders and airfoils. Advantages of applying shape transformations of this type to those biological shapes which may be transformed from circles include, for example, representation of relatively complicated shapes at different stages of growth by circles that differ progressively in radii and center coordinates. The amount of data required to des¬ cribe a shape can be reduced to the Cartesian coordinates of the center and the radius of the circle. Ad hoc methods for describing airfoils also were developed during the first half of this century. One such simple method is the NACA four-digit series, which can also be applied to teardrop-shaped biologi¬ cal forms. Microcomputers, coupled with digitizer boards, provide a precise and quick method of obtaining the digital coordinates necessary for plot¬ ting and drawing the outline shape of physical specimens. In this study, coordinates were taken (digitized) from specimen photographs selected to provide data for the construction of the circles and whose shapes were used subsequently for comparison with the transformed circles. MATERIALS AND METHODS As an example of these techniques we apply the Joukowski trans¬ formation to circles for which size and location were determined from measurements of the length, thickness, and curvature of the two differ¬ ent teeth pictured in Plate 1. We also calculated the NACA 4-digit ser¬ ies that best describes these teeth. Both specimens are isolated lateral incisors from adult olive baboons. A line drawn equidistant from the upper and lower portions of the profile of tooth (A) shown in Plate 1 would be approximately straight (curvature approximately zero). Bio¬ logical forms lacking curvature are referred to as symmetrical. The other tooth shown in Plate 1 has significant curvature of a line equi¬ distant between the upper and lower portions of its profile, and provides data for the unsymmetrical example to be discussed. In Plate 1 the boundaries of the teeth were visually aligned in an object plane and photographed at an object distance of about 116 mm with a 55 mm lens-equipped camera. The aspects forming the bound¬ aries of the forms were estimated to be within 3 mm of the object plane (plane of focus) which leads to a maximum error in relative distance between points on the boundaries of the teeth shown in Plate 1 of less than 3%. Error of this type resulting from photographic technique decreases linearly with increasing object distance. The photographs were printed at a magnification of approximately four times actual tooth size. During early phases of this study, coordinates of points on 70 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Plate 1. Photographs of lateral incisors showing (A) symmetrical tooth (buccal aspect), and (b) unsymmetrical tooth (distal aspect). the boundaries of the teeth were digitized using a TALOS model 611 digitizer board with an advertised accuracy of less than ±0.13 mm for coordinate location. The digitizer board was interfaced with a Hewlett- Packard System 9815A desk-top microcomputer which provided a dig¬ ital display of the coordinate values. As many as seventy locations were digitized per tooth, and the overall accuracy of any location digitized was estimated to be less than 3% of the length of the tooth, with most of the possible error due to the photographic phase. The coordinates were then plotted on graph paper and connected by curved segments in order to obtain outline drawings of the teeth. In an alternative method, the outline drawings were traced from the photographs. All measure¬ ments were made directly on the resulting drawings and are about four times greater than corresponding measurements made on the actual teeth due to the photographic magnification factor. Many microcomputer systems have the capability to provide the drawings directly, either by plotting and connecting the digitized points or by printing closely spaced dots. BIOLOGICAL FORM REPRESENTATION 71 THE JOUKOWSKI TRANSFORMATION A simple transformation that transforms certain circles in the z-plane to teardrop shapes in the w-plane is the Joukowski transformation3 (Pope 1951), w=z + if. (1) z where z and w can both be expressed in complex notation as z = x + iy and w = u + iv, and b is a real constant. Not all circles in the z-plane are transformed into teardrop shapes; for instance, a circle of radius b centered at the origin of the z-plane will be transformed into a straight line between the points (— 2b, 0) and (2b, 0), in the w-plane. A problem in working with some conformal transformations is the lack of general analytical solutions that give information such as the resulting length and thickness. For the Joukowski transformation an approximate ana¬ lytical solution exists, valid when the thickness T is approximately small compared to the length L, and it yields for the symmetrical trans¬ formation (Pope 1951) Xc=T/3\/3 (2) and b= L/4 (3) where Xc is the x-coordinate of the center of the circle and — b is the intersection of the circle and the negative real axis. The y-coordinate of the center of the circle for the symmetrical transformation is, of course, equal to zero, and the circle radius is equal to the sum of Xc and b. Figure 1 is a profile drawing of the symmetrical tooth from Plate 1. The measurements required to obtain the thickness and length for use in Eqs. (2) and (3) are indicated in relation to the outline drawing of the specimen. Substituting the thickness T = 24.5 mm and the length L = 122 mm into Eqs. (2) and (3), respectively, yields Xc = 4.7 mm and b = 31 mm. The circle in the z-plane resulting from these values has radius 36 mm and is shown in Fig. 1. The w-plane containing the Joukowski profile (transformed circle) according to Eq. (1) is superim¬ posed on the z-plane in Fig. 1 also, and shows the teardrop shaped transformation compared to the outline drawing of the actual tooth. 3The Joukowski transformation is sometimes referred to as the Kutta-Joukowski trans¬ formation, after Kutta and Joukowski who worked independently in Germany and Rus¬ sia, respectively, and who both advanced the transformation about 1910. 72 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Figure 1. Diagram of (A) the outline of the symmetrical tooth in Plate 1 showing the thickness T = 24.5 mm and the length L = 122 mm, (B) the circle in the z-plane, and (C) the Joukowski profile in the w-plane. The Joukowski profile is about 2% longer and about 10% thinner than the actual tooth due to the approximations involved in obtaining the analytical solutions for thickness and length. For the unsymmetrical transformation (Piercy 1937) Xc and b are given by Eqs. (2) and (3), and the y-coordinate of the center of the circle is given approximately by yc-(b+Xc)/3 (4) where /3 is a curvature parameter which must be appropriately small in order to obtain Eq. (4). For the unsymmetrical Joukowski transforma¬ tion, J3 is equal to one-half the acute angle formed by the cusp and the x-axis. For the unsymmetrical tooth shown in Plate 1 and drawn in Fig. 2, P = 14 degrees was estimated to be one-half the angle formed between an imaginary curvature line and the x-axis when the tooth was graphically extended to form a point at the narrow end, approximately the shape of mature teeth from certain specimens (Taylor 1978). For the curved tooth shown in Fig. 2, application of Eqs. (2) - (4) to a thickness of 25 mm, an extended length of 113 mm, and P = 14 degrees yields Xc = 4.8 mm, b = 28 mm, and yc = 7.9 mm. The resulting circle (shown in Fig. 2) has a radius (equal to the distance from the center to — b) of 34 mm. The w-plane with the transformation of the z-plane circle in BIOLOGICAL FORM REPRESENTATION 73 Figure 2. Diagram of the (A) outline of unsymmetrical tooth shown in Plate 1 showing the thickness T = 25 mm, (B) the graphically extended root to yield an overall length L = 113 mm, (C) the circle in the z-plane, and (D) the Joukowski profile in the w- plane. Fig. 2 shows the Joukowski profile for comparison, which in this case is about 2% longer and 10% thinner than the tooth from which it was derived. Both Joukowski profiles in Figs. 1 and 2 end in cusps at the narrow ends of the teeth. The cusps are a result of the singular point — b lying on the circumference of each circle. Equation (1) is also not conformal at +b, but this point causes no problem because it lies within both cir¬ cles. For reasons having to do with the air flow about the shape, aero- dynamicists have usually required the desired circles to pass through one singularity and enclose the other (Pope 1951). In working with shapes alone these requirements are not necessary. If the radius of each circle is increased slightly so that the point — b is enclosed, both singu¬ larities are enclosed, and transformation is possible in a manner that is everywhere conformal. The cusps in Figs. 1 and 2 then could be replaced by rounded shapes more suitable for biological forms. In obtaining the approximate Eqs. (1) - (4), Xc/b and fi have been assumed to be small (Piercy 1937; Pope 1951). Requiring Xc/b to be small in equivalent to requiring the thickness T to be small compared to the length L, because dividing Eq. (2) by Eq. (3) yields xc/b = 0.77T/L. Additional results of the approximate method used here to solve Eq. (1) are that the maximum thickness of the Joukowski profile 74 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 occurs at about one-fourth the length, near the rounded end, and that the line of curvature is the arc of a circle (Pope 1951). These results obviously should influence the choice of biological shapes to which the Joukowski transformation may be applied. OTHER CONFORMAL TRANSFORMATIONS The Joukowski transformation described by Eq. (1) is a special case of the general transformation (known as the von Mises transformation) w = z +£L + SL +...+ if. (5) 2 n z z z where the cn are constants (von Mises 1945). For the Joukowski trans¬ formation, ci = b2 and the remainder of the constants are zero. Increas¬ ing the number of terms used in a transformation results in better representation and greater analytical difficulty. Application of Eq. (5) is discussed in von Karman and Burgers (1943), von Mises (1945) and Rauscher (1953). Another simple transformation of interest is the Karman-Trefftz transformation (Von Karman and Burgers 1943) w — mb _ /z - b \ m ^ w + mb \ z + b / where m = 2 — (k/7r) and k is the tail angle. This transformation is similar to the Joukowski transformation, but rather than yielding a cusp, produces a finite angle, k (for k greater than zero), at the trans¬ formation of the point where the circle passes through the singularity in Figures 1 and 2. For k = 0, the Joukowski transformation [Eq. (1)] is obtained from Eq. (6), and for k not equal to zero, Eq. (6) can be shown to correspond to an infinite series (von Karman and Burgers 1943). NACA FOUR-DIGIT SERIES This method of characterizing airfoils has corresponding designa¬ tions used in reference to teeth. The chord of an airfoil finds its corol¬ lary in the length of a tooth, and the camber of an airfoil is designated curvature (Fig. 3) when applied to a tooth (von Mises 1945). The chord and the length are generally the largest physical measurements that can be made on an airfoil profile and a tooth, respectively. The mean camber line may be defined as a curved line generated by the locus of centers of the line segments drawn across the airfoil section perpendicular to the chord. The mean curvature line of a tooth is used here in a similar fashion. Other definitions of camber are possible, and BIOLOGICAL FORM REPRESENTATION 75 Figure 3. Drawing of a cambered airfoil in an orthogonal x-y coordinate system showing the ordinate of maximum camber, ymax; the abcissa of maximum camber, xmax; the chord, c; mean camber line; and thickness t at location x given by the thickness func¬ tion (Eq.ll). Note that the thickness is measured normal to the mean camber line. For a tooth the chord would be designated length and the mean camber line as mean cur¬ vature line. Thickness is defined the same for both airfoil and tooth. usually are approximately equivalent (von Mises 1945). The maximum thickness may be defined in various ways (von Mises 1945). Here we define it as the length of a line segment, locally perpendicular to the mean camber line across the airfoil section or tooth, in accordance with the NACA definition (Jacobs et al. 1933). Generally, the length or chord is oriented parallel to an axis in an orthogonal coordinate system when constructing a graphic representation. The NACA four-digit specification (Jacobs et al. 1933; Jacobs and Pinkerton 1935; Jacobs et al. 1937) for an airfoil shape contains four digits and is often specified as NACA ABCD where the A, B, C, and D are digits. The first two digits determine the form of the mean camber line (graphically indicated in Fig. 3). The first digit indicates the ordi¬ nate ymax (see Fig. 3) of the maximum camber in percent of chord (and thus its utility in this form is limited to airfoils of maximum camber less than 10% of the chord length). For a NACA ABCD airfoil, the digit A = 10 ymax/c, where c is the chord. Applied to a tooth, A = 100 ymax /L (7) where L is the tooth length. The second digit, B, is the abcissa of the location xmax of maximum camber in tenths of the chord length, or B = 10 Xmax / c. For a tooth, B = 10 Xmax/L. (8) 76 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 For a symmetrical airfoil (one having a straight camber line) the A and B are identically zero, e.g., NACA OOCD. The last two digits CD give the relative thickness of the airfoil in percent of chord, CD = 100 T/c, where T is the maximum airfoil thickness measured normal to the mean camber line (see Fig. 3). Notice two digits are used to represent the thickness. For a tooth, CD = 100 T/L, (9) and T here is the maximum tooth thickness measured normal to the curvature line. From the information given in the first two digits of the profile, obviously the x- and y- coordinates of the maximum camber location for unsymmetrical teeth can be derived from Eqs. (7) and (8); e.g., ymax — AL/100 and xmax = BL/10. The mean camber line then can be constructed from the following equations of parabolic arcs (von Mises 1945): — Ymax (2xmax ~ x)x for 0 < X < Xmax ( Xmax ) (10a) and y = _ YHZ _ _(L - x) (L - x - 2xmax) (10b) (L Xmax) for Xmax < x < c. Once the camber line is known, the thickness function t, given by t = ±t[ 1.4845 \/*— 0.6300£ - 1.7580(^)2 + 1.4215(^)3 - 0.5075(^)4], (11) can be used to determine the actual profile. At the abcissa x on the mean camber line, t is measured above and below (along a line normal to) the mean camber line to determine points on the profile (Fig. 3). The length and thickness of the distal aspect of a curved tooth have been measured as L = 25.4 mm and T = 7 mm. The location of the y-coordinate of the maximum curvature was calculated to be ymax — 2.3 mm from measurements indicated in Fig. 4, according to ymax = (yi + yi)/2. (12) Values of yi and y2 and the value xmax — 12.8 mm were estimated directly from the tooth profile in the manner described in Fig. 4. BIOLOGICAL FORM REPRESENTATION 77 Figure 4. Diagram of measurements to be made in order to estimate xmax and ymax. The measurements may be made on the actual specimen, or a photograph or other like¬ ness. Application of Eqs. (7)-(9) resulted in a designation of NACA 9528. Once the profile designation and the length were available, a represen¬ tation of the tooth could be constructed by applying Eqs. (7) and (8) to determine xmax and ymax (had they not been known already, as in this case) and Eq. (9) to determine T. From Eq. (10) the mean camber line was drawn (Fig. 5), and from Eq. (11) the upper and lower portions of the profile were determined (Fig. 5). The NACA 9528 shape fit the profile of the 25.4 mm long tooth rea¬ sonably well (Fig. 5). However, this airfoil profile resulted in a fairly sharp4 end at the root of the tooth. An arbitrary length extension of 10% (thickness still 7mm) improved fit near the root (Fig. 6). This length extension gave, by Eq. (7), a two digit A value of 11 and the complete profile could be written NACA U525.5 The tooth and profile are compared in Fig. 6. Estimated values of ymax and xmax were 3.2 mm and 14 mm respectively, for the lengthened profile. The thickness function for airfoils (Eq. 11) was developed from a polynomial relation with five adjustable constants (Jacobs et al. 1933), which were chosen to yield desirable airfoil characteristics (such as nose shape, location of maximum thickness, and trailing-edge angle). At this time representational similarities between shapes of airfoils and teeth may be regarded as fortuitous and the method ad hoc. The method of development of the airfoil representation does suggest that perhaps an even better fit to teardrop-shaped biological forms may be obtained by 4The airfoil thickness function (Eq. 11) yields 0.10105T at the trailing edge (narrow end) rather than zero as might be expected. 5 A bar is here introduced under the first two digits to show that they represent one item (ordinate of maximum camber, ymax). In particular, this designation should not be con¬ fused with the NACA five-digit series. 78 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 D Figure 5. Schematic of (A) NACA 9528 profile, (B) tracing of the photograph of a tooth, and (C) mean curvature line. further adjustment to an appropriate thickness function such as that used by Jacobs et al. (1933) to fit data taken from average biological forms rather than desirable airfoil characteristics. CONCLUSIONS The Joukowski transformation shown in Eq. (1) yields a reasonable fit to the shapes of the selected unicuspid teeth. Collection, storage, and manipulation of length, thickness, and curvature angle are all that are required to relate the teeth to the simple geometric shape of a circle from which teardrop shapes similar to the original profiles can be gen¬ erated. Alternatively, the data representing a given shape may be stored and manipulated as the center coordinates (xc, yc) and the radius (or the parameter b) for a circle. Different circles may be used to represent dif¬ ferent stages of growth or species. Both distal and buccal aspects of appropriate teeth may be represented. The approximate solution to the Joukowski transformation is valid only for small values of the parameters Xc/b and p. Significant errors (about 10% for the thicknesses in Figs. 1 and 2) in the thickness and length of the Joukowski profiles were introduced here by using speci¬ mens with only marginally small values of Xc/b and p. However, the results are appropriate as an example of the technique. The error introduced by using relatively large values of Xc/b and P rapidly decreases as the sizes of these parameters become smaller. The alignment of the outlines of the actual teeth for comparison with the derived profiles is somewhat arbitrary, and the graphical extension of the length of the tooth in Fig. 2 in order to measure the curvature parameter P is also arbitrary. Other alignments and changes (one is not restricted to length extensions alone) are possible; however, they should be biologically defensible in some manner. In this case the BIOLOGICAL FORM REPRESENTATION 79 Figure 6. Schematics of (A) NACA JJ525 profile, (B) tracing of the photograph of a tooth, (C) mean curvature line, and (D) graphical length extension (the bottom por¬ tion of the graphical extension coincides with the NACA J_1525 profile). sharper point added to Fig. 2 is somewhat characteristic of certain mature specimens (Taylor 1978). A similar extension would have improved the transformed profile in Fig. 1. The fit of the NACA four¬ digit profiles in Figs. 5 and 6 to the selected tooth seems to be very good. The profile in each case results from application of Eq. (7) -(11) to the data stored in the digits of the profiles and the length (the extended length in Fig. 6). Storage and manipulation of the profile designated and the length are obviously easier than storage of photo¬ graphs, models, or several coordinate points to be used in plotting the tooth, and are compatible with modern computational techniques involving electronic computers. Obvious improvements can be made in the system to improve accu¬ racy and versatility, such as allowing A to be two digits as shown here. A further improvement of the NACA four-digit system useful in aero¬ nautics was the NACA five-digit system, which allowed for improved aerodynamic performance. In this system the mean camber line is either an arc of a cubic parabola and a straight line, or portions of two cubic parabolas (von Mises 1945) and might find applicability to a teardrop shaped biological form with an S-shaped curvature line. Original doc¬ uments dealing with the NACA five-digit series are studies by Jacobs and Pinkerton (1935) and Jacobs et al. (1937). This paper deals only with permanent unicuspid teeth. However, premolars and molars may be described as a collection of fused tear¬ drop shapes which can each be described as either a transformed circle or by a NACA 4-digit profile (Taylor 1978). Also human tooth buds develop from a spherical form to the final shape through a series of shapes which may be approximated by transformed circles (Langman 1975). It also might be possible to calculate the NACA series for an 80 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 entire developmental sequence of teeth and show how tooth shape changes through time. Also, fossil teeth can be characterized by a NACA four-digit number which could be used as part of the published description of each find. This would enable other investigators to reconstruct outlines of the teeth. Other biological shapes could also be described by the Joukowski transformation and by NACA 4-digit series. Potentially describable objects include leaves, fish, and wings — any teardrop-shaped object of small thickness-to-length ratio (small Xc/b), small curvature approxi¬ mating that of a circular arc, and possessing maximum thickness at about 25% of the length, near the rounded end. A possible use for the simpler description of teardrop-shaped biological forms is in taxon¬ omy. Brief descriptions generated by the method discussed here may be easier to deal with than those given in standard taxonomic keys. The Joukowski transformation and the NACA 4-digit series are two parsimonious descriptive methods that can adequately represent certain teardrop biological shapes such as teeth. ACKNOWLEDGEMENTS The authors wish to thank Dr. Ordean J. Oyen for supplying the specimens and for helpful discussions about the manuscript. We are also grateful to Dr. Robert S. Rice and Dr. John T. Demel for helpful comments, and to Mr. John Purcell for photographic work. LITERATURE CITED Ashton, E. H., and S. Zuckerman. 1950. Some quantitative dental characteristics of the chimpanzee, gorilla, and orangutan. Phil. Trans. Roy. Soc. (London), Series B. 234:471-484. Bookstein, F. L. 1977. The study of shape transformation after D’Arcy Thompson. Math. Biosci. 34:177-219. Jacobs, E. N., and R. M. Pinkerton. 1935. Tests in the variable-density wind tunnel of related airfoils having the maximum camber unusually far forward, p. 521-529. In NACA Technical Report 537, 21st Annual Report. Government Printing Office, Washington. Jacobs, E. N., R. M. Pinkerton, and H. Greenberg. 1937. Tests of related forward camber airfoils in the variable-density wind tunnel, p. 697-731. In NACA Technical Report 610, 23rd Annual Reprot. Government Printing Office, Washington. Jacobs, E. N., K. E. Ward, and R. M. Pinkerton. 1933. The characteristics of 78 related airfoil sections from tests in the variable density wind tunnel, p. 299-354. In NACA Technical Report 460, 19th Annual Report. Government Printing Office, Washing¬ ton. Von Karman, Th., and J. M. Burgers. 1943. General aerodynamic theory: perfect fluids, p. 1-367. In W. F. Durnat (Ed.), Aerodynamic Theory. Verlag Julius Springer, Berlin. Krogman, W. M. 1969. Growth changes in skull, face, jaws, and teeth of the chimpanzee, p. 104-164. In The Chimpanzee, vol. 1. Karger Press, Basel, Switzerland. BIOLOGICAL FORM REPRESENTATION 81 Langman, J. 1975. Medical Embryology, 3rd ed. The Williams and Wilkins Co., Balti¬ more, MD. Von Mises, R. 1945. Theory of Flight. McGraw Hill, New York, NY. Piercy, N. A. V. 1937. Aerodynamics. D. van Nostrand, New York, NY. Pope, A. 1951. Basic Wing and Airfoil Theory. McGraw Hill, New York, NY. Rauscher, M. 1953. Introduction to Aeronautical Dynamics. John Wiley, New York, NY. Rosen, R. 1978. Dynamical similarity and the theory of bilogical transfomations. Bull. Math. Biol. 40:549-579. Taylor, R. M. S. 1978. Variation in Morphology of Teeth: Anthropologic and Forensic Aspects. Charles C. Thomas, Springfield, IL. Thompson, D. W. 1917. On Growth and Form. Cambridge Unviersity Press, Cambridge, MA. Zeisz, R. C., and J. Nuckolls. 1949. Dental Anatomy. C. V. Mosby. St. Louis, MO. CIRCULATING CORTICOSTEROID AND LEUCOCYTE DYNAMICS IN CHANNEL CATFISH DURING NET CONFINEMENT by J. R. TOMASSO1, BILL A. SIMCO, and KENNETH B. DAVIS Department of Biology Memphis State University Memphis, TN 38152 ABSTRACT Channel catfish ( Ictalurus punctatus ) were stressed by close confinement in a net for periods up to 24 h. Plasma corticosteroid concentrations increased from 0.8 ± 0.3 jug/100 ml (mean ± S.E.) to a peak of 5.7 ± 0.6 pg/lOO ml after 6 h, then declined by 24 h. Leucocrit decreased during the first 6 h, owing to a decline in lymphocyte numbers, then increased by 12 h. Hematocrit did not vary significantly during the 24-h period. INTRODUCTION Increases in circulating corticosteroid concentrations have been dem¬ onstrated in many species of fishes in response to a variety of stressors (Strange et al. 1977; Leach and Taylor 1980; Tomasso et al. 1981). Cor¬ ticosteroids (cortisol, cortisone, corticosterone) are released from the interrenal tissue (Wedemeyer 1970). A detrimental effect of increased corticosteroid release is immunosuppression (Grant 1967). One immu¬ nosuppressive effect identified in fishes is the corticosteroid-mediated decrease in circulating leucocytes (Weinreb 1958; Pickford et al. 1971; McLeay 1973). This study was conducted to determine the effect of stress-induced elevation of circulating corticosteroids on abundance and types of circulating leucocytes in the channel catfish (Ictalurus puncta¬ tus). MATERIALS AND METHODS Channel catfish were obtained from the Southeastern Fish Cultural Laboratory (Marion, Alabama) and maintained in large indoor recircu¬ lating systems (20-22 C) for at least 2 months prior to use. Fish were fed a commercial diet equivalent to approximately 1% of their body wieght per day. Feeding was suspended 48 hours prior to experiments. Blood was obtained from the caudal peduncle by the use of a hepa¬ rinized syringe after the fish were anesthetized in a 0.02% solution of 1 Present address: Department of Biology, Southwest Texas State University, San Marcos, TX 78666. The Texas Journal of Science, Vol. XXXV, No. 1, March 1983 84 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 MS-222. A portion of the blood was then immediately transferred to hematocrit tubes and centrifuged for 5 minutes at 13,000 x g. The remaining blood was also centrifuged and the plasma frozen until used for corticosteroid analysis. Total blood volume and total packed cell volume in the hematocrit tubes were measured with dial calipers (± 0.01 mm) and packed white cells were measured using an ocular micrometer. The hematocrit and leucocrit (McLeay and Gordon 1977) were then determined by dividing the total packed cell volume and packed white cell volume, respec¬ tively, by the total blood volume. All measurements were taken within one hour of sampling. Total plasma corticosteriod concentrations were determined by competitive protein binding (Murphy 1967), as modified by Fagerlund (1970) using chicken serum as a transcortin source. To determine the effect of net confinement on leucocrit and plasma corticosteroid levels, 10 fish (9-15 cm standard length) were netted from the holding system and immediately bled. Thirty more fish were then captured and confined in a dip net suspended in the tank in a way that allowed the fish to be underwater but severely crowded. Some of the confined fish were then bled after 6, 12, and 24 hours of confinement. The initial sampling (time 0) and the sampling after 6 hours of con¬ finement were repeated three times and, the replicate data from each bleeding time being similar, were pooled for further analysis. In all cases, each fish was sampled only once. To determine changes, if any, in types of circulating leucocytes dur¬ ing the confinement, three fish (30-40 cm standard length) were cap¬ tured and immediately bled. Each was fin clipped for further identifica¬ tion, and confined in a net suspended in the holding tank as previously described. After 6 and 12 hours each fish was bled again. Following each bleeding, blood smears were made, stained, and relative numbers of cell types determined. One-way analysis of variance followed by Duncan’s multiple range test was used to compare changes in leucocrits, hematocrits, and corti¬ costeroids during the course of the experiment. A probability level of < 0.05 was considered significant. RESULTS AND DISCUSSION Plasma corticosteroid concentrations increased from baseline levels (0.8 ± 0.3 /Jg / 1 00 ml, mean ± S.E.) to a peak of 5.7 ± 0.6 fJg / 1 00 ml after 6 hours of confinement (Fig. 1). A slight decrease in plasma corti¬ costeroid levels was apparent after 24 hours although the animals were still confined. This decrease, while fish are sill confined, has been observed in channel catfish elsewhere (Davis and Parker, unpublished data) and in chinook salmon (Strange and Schreck 1978) and may CORTICOSTEROIDS AND LEUCOCYTES IN CATFISH 85 8 Figure 1. Leucocrit, hematocrit and plasma corticosteroid dynamics in channel catfish confined in a net for up to 24 hours. Dots with vertical lines represent mean + S.E. Numbers of fish measured are given directly above the x-axis. Sampling periods with statistically similar means share a common line. represent the beginning of adaptation to the stressor (Selye 1950). Boehlke et al. (1966) reported higher resting corticosteroid concentra¬ tions in channel catfish (about 10 /rg/100 ml) than reported here and elsewhere (Strange 1980). It has been suggested that this discrepancy may be due to the use of fluorimetric assay by Boehlke and his coworkers in contrast to the competitive protein binding assay (Strange 1980). Leucocrits decreased significantly from baseline levels (1.42 ±0.05) during the first 6 hours of confinement, but by 12 hours of confine¬ ment leucocrits were significantly higher than baseline levels (Fig. 1). An increase in the leucocrit of eels during social stress was explained by changes in the ratio of lymphocytes to granulocytes (Peters et al. 86 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Figure 2. Circulating leucocyte dynamics in three channel catfish serially sampled dur¬ ing 12 hours of net confinement. Each individual fish is represented by an asterisk, dot or square (gran = granulocytes, lym = lymphocytes, leu = leucocytes, b. c. = total blood cells). 1980). While the total white cell count of the eel decreased due to a decreased number of circulating lymphocytes, the number of granulo¬ cytes actually increased. The increase in number of the larger granulo¬ cytes was apparently more than enough, in terms of volume, to offset the decrease in the small lymphocytes, resulting in an increased leuco- crit. Similar decreases in lymphocyte counts and increases in granulo¬ cyte counts have been described in largemouth bass (Esch and Hazen 1980) and coho salmon (McLeay 1973). However, it should be noted that while granulocyte counts increased in response to stress, numbers of circulating granulocytes are not corticosteriod mediated (Dougherty and White 1944). The decrease in leucocrit observed after 6 hours of confinement in a net may be attributed to different temporal responses of lymphocytes and granulocytes to stress. Figure 2 shows the relationship of circulat¬ ing lymphocytes and granulocytes to confinement time. In all three fish examined, lymphocytes/ 100 cells had decreased after 6 hours of con¬ finement. Granulocytes/ 1000 cells increased, but not substantially, until after 12 hours of confinement. The decreased leucocrit after 6 hours of confinement corresponds to the time when lymphocyte counts CORTICOSTEROIDS AND LEUCOCYTES IN CATFISH 87 are decreased and granulocyte counts are unchanged. Fin clipping and serial bleeding placed additional stress on these animals. However, the increase in numbers of circulating granulocytes would indicate that measured changes in numbers of leucocytes are due to actual changes in leucocyte number and not to serial removal of blood. The absence of a stress effect on hematocrit indicates that changes in leucocyte number were due solely to changes in absolute leucocyte number and not changes in the red to white cell ratio. ACKNOWLEDGEMENTS We thank B. Tabatabai for technical advice and assistance. Fish were supplied by the Southeastern Fish Cultural Laboratory, Marion, Ala¬ bama. Master-Mix Fish Grower No. 971 was provided by Central Soya Company, Fort Wayne, Indiana. LITERATURE CITED Boehlke, K. W., R. L. Church, O. W. Tiemeier and B. E. Eleftheriou. 1966. Diurnal rhythm in plasma glucocorticoid levels in channel catfish ( Ictalurus punctatus). Gen. Comp. Endocrinol. 7:18-21. Dougherty, T. F. and A. White. 1944. Influence of hormones on lymphoid tissue struc¬ ture and function. The role of pituitary adrenotrophic hormone in the regulation of the lymphocytes and other cellular elements of the blood. Endocrinology 35:1-14. Esch, G. W., and T. C. Hazen. 1980. Stress and body condition in a population of large- mouth bass: implications for red-sore disease. Trans. Amer. Fish. Soc. 109:532-536. Fagerlund, U. H. M. 1970. Determining cortisol and cortisone simultaneously in sal- monid plasma by competive protein binding. J. Fish. Res. Bd. Can. 27:596-601. Grant, N. 1967. Metabolic effects of adrenal glucocorticoid hormones, p 269-292. In A. B. Eisenstein (ed.), The Adrenal Cortex. Little, Brown and Company, Boston, MA. Leach, G. J., and M. H. Taylor. 1980. The role of cortisol in stress-induced metabolic changes in Fundulus heteroclitus. Gen. Comp. Encocrinol. 42:219-227. McLeay, D. J. 1973. Effects of ACTH on the pituitary-interrenal axis and abundance of white blood cell types in juvenile coho salmon, Oncorhynchus kisutch. Gen. Comp. Endocrinol. 21:431-440. McLeay, D. J. and M. R. Gordon. 1977. Leucocrit: a simple hematological technique for measuring acute stress in salmonid fish, including stressful concentrations of pulp- mill effluent. J. Fish. Res. Bd. Can. 34:2164-2175. Murphy, B. E. P. 1967. Some studies of the protein binding of steroids and their applica¬ tion to the routine micro and ultramicro measurements of various steroids in body fluids by competitive protein binding radioassay. J. Clin. Endocrinol. 27:973-990. Peters, G., H. Delventhal and H. Klinger. 1980. Physiological and morphological effects of social stress in the eel ( Anguilla anguilla L.). Arch. Fischwiss. 30:157-180. Pickford, G. E., A. K. Srivastava, A. M. Slicher and P. K. T. Pang. 1971. The stress response in the abundance of circulating leucocytes in the killifish, Fundulus heteroc¬ litus. III. The role of the adrenal cortex and a concluding discussion of the leucocyte- stress syndrome. J. Exp. Zool. 177:109-118. Selye, H. 1950. Stress and the general adaptation syndrome. Brit. Med. J. 1:1383-1392. Strange, R. J. 1980. Acclimation temperature influences cortisol and glucose concentra¬ tions in stressed channel catfish. Trans. Amer. Fish. Soc. 109:298-303. 88 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Strange, R. J. and C. B. Schreck. 1978. Anesthetic and handling stress on survival and cortisol concentration in yearling chinook salmon ( Oncorhynchus tshawytscha). J. Fish. Res. Bd. Can. 35:345-349. Strange, R. J., C. B. Schreck and J. T. Golden. 1977. Corticoid stress responses to han¬ dling and temperature in salmonids. Trans. Amer. Fish. Soc. 106:213-218. Tomasso, J. R., K. B. Davis and B. A. Simco. 1981. Plasma corticosteroid dynamics in channel catfish ( Ictalurus punctatus ) exposed to ammonia and nitrite. Can. J. Fish. Aquat. Sci. 38:1106-1112. Wedemeyer, G. 1970. The role of stress in the disease resistance of fishes, p. 30-35. In S. F. Snieszko (ed.), A Symposium on Diseases of Fishes and Shellfishes. The American Fisheries Society, Washington, D. C. Weinreb, E. L. 1958. Studies on the histology and histopathology of the rainbow trout, Salmo gairdneri irideus. I. Hematology: under normal and experimental conditions of inflammations. Zoologica 43:145-153. COMPARATIVE DIGESTIVE EFFICIENCY OF WHITE-TAILED AND SIKA DEER by CHRISTOPHER WHEATON1 and ROBERT D. BROWN Caesar Kleberg Wildlife Research Institute Texas A&I University Kingsville , TX 78363 ABSTRACT The digestive efficiencies of white-tailed and sika deer were compared on a standard pelleted diet. Four deer of each species were housed in individual digestion crates for 14 days. Digestion coefficients for dry matter, crude protein, crude fiber, ether extract, nitro¬ gen free extract, and digestible energy were determined, and total digestible nutrients cal¬ culated. There was no significant difference (P > .05) between the two species in any of the parameters. The greater survivability of sika deer over white-tailed deer on marginal lands is due to factors other than their abilities to better utilize a standard feed. INTRODUCTION The hunting of exotic game on private ranches is a popular sport in Texas. One of these exotic animals, the sika deer ( Cervus nippon), is particularly hardy. The most recent Texas census counted 6,217 sika deer enclosed in game ranches in 49 counties, for an overall increase of 104% over the previous census 6 years earlier (Harmel 1980). Neither census included free ranging animals which may have escaped from game ranches. State biologists are concerned that sika deer and other exotic animals escaping from game ranches may proliferate and compete with native deer. In 1971, 6 sika deer and 6 white-tailed deer ( Odocoileus virginia- nus) were introduced into a 39 ha pasture at the Kerr Wildlife Man¬ agement Area in order to evaluate competition between the species. The sika population increased steadily to a total of 62 animals in 9 years while the white-tailed population increased slightly, then completed died out, largely due to starvation (Armstrong and Harmel 1981). Sika deer apparently compete directly with the white-tails for browse and forbs. The sika, however, seems to have a greater ability to shift its diet to grasses when stressed by drought or overgrazing (Butts 1979). The greater survivability of sika deer may have been related to more opportunistic feeding patterns or to species differences in forage diges¬ tion and nutrient retention. Preliminary to a study of the relationships ‘Present address: Texas Parks 8c Wildlife Department, 1904 Sixth Ave., Canyon, TX 79015. The Texas Journal of Science, Vol. XXXV, No. 1, March 1983 90 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 between forage utilization and survivability, this experiment was con¬ ducted to determine if sika deer and white-tailed deer differ in their ability to digest a high-quality formulated ration. METHODS Research was conducted at the Texas A8cl University Wildlife Research Facility, near Kingsville, Texas. Four white-tailed fawns and 4 sika fawns were captured in the South Texas area during the spring and summer of 1978. The deer were bottle fed on goat’s milk, with var¬ ious pelleted and green feeds offered as available to facilitate weaning. Fawns were weaned at approximately 4 months of age and were subse¬ quently fed a custom mixed pelleted ration for an additional 4 months prior to the digestibility studies. The ration averaged 21.2% crude pro¬ tein and 15.9% crude fiber. Its major ingredients were dried brewer’s grains, alfalfa meal, and ground corn. The ration was formulated to provide adequate or superior levels of all nutritents required for the growth and development of young white-tailed deer (French et al. 1955; French et al. 1956; McEwen et al. 1957; Ullrey et al. 1967; Smith et al. 1975). The comparative digestibility of the ration by the 2 species of deer was determined by digestion trials designed according to procedures outlined by Ullrey et al. (1975), Mothershead et al. (1972), and Smith et al. (1975). The metabolism crates used in the experiment were similar to those designed by Cowan et al. (1969) as modified by Ullrey (pers. comm.). Animals were habituated to the crates for 7 days. A 7 day fecal collection period followed, during which each animal was fed at 90% of its adjustment period ad libitum consumption. The intakes of all 8 animals during the digestion trails were similar. Total fecal collections for each animal were made every 24-28 hours and frozen until the trial was complete. Upon completion of the trial, collections from each animal were thoroughly mixed, and duplicate sub-samples were removed, labeled, and frozen until laboratory analy¬ sis. Feed and fecal samples were dried at 40C and ground in a Wiley mill with a 1 mm screen and analyzed in duplicate via proximate anal¬ ysis (AOAC 1980) and bomb calorimetry (Parr Instrument Co. 1975). Duplicate analyses of all duplicate subsamples were averaged. Digestion coefficients for dry matter (DM), crude protein (CP), crude fiber (CF), ether extract (EE) and nitrogen free extract (NFE) were determined and total digestible nutrients (TDN) calculated. Gross energy (GE) for each feed and fecal sample was determined, and the digestible energy (DE) was calculated. The mean % digestibility of the components of the ration were compared by t-test (Steel and Torrie 1960). DIGESTIVE EFFICIENCY OF DEER 91 _q be -q be \ C u W ^ ^ £ C s 3 u O cs H M 3 Q £ C w & 5 - £ X s- u ^ g w * w 33 cu 3 -Q u S w s *§ 1 S-, O U * Q s CM CD m cm CM CO © © oo oo —I t" tO ITS © CM co id oo — < CO CM © id co co © © CM © 92 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 RESULTS The digestibility of the DM and its components, CP, CF, EE and NFE, were not significantly different (P>.05) between the 2 species of deer (Table 1). The total digestible nutrients (TND) and the DE were also not significantly different (P>.05) between the 2 species. The rela¬ tively large standard deviations of the sika digestibility results were due to low values of one animal. Recalculation of the means exluding this animal still resulted in no significant differences between the groups of deer. One must be cautious in interpreting these results due to the rela¬ tively small number of animals involved and the relative high quality of the ration offered. Nevertheless, it is concluded that the greater sur¬ vivability of the sika deer over white-tailed deer on limited rangeland is not due to superior digestive efficiency. While the ability of the sika deer to digest natural browse and forbs better than the white-tailed deer cannot yet be ruled out, the sika’s superiority may be due to its more opportunistic feeding patterns, nat¬ ural aggression (A.B. Bubenik, pers. comm.) or some other factor. LITERATURE CITED AOAC. 1980. Official Methods of Analysis, 12th ed. Assn. Official Analytical Chemists, Washington, D. C. Armstrong, W. E. and D. E. Harmel. 1981. Exotic mammals competing with the natives. Texas Parks and Wildl. Magazine. February, p. 6-7. Butts, G. L. 1979. The status of exotic big game in Texas. Rangelands 1:152-153. Cowan, R. L., W. E. Hartsook, J. B. Whelan, T. A. Long, and R. S. Wetzel. 1969. A cage for metabolism and radioisotope studies with deer. J. Wildl. Manage. 33:204-208. French, C. E., L. C. McEwen, N. D. Magruder, R. H. Ingram, and R. W. Swift. 1955. Nutritional requirements of white-tailed deer for growth and antler development. Pa. Agric. Exp. Stn. Bull., (600) 8 p. French, C. E., L. C. McEwen, N. D. Magruder, R. H. Ingram, and R. W. Swift. 1956. Nutrient requirements for growth and antler development in the white-tailed deer. J. Wildl. Manage. 20:221-232. Harmel, D. E. 1980. Statewide census of exotic big game animals. Job Peroformance Report (21) 33 p. McEwen, L. C., E. E. French, N. D. Magruder, R. W. Swift, and R. H. Ingram. 1957. Nutrient requirements of the white-tailed deer. Trans. North Am. Wildl. Nat. Resour. Conf. 22:119-130. Mothershead, C. L., R. L. Cowan, and A. L. Amman. 1972. Variations in determinations of digestive capacity of the white-tailed deer. J. Wildl. Manage. 36:1052-1060. Parr Instument Co. 1975. Instructions for the 1241 and 1242 adiabatic calorimeters. Parr Manual No. 153. Parr Insturment Co., Moline, Illinois. Smith, S. H., J. B. Holter, H. H. Hayes, and H. Silver. 1975. Protein requirement of white-tailed deer fawns. J. Wildl. Manage. 39:582-589. Steel, R. G. D. and J. H. Torrie. 1960. Principles and Procedures of Statistics. McGraw- Hill, N. Y. 481 p. Ullrey, D. E., W. G. Youatt, H. E. Johnson, L. D. Fay, and B. L. Bradley. 1967. Protein requirement of white-tailed deer fawns. J. Wild. Manage. 31:679-685. Ullrey, D. E., W. G. Youatt, H. E. Johnson, L. D. Fay, R. L. Covert, and W. T. Magee. 1975. Consumption of artificial browse supplements by penned white-tailed deer. J. Wildl. Manage. 39:699-704. SUMMER DIET OF FINFISH FROM NEARSHORE HABITATS OF WEST BAY, TEXAS by STEVE K. ALEXANDER Department of Marine Biology Texas A&M University at Galveston Galveston, TX 11553 INTRODUCTION The finfish community of the Galveston Bay stystem of Texas has been characterized in studies by Reid (1955), Chin (1961) and Parker (1965). However, little information is available on the diet and trophic position of individual species in this estuarine system. Diener et al. (1974) examined the stomach contents of finfish collected by otter trawl from Clear Lake, a small bay on the northwestern edge of the Galves¬ ton Bay system. Although 40 species were examined, shallow water (nearshore) species were not adequately represented. The present study examined the diet and trophic position of predominant finfish from nearshore habitats of West Bay, a bay on the southwestern edge of the Galveston Bay system. MATERIALS AND METHODS During June and July 1981, shorelines of West Bay were sampled biweekly with a 7-rri long bag seine (3 -mm mesh bag). The net was pulled parallel to the Spartina alterniflora dominated shorelines at water depths of 0.3 to 1.0 m. A cast net (10- mm mesh) was also used to catch larger, more motile shoreline species. A representative number of predominant species was transferred from the net to a plastic bag and stored on ice for transport to the laboratory. Fish were frozen until analysis, which usually occurred within several weeks of collection. The stomach was removed from specimens and opened lengthwise. The contents were placed in a petri dish and identified with the aid of a s tereom icroscope . RESULTS AND DISCUSSION The most abundant finfish in these catches were juveniles of Cypri- nodon variegatus (sheepshead minnow), Fundulus grandis (gulf killif- ish), Menidia peninsulae (tidewater silverside), Lagodon rhomboides (pinfish), Leiostomus xanthurus (spot) and Mugil cephalus (striped The Texas Journal of Science, Vol. XXXV, No. 1, March 1983 94 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 1, 1983 Table 1. Percentage of stomachs containing various food items. Based only on those stomachs which contained food. Cyprinodon variegatus Fundulus grandis Menidia peninsulae Lagodon rhomboides Leiostomus xanthurus Mugil cephalus Stomachs examined which contained food 114 73 50 102 75 37 Total length range (mm) 25-46 35-96 50-72 54-96 42-96 69-199 Food Items Sand 96 4 0 31 100 100 Vascular Plant 89 57 16 59 40 100 Microalgae 99 27 100 95 100 97 Meiobenthos3 7 20 6 84 100 19 Macrobenthosb 0 14 26 17 11 0 Invertebrate larvae' 0 0 94 0 0 0 Calanoid copepods 0 0 30 0 0 0 Small fish /crustaceans 0 99 10 9 0 0 Insects 0 3 16 2 0 0 aHarpacticoid copepods, nematodes, ostracods, foraminifera, and mysids. bPolychaetes and small molluscs. 'Predominantly crab zoea. mullet). The diet of these six species based on stomach analysis is pres¬ ented in Table 1. Cyprinodon variegatus and Mugil cephalus were bottom feeding her¬ bivores in West Bay; their diet consisted almost exclusively of sand, vascular plant material and microalgae. Similar results were obtained by Odum (1970) for M. cephalus in a Georgia salt marsh and by Odum and Heald (1972) for C. variegatus in a Florida mangrove estuary. Small fish and crustaceans were frequent in the diet of Fundulus grandis. This species also consumed with less regularity vascular plant material, microalgae and small benthic animals. Odum and Heald (1975) classified F. grandis as a low level carnivore in a Florida man¬ grove estuary. Menidia peninsulae appears to have the most varied feeding habit of the six species examined. Analysis of stomach contents indicates both a planktonic diet of invertebrate larvae and copepods and a benthic diet principally of microalgae. Two feeding niches for this species, there¬ fore, are suggested: 1) a low level carnivore in the water column, and 2) a herbivore on the bottom. Odum and Heald (1972) likewise reported that M. peninsulae occupies several niches in a Florida mangrove estu¬ ary, feeding in the water column during the day and near the bottom at night. Lagbdon rhomboides and Leiostomus xanthurus were bottom feeders with an omnivorous diet typically of sand, vascular plant material, microalgae and meiobenthos. Specimens of these species from Clear Lake, Texas, consumed small benthic animals, organic detritus and FINFISH DIETS 95 sand (Diener et al. 1974). A review of available literature led Parker (1971) to conclude that L. xanthurus is a non-selective feeder whose diet reflects the availability of bottom food. LITERATURE CITED Chin, E. 1961. A trawl study of an estuarine nursery area in Galveston Bay, with particu¬ lar reference to penaeid shrimp. Ph. D. Dissertation, University of Washington, Seat¬ tle. 123 p. Diener, R. A., A. Inglis, and G. B. Adams. 1974. Stomach contents of fishes from Clear Lake and tributary waters, a Texas estuarine area. Contrib. Mar. Sci. 18:7-17. Odum, W. E. 1970. Utilization of the direct grazing and plant detritus food chains by the striped mullet Mugil cephalus, p. 222-240. In J. Steele (ed.), Marine Food Chains. University of California Press, Berkeley. Odum, W. E., and E. J. Heald. 1972. Trophic analysis of an estuarine mangrove com¬ munity. Bull. Mar. Sci. 22:671-738. Odum, W. E., and E. J. Heald. 1975. The detritus-based food web of an estuarine man¬ grove community, p. 265-286. In L. Cronin (ed.), Estuarine Research, Volume 1. Aca¬ demic Press, New York. Parker, J. C. 1965. An annotated checklist of the fishes of the Galveston Bay System, Texas. Publ. Inst. Mar. Sci. 10:201-220. Parker, J. C. 1971. The biology of the spot, Leiostomus xanthurus Lacepede, and Atlan¬ tic croaker, Micropogon undulatus (Linnaeus), in two Gulf of Mexico nursery areas. Texas A&M University Sea Grant Publ. No. TAMU-SG-71-210. Reid, G. K., Jr. 1955. A summer study of the biology and ecology of East Bay, Texas. Part I. Introduction, description of area, methods, some aspects of the fish commun¬ ity, and invertebrate fauna. Texas J. Sci. 7:316-343. OFFICERS President: President-Elect: Vice-President: Immediate Past President: Secretary-T reasurer: Editor: AAAS Council Representative: Bernard T. Young, Angelo State University Michael Carlo, Angelo State University William J. Clark, Texas A&M University Elray S. Nixon, Stephen F. Austin State University Everett D. Wilson, Sam Houston State University William H. Neill, Texas A&M University Arthur E. Hughes, Sam Houston State University DIRECTORS 1981 Richard L. Noble, Texas A&M University Bob F. Perkins, University of Texas, Arlington 1982 Billy J. Franklin, Texas A&I University Ethel W. McLemore, Dallas 1983 D. Lane Hartsock, Austin Katherine Mays, Bay City SECTIONS I — Mathematical Sciences : Philip S. Morey, Jr., Texas A&I University II — Physical Sciences: R. Charles Ivey, La Jet Corporation, Abilene III — Earth Sciences : S. Christopher Caran, University of Texas, Austin IV —Biological Sciences: Frank W. Judd, Pan American University V — Social Sciences: Rollo K. Newsom, Southwest Texas State University VI — Environmental Sciences: D. Lane Hartsock, Texas Air Control Board VII —Chemistry: John T. Moore, Stephen F. Austin State University VIII — Science Education: Rebecca Sparks, San Marcos IX — Computer Sciences: Charles N. Adams, North Texas State University X — Aquatic Sciences: G. Dan McClung, SK Engineering, San Angelo Collegiate Academy Counselors: Shirley Handler, East Texas Baptist College Helen Oujesky, University of Texas, San Antonio Junior Academy Counselors: Ruth Spear, San Marcos Peggy Carnahan, San Antonio COVER PHOTO Coordinate System of the Heart for a Mitral Valve Model by Hunter, Seaton, Lively, Miller and Stoner, pp. 5-36 2nd CLASS POSTAGE PAID AT HUNTSVILLE TEXAS 77341 AND AT ADDITIONAL MAILING OFFICE AT LUBBOCK TEXAS 79401 LIBRARY ICtfJISIfOffS SHIT9S08IAK INSf g MhSEimtm oc 20560 Volume XXXV, Number 2 PUBLISHED QUARTERLY BY THE TEXAS ACADEMY OF SCIENCE CABLE TO - CHART RECORDER SLOT IN BRASS PLATE WOODEN WELL TOP REMOVABLE SB GALLON DRUM AS' SEDIMENT TRAP SEDIMENT SAMPLER METAL TUBING AS GUIDES FOR DRUM CULVERT WOODEN WELL BOTTOM ^ TUBING FOR _ STABILIZING CLIPS* SECTION I MATHEMATICAL SCIENCES Mathematics, Statistics, Operations Research SECTION VI Economics, History, ENVIRONMENTAL Psychology, Sociology SCIENCES AFFILIATED ORGANIZATIONS Texas Section, American Association of Physics Teachers Texas Section, Mathematical Association of America Texas Section, National Association of Geology Teachers GENERAL INFORMATION MEMBERSHIP. Any person or group engaged in scientific work or interested in the pro¬ motion of science is eligible for membership in The Texas Academy of Science. Dues for members are $20.00 annually; student members, $12.00 annually; sustaining members, at least $30.00 in addition to annual dues; life members, at least $400.00 in one payment; patrons, at least $500.00 in one payment; corporate members, $250.00 annually; corporate life members, $2000.00 in one payment. Library subscription rate is $45.00 annually. Pay¬ ments should be sent to the Secretary-Treasurer, Box 2175, Huntsville, TX 77341. The Journal is a quarterly publication of The Texas Academy of Science and is sent to all members and subscribers. Inquiries regarding back issues should be sent to Dr. Fred S. Hendricks, Dept. Wildlife & Fisheries Sciences, Texas A&M University, College Station, TX 77843. Manuscripts submitted for publication in the Journal should be sent to Dr. W. H. Neill, Dept. Wildlife & Fisheries Sci., Texas A&M Univ., College Station, TX 77843. The Texas Journal of Science (USPS 616740) is published quarterly at Huntsville, Texas U.S.A. Second class postage paid at Post Office, Huntsville, TX 77341, and at additional mailing office at Lubbock, TX 79401. Please send form 3579 and returned copies to Texas Tech Press, Box 4240, Lubbock, TX 79409. THE TEXAS JOURNAL OF SCIENCE Volume XXXV, No. 2 July 1983 CONTENTS Instructions to Authors . . . 99 Observation of Episodic Sedimentation in a Tidal Inlet (Sabine Pass, Texas and Louisiana). By George H. Ward, Jr. . . . . . 101 Midwater Fishes of the Gulf of Mexico Collected from the R/V Alaminos, 1965-1973. By Edward O. Murdy, Richard E. Matheson, Jr., Janice D. Fechhelm, and Michael J. McCoid . . . . 109 In Vitro Analysis of Transfer Factor Activity in Guinea Pig Leukocyte Extracts by the Agarose Drop Assay. By Andrew Paquet, Jr . 129 Variation in Transplantable Tumor Growth-parameters Can Be Reduced. By David G. Morrison, Mary Pat Moyer, Jay C. Daniel, Waid Rogers, and Rex C. Moyer . . . 141 Paleoenvironmental Significance of a Nonmarine Pleistocene Molluscan Fauna from Southern Texas. By Raymond W. Neck . 147 Caloric Value of the Liver Fluke, Fasciola hepatica. By Jeremy M. Jay and Norman O. Dronen . 155 Status of Bighorn Sheep in Texas. By Bruce D. Leopold and Paul R. Krausman . 157 Eggs and Young of Schott’s Whipsnake, Masticophis taeniatus schotti. By Hugh K. McCrystal and James R. Dixon . 161 Observations on Host Selection by Lysathia ludoviciana (Chrysomelidae), a Beetle with Potential for Biological Control of Certain Aquatic Weeds. By John M. Campbell and William J. Clark . . . 165 Characterization of Erythrocyte Esterases on Electrophoretic Gels. By John P. Cherry . . 169 NOTE: Authors with funds for page contributions are expected to make such payments. The contribution of $35.00 per page is encouraged to defray printing costs, and authors of articles exceeding ten printed pages are expected to make some contribution to the publication fund. How¬ ever, payment of printing costs is not a condition for publication in The Texas Journal of Science, and NO AUTHOR, WHO WOULD OTHER¬ WISE SUBMIT A MANUSCRIPT, SHOULD HESITATE TO DO SO BECAUSE OF LACK OF SUCH FUNDS. Members without funds may apply to the Texas Academy of Science for a grant to cover some or all costs of publication. This becomes effective January 23, 1982. INSTRUCTIONS TO AUTHORS Papers intended for publication in The Texas Journal of Science are to be submitted to Dr. William H. Neill, Dept. Wildlife 8c Fisheries Sciences, Texas A8cM University, College Station, TX 77843. The manuscript is not to have been published elsewhere. Triplicate typewritten copies (the original and 2 reproduced copies) must be sub¬ mitted. 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Each illustration should be marked on the back with the name of the principle author, the figure number, and the title of the manuscript of which it is a part. Authors will receive galley proofs plus the original typescript along with information concerning reprints and page charges. Proofs must be corrected (using ink) and returned to the Editor within 3 days. Payment (check or purchase voucher) for page charges (or the publication grant request) must accompany the return of the corrected proofs or a delay in the printing of the manuscript could occur. Reprint orders should be returned directly to Texas Tech Press, Box 4240, Lubbock, TX 79409 NOTICE: IF YOUR ADDRESS OR TELEPHONE NUMBER CHANGES, NOTIFY US IMMEDIATELY SO WE CAN SEND YOUR GALLEY PROOFS TO YOU WITH¬ OUT LOSS OR DELAY. OBSERVATION OF EPISODIC SEDIMENTATION IN A TIDAL INLET (SABINE PASS, TEXAS AND LOUISIANA) by GEORGE H. WARD, JR. Espey , Huston & Associates, Inc. P.O. Box 519 Austin, TX 78767 ABSTRACT Time variation in sedimentation was monitored with a recording tipping-bucket sampler in Sabine Pass, the inlet connecting Sabine Lake (on the Texas-Louisiana bound¬ ary) and the Gulf of Mexico. Observed sedimentation was episodic, characterized by events widely spaced in time. There was no apparent relation to astronomical tide, even at maximum declination. Rather, sedimentation seemed to be dictated by hydrometeoro¬ logical factors. The most intense sedimentation episode of the study period (October and November 1978) was associated with the most energetic frontal passage. INTRODUCTION For purposes of assessing gross sedimentation in a coastal or marine zone, the most common method of routine measurement is the con¬ struction of a sediment trap which yields a long-term rate of sediment accumulation. However, sediment transport is not a constant process, but highly time variable and probably episodic, being dictated by such transient factors as tidal phase, wave climate, and the hydrometeorolog¬ ical regime. In order to examine the detailed time behavior of sedimen¬ tation within a coastal inlet, field measurements were performed employing a recording “bedload” sampler within a trap. The site of this study was the upper segment of Sabine Pass, the inlet connecting Sabine Lake with the Gulf of Mexico (Fig. 1). Sabine Lake is a broad, shallow embayment on the Texas-Louisiana coast which communicates with the Gulf only through the narrow inlet of Sabine Pass. Like most of the Gulf bays, the principal hydrographic controls on Sabine Lake are tides, meteorological events, freshwater inflows and salinity-induced density currents (Ward 1980a). Because of its large surface-area-to-volume ratio and the extended overwater fetch, Sabine Lake is highly responsive to meteorological forcing. The most dramatic routine meteorological effect is denivillation, the tilting of the water surface by imposed windstress. As the Gulf of Mexico exhibits a smiliar response to wind, relatively large head gradients can develop from bay to Gulf, entailing significant flows in Sabine Pass. The occurrence of The Texas Journal of Science, Vol. XXXV, No. 2, July 1983 102 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 wind setup and setdown (elevation and depression of bay levels owing to wind stress) is usually precipitated, not so much by strong wind per se, as by a change in wind, notably that accompanying a frontal pas¬ sage (Ward 1980b). The study site, Upper Sabine Pass, is a hydrodynamically complex region of the inlet, a zone of confluence and difluence of flow, where the natural tidal gorge intersects the present dredged Sabine Pass Channel. Hydrographic studies have indicated that all of the channels and passes offering access to Upper Sabine Pass participate in the cir¬ culation in this reach of the inlet, namely the Port Arthur Canal to the northwest, the natural tidal pass to Sabine Lake to the northeast, the Sabine Pass Channel to the south, and the old natural tidal channel to the southwest (Fig. 1). Under pure tidal conditions, significant flow is carried in all of these channels with a somewhat greater proportion in the Sabine Pass Channel and in the tidal access to Sabine Lake at the causeway (Ward and Johnston 1977). In contrast, most of the frontal efflux, associated with the response of the system to a frontal passage, is confined to the natural tidal channel rather than the dredged channel (Ward and Chambers 1978). A study of historical aerial photographs has revealed the frequent occurrence of a narrow band of extremely turbid water adjacent to the west shore of Upper Sabine Pass. The source of the sediment is EPISODIC SEDIMENTATION IN SABINE PASS 103 unknown, although the source may be erosion of the south bank of the Port Arthur canal, which has exhibited marked shoreline retreat in recent years. The scale of the phenomenon is difficult to estimate, though the width of the turbid band from aerial photographs ranges up to two hundred meters. MEASUREMENTS The sediment sampling station was established in the Upper Sabine Pass area in 1-rri water depths approximately 60 m from shore (Fig. 1). The sediment trap construction consisted of an evacuated circular pit containing a removable drum. The pit well was stabilized by a 1.1 -m diameter steel culvert, jetted into the bed so that its top was flush with bed level, and the contents evacuated by hydraulic pump. The depth of this well (i.e., length of the culvert) was 1.2 m. The well was fitted with a bottom of waterproofed plywood to ensure the integrity of the well. Within this well was placed a 0.21 cu m (55-gallon) drum which served as the actual sediment trap. Appurtenances to the drum were designed for its easy removal and replacement. Finally, the well was capped by a waterproof plywood top, in whose center was bolted a brass plate con¬ taining a slot aperture below which was mounted the sediment sampler. The general construction and installation of the sediment well and trap are shown in Figure 2. The operation of the trap consists of deploying the drum and replacing the top to the well. After an appro¬ priate period of time (two to four weeks in the present study) the top to the well is pulled, and the drum capped, winched out of the well, and transported back to the laboratory where the contents are weighed and analyzed. Clearly, the only aperture to the sediment trap is the slot in the brass plate mounted in the top of the well. From a practical point of view, the slot must be sufficiently large to ensure a valid measurement, yet not be so large as to tax the capacity of the trap. An additional factor is the efficiency of the slot, in that the slot must be made wide enough to intercept the saltating particles. Slot efficiency has been discussed by Poreh et al. (1970). Because the largest grain size expected in any signif¬ icant proportion in this area was that of coarse sand (1-2 mm diame¬ ter), the slot width was sized to 5 cm, which would entail 100% effi¬ ciency in these grain-size ranges. (Though one might expect this slot dimension to represent 100% efficiency for smaller diameters as well, once grain sizes decrease below those of fine sands and into the silts, particle transport becomes quasi-suspended, so that the slot efficiency in fact decreases.) A slot length of 20 cm was used in the present study to present an adequate aspect ratio to the flow. At installation the long dimension of the slot was oriented normal to the shorelines on the pre- 104 THE TEXAS JOURNAL OF SCIENCE-VOL. XXXV, NO. 2, 1983 CONSTRUCTION REMOVABLE 55 GALLON DRUM AS' SEDIMENT TRAP SEDIMENT SAMPLER METAL TUBING AS GUIDES FOR DRUM CULVERT ■WOODEN WELL BOTTOM TUBING FOR CABLE TO CHART RECORDER WOODEN WELL TOP SLOT IN BRASS PLATE INSTALLATION Figure 2. Construction of recording sediment sampler and installation in trap. sumption that sediment transport would be directed primarily parallel to the shore. The continuous sediment sampling device was adapted from the tra¬ ditional tipping bucket that has been used for many years for the moni¬ toring of rainfall or snowfall rates in meteorology. The particular EPISODIC SEDIMENTATION IN SABINE PASS 105 tipping-bucket design utilized in this study was modeled after that of Racotch and Sagi (1977; see also Amin 1978), although modified some¬ what for present purposes. The basic sampler design is shown in Fig¬ ure 2. The sampler was constructed primarily of brass parts for resist¬ ance to corrosion in the saline environment. The sampler has two stable configurations, exposing one side or the other of the median plate to sediment falling through the slot. Once sufficient material has accumulated, this side is overbalanced, the bucket tips on the knife edges to the other side, and the collected sediment falls into the trap. Depending upon the attitude of the sample bucket, a magnetic reed switch is either engaged or disengaged, closing a circuit when engaged. An event recorder, i.e., a two-state chart recorder, continuously records the status of the reed switch, a change corresponding to a trip of the bucket. The counterbalance was set to trip under water at 300 grams of material. Cables were run to shore where the battery-powered event recorder was housed in a weatherproof locked steel case hidden from view in the heavy vegetation. Grain-size analysis of the intercepted material showed a high proportion of silts and clays. In much of the data there was a discrepancy between the recording sampler deposition rates and the accumulation in the trap, the latter being larger. Since about half the entrapped sediment was disaggregated clays, we specu¬ late that clays short-circuit the bucket through low-intensity turbu¬ lence. RESULTS AND DISCUSSION The scheduled period of operation was the two months of October and November 1978. These two months were chosen on the basis of climatology, in order to provide a range of hydrometeorological condi¬ tions from pure tidal to energetic frontal passages. Upper Sabine Pass proved to be a very hostile environment for the operation of this sampler system, and various mishaps prevented continuous data collec¬ tion in this period: the periods 1-3 October, 7-17 October and 22-30 November were lost. The intent of encountering a range of hydrome¬ teorological conditions was somewhat frustrated by the vagaries of 1978 weather. Early in the October-November period, the area came under the domination of a pressure ridge, which eliminated or ameliorated frontal passages and produced largely light winds and clear conditions. The tide record of the Mesquite Point gauge (Fig. 1) shows an almost undistorted astronomical tide for the entire October-November period, a remarkable occurrence for this season of year. The most intense cold front of the period (in terms of wind shift and speed) passed the area late 16 November; because the north winds coincided with the falling tide, a total water-level depression of 0.64 m occurred, still a rather modest response (cf. Ward 1980b). 106 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 The data from the recording sampler provide some insight into the time behavior of the nearshore sediment transport. Contrary to our expectations, there appeared to be no correlation between sediment transport and phase or amplitude of the tide (at least to the 300-gram resolution dictated by the counterbalance weight of the sampler), even at maximum lunar declination. The main sedimentation was of an event-type character, widely isolated in time. For example, during the period 10-21 November, some half-dozen sediment-accumulation events were recorded in which the sampler indicated a series of trips of the bucket within a few hours. During the intervening times, no trips were recorded. The most significant of these, 17 and 19 November, appear to be associated with strong winds from the northerly quadrant produced by the frontal passage of 16 November and reinforced by a frontal pas¬ sage on 20 November. (Indeed, during 17-20 November there occurred the highest sustained northerly winds of the study period.) The time relation between the frontal passage and the 17 November sedimentation event is displayed in detail in Figure 3. The reasons for the 26-hour lag between frontal passage and sediment response are not known. Sabine Lake will become fetch-limiting for a 15-knot north wind after about 2-3 hours. Further, propagation speed of shoaling waves within Sabine Lake is 7-8 knots. Thus maximum wave activity impingent upon the shore, due to the orientation of the body of Sabine Lake with frontal (northerly) winds, should be established within a few hours. Therefore, wave development cannot account for the delay. (There is also the possibility that a portion of the sediment deposition measured in this study originated in the erosion of the shoreface along the project area itself, though this cannot have been the source of all the sediment load since historical aerial photography establishes the reality of the nearshore plume.) The sedimentation event may be associated with transport of mate¬ rials out of the system due to north-wind setdown, in which case the lag may arise from the response of the system and the travel time from the origin of the sediment. It is my hypothesis that most of this sedi¬ ment originates in the erosion of the south bank of the Port Arthur Canal upstream from the study area, and is transported into the area along the south shore. If this is the case, then the lag would be the result of the time of travel from the eroding banks plus the time required for the increased current (due to frontal setdown) to erode — perhaps undercut — the channel sides. Finally, the reader is cautioned that the findings reported here are based on data collected at a single station within a very complex sys¬ tem. In Sabine Pass, flow is influenced by channel bathymetry and shifts its axes with ebb and flood (Ward and Johnston 1977). Thus, the single station probably was biased towards one or the other conditions. A EPISODIC SEDIMENTATION IN SABINE PASS 107 CENTRAL STANDARD TIME 16 NOV 17 NOV Figure 3. Time variation of wind velocity (left axis) and sedimentation rate (right axis) during frontal passage of 16 November 1978. quantitative estimate of total sediment-mass transport due to an event like the frontal passage on 16 November would require several sedi¬ ment traps deployed throughout the system, and attendant current mea¬ surements. ACKNOWLEDGMENTS The sediment sampler was installed on land of the State of Texas. I am grateful to the General Land Office for granting us access to state property for this purpose. Tide data were graciously provided by the Houston Office of U.S. Geological Survey, from their Mesquite Point gauge. Phillip Winsborough and Lowell Eck were responsible for the fabrication and installation of the equipment. This study was sup¬ ported in part by Mobil Research and Development. LITERATURE CITED Amin, M. L. 1978. Bedload sampler for streams with sandy bed (discussion). Proceed¬ ings, American Society of Civil Engineers 104 (HY5):805-806. Poreh, M., A. Sagui, and I. Seginer. 1970. Sediment sampling efficiency of slots. Pro¬ ceedings, American Society of Civil Engineers 96 (HY10):2065-2078. Racotch, A., and R. Sagi. 1977. Bedload sampler for streams with sandy bed. Proceed¬ ings, American Society of Civil Engineers 103 (HY8):923-928. Ward, G. H. 1980a. Hydrography and circulation processes of Gulf estuaries, p. 183- 215. In P. Hamilton and K. MacDonald (Eds.), Estuarine and wetland processes. Ple¬ num Publishing Corp., New York. 108 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Ward, G. H. 1980b. Frontal-induced hydrographic responses of the Texas bays, p. 304- 307. In Second conference on coastal meterology, preprint volume American Meteoro¬ logical Society, Boston. Ward, G. H., and C. L. Chambers. 1978. Meteorologically forced currents in Upper Sabine Pass, Texas. Document number 7869, Espey, Huston & Associates, Inc., Aus¬ tin, TX. 131 p. Ward, G. H., and W. A. Johnston. 1977. Hydrographic survey of Upper Sabine Pass, Texas. Document number 7730-R1, Espey, Huston & Associates, Inc., Austin, TX 114 P- MIDWATER FISHES OF THE GULF OF MEXICO COLLECTED FROM THE R/V ALAMINOS, 1965-1973 by EDWARD O. MURDY, RICHARD E. MATHESON JR., JANICE D. FECHHELM, and MICHAEL J. McCOID Department of Wildlife and Fisheries Sciences Texas A&M University College Station, TX 77843 ABSTRACT Cruises of the R/V Alaminos during 1965-1973 involved the collection of fishes by midwater trawl from 38 locations in the Gulf of Mexico and the northwestern Caribbean. The 4,232 specimens comprised 32 families, 75 genera, and at least 116 species of meso- and bathypelagic fishes. Considering the collections as a whole, gonostomatids were the dominant group and Cyclothone the dominant genus. The families Gonostomatidae, Myctophidae, Sternoptychidae, and Melamphaidae accounted for 95% of the catch. Rela¬ tive abundance of gonostomatids varied little with sampling depth (to 1,000 m); mycto- phids were relatively most abundant in samples from the upper 500 m; sternoptychids and melamphaids were relatively most abundant in samples extending to depths of 1,000 m. INTRODUCTION The Texas Cooperative Wildlife Collection (TCWC) recently ac¬ quired the fishes taken during cruises of the R/V Alaminos in the years 1965-1973. This paper deals with those juvenile and adult specimens collected in 35 midwater-trawl (MWT) samples from various locations in the Gulf of Mexico and 3 MWT samples from the northwestern Caribbean (Table 1 and Fig. 1). All samples were taken with oblique tows of a 3.0 m (10-foot) Isaacs- Kidd midwater trawl (IKMT; Isaacs and Kidd 1953). Water depth, sam¬ pling depth, and start-stop times are provided for each sample in Table 1. This represents the most comprehensive survey, to date, of the mid¬ water fishes from the entire Gulf of Mexico. It complements and extends the work of Becker et al. (1975), who dealt primarily with midwater fishes from the Caribbean Sea and eastern Gulf of Mexico. OVERVIEW The 38 MWT samples consisted of 4,232 specimens (excluding epipe- lagic, benthic, and miscellaneous larval fishes) representing at least 116 species of meso- and bathypelagic fishes in 75 genera and 32 families. The following section provides a species-by-species account; here we The Texas Journal of Science, Vol. XXXV, No. 2, July 1983 110 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Table 1. Summary of collection data. Sample Position Sampling Depth Start-Stop (m) Maximum Water Depth (m) Time Start-Stop (CST) Date Lat. (N) Long. (W) 11 7 Mar 65 26° 15' 95° 00' 0-930 2322 1700-1800 104 4-5 Jul 65 23° 15' 84°02' 0-2500 2622 1820-0035 107 6 Jul 65 20°35' 84°47' 0-1875 4529 0935-1720 120 14-15 Jul 65 24° 58' 84° 16' 0-1410 3285 2255-0310 123 16 Jul 65 27° 17' 89°59' 0-980 2057 1545-1915 127 3 Jul 65 24°03' 83°07' 0-675 1028 1835-2110 129 7-8 Jul 65 19° 58' 85° 14' 0-2400 4721 2215-1130 132 9-10 Jul 65 20° 53' 85° 3 5' 0-2600 4474 2355-1005 133 12-13 Jul 65 23°43' 85°51' 0-2800 3574 2340-1220 140 2 Oct 65 26° 17' 94° 50' 0-1250 1625 1355-1650 143 3 Oct 65 24° 11' 95° 06' 0-2500 3605 1235-1745 153 27 Mar 66 25°33' 88° 5 7' 150-350 3294 2255-2340 156 30 Mar 66 25°34' 86° 28' 0-375 3252 1320-1440 166 4 Apr 66 28°45' 87°46' 0-1000 1870 1028-1230 169 3 Jul 66 23°03' 94° 3 4' 0-100 3737 0731-0845 171 4-5 Jul 66 23°34' 93° 3 O' 0-900 3658 2400-0300 175 8 Jul 66 24°01' 86° 52' 0-300 1171 1730-1740 182 11 Jul 66 28° 13' 87° 17' 0-150 1470 1345-1520 184 11 Jul 66 28° 13' 87°21' 250-500 2683 1627-1727 187 12 Jul 66 27° 18' 88°51' 0-175 2200 1138-1230 189 12 Jul 66 27° 18' 88°51' 500-950 2200 1330-1420 190 12 Jul 66 27° 18' 88°51' 1000-0 2200 1420-1500 192 13 Jul 66 27° 19' 88°53' 175-500 2141 2030-2250 198 22 Aug 69 21°27' 96° 53' 700-750 1180 1340-1440 200 26-27 Aug 69 22°52' 96° 18' 0-1500 2150 2335-0300 203 27 Aug 69 23°52' 95° 3 5' 2300-0 3109 2135-0300 205 5 Oct 69 24°53' 90° 45' 2500-1600 3569 1735-1930 206 5 Oct 69 24°53' 90° 45' 1600-0 3569 1930-2025 209 6 Oct 69 24° 3 6' 90°25' 3600-0 3687 1430-1620 210 7 Oct 69 24° 33' 88°27' 0-600 1829 0910-1105 213 7 Oct 69 24°41' 88° 11' 650-1100 1565 1550-1650 214 7 Oct 69 24°41' 88° 11' 1100-0 1565 1650-1745 216 8 Oct 69 25°22' 86° 3 6' 1000-1225 3248 1100-1200 219 8 Oct 69 25°25' 86° 28' 750-0 3248 1405-1505 221 4 Jul 70 25°54' 90° 58' 0-2500 3418 1705-2020 234 9 Jul 72 24° 3 6' 96° 19' 900-0 1290 1745-1815 239 2 Mar 73 26°45' 94°53' 0-480 641 1255-1742 247 3 Mar 73 26° 02' 93°50' 0-800 p 1700-2120 present only a summary of our observations regarding species composi¬ tion of the samples. Considering the samples as a whole, gonostomatids were clearly the dominant group: 2,858 specimens (2,731 of them Cyclothone spp.), or 67.5% of the total number of fishes caught, were of this family. Next in relative abundance were the Myctophidae with 15.5% of the catch by MIDWATER FISHES OF THE GULF 111 Figure 1. Map showing approximate location of each midwater trawl station. Dashed line indicates division of stations into more temperate (north of line) and more tropi¬ cal (south of line) categories. number; Sternoptychidae with 10.2%; and Melamphaidae with 1.8%. These four families represented 95% of the catch. Craddock and Mead (1970) found the same four families dominating the midwater ichthy¬ ofauna of the eastern Pacific. The importance to the total fauna of relatively few forms was also evident at the species level. Nearly 65% of all fishes caught were Cyclo- thone spp. Cyclothone spp. were found in 71% of the tows, whereas Valenciennellus tripunculatus was collected in 52.6%. The three most abundant taxa — Cyclothone spp., Sternoptyx pseudobscura and Lepid- ophanes guentheri — comprised 71.3% of the total. The ten most abund¬ ant species formed over 83.6% of the fauna, while the 36 least abundant species contributed an almost negligible 0.9%. The most speciose families were Myctophidae, with 45 species; Ster¬ noptychidae, 10; Gonostomatidae, 8; Melamphaidae, 8; and Photich- thyidae, 7. The relative abundance of the dominant families varied with respect to depth. The percentage composition of each MWT collection is pro¬ vided in Table 2 for the dominant families. (We follow Craddock and 112 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Table 2. Percentage composition of collections by sampling depth. A, 0-500 m; B, 0-1000 m; C, 0-1000+ m. Totals exclude values for the genus Cyclothone, which is already accounted for in the values for Gonostomatids. Collection Gonostomatids Cyclothone Myctophids Sternoptychids Melamphaids Total A. 153 2.2 2.2 91.1 2.2 95.6 156 74.7 74.7 4.0 9.3 88.0 169 175 41.4 35.7 49.3 2.9 93.6 182 184 98.9 96.6 0.3 0.3 0.3 99.5 187 192 11.1 22.2 22.2 55.6 239 64.5 48.4 26.1 5.0 95.6 X 67.8 59.8 18.4 7.5 0.4 94.2 B. 11 50.0 50.0 12.5 62.5 123 48.3 47.6 30.3 15.6 2.2 96.4 127 18.9 16.9 66.0 5.7 90.6 166 61.4 61.4 20.5 8.4 1.2 91.5 171 91.8 91.2 2.1 2.7 96.6 189 18.2 18.2 81.8 100.0 190 70.4 69.8 8.8 16.9 1.3 97.4 198 25.0 25.0 50.0 210 77.3 77.3 12.4 6.6 0.8 97.1 213 58.8 58.8 19.1 11.8 5.9 95.6 214 31.8 68.2 100.0 219 73.5 70.1 16.6 4.9 0.6 95.6 234 69.9 68.5 10.9 1.4 6.8 89.0 247 67.9 64.6 4.4 17.4 3.2 93.4 X 64.8 63.2 15.8 12.3 2.3 95.2 C. 104 83.8 83.4 9.2 4.4 97.4 107 65.2 63.8 15.9 10.1 2.9 94.1 120 52.9 50.0 12.9 22.9 2.9 91.6 129 45.0 45.0 35.0 10.0 90.0 132 133 8.3 8.3 75.0 8.3 91.7 140 100 100.0 143 37.5 50.0 12.5 100.0 200 72.4 69.0 9.6 7.7 3.5 93.2 203 100.0 100.0 205 83.3 83.3 5.6 88.9 206 5.3 10.5 31.6 21.1 68.5 209 77.8 73.3 6.7 8.9 2.2 95.6 216 95.3 95.3 1.9 0.9 98.1 221 72.6 72.6 16.6 6.4 1.3 96.9 X 72.6 71.1 12.1 8.1 2.2 94.9 MIDWATER FISHES OF THE GULF 113 Mead (1970) in the organization of this table, while recognizing the limitations of data based on non-closing nets.) Gonostomatids were the dominant fishes in samples from depths less than 500 m (67.8%), from depths between the surface and 1,000 m (64.8%), and from depths extending to more than 1,000 m (72.6%). Myctophids reached their max¬ imum abundance at depths less than 500 m (18.4%) and were much less abundant (12.1%) at depths between 0 and 1,000 m. Sternoptychids achieved their maximum relative abundance in the 0-1,000 m stratum (12.3%) but were also well represented in the 0-500 m stratum (7.5%) and 0-1,000+ m stratum (8.1%). Melamphaids were almost equally important from 0-1,000 m (2.3%) and 0-1,000+ m (2.2%), while their importance was least from 0-500 m (0.4%). A straight line from Tampico, Mexico, to Miami, Florida (Fig. 1), approximately bisects the Gulf of Mexico based on the tropical- temperate inshore fish faunal boundary of Hoese and Moore (1977). The 24 collections taken north of this line represented 53 hours of fish¬ ing effort and contained 2,804 specimens comprising 87 species. The 14 hauls, amounting to 65.5 total fishing hours, south of the line yielded 1,428 specimens representing 80 species. Thus, the number of speci¬ mens taken per unit of fishing effort was more than twice as great north of the line than south. However, the number of species taken per hour north of the line was only 1.3 times greater than that south of the line. Several individual samples were of particular interest. MWT 175 resulted in the collection of the only representatives of Taracichthys longipinnis, I diacanthus fasciola, Diaphus effulgens, D. anderseni, and D. termophilus. MWT 219 was the only haul to yield representatives of Evermannellidae. The samples with the largest diversity were MWT 123 (39 spp.), MWT 200 (38 spp.), and MWT 247 (33 spp.). As indicated by Backus et al. (1977) for myctophids, the midwater fish fauna of the Gulf of Mexico closely parallels that of the northwest Atlantic and Caribbean. The number of species appears substantial (116), and the number of specimens per fishing hour (935.7) in our col¬ lections is quite similar to that (40) obtained in the Gulf by Becker et al. (1975), but considerably less than that (82.8) reported by Craddock and Mead (1970) for the eastern Pacific. SPECIES ACCOUNT Each entry below gives the specific name, the IKMT collection(s) in which the species was taken, and the number of specimens followed, in parentheses, by the range of standard lengths. We have adopted the phylogenetic arrangement proposed by Nelson (1976), except in a few 114 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 cases where recent work has indicated otherwise; exceptions are noted and documented as they occur. Species that comprised at least 1% of the total number of non- Cyclothone specimens are followed by numbers in brackets. Numbers in brackets are, respectively, (1) total number of specimens of that spe¬ cies; (2) percentage of the total number of specimens of all species; (3) percentage of the total number of non -Cyclothone specimens; (4) number of collections in which the species occurred; and (5) percentage of collections in which the species occurred. All specimens are deposited in the TCWC, Texas A&M University, College Station, Texas. Anguilliformes Anguilloidei Serrivomeridae Serrivomer sp. MWT 166:1 (480 mm); MWT 247:1(567 mm) Salmoniformes Argentinoidei Argentinidae Microstoma microstoma (Risso, 1810) MWT 221:1 (39 mm) This seems to be only the second specimen of A/, microstoma recorded from the Gulf of Mexico (see Cohen 1964). One larval Micro¬ stoma sp. reported by Houde et al. (1979) from the eastern Gulf of Mex¬ ico should, however, be M. microstoma since this genus currently is considered monotypic (Cohen 1964). Bathylagidae Bathylagus c.f. berycoides (Borodin, 1929) MWT 153:1(103 mm) This seems to be only the second specimen of B. berycoides recorded from the Gulf of Mexico (see Cohen 1964). Bathylagus longirostris Maul, 1948 MWT 123:2(27-28 mm); MWT 171:1(28 mm) Alepocephalidae Photostylus pycnopterus Beebe, 1933 MWT 171:1(70 mm); MWT 206:1(100 mm); MWT 247:2(16-37 mm) Based on the records of Wisner (1976), our 100 mm specimen is the largest yet collected from the western Atlantic. Searsiidae Holtbyrnia sp. MWT 200:1(65 mm) Pellisolus facilis Parr, 1951 MWT 247:3(25-47 mm) MIDWATER FISHES OF THE GULF 115 This rare searsiid is known from California to Peru in the eastern Pacific Ocean (Parr 1960; Bussing 1965; Anderson et al. 1979) and from one previous record (Becker et al. 1975) in the Gulf of Mexico. Stomiiformes (^Salmoniformes (in part) of Nelson 1976, see Rosen 1973 and Steyskal 1980) Gonostomatoidei (=Stomiatoidei (in part) of Nelson 1976, change made due to ranking and Weitzman 1974) Gonostomatidae Bonapartia pedaliota Goode and Bean, 1896 MWT 104:1(35 mm); MWT 175:2(41-53 mm); MWT 200:1(83 mm) Grey (1964) lists the known maximum size as 72 mm S.L. Our 83 mm specimen represents a new size record. Cyclothone spp. [2731, 64.5%, - , 27, 71.0%] MWT 11:4(29-31 mm); MWT 104:191(8-50 mm); MWT 107:44(13-27 mm); MWT 120:35(23-47 mm); MWT 123:286(17- 50 mm); MWT 127:9(20-50 mm); MWT 129:9(28-48 mm); MWT 133:1(31 mm); MWT 153:1(16 mm); MWT 156:56(14-40 mm); MWT 166:51(10-46 mm); MWT 171:299(17-50 mm); MWT 175:50(18-32 mm); MWT 184:283(14-43 mm); MWT 189:4(16-26 mm); MWT 190:111(13-48 mm); MWT 200:180(16- 49 mm); MWT 205:15(23-48 mm); MWT 209:33(15-48 mm); MWT 210:187 (16-34 mm); MWT 213:40(18-46 mm); MWT 216:102(19-49 mm); MWT 219:128(15-47 mm); MWT 221:114(20-53 mm); MWT 234:50(12-46 mm); MWT 239:184(15- 47 mm); MWT 247:264(15-51 mm) Due to the poor condition of many of our specimens of Cyclothone, we decided to combine all specimens under Cyclothone spp. At least four species, C. braueri, C. pseudopallida, C. pallida, and C. acclinid- ens, occur in the Gulf of Mexico (Baird et al. 1975; Becker et al. 1975). Based on the distinguishing characters utilized by Kawaguchi (1971) and Bond and Tighe (1974), our collections contain at least the first three of these species. Diplophus taenia Gunther, 1873 MWT 171:1(102 mm); MWT 200:1(65 mm); MWT 239:1(66 mm) Gonostoma atlanticum Norman, 1930 MWT 120:1(34 mm); MWT 123:3(25-45 mm); MWT 198:1(49 mm); MWT 200:1(34 mm); MWT 247:1(51 mm) Gonostoma elongatum Gunther, 1878 [97, 2.3%, 6.4%, 14, 36.8%] MWT 107:1(90 mm); MWT 120:1(138 mm); MWT 127:1(122 mm); MWT 171:1(90 mm); MWT 175:5(89-165 mm); MWT 184:7(27-106 mm); MWT 190:1(114 mm); MWT 192:1(147 mm); MWT 200:4(24-176 mm); MWT 209:2(163-164 mm); 116 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 MWT 219:5(26-204 mm); MWT 234:1(34 mm); MWT 239:60(24-93 mm); MWT 247:7(34-76 mm) Gonostoma spp. MWT 123:1(24 mm); MWT 175:1(30 mm); MWT 200:2(34-34 mm); MWT 206:1(37 mm); MWT 247:6(damaged) Margrethia obtusirostra Jespersen and Taning, 1919 MWT 219:1(22 mm); MWT 239:1(19 mm) Maurolicus muelleri (Gmelin, 1788) MWT 182:1(18 mm); MWT 184:1(17 mm); MWT 247:1(14 mm) Sternoptychidae Argyropelecus aculeatus Valenciennes, 1849 MWT 120:1(60 mm); MWT 200:1(30 mm); MWT 206:1(10 mm); MWT 219:1(57 mm); MWT 247:1(14 mm) Argyropelecus affinis Garman, 1899 MWT 175:2(12-14 mm); MWT 205:1(29 mm); MWT 239:2(13- 15 mm) Argyropelecus gigas Norman, 1930 [15, 0.4%, 1.0%, 4, 10.5%] MWT 123:1(23 mm); MWT 210:9 (22-28 mm); MWT 214:1(22 mm); MWT 239:4(30-32 mm) Argyropelecus hemigymnus Cocco, 1829 MWT 206:1(11 mm); MWT 210:1(15 mm); MWT 239:2(16-19 mm); MWT 247:1(22 mm) Argyropelecus spp. MWT 107:2(10-16 mm); MWT 123:3(7-9 mm); MWT 153:2(8-9 mm); MWT 200:2(11-24 mm); MWT 214:2(9 mm) Polyipnus asteroides Schultz, 1938 MWT 171:1(31 mm); MWT 210:2(30-32 mm) Sternoptyx diaphana Hermann, 1781 [72, 1.7%, 4.8%, 17, 44.7%] MWT 11:1(22 mm); MWT 104:2(15-20 mm); MWT 107:4(10-25 mm); MWT 120:5(11-29 mm); MWT 123:9(11-32 mm); MWT 153:5(10-27 mm); MWT 156:2(17-21 mm); MWT 189:10(9-26 mm); MWT 190:3(17-19 mm); MWT 200:5(12-26 mm); MWT 203:1(13 mm); MWT 209:2(11-12 mm); MWT 213:2(11-16 mm); MWT 214:2(17-30 mm); MWT 221:4(10-25 mm); MWT 239:10(16-29 mm); MWT 247:5(17-42 mm) Sternoptyx pseudobscura Baird, 1971 [147, 3.5%, 9.8%, 13, 34.2%] MWT 104:3(23-36 mm); MWT 120:4(19-26 mm); MWT 123:18(11-44 mm); MWT 153:8(11-35 mm); MWT 190:24(6-46 mm); MWT 200:7(14-28 mm); MWT 206:2(15-30 mm); MWT 213:6(15-35 mm); MWT 214:4(27-33 mm); MWT 219:5(6-11 mm); MWT 221:3(8-23 mm); MWT 239:1(20 mm); MWT 247:62(9-45 mm) Sternoptyx spp. [105, 2.5%, 6.9%, 12, 31.6%] MWT 104:5(8-11 mm); MWT 120:4(7-10 mm); MWT 123:49(6- 14 mm); MWT 143:4(damaged); MWT 153:18(6-11 mm); MWT MIDWATER FISHES OF THE GULF 117 156:3(9-10 mm); MWT 166:1(7 mm); MWT 171:5(7-13 mm); MWT 189:8(7-9 mm); MWT 209:1(8 mm); MWT 214:6(7-10 mm); MWT 216:1(9 mm) V alenciennellus tripunctulatus (Esmark, 1871) [65, 1.5%, 4.3%, 20, 52.6%] MWT 107:1(26 mm); MWT 120:2(21-24 mm); MWT 123:14(18- 29 mm); MWT 127:3(21-28 mm); MWT 129:2(27-29 mm); MWT 153:8(16-30); MWT 156:2(23-24 mm); MWT 166:6(12-27 mm); MWT 171:1(22 mm); MWT 175:2(13-23 mm); MWT 184:1(17 mm); MWT 192:2(28-28 mm); MWT 200:5(22-30 mm); MWT 206:2(23-24 mm); MWT 209:1(26 mm); MWT 210:4(24- 29 mm); MWT 219:3(23-27 mm); MWT 221:3(28-28); MWT 234:1(25 mm); MWT 247:2(24-27 mm) Photichthyoidei (=Stomiatoidei (in part) of Nelson 1976, change made due to ranking and Weitzman 1974) Photichthyidae (=Gonostomatidae (in part) of Nelson 1976, see Weitzman 1974) Ichthyococcus ovatus (Cocco, 1838) MWT 221:1(15 mm) Pollichthys mauli (Poll, 1953) MWT 104:1(26 mm); MWT 156:4(22-39 mm); MWT 171:1(39 mm); MWT 216:1(28 mm); MWT 234:1(15 mm) Polymetme corythaeola (Alcock, 1898) MWT 104:1(32 mm) Vinciguerria attenuata (Cocco, 1838) MWT 166:2(18-34 mm); MWT 184:3(13-16 mm); MWT 192:1(20 mm); MWT 247:3(15-37 mm) Vinciguerria nimbaria (Jordan and Williams, 1895) [16, 0.4%, 1.1%, 8, 21.1%] MWT 104:1(24 mm); MWT 107:1(28 mm); MWT 123:3(15-18 mm); MWT 127:1(29 mm); MWT 156:1(25 mm); MWT 166:2(22-36 mm); MWT 184:1(16 mm); MWT 247:1(23 mm) Vinciguerria poweriae (Cocco, 1838) MWT 123:4(13-17 mm); MWT 156:1(14 mm); MWT 171:1(19 mm); MWT 200:4(19-26 mm); MWT 210:1(26 mm); MWT 221:2(19-21 mm); MWT 247:3(15-23 mm) Vinciguerria spp. MWT 200:4(16-20 mm) Chauliodontidae Chauliodus sloani Bloch and Schneider, 1801 MWT 171:1(26 mm); MWT 175:1(27 mm); MWT 184:3(58-104 mm); MWT 206:1(109 mm); MWT 210:6(22-35 mm); MWT 219:1(60 mm); MWT 239:1(102 mm) Chauliodus spp. MWT 132:1(140 mm); MWT 239:5(26-52 mm) 118 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Astronesthidae Astronesthes indicus Brauer, 1902 MWT 133:1(100 mm) Astronesthes micropogon Goodyear and Gibbs, 1969 MWT 234:1(49 mm) Astronesthes richardsoni Poey, 1853 MWT 239:1(41 mm) The only previous record of A. richardsoni from the Gulf of Mexico seems to be that of Becker et al. (1975). Astronesthes similis Parr, 1927 MWT 205:1(24 mm) Melanostomiidae (=Melanostomiatidae of Nelson 1976, see Steyskal 1980) Eustomias brevibarbatus Parr, 1927 MWT 175:1(77 mm); MWT 234:1(51 mm) Eustomias spp. MWT 123:2(72-75 mm); MWT 190:1(60 mm) Flagellostomias boureei (Zugmayer, 1913) MWT 171:1(164 mm) We find no previous records of F. boureei from the Gulf of Mexico, but the record of Flagellostomias sp. from the Gulf by Bullis and Thompson (1965) probably refers to this species (see Morrow and Gibbs 1964.) Leptostomias spp. MWT 171:1(88 mm); MWT 175:1(67 mm) Photonectes c.f. braueri (Zugmayer, 1913) MWT 153:1(28 mm) This species has not been reported previously in the Gulf of Mexico, but is known to occur in the Bahamas (Morrow and Gibbs 1964). Photonectes margarita (Goode and Bean, 1895) MWT 200:1(87 mm) Malacosteidae Aristostomias sp. MWT 209:1(26 mm) Malacosteus niger Ayres, 1848 MWT 200:1(36 mm); MWT 219:1(53 mm) Photostomias guernei Collett, 1889 MWT 166:1(96 mm); MWT 171:1(109 mm); MWT 184:1(32 mm); MWT 234:2(93-96 mm); MWT 239:2(25-77 mm); MWT 247:1 (damaged) Idiacanthidae I diacanthus fasciola Peters, 1877 MWT 175:1(101 mm) MIDWATER FISHES OF THE GULF 19 Aulopiformes (=Myctophiformes (in part) of Nelson 1976, see Rosen 1973) Aulopoidei (no suborder designated by Nelson 1976, see Rosen 1973) Scopelosauridae Scopelosaurus lepidus (Krefft and Maul, 1955) MWT 239:2(34-35 mm) Alepisauroidei (no suborder designated by Nelson 1976, see Rosen 1973) Paralepididae Lestidiops af finis (Ege, 1930) MWT 120:1(43 mm); MWT 123:3(30-44 mm); MWT 156:1(71 mm); MWT 169:4(38-55 mm); MWT 198:1(37 mm); MWT 200:1(59 mm) Lestidium atlanticum Borodin, 1928 MWT 120:1(70 mm) Par ale pis c.f. atlantica Krpyer, 1891 MWT 200:1(27 mm) Sudis atrox Rofen, 1963 MWT 198:1(17 mm) Our identification of this specimen is based on the characters given by Shores (1969) for small specimens. Omosudidae Omosudis lowei Gunther, 1887 [22, 0.5%, 1.5%, 11, 28.9%] MWT 104:1(16 mm); MWT 120:2(18-28 mm); MWT 123:3(15- 20 mm); MWT 171:2(15-17 mm); MWT 200:1(25 mm); MWT 205:1(26 mm); MWT 206:1(75 mm); MWT 209:1(33 mm); MWT 213:2(26-30 mm); MWT 234:1(16 mm); MWT 247:7(1 1- 49 mm) Alepisauridae Alepisaurus spp.? MWT 206:1(8 mm); MWT 221:1(10 mm) Evermannellidae Coccorella atrata (Alcock, 1893) MWT 219:1(97 mm) According to Rofen (1966), large specimens of C. atrata (>40 mm) are relatively rare in collections. Odontostomops normalops (Parr, 1928) MWT 219:1(47 mm) Scopelarchidae Scopelarchus analis (Brauer, 1902) MWT 127:1(42 mm); MWT 234:1(22 mm); MWT 239:1(31 mm); MWT 247:1(24 mm) Scopelarchus guentheri Alcock, 1896 MWT 175:1(41 mm); MWT 206:1(20 mm) 120 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Myctophiformes Myctophidae Benthosema suboritale (Gilbert, 1913) [81, 1.9%, 5.4%, 11, 28.9%] MWT 104:1(22 mm); MWT 123:19(14-29 mm); MWT 127:3(23- 24 mm); MWT 175:3920-27 mm); MWT 190:1(26 mm); MWT 200:5(24-27 mm); MWT 210:11(12-27 mm); MWT 219:1(22 mm); MWT 221:8(16-29 mm); MWT 239:25(12-31 mm); MWT 247:4(11-30 mm) Bolinichthys photothorax (Parr, 1928) MWT 129:1(57 mm); MWT 175:2(17-22 mm); MWT 219:2(18- 30 mm); MWT 234:1(21 mm); MWT 239:1(24 mm); MWT 247:1(33 mm) Bolinichthys supralateralis (Parr, 1928) MWT 200:1(21 m); 213:1(16 mm); MWT 221:1(13 mm); MWT 239:9(20-35 mm) Bolinichthys spp. MWT 123:1(56 mm); MWT 219:1(12 mm) Centrobranchus nigroocellatus (Gunther, 1873) MWT 104:2(12-14 mm); MWT 175:1(17 mm); MWT 239:1(34 mm) Ceratoscopelus warmingi (Liitken, 1892) [86, 2.0%, 5.7%, 11, 28.9%] MWT 104:1(21 mm); MWT 107:3(22-36 mm); MWT 123:45(17- 51 mm); MWT 127:5(24-33 mm); MWT 143:1(26 mm); MWT 175:9(20-38 mm); MWT 190:5(22-25 mm); MWT 200:6(21-36 mm); MWT 213:3(21-32 mm); MWT 221:7(17-22 mm); MWT 247:1(59 mm) Diaphus c.f. anderseni Taning, 1932 MWT 175:1(19 mm) Nafpaktitis el al. (1977) consider D. anderseni uncommon in the North Atlantic and record only one specimen from the Gulf of Mexico. The identification of our specimen is somewhat questionable due to its damaged condition; however, it agrees with the description of D. ander¬ seni in the placement and size of the luminous organs on the head. Diaphus dumerili (Bleeker, 1856) MWT 127:1(27 mm); MWT 210:1(61 mm); MWT 214:2(24-28 mm); MWT 247:1(54 mm) Diaphus effulgens (Goode and Bean, 1896) MWT 175:1(106 mm) Diaphus fragilis Taning, 1928 MWT 107:1(34 mm) Diaphus garmani Gilbert, 1906 MWT 210:1(32 mm) MIDWATER FISHES OF THE GULF 121 Diaphus lucidus (Goode and Bean, 1896) MWT 123:1(70 mm); MWT 175:2(23-25 mm); MWT 239:1(83 mm) Diaphus luetkeni (Brauer, 1904) MWT 120:1(42 mm); MWT 123:1(39 mm); MWT 127:1(38 mm); MWT 143:1(18 mm); MWT 166:1(52 mm); MWT 200:1(40 mm); MWT 239:2(42-48 mm) Diaphus mollis Taning, 1928 MWT 175:1(48 mm); MWT 190:1(17 mm); MWT 200:1(51 mm); MWT 213:1(20 mm); MWT 247:2(47-51 mm) Diaphus perspicillatus (Ogilby, 1898) MWT 239:1(54 mm) Diaphus problematicus Parr, 1928 MWT 107:2(33-54 mm); MWT 127:1(50 mm); MWT 175:1(48 mm); MWT 210:4(33-58 mm); MWT 219:4(23-39 mm); MWT 247:1(42 mm) Diaphus rafinesqui (Cocco, 1838) MWT 107:1(83 mm); MWT 184:1(78 mm); MWT 210:6(31-80 mm) Diaphus splendidus (Brauer, 1904) MWT 133:1(32 mm); MWT 175:1(61 mm) Diaphus taaningi Norman, 1930 MWT 123:1(57 mm) Diaphus termophilus Taning, 1928 MWT 175:2(34-38 mm) Diaphus spp. MWT 120:1(63 mm); MWT 127:2(66-74 mm); MWT 129:2(29- 35 mm); MWT 166:1(14 mm); MWT 219:1(61 mm); MWT 239:1(20 mm) Diogenichthys atlanticus (Taning, 1928) [127, 0.6%, 1.8%, 8, 21.1%] MWT 104:2(12-14 mm); MWT 120:1(12 mm); MWT 123:9(11- 21 mm); MWT 166:1(21 mm); MWT 190:1(12 mm); MWT 200:1(18 mm); MWT 239:10(16-22 mm); MWT 247:2(22-23 mm) Gonichthys coccoi (Cocco, 1829) [15, 0.4%, 1.0%, 3, 7.9%] MWT 123:9(18-22 mm); MWT 127:1(27 mm); MWT 210:5(20- 26 mm) Hygophum benoiti (Cocco, 1838) [64, 1.5%, 4.3%, 8, 21.1%] MWT 104:9(9-12 mm); MWT 120:4(11-13 mm); MWT 123:36(10-23 mm); MWT 190:4(10-12 mm); MWT 192:1(12 mm); MWT 210:1(23 mm); MWT 214:2(20-22 mm); MWT 221:7(11-15 mm) 122 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Hygophum hygomi (Lutken, 1892) MWT 123:1(44 mm); MWT 156:1(14 mm); MWT 239:2(16-23 mm) Hygophum macrochir (Gunther, 1864) MWT 123:1(38 mm); MWT 127:3(30-44 mm); MWT 206:1(13 mm) Hygophum reinhardti (Lutken, 1892) MWT 104:1(14 mm); MWT 107:1(14 mm); MWT 143:1(13 mm); MWT 200:1(14 mm) Hygophum taaningi Bekker, 1965 MWT 123:2(20-32 mm); MWT 127:1(32 mm); MWT 156:2(12- 14 mm) MWT 166:1(32 mm); MWT 200:2(23-27 mm); MWT 209:2(20-21 mm); MWT 214:1(14 mm) According to Nafpaktitis el al. (1977), H. taningi and H. macrochir are easily confused. Based on photophore patterns, some of our speci¬ mens identified as H. taaningi could be H. macrochir ; however, gill raker counts clearly separate the two species: 19-20 in H. macrochir vs. 17 in H. taaningi. LampecLena luminosa (Garman, 1899) MWT 140:1(47 mm); MWT 175:2(20-25 mm); MWT 219:2(37- 43 mm); MWT 239:4(43-68 mm) Lampedena sp. MWT 219:1(14 mm) Lampanyctus alatus Goode and Bean, 1896 [45, 1.1%, 3.0%, 14, 36.8%] MWT 107:1(37 mm); MWT 120:1(34 mm); MWT 123:16(23-47 mm); MWT 127:2(44-45 mm); MWT 133:1(36 mm); MWT 166:4(43-46 mm); MWT 175:2(32-33 mm); MWT 200:1(41 mm); MWT 209:1(21 mm); MWT 214:1(27 mm); MWT 219:2(32-38 mm); MWT 221:1(30 mm); MWT 239:9(32-44 mm); MWT 247:3(37-43 mm) Lampanyctus ater Taning, 1928 MWT 234:1(86 mm) Lampanyctus cuprarius Taning, 1928 MWT 213:1(66 mm) Lampanyctus nobilis Taning, 1928 MWT 129:2(34-53 mm); MWT 166:1(36 mm); MWT 200:1(37 mm); MWT 234:2(32-50 mm) Lampanyctus spp. MWT 127:2(39-84 mm); MWT 133:1(110 mm); MWT 192:1(105 mm); MWT 216:2(77-99 mm); MWT 239:2(20-41 mm) MIDWATER FISHES OF THE GULF 123 Lepidophanes guentheri (Goode and Bean, 1896) [140, 3.3%, 9.3%, 15, 39.5%] MWT 104:2(16-17 mm); MWT 107:3(24-30 mm); MWT 120:1(19 mm); MWT 123:20(16-60 mm); MWT 127:13(26-53 mm); MWT 129:3(23-37 mm); MWT 133:6(33-48 mm); MWT 140:1(20 mm); MWT 166:4(20-57 mm); MWT 175:38(17-43 mm); MWT 200:1(25 mm); MWT 213:2(21-47); MWT 219:16(16-44 mm); MWT 239:27(30-51 mm); MWT 247:3(50-54 mm) Lobianchia gemellari (Cocco, 1838) MWT 166:1(41 mm); MWT 200:2(31-46 mm); MWT 206:1(47 mm); MWT 210:1(44 mm) Lobianchia sp. MWT 213:1(48 mm) Myctophum affine (Lutken, 1892) MWT 123:8(16-33 mm); MWT 239:4(17-52 mm) Myctophum nitidulum Garman, 1899 MWT 104:2(15-71 mm); MWT 166:1(15 mm); MWT 200:1(34 mm) Myctophum selenops Taning, 1928 MWT 190:2(11-36 mm); MWT 200:1(47 mm) Notolychnus valdiviae (Brauer, 1904) MWT 104:1(19 mm); MWT 123:1(19 mm); MWT 166:3(15-21 mm); MWT 175:2(11-20 mm); MWT 198:1(19 mm); MWT 221:1(18 mm); MWT 234:4(16-20 mm) Notoscopelus resplendens (Richardson, 1845) [17, 0.4%, 1.1%, 4, 10.5%] MWT 123:11(36-56 mm); MWT 213:4(45-57 mm); MWT 214:1(56 mm); MWT 221:1(42 mm) Symbolophorus rufinus Taning, 1928) MWT 123:1(16 mm); MWT 175:1(26 mm); MWT 239:1(44 mm) Taaningichthys minimus (Taning, 1928) MWT 239:1(27 mm) Gadiformes Gadoidei Melanonidae Melanonus zugmayeri Norman, 1930 MWT 123:1(105 mm); MWT 127:1(120 mm) Bregmacerotidae Bregmaceros atlanticus Goode and Bean, 1886 MWT 104:1(28 mm); MWT 107:1(42 mm); MWT 123:1(35 mm); MWT 127:2(27-32 mm); MWT 243:1(55 mm) Bregmaceros macclellandi Thompson, 1840 MWT 190:2(37-39 mm); MWT 216:1(48 mm) 124 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Bregmaceros spp. MWT 129:1(18 mm); MWT 175:3(18-27 mm); MWT 190:1(21 mm); MWT 200:1(26 mm); MWT 219:1(20 mm); MWT 247:2(20-25 mm) Based on Houde et al. (1979) and Belyanina (1980), there are at least three species of Bregmaceros in the Gulf of Mexico. Using Belyanina (1974), we were able to identify our larger specimens as either B. atlan- ticus or B. macclellandi. However, due to the difficulty in counting anal and dorsal fin rays in small specimens, we have designated such specimens as Bregmaceros spp. Lophiiformes Ceratioidei Melanocetidae Melanocetus murrayi Gunther, 1887 MWT 247:1(49 mm) Melanocotus sp. MWT 200:1(12 mm) Ceratiidae Cryptopsaras couesi Gill, 1883 MWT 171:1(8 mm); MWT 187:1(11 mm); MWT 234:1(11 mm) Beryciformes Cetomimoidei Cetomimidae Ditropichthys storeri (Goode and Bean, 1895) MWT 200:1(31 mm) This represents the first definitive record of this cetomimid for the Gulf of Mexico (see Harry 1952.) Stephanoberycoidei Melamphaidae ( = M e 1 a m p h a e i d a e of Nelson 1976, see Steyskal 1980) Melamphaes pumilis Ebeling, 1962 MWT 200:1(18 mm); MWT 206:1(20 mm); MWT 213:1(17 mm); MWT 234:5(21-25 mm) Melamphaes simis Ebeling, 1962 MWT 123:2(13-15 mm); MWT 166:1927 mm); MWT 171:3(17- 28 mm); MWT 184:1(27 mm); MWT 192:2(20-21 mm) Melamphaes typhlops (Lowe, 1843) [17, 0.4%, 1.1%, 4, 10.5%] MWT 123:7(22-29 mm); MWT 200:5(19-28 mm); MWT 210:2 (21-25 mm); MWT 247:3(22-24 mm) Melamphaes spp . MWT 107:2(24-25 mm); MWT 206:3(18-27 mm) Poromitra crassiceps (Gunther, 1878) MWT 190:1(88 mm) Poromitra megalops (Liitken, 1877) MWT 247:2(44-50 mm) MIDWATER FISHES OF THE GULF 125 Scopeloberyx opisthopterus (Parr, 1933) [26, 0.6%, 1.7%, 9, 23.7%] MWT 120:1(27 mm); MWT 123:2(19-28 mm); MWT 133:1(27 mm); MWT 143:1(28 mm); MWT 171:6(22-27 mm); MWT 200:2(26-27 mm); MWT 213:3(18-23 mm); MWT 221:2(22-26 mm); MWT 247:8(18-26 mm) Scopeloberyx robustus (Gunther, 1887) MWT 120:1(18 mm); MWT 123:2(17-21 mm); MWT 153:1(40 mm); MWT 190:1(85 mm); MWT 200:1(24 mm); MWT 209:1(52 mm); MWT 219:2(11-14 mm) Trachichthyoidei (=Berycoidei (in part) of Nelson 1976, see Zehren 1979) Anoplogastridae (=Anoplogasteridae of Nelson 1976, see Steyskal 1980) Anoplogaster cornuta (Valenciennes, 1833) MWT 192:1(84 mm); MWT 206:1(16 mm) Diretmidae Diretmus argenteus Johnson, 1863 ? MWT 247:1(13 mm) Trachichthyidae Gephyroberyx darwini (Johnson, 1866) ? MWT 187:2(5-9 mm) Perciformes Percoidei Bramidae Brama caribbea Mead, 1972 MWT 120:1(12 mm) Pterycombus brama Fries, 1837 MWT 104:1(10 mm); MWT 156:1(17 mm) Taracichthys longipinnis (Lowe, 1843) MWT 175:1(9 mm) Trachinoidei (— Trachinoidea of Nelson 1976, change due to ranking) Chiasmodontidae Kali spp. ? MWT 120:1(32 mm); MWT 123:1(29 mm) Scombroidei Gempylidae Diplospinus c.f. multistriatus Maul, 1948 MWT 156:1(163 mm); MWT 219:1(138 mm) Promethichthys c.f. prometheus (Cuvier, 1832) MWT 11:3(11-18 mm); MWT 107:1(13 mm); MWT 123:1(12 mm); MWT 187:1(28 mm); MWT 200:1(41 mm); MWT 247:2(15-16 mm) Trichiuridae Lepidopus c.f. caudatus (Euphrasen, 1788) MWT 239:2(90-102 mm) 126 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 ACKNOWLEDGEMENTS We acknowledge W. E. Pequenat and J. H. Wormuth for their help in making these collections available to us. We thank Janet Gomon (USNM) for identifying the species of Eustomias. The 1978 and 1979 classes in Systematic Ichthyology, Texas A&M University, also aided in identification of specimens. The manuscript benefitted from the review given it by John D. McEachran. LITERATURE CITED Anderson, M. E., G. M. Caillet, and B. S. Antrium. 1979. Notes on some uncommon deep-sea fishes from the Monterey Bay area, California, U.S.A. Calif. Fish Game 65(4):256-264. Backus, R. H., J. E. Craddock, R. L. Haedrich, and B. H. Robison. 1977. Atlantic mesopelagic zoogeography. In Fishes of the western North Atlantic, Mem. Sears Found. Mar. Res. l(7):226-287. Baird, R. C., N. P. Thompson, J. L. Hopkins, and W. R. Weiss. 1975. Chlorinated hydrocarbons in mesopelagic fishes of the eastern Gulf of Mexico. Bull. Mar. Sci. 25(4):473-481. Becker, V. E., Y. N. Scherbachev, and V. M. Chuvasov. 1975. (Deep-sea pelagic fishes of the Caribbean Sea, Gulf of Mexico, and Puerto Rican Trench.) Trudy Inst. Okea- nol. (100):289-336. (In Russian). Belyanina, T. N. 1974. (Material on the development, systematics, and distribution of the fishes of the family Bregmacerotidae.) Trudy Inst. Okeanol. (96): 143-188. (In Rus¬ sian). Belyanina, T. N. 1980. Codiets (Bregmacerotidae, Osteichthyes) of the Caribbean Sea and the Gulf of Mexico. J. Ichthyol. (Engl, trans.) 20(1): 138- 141. Bond, G. W., Jr., and K. A. Tighe. 1974. A diagnostic character for rapid identificai- ton of lightly pigmented species of the genus Cyclothone (Gonostomatidae) in the North Atlantic. Copeia 1974 (l):272-275. Bullis, H. R., Jr., and J. R. Thompson. 1965. Collections by the exploratory fishing vessels Oregon, Silver Bay, Combat, and Pelican made during 1956-1960 in the southwestern North Atlantic. U.S. Fish and Wildlife Service, SSR-F510. 130 p. Bussing, W. A. 1965. Studies of the midwater fishes of the Peru-Chile Trench. Biol. Antarct. Seas II. Anarct. Res. Ser. 5:185:227. Cohen, D. M. 1964. Suborder Argentinoidea. In Fishes of the western North Atlantic. Mem. Sears Found. Mar. Res. 1(4): 1-70. Craddock, J. E., and G. W. Mead. 1970. Midwater fishes from the eastern South Pacific Ocean. Anton Bruun Rep. 3, Sci. Res. of S. E. Pac. Exped. 46 p. Grey, M. 1964. Family Gonostomatidae. In Fishes of the western North Atlantic. Mem. Sears Found. Mar. Res. l(4):77-238. Harry, R. R. 1952. Deep sea fishes of the Bermuda Oceanographic Expeditions. Fami¬ lies Cetomimidae and Rondeletiidae. Zoologica (N.Y. Zool. Soc.) 37:55-72. Hoese, H. D., and R. H. Moore. 1977. Fishes of the Gulf of Mexico: Texas, Louisiana and adjacent Waters. Texas A&M University Press, College Station, TX. 327 p. Houde, E. D., J. C. Leak, C. E. Dowd, S. A. Berkeley, and W. J. Richards. 1979. Ich- thyoplankton abundance and diversity in the eastern Gulf of Mexico. Report to the Bureau of Land Management, contract no. AA550-CT7-28. 546 p. Isaacs, J. D., and L. W. Kidd. 1953. Isaacs-Kidd midwater trawl. Scripps Inst. Ocea- nogr., Ref. 53-3. 21 p. MIDWATER FISHES OF THE GULF 127 Kawaguchi, K. 1971. Gonostomatid fishes of the western North Pacific. Japan. J. Ich- thyol. 18:1-16. Morrow, J. E., Jr., and R. H. Gibbs. 1964. Family Melanostomiatidae. In Fishes of the western North Atlantic. Mem. Sears Found. Mar. Res. 1 (4):35 1-51 1 . Nafpaktitis, B. G., R. H. Backus, J. E. Craddock, R. L. Haedrich, B. H. Robison, and C. Karnella. 1977. Family Myctophidae. In Fishes of the western North Atlantic. Mem. Sears Found. Mar. Res. 1(7): 13-258. Nelson, J. S. 1976. Fishes of the world. John Wiley 8c Sons, Inc., N.Y. xvi + 416 p. Parr, A. E. 1960. The fishes of the family Searsidae. Dana-Report No. 51. 108 p. Rofen, R. R. 1966. Family Evermannellidae. In Fishes of the western North Atlantic. Mem. Sears Found. Mar. Res. 1 (5):5 1 1-565. Rosen, D. E. 1973. Interrelationships of higher euteleostean fishes, p. 397-513. In P. H. Greenwood, R. S. Miles, and C. Patterson (Eds.), Interrelationships of fishes. Aca¬ demic Press, New York, N.Y. Shores, D. L. 1969. Postlarval Sudis (Pisces: Paralepididae) in the Atlantic Ocean. Bre- viora (334): 1-14. Steyskal, G. C. 1980. The grammar of family-group names as exemplified by those of fishes. Proc. Biol. Soc. Wash. 93( 1 ): 168- 1 77. Weitzman, S. H. 1974. Osteology and evolutionary relationships of the Sternoptychi- dae, with a new classification of stomiatoid families. Bull. Am. Mus. Nat. Hist. 153:329-478. Wisner, R. L. 1976. New data on the rare alepocephalid fish Photostylus pycnopterus. Bull. South. Calif. Acad. Sci. 75(2): 153-158. Zehren, S. J. 1979. The comparative osteology and phylogeny of the Beryciformes (Pis¬ ces: Teleostei). Evol. Monogr. 1:1-389. m IN VITRO ANALYSIS OF TRANSFER FACTOR ACTIVITY IN GUINEA PIG LEUKOCYTE EXTRACTS BY THE AGAROSE DROP ASSAY by ANDREW PAQUET, JR. Biology Department Texas Christian University Fort Worth, TX 76129 and GEORGE B. OLSON and C. G. DRUBE Department of Microbiology University of Arizona Tucson, AZ 85721 ABSTRACT The agarose drop migration inhibition test of Harrington and Stastny was used for in vitro assay of transfer factor (TF) activity in leukocyte extracts from guinea pigs sensitized to Listeria monocytogenes. These cell-free extracts were also assayed by passive transfer of delayed hypersensitivity-type skin reactions. Only the combination of TF plus specific Listeria antigens caused significant migration inhibition in vitro ; neither substance alone was effective. However, TF preparations could be incubated simultaneously with normal peritoneal exudative cells plus Listeria antigens to produce migration inhibition in 18 hours. This procedure eliminates the need for incubation of cells with TF prior to anti¬ gen addition, thus saving considerable time over some previously used assays. Migration inhibition factor (MIF) was able to inhibit macrophage migration in the absence of anti¬ gen, whereas gamma globulin from sensitized animals had no effect on this in vitro assay. The most active TF preparations were in the molecular weight fractions between 500 and 10,000. Because this assay requires fewer cells and can be performed with much smaller volumes of leukocyte preparations than capillary tube assays, it together with the Listeria-sensitized guinea pig, comprises a good animal model for in vivo and in vitro studies of TF activity. INTRODUCTION Cellular immunity is important in combatting many microbial infec¬ tions, in rejecting foreign tissue transplants, and in tumor suveillance. One of the active materials believed responsible for these expressions of cellular immunity has been termed “transfer factor” (Lawrence and Pappenheimer 1956). Transfer factor from human leukocyte extracts has been studied and characterized extensively (Lawrence 1971). Its use in the clinical treatment of immunodeficiency disease, infectious dis¬ eases, and cancers has been promising (Fudenberg el al. 1974). How¬ ever, study of the exact mode of action of transfer factor has been ham- The Texas Journal of Science, Vol. XXXV, No. 2, July 1983 130 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 pered by the lack of good in vitro assays (Petersen and Kirkpatrick 1979). Success in assaying transfer factor activity by in vitro lymphocyte transformation has been reported (Arala-Chaves et al. 1974; Ascher et al. 1974); yet, this technique has been criticized (Petersen and Kirkpa¬ trick 1979) as inconsistent and not dependent on the antigen-specific sensitivities of the transfer factor donor. Other investigators (e.g. Sala- man 1974) have used the capillary tube migration inhibition test suc¬ cessfully. Apparently, transfer factor has the ability to cause normal peritoneal exudative cells, cultured with mixtures of specific transfer factor and antigen, to respond to the specific antigen by producing migration inhibition factor (MIF). The disadvantage of the capillary tube assay is that large numbers of cells are required and some methods require 36-48 hours to complete. A positive correlation between skin- test results and the inhibition of human peripheral blood leukocyte migration in vitro from wells cut in agarose plates has also been reported (Wilson et al. 1979) but, again, large numbers of leukocytes are required. Transfer factor from leukocyte extracts and from “incubation fluids’’ of other cells of the guinea pig has also been described (Burger and Jeter 1971). Additionally, Dunnick and Bach (1975, 1977) reported in vitro analysis of guinea pig transfer factor by capillary tube migration inhibition assay. Yet, they did not report any in vivo results, and their assay required more cells and a longer incubation time (38-60 h) than we describe in this study. Nevertheless, these studies indicate that gui¬ nea pig transfer factor has many characteristics in common with human transfer factor. The guinea pig thus offers an animal model to study both in vivo and in vitro activities of transfer factor. The purpose of the present paper is two-fold: First, to report on the production and characterization, both in vivo and in vitro , of transfer factor activity in leukocyte extracts from guinea pigs sensitized to Liste¬ ria monocytogenes ; and second, to report on the agarose drop migra¬ tion inhibition test as an in vitro assay for transfer factor. The agarose drop assay of Harrington and Stastny (1973) is technically simple and requires only small amounts of media and cells; usually enough can be obtained from a single animal for several hundred wells. This elimi¬ nates the variability caused by using pools of cells from several anim¬ als. MATERIALS AND METHODS Animals and Antigen Hartley guinea pigs of either sex were used. The animals were housed in individual cages and were given Purina guinea pig chow, fresh cabbage, and water supplemented with ascorbic acid (300 mg/li¬ ter). LEUKOCYTE TRANSFER-FACTOR ACTIVITY 131 Listeria monocytogenes was grown in tryptose phosphate broth (Difco) in a New Brunswick fermentor at 37 C for 48 h with constant stirring and aeration. The culture was killed by treatment with an equal volume of 2% Formalin for 24 h at room temperature, then cen¬ trifuged. The killed organisms then were washed seven times with 0.15 M saline, pH 7.2; suspended in distilled H2O; sonicated; lyophilized; and, stored at 4 C. Endotoxin content was determined to be less than 0.5 ng/ml via the Limulus assay (Sigma). Sensitization and Skin Testing Guinea pigs (500 g) were sensitized to the Listeria antigens by subcu¬ taneous injection, into three sites in the back of the neck, of 1 mg of the antigen emulsified in Freund’s incomplete adjuvant (1 ml volume). Three weeks following sensitization, the guinea pigs were skin tested by intradermal injection of 10 ug of Listeria antigen (0.1 ml) at pre¬ viously shaved (24 h prior) surfaces of the abdomen. Skin-test sites were observed immediately and at 6 and 24 h following the injection. Length and width of any erythematous induration were measured to the nearest millimeter and recorded. Passive transfer recipients were skin-tested 48 h after the intraperitoneal (IP) injection of the various leukocyte extracts or other factors and the skin reactions were observed at 0, 6, 24, 48 and 72 h. Collection of Leukocytes and Serum from Actively Sensitized Animals Two days prior to skin testing, 20 ml of sterile light mineral oil was injected IP into each donor guinea pig to induce peritoneal exudative cells. On the day after skin testing, the animals were sacrificed by cervi¬ cal dislocation, exsanguinated and the peritoneal exudates were harv¬ ested by washing out the peritoneal cavity with approximately 200 ml of ice-cold Hanks’ balanced salt solution (HBSS). Cervical and supras¬ capular lymph nodes and spleens were removed at the same time and teased apart into ice-cold HBSS. All cell populations were washed three times and certrifuged (400 X g, 10 min) in a refrigerated centrifuge. Cells were collected quickly and kept at 4 C until put into culture media. Serum was collected and fractionated by Geon Pevikon block electrophoresis to obtain the gamma globulin fraction according to the procedure of Fahey and McLaughlin (1963). Preparation of Guinea Pig Transfer Factor (TF) Transfer factor was prepared according to the procedure of Burger and Jeter (1971), from peritoneal exudates, lymph node cells, and spleen cells obtained from sensitized animals. In brief, 109 cells were incubated in 7.5 ml of HBSS for 4 h at 37 C in a water bath with intermittent shaking. The incubation fluid was centrifuged (800 X g) 132 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 for 10 minutes, then desalted and concentrated by ultrafiltration on an Amicon UM05 membrane and then lyophilized. The salt-free material retained by the UM05 membrane (Transfer Factor) was stored at —20 C or used immediately in passive transfer experiments. Control TF was prepared in the same manner, except with cell populations from non- sensitized animals. Preparation of Guinea Pig Migration Inhibition Factor ( MIF ) Peritoneal exudative cells from sensitized animals were cultured at a concentration of 2.5 X 10-7 cells/ml in TC 199 medium [penicillin (100 U/ml), streptomycin (100 ug/ml), and 0.01 M HEPES buffer and no serum] and 5 ug of Listeria antigen/ml for 24 h at 37 C in a humidi¬ fied air incubator. The cells were removed by centrifugation (800 X g, 10 min) and the supernatant fluid was desalted and concentrated by ultrafiltration on an Amicon UM05 membrane, lyophilized, and stored at —20 C. Control MIF was also prepared in the same manner, except with cells from non-sensitized animals. Passive Transfer of Activity Transfer factor, MIF and gamma globulin preparations were injected IP into normal, 300-g guinea pigs. The concentration of TF was equi¬ valent to material obtained from 109 cells, and an average of 5 mg of MIF and gamma globulin was injected. Protein concentrations of MIF and gamma globulin were determined by the method of Lowry et al. (1951). The activity of TF in vitro was assayed by using a slight modifica¬ tion of the agarose drop migration inhibition test of Harrington and Stastny (1973). The various TF, MIF, and gamma globulin prepara¬ tions were assayed for their ability to inhibit the migration of normal guinea pig peritoneal exudative macrophages in the presence and absence of antigen. One-microliter agarose droplets containing 5 X 105 cells were dispensed in flat-bottom microtiter plates (Falcon, Microtest II) without precoating the wells with agarose. The droplets of cells were gelled by placing in the refrigerator for 5 minutes. The medium used for the cell suspension was TC-199 medium containing 15% nor¬ mal guinea pig serum (heated 56 C, 30 min), streptomycin (100 ug/ml), penicillin (100 U/ml), 0.2% agarose, and 0.01 M HEPES buffer. Each well containing an agarose droplet of cells was then filled (0.3 ml) with TC-199 medium alone (without agarose) or TC-199 medium containing the various factors to be tested with or without Listeria antigen. The chambers were incubated at 37 C in humidified air for 18 to 24 h before the distances of cellular migration were determined. All materials were tested in quadruplicate. Inhibition was considered significant when the percent migration dropped below 80%. The range of variation observed LEUKOCYTE TRANSFER-FACTOR ACTIVITY 133 Table 1. Skin test reactions in non-sensitized and Listeria sensitized guinea pigs. Pro¬ ducts represent length X width (both in mm) of erythematous induration following injection with 10 ug Listeria antigen. Non-sensitized Antigen-sensitized Animal 6 hr. 24 hr. Animal 6 hr. 24 hr. 1 1 X la 1 X 1 1 4X6 5X8 2 1 X 1 2X2 2 1 X 1 20 X 21 3 1 X 1 1 X 1 3 1 X 1 11 X 11 4 1 X 1 1 X 1 4 1 X 1 11 X 12 5 1 X 1 2X2 5 2X2 13 X 15 6 1 X 1 1 X 1 6 1 X 1 11 X 12 7 1 X 1 2X2 7 1 X 1 11 X 12 8 1 X 1 1 X 1 8 2X2 10X 10 9 1 X 1 1 X 1 9 IX 1 11 X 12 10 1 X 1 2X2 10 1 X 1 8X9 11 4X4 10X 10 12 1 X 1 12 X 12 13 1 X 1 1 X 11 14 2X2 5X7 15 1 X 1 11 X 12 Average 1 X 1 1.4 X 1.4 1.6 X 1.6 10.6 X 11.6 aAnimals with no visible skin reactions were scored as 1 X 1 in order to have a numerical average for comparison. in data from this technique is quite small; typically, 95% confidence limits about the means of distances of migration amount to only X ± 5% (Paquet et al. 1975). Molecular Weight Determinations The molecular weight of the fractionated transfer-factor preparation was determined by using a thin layer gel filtration apparatus (Pharma¬ cia) with superfine Sephadex G-75. The migration distances of the TF fractions were compared with those of known molecular weight stand¬ ards. RESULTS Table 1 presents data from non-sensitized and Listeria-sensitized animals when skin tested with 10 ug of the Listeria antigen. Skin-test reactions in non-sensitized animals were negative at 6 and 24 h. Sensit¬ ized animals showed minimal reactions at 6 h and strong positive reac¬ tions 24 h after testing (avg. diameters of erythema and induration, 11 X 12 mm). Histological evaluation of these positive reactions showed the classi¬ cal responses of mononuclear cellular inflitration throughout the epi¬ dermis and dermis to the striated muscle layer. In some cases, large 134 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 deposits of cells were noted in the papillary layer of the dermis. Even animals with minimal skin reactions (5X5 mm) showed considerable mononuclear cell infiltration. Passive transfer recipients were tested with the same concentration of antigen (10 ug) and only reactions involving 5X5 mm or greater erythema and induration were considered positive. Since the agarose drop migration inhibition test was to be used to assay for transfer factor in vitro and as a direct migration inhibition test to detect in vivo sensitization of TF recipients, its credibility first had to be established by testing peritoneal exudative cells from non- sensitized, but skin-tested animals. Cells from ten such animals (those listed in Table 1) were tested. Average migration was 102 % that of con¬ trols. Hence, the skin testing of a non-sensitized animal did not appear to cause positive migration inhibition in vitro three days later. Appar¬ ently the amount of antigen in a skin test is not enough to sensitize an animal (i.e., not enough to convert a migration inhibition test from negative to positive). However, peritoneal exudative cells from sensi¬ tized donors when tested in the presence of antigen always showed inhibition of migration, with distances comparable to only 40-70 % of the control values. Table 2 shows a summary of passive-transfer attempts and macro¬ phage migration inhibition assays for different batches of transfer fac¬ tor, migration inhibition factor, and serum gamma globulin. Some¬ times we did not have enough material for both in vivo and in vitro assays. Generally when the transfer-factor preparations caused a posi¬ tive passive transfer (11 positive/ 13 attempts, 84 %), the same prepara¬ tion would cause a positive inhibition of macrophage migration (values in Table 3) in the presence of the Listeria antigen, and no inhi¬ bition in the absence of antigen. The MIF preparations, on the other hand, were able to inhibit macrophage migration in the absence of antigen. Serum gamma globulin as a control had no effect in either assay. Control or “mock” transfer factor and MIF preparations, pre¬ pared from normal cells by the same procedure used for sensitized cells, did not inhibit macrophage migration and did not cause passive transfer to recipients. In further experiments, the recipients of two different TF (TF 1 and 3) and two different MIF (MIF 2 and 4) preparations were injected IP with sterile mineral oil on the day of skin testing (Table 2). Three days later, the peritoneal exudative cells were removed and assayed in a direct migration inhibition test to determine if the passive transfer of Listeria sensitivity could be detected by in vitro tests. Cells from the 4 recipients of TF-1 and the 2 recipients of TF-3 showed positive inhibi¬ tion of macrophage migration in the presence of the Listeria antigen (34-38 %); yet, it should be noted that recipients of the TF-3 preparation LEUKOCYTE TRANSFER-FACTOR ACTIVITY 135 Table 2. Summary of in vitro and in vivo activity of leukocyte factors from Listeria- sensitized guinea pigs. Factor Inhibition of Macrophage Migration in vitro a Passive Transfer of Sensitivity in vivo Antigen absent Antigen present Skin Test Reactions Recipient MMIC TF 1 No N.D.d 12,10,8,8(4+/4) Yes, 34% TF 3 No Yes 3,4(0+/2) Yes, 38% TF 5 No Yes TF 7 No Yes TF 8 No Yes TF 9 N.D. N.D. 8(1+/1) TF 10 No Yes 8(1+/1) TF 12 No Yes 8(1+/1) TF 14 No Yes 5(1+/1) TF (>104MW)e No Yes 8,8(2+/2) TF (<104MW)e No Yes 8(1+/1) MIF 2 Yes N.D. -e,6,8,8(+/4) Yes, 21% MIF 4 Yes N.D. -,-(0+ /2) No, 4% MIF 6 Yes Yes MIF 11 Yes Yes MIF (>104MW)e Yes Yes MIF (<104MW)e No No gamma globulin No No -,-,-,-(0+/4) aPercent migration values of these factors are given in Table 3. bRecipient skin test avg. diameter in mm (number positive/number tested). CMMI = Macrophage migration inhibition of cells from passive transfer recipient, recorded as percent inhibition. dN.D. denotes not done. 'Fractions with molecular weights greater than (>) or less than (<) 10,000. f-denotes no visible reaction. were negative by skin-test standards. As shown earlier (see Table 1), the injection of antigen for skin testing would not have been responsible for the positive macrophage migration inhibition responses. Cells from recipients of the MIF preparations gave variable results. Three of four animals treated with the MIF-2 preparation became skin-test positive and cells from these animals demonstrated borderline inhibition of macrophage migration in the presence of antigen (21 %). Animals treated with the MIF-4 preparation did not become skin-test positive, and the cells of these recipients were not inhibited from migrating in the presence of antigen. Table 3 shows the average values from ten experiments for the migration of normal peritoneal exudative cells when cultured with the different TF preparations from Table 2. In the absence of antigen the crude TF had little effect on the migration of normal cells; however, in the presence of antigen and transfer factor simultaneously there was 136 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Table 3. Percent migration of normal peritoneal exudative cells incubated in vitro with leukocyte extracts from Listeria sensitized guinea pigs. Type of material Concentration of material (ug/ml) Concentration of Listeria antigen (ug/ml) 0 5 Crude TF extracts 800a 83 58 400 91 72 200 93 68 Fraction from TF 800 78 54 with MW greater 400 83 59 than 10,000b 200 93 68 Fraction from TF 125 lb 57 with MW between 60 74 66 500 and 10,000c 30 80 66 Media alone - 100 90 aMean values from separate assays on nine different preparations. bMaterial > 10,000 M.W. retained by Amicon P-10 membrane. Actual M.W. determined to be 20,000 by gel filtration. cMaterial < 10,000 M.W. passing through P-10 membrane but retained by Amicon UM05 membrane. significant reduction (values 54-72 %) compared to the cell controls. The responses appeared concentration-dependent, and the higher con¬ centrations of TF alone seemed to cause slight inhibition (83 % migra¬ tion). One TF preparation (TF-13) was fractionated into components with M.W. greater than 10,000 and into components with M.W. between 500 and 10,000. Both fractions caused inhibition of migration of macro¬ phages in the presence of antigen. The effect was more pronounced in the presence of the 500-10,000 M.W. fraction. Some non-antigen dependent inhibition was noted at the higher concentratins with the 500-10,000 M.W. material. Table 4 shows the effect of MIF and serum gamma globulin on the migration of normal peritoneal exudative cells when tested in the same manner. Crude MIF was active in the absence of antigen and, when fractionated, the activity remained in the preparation having substances with M.W. greater than 10,000. Data shown in Tables 3 and 4 suggest that fractions with M.W. greater than 10,000 may have been contami¬ nated with TF as both fractions showed an antigen-dependent inhibi¬ tion of macrophages. Gamma globulin preparations had essentially no effect on the migration of normal peritoneal exudate cells in the pres¬ ence or absence of antigen. DISCUSSION The sensitization of guinea pigs to Listeria monocytogenes offers an animal model for study of cellular immunity. Sensitization of animals LEUKOCYTE TRANSFER-FACTOR ACTIVITY 137 Table 4. Percent migration of normal peritoneal exudative cells incubated in vitro with MIF and gamma globulin. Type of material Concentration of material (ug/ml) Concentration of Listeria antigen (ug/ml) 0 5 MIF 400a 58 56 Fraction from MIF 800 61 55 with MW greater 400 75 55 than 10,000 b 200 96 66 Fraction from MIF 200 100 92 with MW between 100 105 94 500 and 10,000c Gamma globulin 400d 115 93 200 107 103 100 115 96 Media alone - 100 90 aMean values from separate assays on five different MIF preparations. bMaterial > 10,000 M.W. retained by Amicon P-10 membrane. cMaterial < 10,000 M.W. passing through P-10 membrane but retained by Amicon UM05 membrane. dMean values from separate assays on two different gamma globulin preparations. was easily established as evidenced by skin-test results done 3 weeks later. The skin tests showed typical delayed-type responses, with mononuclear cell infiltration and visible erythematous induration reaching a peak after 48 hours. Transfer factor was easily obtained from Listeria-sensitized guinea pigs, provided a conscientious effort was made to keep the cells cold and to do the processing quickly. Transfer factor preparations were effective in achieving passive transfer of sensitivity to recipient guinea pigs as measured by skin testing (11 positive/ 13 attempts, 84 % success). This success rate is comparable to that obtained with human dialyzable transfer factor (Spitler 1979). Ours, we believe, is the first report of pas¬ sive transfer with cell-free extracts using a Listeria model. Migration inhibition factor also was easily obtained by culturing Listeria- sensitive cells in the presence of the antigen. In one case, an MIF preparation (MIF-2) appeared to cause the passive transfer of anti¬ gen specificity to recipients. The positive transfer with MIF-2 may be due to the presence of antigen in the preparation, although the time interval of 48 h prior to skin testing of recipients is quite short for active sensitization to have developed. Sensitized human cells mixed with antigen may release TF into the supernatant (Lawrence 1971). This possibly could occure in the guinea pig system also. The agarose drop migration inhibition test of Harrington and Stastny (1973) was easily adapted to assay the biological activity of transfer factor and to compare the activities of TF, MIF and gamma 138 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 globulin. The agarose drop assay has several advantages over the capil¬ lary tube method. It certainly requires fewer cells and less incubation time than the method of Dunnick and Bach (1975). The agarose drop assay should be a considerable aid in studying the mode of action of purified TF preparations that may be available only in limited amounts. Ten different batches of TF were assayed by the agarose drop migra¬ tion inhibition test. Transfer factor activity was detected routinely and appeared to correlate with results obtained by skin test. The TF prepa¬ ration TF-3 was positive by the agarose drop assay, but negative by skin test standards (3-4 mm), although this diameter is double the aver¬ age value of non-sensitized, skin-test controls (Table 1). Furthermore, the histology of these reactions showed mononuclear cell infiltration exceeding that of control sites. Hence, study of the biological activity of TF on the basis of skin testing alone would be quite limiting. It is therefore most appropriate to have other measurements such as the in vitro migration inhibition test. Transfer factor preparations showed little effect on the migration of normal peritoneal exudative cells unless the specific antigen was pre¬ sent. Then, the migration was considerably reduced in a concentration- dependent way. This agrees with data obtained by the capillary tube method (Salaman 1974). However, both antigen-dependent and inde¬ pendent migration inhibition have been reported for human dialyzable leukocyte extracts (DLE). Wilson et al. (1979) report that with high amounts of DLE, a non-cytotoxic antigen-independent leukocyte migration inhibition occurs which may be accompanied by antigen- dependent specific migration inhibition, the latter activity denoting the presence of TF in DLE. The apparent specificity of the TF preparation was studied in a few experiments where normal peritoneal exudative cells were cultured in the presence of Listeria TF and either Listeria antigens or Candida albicans antigens. These studies showed inhibition of macrophage migration only when the specific Listeria antigen was present. The agarose drop assay with MIF and gamma globulin preparations showed distinctly different responses. The MIF, as expected, was capa¬ ble of strong inhibition of macrophage migration in the absence of antigen. Upon fractionation, all the MIF activity remained in the frac¬ tion above 10,000 M.W., which agrees with the 35,000-65,000 M.W.- values reported for guinea pig MIF (Bennett and Bloom 1968; Remold, et al., 1972). This fractionated MIF preparation may also contain some TF activity, as some antigen dependent inhibition was occasionally noticed. Unlike the TF fractions, the smaller molecular weight frac¬ tions from MIF preparations were devoid of activity. Likewise, gamma LEUKOCYTE TRANSFER-FACTOR ACTIVITY 139 globulins had essentially no effect, evidencing the cellular nature of immunity to Listeria. Until now, there has been concern regarding the lack of animal models with which to characterize TF. Our Listeria system would seem more than adequate, but regardless of the sensitizing antigen, the aga¬ rose drop migration inhibition test provides a simple micromethod for in vitro studies with transfer factor and other biological factors. ACKNOWLEDGEMENTS This research was supported in part by a grant from the TCU Research Foundation and a grant from Schering Corporation, Bloom¬ field, New Jersey. LITERATURE CITED Arala-Chaves, M., M. T. F. Ramos, R. Rosado, and P. Branco. 1974. Transfer factor in vitro. Int. Arch. Allergy 46:612-618. Ascher, M. S., W. J. Schneider, F. T. Valentine, and H. S. Lawrence. 1974. In vitro properties of leukocyte dialysates containing transfer factor. Proc. Nat. Acad. Sci. USA 71:1178-1182. Bennett, B., and B. R. Bloom. 1968. Reactions in vivo and in vitro produced by a sol¬ uble substance associated with delayed type hypersensitivity. Proc. Natl. Acad. Sci. USA 59:756-762. Burger, D. R., and W. S. Jeter. 1971. Cell-free passive transfer of delayed hypersensiti¬ vity to chemical in guinea pigs. Infect, and Immunity. 4:575-580. Dunnick, W., and F. H. Bach. 1975. Guinea pig transfer factor-like activity detected in vitro. Proc. Natl. Acad. Sci. USA 72:4573-4576. Dunnick, W., and F. H. Bach. 1977. Specificity and structural analysis of a guinea pig transfer factor-like activity. J. Immunol. 1 18:1944-1950. Fahey, J. L., and C. McLaughlin. 1963. Preparation of antisera specific for 6.6s y- globulins, /^Aglobulins, 7-macroglobulins, and for type I and II common 7-globulin determinants. J Immunol. 91:484-497. Fundenberg, H. H., A. S. Levin, L. E. Spitler, J. Wybran, and V. Byers. 1974. The the¬ rapeutic uses of transfer factor. Hospital Practice, Jan:95-104. Harrington, J. T., and P. Stastny. 1973. Macrophage migration from an agarose drop¬ let: Development of a micromethod for assay of delayed hypersensitivity. J Immunol. 110:752-759. Lawrence, H. S. 1971. Transfer factor and cellular immunity, p. 104-113. In R. A. Good and D. W. Fischer (Eds.), Immunobiology. Sinauer Associates, Inc., Stamford, Connecticut. Lawrence, H. S., and A. M. Pappenheimer, Jr. 1956. Transfer of delayed hypersensitiv¬ ity to diptheria toxin in man. J. Exp. Med. 104:321-336. Lowry, D. H., H. J. Rosenbrough, and R. J. Randall. 1951. Protein measurement with the folin phenol reagent. J. Biol. Chem. 193:264-275. Paquet, A., Jr., E. D. Rael, and G. B. Olson. 1975. Cellular immunity in Listeria sen¬ sitized young chickens: assayed by an agarose drop macrophage migration inhibition test. Microbios 14:175-182. 140 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Petersen, E. A., and C. H. Kirkpatrick. 1979. Nature and analysis of transfer factor, p. 216-227. In H. Friedman (Ed.), Subcellular factors in immunity. Annals of the New York Academy of Sciences, vol. 332. Remold, H. G., R. A. David, and J. R. David. 1972. Characterization of migration inhibition factor from lymphocytes stimulated with Concanavalin A. J. Immunol. 109:578-586. Salaman, M. R. 1974. Studies on the transfer factor of delay hypersensitivity. Immu¬ nology 26:1069-1080. Spitler, L. E. 1979. Transfer factor in immunodeficiency diseases, p. 228-235. In H. Friedman (Ed.), Subcellular factors in immunity. Annals of the New York Academy of Science, Vol. 332. Wilson, G. B., H. H. Fundenberg, and G. V. Paddock. 1979. Detection of a “dialyzable transfer factor” in vitro: Structural and chemical characterization of the activity spe¬ cific for tuberculin, p. 579-590. In H. Friedman (Ed.), Subcellular actors in immunity. Annals of the New York Academy of Sciences, vol. 332. VARIATION IN TRANSPLANTABLE TUMOR GROWTH-PARAMETERS CAN BE REDUCED 12 3 by DAVID G. MORRISON ab4, MARY PAT MOYERab, JAY C. DANIEL", WAID ROGERS", and REX C. MOYERa aT h or man Cancer Research Laboratory Trinity University, San Antonio, TX 78284 b Department of Surgery, The University of Texas Health Science Center, San Antonio, TX 78284 ABSTRACT The conventional procedure for transplanting rodent tumors was improved by contin¬ uous stirring of the tumor brei or ascites tumor cells with a magnetic stirrer at 500-800 rpm and 4 C, then vigorously shaking the suspension-filled syringe immediately prior to injection. In each case, these extra steps produced better results than the standard proce¬ dure without continuous stirring of the tumor brei. The standard and modified proce¬ dures were compared in four different transplantable tumor/mouse systems — C3H mam¬ mary adenocarcinoma (C3HMA) in C3H/HeJ mice, Lynd A/J mammary adenocarcinoma in A/J mice, P388 lymphocytic leukemia in CDFi mice. The modifica¬ tion required neither enzymatic treatments nor significantly more time and effort to yield reproducible results with regard to the uniformity of the resulting tumor growth parame¬ ters (survival and tumor growth). Key Words: transplantable tumors, mammary adenocar¬ cinoma, transplantation techniques. INTRODUCTION Transplantable rodent tumors are used in many aspects of cancer research, including the screening of potential cancer chemotherapeutic agents. Statistically acceptable ranges of host survival time and solid- turmor growth-parameters have been well defined (Goldin et al. 1977). This paper describes a simple modificaiton of a widely used tumor transplantation technique (Goldin et al. 1977) that results in more uni¬ form tumor growth-parameters. The few extra steps significantly reduce the amount of variability in host survival time and in solid tumor 'This work was supported by the Thorman Trust and The Robert J. Kleberg and Helen C. Kleberg Foundation of Trinity University and by the Department of Surgery of The University of Texas Health Science Center, San Antonio, TX 78284. The technical assistance of Mr. Gay Morrison, Jr., Miss Denise Miller, and Miss Leticia Soria is grate¬ fully acknowledged. 2Address correspondence to Dr. Rex C. Moyer, Thorman Cancer Research Laboratory, Trinity Univeristy, 715 Stadium Drive, San Antonio, TX 78284. 3 Lynd A/J mammary adenocarcinoma designated in memory of our deceased colleague, Dr. Frederick T. Lynd. 4Present Address: Depart, of Cell Biology, Baylor College of Medicine, Houston, TX 77030. The Texas Journal of Science, Vol. XXXV, No. 2, July 1983 142 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 growth; therefore, the number of animals required to achieve statisti¬ cally reliable results can be reduced. MATERIALS AND METHODS Solid and ascites tumors were harvested and prepared for injection essentially in accordance with the conventional method as described by Goldin et al. (1977). The only differences between the conventional method and the technique used in this study are that suspensions of tumor brei or ascites tumor cells were stirred continuously during preparation and loading of the syringes, each of which was vigorously agitated by hand immediately prior to injection to prevent clumps of tumor cells from plugging the needle. For injecting mice, we used 23 or smaller gauge needles to avoid creating large wounds that might result in tumor contamination. A magnetic stirrer and magnetic stir bar (Nalgene 6600-035), which minimizes air bubble formation, were used to stir the solutions at 500 to 800 rpm. The sterile vessel containing the diluted brei or ascites fluid was maintained at 4 C during preparation of transplant material and loading of syringes in a biohazard hood. In all experiments reported, the animals were injected with tumor mate¬ rial from the same donor, and samples of tumor preparation were inoculated into brain-heart infusion, tryptose phosphate, and thioglyc- ollate broths to check sterility. One beaker of tumor material was kept at 4 C as described and the other beaker of tumor material was kept at 4 C and only gently agitated by hand, equivalent to 20 to 30 rpm, just prior to loading each syringe. Animals were injected either subcutaneously or intraperitoneally with 0.05 grams harvested tumor brei or 106 ascites tumor cells. The C3HMA mammary adenocarcinoma (obtained from National Cancer Institute) was studied in female C3H/HeJ mice weighing 20-22 grams (Jackson Lab, Bar Harbor, Maine). The Lynd3 A/J solid and ascites tumors were derived from a spontaneous mammary adenocarcinoma of an eight-week-old female A/J mouse in the laboratory of W. Rogers. The Lynd A/J solid and ascites tumors were tested in female A/J mice (Jackson Lab, Bar Harbor, Maine) weighing 20-22 grams. The P388 lymphocytic leukemia (obtained from EG 8c G Mason Research Insti¬ tute, Worcester, Massachusetts) was studied in female CDFi mice (BALB/c X DBA/2, Fp Lab Animal Supply Co., Indianapolis, Indiana) weighing 20-22 grams. The J774A. 1 reticulum cell sarcoma (obtained from Mr. Bradly Fox, Cell Distribution Center, Salk Institute, San Diego, California) was studied in male and female CDFi mice (Lab Animal Supply Co., Indianapolis, Indiana) weighing 20-22 grams. Animals were observed daily. Solid tumor diameters were measured every three days with a Vernier caliper, and the day of death was Table 1. Reduction of variation in survival times (days). REDUCING VARIATION IN TUMOR TRANSPLANTS 143 QJ ©O ° CTs S22 ^ eo O « if) ^ +| ^ ^ w o (M ^ o N CM CM MO CM id GO ^ o T3 CM c3 © O 0 13 o , , CM C 2 iO -H — CM CM c7i 1 o o 6 ’S H 2 o> © CM -|-| iO — , — ^ CM CM ^ ^ CM CM CM S +1 O •5 qj +i c ^ a c -2 JJj be c3 os -a 13 c 'C ^ jy ,2 & § § S > c o QJ QJ N * 13 G r- es G QJ --1 6 ~ js£ QJ o c 1-, QJ O T3 fi? -H 8 •3 o c ^ 2 S " © 3! M X) 144 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Table 2. Reduction of variation in solid-tumor growth-parameters.3 Tumor Lynd A/J C3HMA Method Standard Modified Standard Modified Number of mice/group 11 12 25 25 Mean ± s.e.m. 3.4 ± 0.5b 4.9 ± 0.2b 6.3 ± 0.7C 7.0 ± o.r Median 3.2 5.2 7.5 7.0 Mode NAd NAd 0(5) 7(18) Range 0.8 - 6.1 2.9 - 6.0 0.0 - 12.0 6.0 -8.0 Variance Variance ratio 2.8 0.8 13.3 0.30 for F test Level of significance of difference between variances Calculated sample size6 mice/group for future experiments Power of sample size test 3.5 p < 0.50 27 8 p= 0.001 44.33 p < 0.005 32 3 p = 0.001 aThe same conclusions were reached when the length and width were put into formulas used to calculate volume or estimate mass. bTumor area (cm2) based on greatest perpendicular diameters 15 days after injection; mean ± s.e.m. (standard error of mean). cGreatest diameter (mm) 10 days after injection; mean ± s.e.m. dNot applicable. 'These are the “d” values used in the formula to calculate the number of mice needed per group in future experiments to obtain reliable results at the powers indicated. recorded. Statistical analyses of experiments were performed according to Daniel (1977) to determine the number of mice per group that will probably provide statistically reliable data in the future according to this formula: n = z2’o2/d2 where n = expected number of animals needed in future experiments; z = desired level of confidence from standard normal table; o2 = variance in present experiment; and d = one-half of the width of the acceptable confidence interval selected by investigator. We used d = 2 days for all projections relative to survival-time stu¬ dies (Table 1) and d — 1. cm and 0.2 cm for the Lynd A/J and C3HMA projections (respectively) given in Table 2. RESULTS AND DISCUSSION The modified transplantation method effectively reduced the varia¬ tion in survival times of animals injected with ascites or solid tumors (Table 1), when compared with the standard method. Favorable results REDUCING VARIATION IN TUMOR TRANSPLANTS 145 Table 3. Calculation of test power and sample size for future experiments using modified method. Number Animals Injected3 Number Control Animals Mean ± s.e.m.b Median Mode Range Powerc Estimatedd Sample Size 44 5 13.2 + 0.1 13 13(4) 13-14 0.05 5 68 6 13.3 + 0.1 13 13(4) 13-14 0.01 3 83 5 13.4+0.2 13 13(4) 13-15 0.05 4 83 7 13.7 + 0.1 14 None 12-15 0.05 3 a All mice were injected i.p. with 106 viable J774A.1 reticulum-cell-sarcoma cells. Controls were chosen at random. bData collected from four different investigators using the modified technique. The means in this column represent the mean survival times of the control animals selected at ran¬ dom from their respective separate experiments. Tndicates the probability that this test will reject a false null hypothesis (Daniel 1977). d Number of mice necessary for future experiments to achieve reliable results at the power calculated (Daniel 1977). also were obtained when tumor area or diameter was used to compare the standard and modified methods (Table 2). For both the Lynd A/J and C3HMA solid tumor systems, the range of sizes was narrower and the variance much less, for tumors injected by the modified method. The numbers of mice predicted as being necessary to achieve statisti¬ cally reliable results at the P = 0.001 level in future experiments using the modified method were markedly reduced. For the modified method fewer animals were predicted as being necessary for future experiments using the Lynd A/J and C3HMA solid tumors. Follow-up experiments using these tumor systems and several others (Table 3) demonstrated that these predictions were accurate even when the technique was used by three other investigators. The results shown in Tables 1, 2 and 3 (as well as those obtained in other studies where this method has been employed: Morrison et al. 1980, 1982) demonstrate that continuous stirring of the tumor cell sus¬ pension during the loading of syringes significantly reduces variability in host survival time and tumor growth. The viability of the cells treated with the modified technique was not reduced below that obtained by the standard technique as determined by trypan blue dye exclusion and tumor growth rates. Other advantages, with respect to growth variability and tumor heterogeneity (Fidler and Hart 1981), are that there is no selection for a specific tumor region and no need for proteolytic enzymes. Moreover, the demonstration that mean tumor size was not significantly different in separate experiments, suggests that “investigator-induced” variation can be reduced. Implementation of our simple modification has the benefit of greatly decreasing the number of animals required to obtain reliable data. This 146 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 should be especially important to investigators conducting research with limited budgets and also should allow more consistent and relia¬ ble data to be obtained on novel anticancer drugs that are available only in small quantity. Use of this technique and other procedures that reduce variability in tumor growth parameters will allow one to recog¬ nize atypical test results and abnormally slow tumor growth earlier in the course of an experiment. LITERATURE CITED Daniel, W. W. 1977. Introductory statistics with applications. Houghton Mifflin Co., Boston, p. 122-125, 141-143, 272-275. Fidler, I. J., and I. R. Hart. 1981. Biological and experimental consequences of the zonal composition of solid tumors. Cane. Res. 41:3266-3267. Goldin, A., J. M. Venditti, and S. K. Carter. 1977. Screening at the National Cancer Institute, p. 37-48. In J. F. Saunders and S. K. Carter (Eds.), Methods of development of new anticancer drugs. National Cancer Institute Monographs, vol. 45, NIH, Bethesda, MD. Morrison, D. G., F. T. Lynd, G. Morrison, D. R. Martel, K. A. Koester, S.C. Frink, M. M. MacDonell, J. W. G. LaValley, M. P. Moyer, W. Rogers, and R. C. Moyer. 1980. Host survival and tumor metastastes as affected by vitamin A, vitamin C, and a corticosteroid. Proc. 11th Internat. Congr. Chemotherapy: Current chemotherapy and infectious diseases, vol. 2: 1501-1503. Morrison, D. G., M. P. Moyer, F. T. Lynd, W. Rogers, and R. C. Moyer. 1982. Suscep¬ tibility of BALB/c GnDu mice to transplantable tumors, in vitro transformed cells, BK and SV40 viruses, and chemical carcinogens. Oncology 39:228-233. PALEOENVIRONMENTAL SIGNIFICANCE OF A NONMARINE PLEISTOCENE MOLLUSCAN FAUNA FROM SOUTHERN TEXAS by RAYMOND W. NECK Texas Parks and Wildlife Department 4200 Smith School Road Austin , TX 78744 ABSTRACT Examination of a non-marine molluscan fauna from the Beaumont Formation in Kle¬ berg County, Texas, suggests that during Sangamon time a substantial water course existed in an area that presently has only intermittent drainages. During Sangamon time this general area received either greater effective precipitation that at present or inflow of water from more mesic areas. INTRODUCTION Recent excavation at a Pleistocene mammoth site in south Texas has produced a noteworthy non-marine molluscan fauna. Species recovered include freshwater mussels in addition to terrestrial and freshwater snails. The purpose of this report is twofold: 1) to provide paleoenvir- onmental interpretation of the fossil locality, and 2) to interpret the significance of this locality in relation to the present unionid clam fauna. Few records of non-marine invertebrates of Pleistocene age have been reported from south Texas. Trowbridge (1932:219) reported several spe¬ cies of nonmarine molluscs from lower Rio Grande terraces. Richards (in Price 1958) reported a list of gastropods from the Ingleside Site; only modern species characteristic of shallow freshwater environments were recovered. Hubricht (1962) reported a fossil molluscan fauna from silt of Palo Blanco Creek in Brooks County, about 40 kilometers west of the Taylor Ranch Site. The terrestrial and aquatic gastropod fauna at Palo Blanco Creek consisted of species with both boreal and austral affinities indicating either an “ecologically incompatible” fauna (Hol¬ man 1976) or quite possibly a mixing of discrete depositional units. Neck (in Suhm 1978) reported only extant species characteristic of “reduced water currents and varying water quality” from the La Paloma Mammoth Site (8,000-10,000 years B.P.). Richards (1939) des¬ cribed several fossil localities in southern Texas but was concerned The Texas Journal of Science, Vol. XXXV, No. 2, July 1983 148 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Figure 1. Location of Taylor Ranch site, Kleberg Co., Texas. more with regional geological phenomena than with local environmen¬ tal reconstruction. Several Pleistocene fossil faunas are known from south central Texas. Nonmarine fossils of the Berclair Terrace (believed to be of Sangamon age) from Bee and Goliad Counties include species present in the area today (Conkin and Conkin 1962; Sellards 1940). Somewhat older (Plio¬ cene) fossils from the Goliad Formation of DeWitt County do not represent living species although they may be immediately ancestral to present day forms (Marshall 1929). FOSSIL LOCALITY The Taylor Ranch Mammoth Site is located on a small tributary of Jarachinal Creek about three kilometers southeast of Ricardo, Kleberg County, Texas (Fig. 1). The skeleton of a mammoth, approximately fifty percent complete, has been excavated by Suhm (1980). Lack of dentition has prevented specific identification of the mammoth, but it is believed to be Mamrnuthus imperator. The mammoth appears to have died in a stream course. Although the bones have been somewhat disarticulated, probably by scavengers and/or moving water, rapid bur¬ ial is suggested by partially natural orientation of the skeletal elements. Parts of the skeleton have been worn away by modern erosional events. PLEISTOCENE MOLLUSCS FROM SOUTH TEXAS 149 The fossils occur in deposits identified as belonging to the Beaumont Formation (Late Pleistocene) by Suhm (1980). The age of this forma¬ tion in south Texas has not been well established. Brown et al. (1977) pointed out the difficulty in differentiating between the Sangamon Interglacial and the Peorian (an interglacial interlude during Mid- Wisconsin time). However, the Taylor Ranch fauna is probably San¬ gamon, given that the more recent dates from the Beaumont of Texas are non-typical (Aronow 1971). The Sangamon Interglacial Stage has been dated approximately 125,000 B.P. to 250,000 B.P. while the Peo¬ rian Interglacial Stage has been dated 60,000 B.P. to 80,000 B.P. (Ber¬ nard and LeBlanc 1965). The Beaumont is lithologically somewhat variable in this portion of south Texas (Plummer 1932; Price 1933; Aronow 1971). The following description of the Taylor Ranch site is taken from Suhm (1980). Most sediment in the exposed section consists of sandy clays or clayey sands with gypsum granules. Modern bioturbation of upper layers due to burrowing activity by fiddler crabs has occurred. The bone/shell level also contains several lenses (up to 5 cm thick) of siliceous and calcare¬ ous fragments of granule-to-pebble size. The bone/shell bed is approx¬ imately 30 cm below the top of the floodplain deposit and 90 cm below the top of the modern soil. Above the bone/shell bed level is a layer of clayey sand with well-sorted, very fine quartz grains. An undated paleo- sol topped by modern wind-blown sand occurs at the top of the section. The present environment is cattle-impacted grassland now dominated by weedy brush species. Most abundant are honey mesquite ( Prosopis glandulosa ), prickly pear ( Opuntia lindheimeri), tasajillo ( Opuntia lep- tocaulis) and lotebush (Ziziphus obtusifolia ). Jarachinal Creek is an intermittent saline stream (see Russell and Wood 1976). No aquatic molluscs have been located in Jarachinal Creek during an ongoing sur¬ vey of this portion of southern Texas. No survey of modern terrestrial gastropods has covered the area of the fossil site. MOLLUSCAN FAUNA Associated with the mammoth bones were a number of individuals of several molluscan species. Molluscan remains were recovered by R. W. Suhm from materials immediately adjacent to the mammoth skeleton. Also, shells were visually detected in nearby sediments and collected by the author. No microfossil remains were recovered from the screened material, probably due to the coarseness of screen utilized. Discussed below are the species present and descriptions of the individual fossils. Bivalvia: Eulamellibranchiata: Unionacea: Unionidae U niomerus tetralasmus (Say, 1831), 4 specimens. This clam today is found from Lake Erie through the Mississippi River drainage eastward 150 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 to the Coosa River, Alabama, and southwestward into Northern Mex¬ ico. The taxonomic situation within the genus Uniomerus is not yet clear. Johnson (1970) and Burch (1973) place all members in a single variable taxon, tetralasmus. Frierson (1903) separates two southern taxa, tetralasmus and declivus Say, 1832, stating that tetralasmus occurs in small streams and ponds while declivus is found in rivers; exceptions to this rule were considered erroneously curated specimens. Morrison (1977) also separates the above forms as species and included Texas in the range of both forms. Atlantic slope forms are classified as carolini- anus Bose, 1801. Given the tendency for unionid clams to express vari¬ able height and width indices under different environmental conditions (Isley 1914; Coker et al. 1921), these forms could be ecomorphs respond¬ ing to differential environmental conditions. Lack of preserved material with posterior margin of the shell intact precludes definitive assignment of tetralasmus /declivus classification to the Taylor Ranch Unionmerus. However, the lack of shell malforma¬ tions or major growth ridges indicates permanent water (or nearly so) and lack of severe winters. One of the fossil shells exhibits minor growth ridges similar to those found on contemporary shells from permanent water. Intermittent ponds tend to produce “many variations and malformed specimens” (Frierson 1903), a circumstance which I also have observed. Uniomerus is able to withstand periods of dessication of its habitat (Strecker 1908; Van der Schalie 1940). Uniomerus can survive for more than six months in a non-aqueous environment under ambient laboratory conditions (Neck unpub. data). Fossil remains of Uniomerus from the Taylor Ranch site consist of internal molds or “steinkerns” of variable completeness with associated original shell material. The remnant shell material has experienced dis¬ solution to the extent that there has been separation of individual growth layers representing discrete active periods of secretion by mantle cells. The curved umbonal ridges typical of Uniomerus are detectable on several of the shells. No periostracum remains have been identified. The internal molds consist of calichified concretions containing sand, silt, clay and small pebbles which have become moderately indurated. These remains represent medium-to-large (full-sized) adult individuals. Living specimens of this size in the area of the Taylor Ranch site occur only in stock tanks; individuals from the various creeks are much smaller. Gastropoda: Prosobranchiata: Archeogastropoda: Helicinidae Helicina orbiculata (Say, 1818), 1 specimen. This snail is the only terrestrial operculate present today in south central North America. Geographical range includes the southeastern United States from Geor¬ gia and Oklahoma south to Texas and northeastern Mexico. A variety with a heavy apertural lip has been known as the variety or subspecies PLEISTOCENE MOLLUSCS FROM SOUTH TEXAS 151 tropica Pfeiffer, 1852. The individual recovered from the Taylor Ranch Mammoth Site (width 8.0 mm; height 7.0 mm) exhibits the expanded lip of tropica. Pilsbry (1948:1084) stated that although tropica reached its “fullest development” in the limestone area of central Texas, this form was absent in calcareous areas of Florida and Alabama. Pilsbry (1948:1084) concluded that “the modification is correlated with geogra¬ phical range, therefore of subspecific significance.” Considering that tropica is known from Tennessee and well-drained, acid sandy soils in East Texas, a phenotypic response to increased xeric conditions is likely (Fullington and Pratt 1974). This species today is found typically in woodlands and savannahs. Gastropoda: Pulmonata: Basommatophora: Planorbidae Helisoma trivolvis (Say, 1816), 1 specimen. One large-sized individual (greatest diameter = 15.4 mm) of this aquatic snail was recovered at the Taylor Ranch site. H. trivolvis occurs today over a large part of North America from the southern plains and Gulf coast to New Mexico and south into Mexico. In Texas, this species has been found most com¬ monly in shallow, slow-moving, usually permanent water, although it does occur in large floodplain pools. Gastropoda: Pulmonata: Stylommatophora: Bulimulidae Rabdotus alternatus alternatus (Say, 1830), 2 specimen. The south Texas tree snail today is found throughout the south Texas plains from the Big Bend area to Corpus Christi (just north of the fossil locality) and south into northeastern Mexico. One of the fossil specimens appears to be an adult (only body whorl remaining; original height, 15-17 mm), although deposition of calcium carbonate as “apertural ridges” (MacMillan 1944) during periods of aestivation causes confu¬ sion in interpretation of maturity for this species. One juvenile speci¬ men (height, 6.2 mm) was also recovered. R. a. alternatus is known from variable habitats but generally occurs where there is significant woody vegetation. The vegetational character may vary from chaparral to open woodland. R. a. alternatus is charac¬ teristic of the Tamaulipan Biotic Province (see Dice 1943; Blair 1950, 1952); its presence indicates warm temperate or subtropical climatic conditions. PALEOENVIRONMENTAL INTERPRETATION The fossil molluscan assemblage recovered from the Taylor Ranch site suggests permanent or semi-permanent, slow-moving, shallow, non-brackish water with open woodland or chaparral present upstream or surrounding the actual site. The depositional environment of the Taylor Ranch site’s fossil assemblage could have included periodic flooding, as suggested by Suhm (1980). A floodplain pool or backwater 152 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 slough is the most likely environment. Flowing water may have carried the snails to the site after they died. However, the clams lived very close to the place of deposition, because their valves were still articulated and closed when they were recovered. In comparison to present conditions the molluscan fauna of the Tay¬ lor Ranch site indicates one of two alternatives: 1) higher effective pre¬ cipitation or 2) inflow of a river from a more mesic region. Increased effective precipitation is produced by increased precipitation and/or decreased evaporation; alteration of seasonal distribution of precipita¬ tion may or may not be involved. The putative river with water origi¬ nating from more mesic climes could be the Nueces River or one of several buried Pleistocene river valleys (associated with the Palo Blanco drainage to the south) known from the area. BIOGEOGRAPHICAL SIGNIFICANCE The Taylor Ranch site’s, molluscan fauna has biogeographical sig¬ nificance because of the rarity of fossil sites in southern Texas. All of the molluscan species present in the Taylor Ranch fauna occur in the general area today. An ongoing survey (Neck unpub.) has revealed populations of Uniomerus south of the Nueces River in the drainage of Baffin Bay (which includes Jarachinal Creek), but these populations probably represent introductions. Uniomerus is known from the Nue¬ ces River (Taylor unpub.) but is not known from Lake Corpus Christi (Murray 1979). To the south, Uniomerus is known from the Rio Grande system (Strecker 1931). Age of origin of Uniomerus in south Texas is unknown but probably quite remote, as much of south Texas was probably suitable habitat for Uniomerus during the glacial max¬ ima of the Wisconsin. Trowbridge (1932:219) reported Uniomerus from undated Pleistocene terraces of the lower Rio Grande. Prior to the Altithermal (a warm, dry episode of the Middle Holocene), significant water was available in the presently semi-arid Llano Mesteno southwest of the Taylor Ranch site (Suhm 1978). Quite possibly, Uniomerus existed in the Baffin Bay drainages until intense dessication during the Altithermal. The Taylor Ranch Mammoth Site is peripheral or close to the Sangamon-age deposits of the migratory delta of the Nueces River (Aronow 1971). A Late Pleistocene route of the lower Nueces River to the Baffin Bay area was postulated by Bailey (1926). This hypothesis has not been widely accepted but is compatible with conclusions reached by Aronow (1971) concerning the Beaumont Nueces River del¬ taic deposits. Behrens (1963) reported the existence of several buried river valleys of undifferentiated Pleistocene age. One or all of these river valleys are channels of the Palo Blanco River, a broad meandering river which drained a large area of south Texas during the Wisconsin PLEISTOCENE MOLLUSCS FROM SOUTH TEXAS 153 (now without permanent water due to subsequent aridity); substantial water flow existed in this now intermittent creek as late as 8,000-10,000 years B.P. (Suhm 1978). The Taylor Ranch fauna may have lived in a floodplain pool along a water course; perhaps the Palo Blanco River existed during the Sangamon. A number of marine molluscan Pleistocene faunas has been reported from the middle and upper portions of the Gulf coast of Texas. Pampe (1971) reported a Late Pleistocene (Sangamon or Early Wisconsin) mol¬ luscan fauna consisting of contemporary species on the Texas coast. Interglacial faunas tend to be similar or identical to present-day com¬ munities (Richards 1939; Parker 1959). Indeed, many of the present-day marine molluscs appear to have inhabited Texas waters since late Ter¬ tiary time (Parker 1959). The temporal dynamics of the freshwater mol¬ luscs of coastal Texas will remain unknown until additional intergla¬ cial and glacial period faunas have been discovered and investigated. ACKNOWLEDGEMENTS I thank Saul Aronow for constructive criticism of an early draft of this communication. Molluscan fossils described herein were kindly supplied by R. W. Suhm. T. B. Samsel III drafted Figure 1. LITERATURE CITED Aronow, S. 1971. Nueces River delta plain of the Pleistocene Beaumont Formation, Corpus Christi region. Texas. Bull. Amer. Assoc. Petrol. Geol. 55:1231-1248. Bailey, T. L. 1926. The Gueydan, a new middle Tertiary formation from the south¬ western coastal plain of Texas. Bull. Univ. Texas 2645. 187 p. Behrens, E. W. 1963. Buried Pleistocene river valleys in Aransas and Baffin Bays, Texas. Publ. Mar. Sci. Inst. Univ. Texas 9:7-13. Bernard, H. A., and R. J. LeBlanc. 1965. Resume of the Quaternary geology of the northwestern Gulf of Mexico province, p. 137-185. In H. E. Wright, Jr. and D. G. Frey (Eds.), The Quaternary of the United States, Princeton Univ. Press, Princeton, N.J. Blair, W. F. 1950. The biotic regions of Texas. Tex. J. Sci. 2:93-1 17. Blair, W. F. 1952. Mammals of the Tamaulipan biotic province in Texas. Tex. J. Sci. 4:230-250. Brown, L. F. Jr., J. H. McGowen, T. J. Evans, C. G. Groat, and W. L. Fisher. 1977. Environmental geologic atlas of the Texas coastal zone-Kingsville area. Univ. Tex. Austin, Bur. Econ. Geol. 131 p. Burch, J. B. 1973. Freshwater unionacean clams (Mollusca: Pelecypoda) of North America. U.S. Environ. Protect. Agency, Ident. Manual 11. 176 p. Coker, R. E., A. F. Shira, H. W. Clark, and A. D. Howard. 1921. Natural history and propagation of freshwater mussels. U.S. Fish. Bull. 37:77-181. Conkin, J. E., and B. M. Conkin. 1962. Pleistocene Berclair Terrace of Medio Creek, Bee County, Texas. Bull. Amer. Assoc. Petrol. Geol. 46:344-353. Dice, L. R. 1943. The biotic provinces of North America. Univ. Mich. Press, Ann Arbor. 78 p. Frierson, L. S. 1903. The specific value of Unio declivus, Say. Nautilus 17:49-51. 154 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Fullington, R. W., and W. L. Pratt, Jr. 1974. The Helicinidae, Carychiidae, Achatini- dae, Bradybaenidae, Bulimulidae, Cionellidae, Haplotrematidae, Helicidae, Oreoheli- cidae, Spiraxidae, Streptaxidae, Strobilopsidae, Thysanophoridae, Vallonidae (Gas¬ tropoda) in Texas. Bull. Dallas Mus. Nat. Hist. 1(3). 48 p. Holman, J. A. 1976. Paleoclimatic implications of “ecologically incompatible’’ herpe- tological species (Late Pleistocene: southeastern United States). Herpetological 32:290- 295. Hubricht, L. 1962. Land snails from the Pleistocene of southern Texas. Sterkiana 7:1- 3. Isley, F. B. 1914. Experimental study of the growth and migration of freshwater mus¬ sels. Rpt. U.S. Comm. Fish. 1913, App. 3. 24 p. Johnson, R.I. 1970. The systematics and zoogeography of the Unionidae (Mollusca: Bivalvia) of the southern Atlantic Slope Region. Bull. Mus. Comp. Zool. 140:263-450. MacMillan, G. K. 1944. The “apertural ridge” in Bulimulus. Nautilus 57:98-99. Marshall, W. B. 1929. New fossil land and fresh-water mollusks from the Reynosa Formation of Texas. Proc. U.S. Nat. Mus. 76:1-6. Morrison, J. P. E. 1977. Species of the genus Uniomerus. Bull. Amer. Malacol. Union 1976:10-11. Murray, H. D. 1979. Freshwater mussels of Lake Corpus Christi, Texas. Bull. Amer. Malacol. Union 1978:5-6. Pampe, W. R. 1971. A new Pleistocene marine fossil locality in Chambers County, Texas. Trans. Gulf Coast Assoc. Geol. Soc. 21:395-410. Parker, R. H. 1959. Macro-invertebrate assemblages of Central Texas coastal bays and Laguna Madre. Bull. Amer. Assoc. Petrol. Geol. 43:2100-2166. Pilsbry, H.A. 1948. Land mollusca of North America (north of Mexico). Acad. Nat. Sci. Phil. Monog. 3, vol. II, pt. 2. Plummer, F. B. 1932. Cenozoic systems in Texas, p. 519-818. In E. H. Sellards, W. S. Adkins and F. B. Plummer (Eds.), The geology of Texas. Bull. Univ. Texas 3232, Austin, TX. Price, W. A. 1933. Lissie Formation and Beaumont Clay in south Texas. Bull. Amer. Assoc. Petrol. Geol. 18:948-959. Price, W. A. 1958. Sedimentology and Quaternary geomorphology of South Texas. Trans. Gulf Coast Assoc. Geol. Soc. 8:41-75. Richards, H. G. 1939. Marine Pleistocene of Texas. Bull. Geol. Soc. Amer. 50:1885- 1898. Russel, J. L., and C. E. Wood. 1976. The effects of Tropical Storm Fern (September, 1971) on Baffin Bay, Texas. Texas A8cl Univ. Stud. 9:133-145. Sellards, E. H. 1940. Pleistocene artifacts and associated fossils from Bee County, Texas. Bull. Geol. Soc. Amer. 51:1627-1664. Strecker, J. K. 1908. The Mollusca of McLennan County, Texas. Nautilus 22:63-67. Strecker, J. K. 1931. The distribution of the naiades of pearly freshwater mussels of Texas. Baylor Univ. Spec. Bull. 2. 69 p. Suhm, R. W. 1978. Preliminary investigation of the La Paloma Mammoth Site (Late Pleistocene), Kenedy County, Texas. Texas A8cl Univ. Stud. 11:13-35. Suhm, R. W. 1980. Preliminary investigation of the Taylor Ranch Mammoth Site (Late Pleistocene), Kleberg County, Texas, p 46-51. In J. L. Russel and R. W. Suhm (Eds.), Geology of clay dunes, Baffin Bay and the South Texas Sand Sheet. (Geologi¬ cal field trip, Texas Acad. Sci. Meeting, Corpus Christi, Texas). Texas A8cl Univ., Kingsville. 86 p. Trowbridge, A. C. 1932. The Tertiary and Quaternary geology of the lower Rio Grande region, Texas. Bull. U.S. Geol. Surv. 837. 260 p. van der Schalie, H. 1940. Aestivation of freshwater mussels. Nautilus 53:137-138. CALORIC VALUE OF THE LIVER FLUKE, FASCIOLA HEPATICA by JEREMY M. JAY and NORMAN O. DRONEN Department of Biology Texas AirM University College Station, TX 77843 ABSTRACT Adult liver flukes ( Fasciola hepatica) from infected cattle yielded an average of 5.056 kcal/g dry weight, when combusted in a bomb calorimeter. As part of a continuing investigation into the bioenergetics of Fasci¬ ola hepatica, caloric values for whole, adult flukes were determined in an oxygen bomb calorimeter. The flukes were removed alive from the livers of infected cattle, rinsed in distilled water and air dried at 60 C for 24 hours. Caloric values were determined in a Parr oxygen bomb calorimeter with a semi-micro adapter, using standard calorimetric techniques. Samples were desiccated before weighing, and to each was added a known amount of benzoic acid to increase burning efficiency. Finally, the mixture was pelleted to prevent loss during the initial stages of combustion. Nineteen flukes were bombed individually. Mean caloric yield ± the 95% confidence limit (to.os+ is * s/\/n) was 5.056 + 0.094 kcal/g dry weight. Calow and Jennings (1974) reported corresponding values of 5.205 ± 0.201 for F. hepatica they assayed. Our mean value is within 3% of theirs, but our confidence interval is less than half theirs. The latter difference may reflect the fact that our sample size was nearly double that of Calow and Jennings (1974). The average dry weight of our flukes was 0.0255 g. Thus, the average energy content per fluke was 0.1289 kcal. We thank Dr. Rural R. Bell and Les Dees, Department of Veterinary Microbiology and Parasitology, Texas A&M University, for their assist¬ ance in supplying specimens. LITERATURE CITED Calow, P. and J. B. Jennings. 1974. Calorific values in the phylum Platyhelminthes: The relationship between potential energy, mode of life and the evolution of entopar- asites. Biol. Bull. 147:81-94. The Texas Journal of Science, Vol. XXXV, No. 2, July 1983 STATUS OF BIGHORN SHEEP IN TEXAS by BRUCE D. LEOPOLD and PAUL R. KRAUSMAN Division of Wildlife , Fisheries and Recreation Resources School of Renewable Natural Resources University of Arizona Tucson, AZ 85721 ABSTRACT Native bighorn sheep ( Ovis canadensis) last were observed in Texas in 1960. Attempts to reintroduce the bighorn to Texas have been largely unsuccessful, owing to predation and disease problems; however, escapees from the reintroduction experiment may account for infrequent sightings of bighorn sheep in Big Bend National Park between 1970 and 1980. As human activities increased in west Texas, populations of bighorn sheep ( Ovis canadensis) decreased (Davis and Taylor 1939; Carson 1941). Native bighorn sheep were last observed in Texas in Victoria Canyon, Culberson and Hudspeth Cos., in 1960 (Texas Parks and Wildlife Department 1980). Through cooperation of the U.S. Fish and Wildlife Service, the Boone and Crockett Club, the Wildlife Manage¬ ment Institute, the Arizona Game and Fish Department, and the Texas Parks and Wildlife Department, an effort began in the late 1950’s to reintroduce desert bighorn sheep to Texas. The reintroduction program has been discussed in detail by the Texas Parks and Wildlife Depart¬ ment (1980), Kilpatrick (1980, 1981), and Winkler (1981). The present paper provides a brief history of the reintroduction effort and ends with a consideration of the bighorn sheep’s present status in Texas. Beginning in 1957, sheep were trapped on the Kofa Game Range in southwestern Arizona and transplanted to a 173 ha enclosure on the Black Gap Wildlife Management Area (BGWMA), Brewster Co., Texas. Sixteen sheep had been transplanted by 1959, but by December of that year only four rams and five ewes remained. The others had died from unknown causes (Texas Parks and Wildlife Department 1980). From 1960 to 1971 the herd increased from the nine remaining sheep to an estimated 68 sheep. Twenty bighorn sheep were released from the enclosure into BGWMA in January 1971 (Kilpatrick 1980; Texas Parks and Wildlife Department 1980; Kilpatrick 1981). These 20 animals either fell prey to mountain lions ( Felis concolor) or moved off the area (Kilpatrick 1980, 1981). Attempts to locate survivors have been largely unsuccessful. The Texas Journal of Science, Vol. XXXV, No. 2, July 1983 158 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 In the summer of 1971 a die-off began in the enclosure, and 17 sheep perished. Probable causes included nutritional stress from poor range conditions complicated with penumonia and blue tongue. Problems with disease continued through 1975 when predators, primarily moun¬ tain lions, began killing desert sheep. Six additional ewes were cap¬ tured in Mexico and transplanted to the enclosure in January 1977, but propogation efforts had to be terminated because predation was a serious limiting factor. Between 1975 and 1980, predators killed 21 sheep in the BGWMA enclosure. In November 1977 most sheep were removed from the BGWMA brood pasture. Four ewes and three rams were moved to Chilicote Ranch, Presidio Co., Texas. Of the two rams still in the enclosure, one escaped in 1980. As of 1981 only one adult ram remained in the brood pasture. There are now approximately six free-ranging sheep on BGWMA (Winkler 1981). Coincident with the sheep release at BGWMA was a series of observa¬ tions in Big Bend National Park (BBNP), Brewster Co., Texas. The BGWMA is 8 km northeast of BBNP. Sixteen observations totaling 25 sheep were reported by park visitors from 4 October 1970 to 4 October 1980. No observations of sheep were reported prior to the BGWMA transplant. Not all visitor observations may have been accurate, but one of the observations was verified. On 4 October 1980 an adult male was observed and photographed (BBNP Case Incident Report) in Green Gulch approximately 45 km from BGWMA. Another observation of a sheep on the same day in the same area was reported. The ram that escaped from the breeding pasture at BGWMA early in 1980 was last observed on BGWMA in March 1980. This may have been the same ram observed in BBNP in October 1980. This observation leads us to believe that some of the observations may be accurate and that some of the sheep leaving BGWMA moved into or through BBNP. Historically, bighorn sheep occupied Santa Elena Canyon in BBNP (Carson 1941) and probably also the surrounding rock outcrops and mesas (Borell and Bryant 1942). However, they were never common in BBNP, and they disappeared shortly after the first white settlers arrived (Borell and Bryant 1942). We doubt that desert bighorn sheep will nat¬ urally reestablish a population in BBNP due to the limited number of sheep entering the park, the small amount of suitable sheep habitat available, and the high density of predators (Krausman and Abies 1981). LITERATURE CITED Borell, A. E., and M. D. Bryant. 1942. Mammals of the Big Bend area of Texas. Univ. California Publ. 48:1-62. BIGHORN SHEEP IN TEXAS 159 Carson, B. 1941. Man— the greatest enemy of desert bighorn mountain sheep. Texas Game, Fish and Oyster Comm. Bull. No. 21:5-23. Davis, W. B., and W. P. Taylor. 1929. The bighorn sheep of Texas. J. Mammal. 20:440-455. Kilpatrick, J. S. 1980. Status of bighorn sheep. Fed. Aid Project No. W-109-R-3, Job No. 11. Texas Parks and Wildl. Dept., Austin, TX. Kilpatrick, J. S. 1981. Status of bighorn sheep. Fed. Aid Project No. W-109-R-4, Job No. 11. Texas Parks and Wildl. Dept., Austin, TX. Krausman, P. R., and E. D. Abies. 1981. Ecology of the Carmen Mountains white¬ tailed deer. National Park Serv. Sci. Monogr. 15:1-114. Texas Parks and Wildlife Department. 1980. Status of desert bighorn sheep in Texas. Texas Parks and Wildl. Dept., Austin, TX., mimeo. 14 p. Winkler, C. K. 1981. Status of desert bighorn sheep in Texas - 1981. Trans. Desert Bighorn Council. 25:63. EGGS AND YOUNG OF SCHOTT S WHIPSNAKE, MA S TIC OPHIS TAENIATUS SCHOTTI by HUGH K. McCRYSTAL and JAMES R. DIXON Department of Wildlife and Fisheries Sciences Texas A&M University College Station, TX 77843 ABSTRACT A gravid female Masticophis taeniatus schotti (Serpentes: Colubridae) from Mexico laid five eggs in captivity. Three of the sand-textured eggs hatched 80, 81, and 81 days later, producing neonates that averaged 389 mm in total length and 9.85 g in weight. The neo¬ nates differed from typical adults in color and pattern of pigmentation. There is little information regarding the reproductive biology of Schott’s whipsnake, Masticophis taeniatus schotti. A report on one clutch of eggs and the subsequent hatchlings is presented here. This is apparently the first record of M. t. schotti hatchlings. A gravid female [Texas Cooperative Wildlife Collections (TCWC) specimen 60760: snout-vent length 994 mm; total length 1479 mm] was collected from a site 419 m above mean sea level and 24.8 km south of Sabinas Hidalgo, Nuevo Leon, Mexico, on 14 June 1982. On 17 June 1983 she deposited five ellipsoidal, non-adherent eggs. The leathery shells were rough to the touch, resembling fine sandpaper. This unus¬ ual shell texture has been noted in M. t. schotti by Gloyd and Conant (1934) and also in M. t. taeniatus by Maslin (1947). The eggs were weighed, measured (Table 1) and incubated in a sealed three-liter French jar by the method described by Tryon (1975). Incubation temperature ranged from 25 to 27 C. On 24 June egg number five was found to be infertile and was dis¬ carded. On 26 July egg number one ruptured and collapsed. A necrotic, but well-developed embryo was found inside. At 0800 hours on 5 Sep¬ tember egg number two had pipped. The juvenile emerged by 1300 hours. Both eggs three and four pipped the following morning with the neonates emerging by 1400 hours. The hatchlings (TCWC 60761- 763) were weighed, measured (Table 1) and housed in 3.8-liter glass jars. All three were males. Sex was determined by manually everting the hemipenes. Gloyd and Conant (1934) reported egg clutches from four captive female M. t. schotti. Clutch size varied from three to twelve. The eggs were shorter than ours (X = 41.3 mm), slightly heavier (X = 16.8 g) The Texas Journal of Science, Vol. XXXV, No. 2, July 1983 162 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Table 1. Data on the eggs of Masticophis taeniatus schotti deposited 17 June 1982, and the young at hatching. Egg Width (mm) Length Weight (mm) (g) Days to hatching Snout-vent length (mm) Total length (mm) Weight (g) 1 19.7 62.4 15.87 — (embryonic death) 2 19.0 60.2 14.6 80 279 400 10.60 3 19.3 65.4 15.88 81 275 394 9.68 4 19.8 58.7 14.65 81 258 372 9.27 5 17.2 80.2 11.31 — (infertile) X 19.0 65.4 14.47 81 271 389 9.85 and all were apparently infertile. Maslin (1947) collected two gravid female M. t. taeniatus during June in Colorado; each contained four eggs. Parker and Brown (1972) reported clutch sizes for three M. t. tae¬ niatus to be three, six and seven. They indicated that length of incuba¬ tion in the wild ranged from 44-58 days. Minton (1959) reported that a gravid M. t. ornatus, collected in May, laid five eggs on 1 June, two of which hatched 62 days later. The neonates were slightly shorter in total length (X = 352 mm) than our hatchlings. Our juvenile M. t. schotti differed in color and pattern from typical adults. Gloyd and Conant’s (1934) color description of Schott’s whip- snake makes no mention of juvenile color, pattern or ontogenetic color change. A color description, based on the color charts of Ridgeway (1912), of one of our live neonate M. t. schotti follows: dorsal area of head uniform raw umber, except parietals, which are antique brown with raw umber edges; upper half of rostral raw umber, lower half white; nasals blackish-brown posteriorly and white anteriorly; loreal, pre- and postoculars edged with blackish-brown and with white cen¬ ters; temporals dark olive edged with white; a few dark olive dorsolat¬ eral scales immediately posterior to temporals also edged with white; iris black with yellow ocher ring around pupil; supralabials predomi¬ nantly white with blackish-brown upper edges; most posterior supra- labial with blackish-brown posterior edge; mental, infralabials, genials, gulars and throat (to about tenth ventral) white; white dorsolateral stripe with very pronounced light pinkish-cinnamon and blackish- brown borders immediately posterior to angle of jaw; this stripe inter¬ rupted at angle of jaw by dark olive ground color which descends to gulars; latter become progressively more light pinkish-cinnamon ven- trally, grading into white throat color; color between dorsolateral stripes dark olive; lower two-thirds of scale row three and upper two- thirds of scale row four blackish-brown; white dorsolateral stripe occu¬ pies upper third of scale row three and lower third of scale row four; this stripe extends from angle of jaw to ventral 115 and fades com¬ pletely by ventral 137 (47.2% total body length); diffuse cinnamon buff EGGS AND YOUNG OF SCHOTT’S WHIPSNAKE 163 spots found on adjacent scale rows above and below stripe; upper three- fourths of scale row one and scale row two dark olive, except anteriorly where upper three-fourths of scale row one blackish-brown; distinct ventrolateral light pinkish-cinnamon stripe extends posteriorly on lower scale row one and outer edge of adjacent ventrals from throat to ventral 107 fading completely by ventral 129 (40.9% total body length); tail dark olive above, fading to light pinkish-cinnamon on scale row two; subcaudals and scale row one light pinkish-cinnamon; ventrals change from white to pale pinkish-buff at about tenth ventral; at mid¬ body, color darkens to light pinkish-cinnamon; lateral edges of venter light pinkish-cinnamon throughout. The other two neonates were virtually identical to the one described above, except that the ground color was blackish-brown instead of dark olive. There was no evidence of the anterolateral gold edging of the dorsal scales characteristic of adult M. t. schotti in any of the hatch¬ lings. We thank Michael McCoid and Edward Michaud for their comments on the manuscript. LITERATURE CITED Gloyd, H. K., and R. Conant. 1934. The taxonomic status, range and natural history of Schott’s Racer. Occ. Pap. Mus. Zool., Univ. Michigan (287): IT 7. Maslin, T. P. 1947. Range extensions of three reptiles in Colorado. Copeia 1947:138. Minton, S. A. 1959. Observations on amphibians and reptiles of the Big Bend Region of Texas. Southwest. Nat. 3:28-54. Parker, W. S., and W. S. Brown. 1972. Telemetric study of movements and oviposition of two female Masticophis t. taeniatus. Copeia 1972:892-895. Ridgeway, R. 1912. Color standards and nomenclature. Published by the author, Washington, D.C. 43 p. Tryon, B. W. 1975. How to incubate reptile eggs: a proven technique. Bull. New York Herp. Soc. 11:33-37. OBSERVATIONS ON HOST SELECTION BY LYSATHIA LUDOVICIANA (CHRYSOMELIDAE), A BEETLE WITH POTENTIAL FOR BIOLOGICAL CONTROL OF CERTAIN AQUATIC WEEDS by JOHN M. CAMPBELL and WILLIAM J. CLARK Department of Wildlife and Fisheries Sciences Texas A&M University College Station, TX 77843 ABSTRACT Larvae of the beetle Lysathia ludoviciana were observed feeding selectively on the aqua¬ tic plant Ludwigia peploides in ponds of Brazos County, Texas. In experiments, the lar¬ vae readily consumed leaves and flowers of L. peploides, but refused leaves of Juncus effusus, Hydrolea ovata, and Salix nigra. Of these plants, only L. peploides contains dense accumulations of crystalline calcium oxalate, or raphides. Some insects (including other chrysomelids) have a dietary preference for biochemicals such as raphides. Adults of the chrysomelid beetle Lysathia ludoviciana (Fall) have been collected from many species of plants, but only the aquatic plant Myriophyllum aquaticum has been observed to support larval develop¬ ment (Habeck and Wilkerson 1980). However, larvae were not very abundant on M. aquaticum in Florida, where the discovery was made, and Vogt and Cordo (1976) implied that Ludwigia may be the primary natural host. During an investigation of the microcrustacean fauna inhabiting submerged parts of the sprawling emergent plant Ludwigia peploides (H.B.K.) Raven (Onagraceae) in several ponds in Brazos County, Texas, we found evidence that this plant is the primary natural host for L. ludoviciana. During the spring-summer periods of 1981 and 1982, we found larvae of the beetle feeding on L. peploides in three different ponds. Adults were seen on the plant at these and two additional locations — a fourth pond in Brazos County and at the narrow end of a small cove on Lake Conroe in Montgomery County. In all situations a variety of other plants was available to the insects, but L. peploides was the only plant utilized. The adult beetles never ventured very far from Ludwigia grow¬ ing over the water, suggesting that this chrysomelid requires or prefers the humid environment above the water’s surface. The feeding larvae did not completely consume leaves, but rather ate small holes, then moved to other locations (or leaves) before eating again. Cells adjacent to the damaged part of a leaf died, and the zone of The Texas Journal of Science, Vol. XXXV, No. 2, July 1983 166 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 dying cells progressed outward from the damaged point, eventually de¬ stroying the leaf. The insects appeared not to be very mobile. In April 1981 we observed a dense population almost completely destroy the leafy foliage of a L. peploides mat that had covered the surface of a small (0.04 ha) pond located in College Station Central Park, while a pond only five meters away and containing abundant L. peploides had no infestation. We collected healthy leaves from all of the plants present at the mar¬ gin of one of the ponds and offered them to L. ludoviciana larvae of various sizes in repeated “no-choice” experiments. The larvae placed in chambers with leaves of Juncus effusus (Juncaceae), Hydrolea ovata (Hydrophyllaceae), or Salix nigra (Salicaceae) invariably ignored these potential foods; whereas, larvae placed with leaves or even flowers of L. peploides began feeding almost immediately. Microscopic examination of the plants revealed that L. peploides dif¬ fered from the others in having dense accumulations of raphides (needle-shaped crystals of calcium oxalate) throughout its leaves, stems and flowers. Raphides act as a deterrent to most plant feeders (Raven and Curtis 1970), but host specificity of some chrysomelid beetles and other plant-feeding insects has been attributed to these insects’ prefer¬ ence for specific biochemical substances, such as raphides, in the plants (Feeny 1975; Hicks and Tahvanainen 1974). Some species of Myriophyl- lum contain calcium oxalate crystals in the form of druse (Hasman and Inane 1957), which may account for the occurrence of L. ludoviciana on Myriophyllum. The observed impact of L ludoviciana on Ludwigia, its apparent res¬ triction to the “supra-aquatic” habitat, its lack of mobility and its host specificity suggest that this chrysomelid beetle has potential as a biolog¬ ical agent for control of L. peploides and other aquatic plants produc¬ ing calcium oxalate. Habeck and Wilkerson (1980) report successful laboratory rearing of the insects, which suggests that large-scale produc¬ tion may be feasible. This note is based on a paper presented at the Annual Technical Ses¬ sion of the Texas A8cM Chapter of the American Fisheries Society, April 22, 1982, College Station, Texas. We thank Horace R. Burke (Department of Entomology, Texas A&M University) and Edward G. Riley (Department of Entomology, Louisiana State University), who assisted in identifying the insect. LITERATURE CITED Feeny, P. 1975. Biochemical coevolution between plants and their insect herbivores, p. 3-19. In L. E. Gilbert and P.H. Raven (Eds.), Coevolution of animals and plants. Uni¬ versity of Texas Press, Austin, TX. HOST SELECTION BY LYSATHIA LUDOVIC1ANA 167 Habeck, D. H., and R. Wilkerson. 1980. The life cycle of Lysathia ludoviciana (Fall) (Coleoptera: Chrysomelidae) on parrot-feather, Myriophyllum aquaticum (Velloso) Verde. Coleopt. Bull. 34:167-170. Hasman, M., and N. Inane. 1957. Investigations on the anatomical structure of certain submerged, floating and amphibious hydrophytes. Rev. Fac. Sci. Univ. Istanbul Set. B Sci. Nat. 22:137-153. Hicks, K. L., and J. O. Tahvanainen. 1974. Biology of plants. Worth Publishers, Inc., New York, N.Y. Vogt, G. B., and H. A. Cordo. 1976. Recent South American field studies of prospective biocontrol agents of weeds. Proceedings, Research Planning Conference on the Aqua¬ tic Plant Control Program, Charleston, S. C., U.S. Army Engineer Waterways Experi¬ ment Station Misc. Paper A-76-1, p. 36-55. CHARACTERIZATION OF ERYTHROCYTE ESTERASES ON ELECTROPHORETIC GELS1 by JOHN P. CHERRY Eastern Regional Research Center ARS, U.S. Department of Agriculture 600 E. Mermaid Lane Philadelphia, PA 19118 ABSTRACT Polyacrylamide gel electrophoresis revealed a complex array of esterases in hypotonic washings and membrane fractions from rabbit erythrocytes prepared in the presence of Triton X-100. By the use of on-gel techniques, these esterases were characterized on the basis of substrate specificities, susceptibilities to inhibitors, and sensitivities to urea and heat. In addition to acetylcholinesterase, known to be present in erythrocyte membranes, the classes of enzymes were shown to be heteromorphic and examples were found for car- boxylesterases, arylesterases, acetylesterases and cholinester hydrolases. These data estab¬ lish electrophoretic patterns of rabbit erythrocyte esterases that may serve as standards to which enzymes from physiologically altered test animals might be compared. INTRODUCTION Enzymes distinguished qualitatively by gel electrophoretic techniques are useful as biological indicators of changes in composition of edible substances during preharvest, harvest, storage, and processing (Manwell and Baker 1970; Cherry 1977, 1978; Cherry et al. 1978). Changes include deletion of some enzymes, intensification of others, and/or production of new components as evidenced by quantitative and qualitative changes in bands appearing on electrophoretic gels. Enzymes in ery¬ throcyte membrane and cytoplasm fractions may be useful in elucidat¬ ing physiological changes due to nutritional inbalances in diets. Gel electrophoretic tests of enzymes in blood and other tissues are used to indicate the existence of certain disease-related physiological disorders (Wilkinson 1976; Ray and Cherry 1977). However, enzyme multiplicity that results from genetic variability, tissue ontogeny, and method of preparation (Cherry 1977, 1978) can complicate gel electrophoretic analysis. Thus, care should be taken to insure that known gel patterns This work was supported in part by contract F41609-C-0003 from the U.S. Air Force School of Aerospace Medicine, and by Grant A-003 of the Robert A. Welch Foundation while the author was in the Department of Biochemistry and Biophysics, Texas A8cM University, College Station, TX. Special appreciation for the support is extended to John M. Prescott. The Texas Journal of Science, VoL XXXV, No. 2, July 1983 170 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 of enzymes are developed as standards for the materials to be examined prior to evaluation of treatment effects. Previous workers (Markert and Hunter 1959; Augustinsson 1961; Holmes and Masters 1967, 1968) showed by non-gel-electrophoretic techniques that esterase activity in mammalian tissues is due to multi¬ ple enzyme forms with widely differing substrate specificities, suscepti¬ bilities to inhibitors, pH optima, and sensitivities to urea and heat. Esterases that have been observed by quantitative methods in tissues include carboxylesterases (E. C. 3. 1.1.1), arylesterases (E. C. 3. 1.1.2), ace- tylesterases (E. C. 3. 1.1.6), acetylcholine hydrolases (E.C. 3. 1.1.7), and cholinester hydrolases (E. C. 3. 1.1.8). Erythrocytes of some mammalian species contain, in addition to the well-known membrane-bound ace¬ tylcholinesterases, other esterases that are relatively nonspecific, includ¬ ing arylesterases (Augustinsson et al. 1973). The present study was undertaken to demonstrate how the diversity of esterases present in rab¬ bit erythrocytes can be standardized, using polyacrylamide disc gel elec¬ trophoretic techniques. MATERIALS AND METHODS Extraction of Erythrocyte Constituents Blood from New Zealand white rabbits, 8 to 12 months old and weighing approximately 2500 g, was collected by cardiac puncture (approximately 45 ml per rabbit) in the presence of an anticoagulant acid-citrate-dextrose solution. Procedures for hemolyzing and washing the erythrocytes and preparing membrane ghosts were those of Cherry and Prescott (1974); membrane constituents were solubilized with 2.5% Triton X-1002 in the presence of 1 m M EDTA, with or without 10 m M dithiothreitol (DTT). Gel Electrophoresis and Detection of Esterases Electrophoretic separation of these components was by a “standard” gel electrophoretic technique (Cherry and Prescott 1974). The identities of esterase bands on the electrophoretic gels were determined by direct on-gel staining techniques. Nonspecific esterases (general staining procedure for esterase activity) were detected by incubating duplicate gels in a mixture of a- and /3-naphthyl acetate at room temperature for 30-60 min (Cherry and Katterman 1971). The substrate mixture con¬ tained 100 ml sodium phosphate (0.1 M, pH 6.1), 5 ml 1 -propanol, 30 mg fast blue salt, 1.5 ml cx-naphthyl acetate stock solution, and 1 ml 2Names of companies or commercial products are given solely for the purpose of provid¬ ing specific information; their mention does not imply recommendation or endorsement by the U.S. Department of Agriculture over others not mentioned. ERYTHROCYTE ESTERASES 171 /3-naphthyl acetate stock solution; the stock solutions contained 1 g of the respective naphthyl acetate in 100 ml of 50% acetone. Acetylcholinesterase and butyrylcholinesterase activities were tested by modification of the method of Shafai and Conner (1971). To 13 ml of sodium phosphate (0.5 M, pH 6.1) 50 mg acetylthiocholine iodide (for acetylcholinesterase) or 50 mg butyrylthiocholine iodide (for buty¬ rylcholinesterase), 1 ml sodium citrate (1 M), 4 ml copper sulfate (0.15 M), and 2 ml potassium ferricyanide (0.05 M) were added in that order and mixed thoroughly; the gels were placed in this solution and kept at room temperature for 30-60 min. Other substrates utilized to determine the specificities of individual esterase bands included a-naphthyl butyrate, /3-naphthyl laurate, indoxyl acetate, thiophenyl acetate, and leucyl-/3-naphthylamide. These preparations were made as stock solutions each containing 1 g of sub¬ strate per 100 ml 50% acetone, and fast blue salt was used as above (Cherry and Katterman 1971) to make the enzyme bands visible. Insolu¬ ble substrates were made as suspensions by subjecting the mixture to sonication. Esterase Inhibition Inhibitors of esterase activity tested in this study were diisopropyl- phosphorofluoridate (DPF), tri-o-tolyl phosphate (T-o-TP), phenylme- thanesulfonylfluoride (PMSF), p-chloromercuribenzene sulfonic acid (CMBSA), eserine (physostigmine), mercuric chloride, and acetazola- mide. The concentrations of inhibitors used for each experiment ranged from 0.01 to 1 rnM, with each sample being subjected to the inhibitor for 15-20 min both before and after electrophoresis. Heat Sensitivity Sensitivity of esterases to heat was determined by incubating the elec¬ trophoretic gels in phosphate buffer (0.1 M, pH 6.1) at 55 C, and the effects of urea were investigated by soaking the gels in a solution of 10 M urea at room temperature. Both stability experiments were conducted for varying periods up to 40 min, after which the gels were equilibrated at room temperature in phosphate buffer, then incubated with the sub¬ strate that included fast blue salt for staining the enzyme bands. RESULTS AND DISCUSSION Electrophoretic gels of both the hypotonic washings and the mem¬ branes of rabbit erythrocytes showed multiple, discrete bands of non¬ specific esterases (Fig. 1). Region 1.5 - 6.5 cm of the gel patterns revealed that several of the same enzyme bands were present both in the membranes (gels A-D) and in the washings (gels G-J). The membrane fraction, however, contained esterase activity in regions 0.5 - 1.5 cm and 172 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Nonspecific Esterases of Membranes: A -DTT + EDTA B + DTT + EDTA Acetylcholinesterases of Membranes: E — DTT + EDTA F + DTT + EDTA Nonspecific Esterases of Washings: G - DTT+ EDTA H I + DTT+ EDTA J Composite Groups of Esterases t | i | i | i | i \ » f » j M or,g,n cm 7 6 5 4 3 2 1 0 Migration Figure 1. Standard polyacrylamide gel electrophoretic patterns of esterase activity in membranes and washings of rabbit erythrocytes. Esterases were solubilized in the pres¬ ence of 2.5% Triton X-100 and 1 mM EDTA without (gels A, B, E, G, and H) or with 10 mM DTT (gels C, D, F, I, and J). Gels E and F were stained specifically for acetyl¬ cholinesterases, and the others were stained for nonspecific esterase activity with a mixture of a- and /8-naphthyl acetate as the substrate solution. Gels A, C, G and I, and B, D, H and J distinguish the esterases of two groups of rabbits; E and F were the same for both groups. A composite drawing showing the classes of esterase activity (I, acetylcholinesterases; II, acetylesterases; III, a, b, and c, IV, and VI, carboxylesterases; V and VII, arylesterases). The bands in region 3.0 - 3.5 cm of gels G - J are hemoglobin. 4.5 - 5.5 cm, a result not clearly evident in the washings. Acetylcholi¬ nesterase activity (gels E-F; region 0-1.3 cm) was found only in the membrane fractions, as would be expected in light of previous reports showing that this enzyme is membrane-bound (Shafai and Cortner ERYTHROCYTE ESTERASES 173 1971; Wright and Plummer 1972; Ciliv and Ozand 1972; Srinivasan et al. 1972; Wheeler et ah 1972; Augustinsson et ah 1973). Membranes and washings showed evidence of enzyme polymorphism in region 2.0 - 2.5 cm, possibly resulting from genetic variability among the rabbits (cf. gels A, C, G, and I to B, D, H, and J which distinguish two groups of rabbits). In addition, the presence of dithio- threitol (DTT) affected the number and intensity of bands in some of the samples (Fig. 1). These data indicate that the addition of reducing agents to samples, as well as genetic vaiability in tissues, can affect electrophoretic patterns (Carter 1973; Cherry and Ory 1973), which therefore should be interpreted cautiously, by careful comparison with adequate controls. The results of testing the gels against various esterase substrates and with different inhibitors of esterase activity in membrane and wash fractions are presented in Table 1; the enzymes are grouped (I- VII) according to the mobilities shown in the diagram in Figure 1. The members of Group I, the slowest migrating enzymes, hydrolyze acetyl- thiocholine, butyrylthiocholine, thiophenyl acetate, and indoxyl ace¬ tate, in addition to the two substrates for nonspecific esterases (namely, a- and /3-naphthyl acetate). This group of enzymes is inhibited by DPF, PMSF, and eserine but not by mercuric chloride or CMBSA, and it seems to be composed largely of acetylcholinesterases. Group II consists of esterases that did not hydrolyze acetylthiocholine or butyrylthiocho¬ line and were not inhibited markedly by any of the inhibitors tested. The enzymes in Groups III (a, b, c), IV, and VI, consisting of slow, intermediate, and rapidly migrating carboxylesterases, respectively, were inhibited partially or completely by DPF and PMSF but not by mercur¬ ials or T-o-TP. Only Groups I and VI were inhibited by eserine. Groups V and VII showed specificity typical of arylesterases, being inhibited partially by DPF, PMSF, and the mercurial reagents. Acetazo- lamide did not alter the activity of any esterases distinguished in the gel patterns; thus, it seems that none of these enzymes was a carbonic anhy- drase. All of the esterases (Groups I-VII) showed some degree of activity against a-naphthyl acetate, /3-naphthylacetate, and indoxyl acetate, but none showed arnidase activity toward leucyl— /Tnaphthylamide. Enzymes tentatively identified as acetylcholinesterases (I) showed speci¬ ficity toward acetylthiocholine iodide and thiophenyl acetate, and all of the suggested carboxylesterases (III a, b, c, IV, and VI) were highly active toward a-naphthyl butyrate. Similar to the acetylcholinesterases (I), the carboxylesterases with intermediate mobilities in the gels (IV) showed activity toward butyrylthiocholine iodide, a substrate that is specifically hydrolyzed by butyrylcholinesterases. Bands in Region II 174 THE TEXAS JOURNAL OF SCIENCE — VOL. XXXV, NO. 2, 1983 Table 1. Characterization of esterases from rabbit erythrocyte washings and membranes according to substrate specificity and susceptibility to inhibition and inactivation. Activity of Esterases of Group3 Treatment I II IIIa,c mb IV V VI VII Substrates a-Naphthyl acetate ++++ ++++ ++++ ++++ ++++ +++ ++++ +++ /3-Naphthyl acetate +++ +++ +++ +++ + + ++ + a-Naphthyl butyrate - ++ ++++ ++++ ++++ - ++++ - /3-Naphthyl laurate + ++ - - - - - - Indoxyl acetate +++ ++ ++++ ++++ + ++ + ++ Acetyl thiocholine iodide +++++ - - - - - - - Butyrylthiocholine iodide +++ - - - ++ - - - Thiophenyl acetate ++++ + +++ ++ + - - - L-Leucyl-/3-naphthylamide - - - - - - - - Inhibitors* DPF + ++++ + - - + - ++ T-o-TP ++++ ++++ +++ +++ +++ ++++ ++++ ++++ PMSF + ++++ + - - + - ++ Eserine + ++++ ++++ ++++ + -H- + ++++ - ++++ CMBSA ++++ ++++ ++++ ++++ ++++ - ++++ . Mercuric chloride +++ +++ +++ +++ ++ + ++ + Acetazolamide ++++ ++++ ++++ ++++ ++++ ++++ ++++ ++++ Minutes of exposure to 55 C 0 ++++ ++++ ++++ ++++ +++ + ++++ ++++ ++++ 3-7 ++++ +++ +++ + ++ ++ +++ ++ 12-18 +++ ++ ++ + + ++ + 25-32 ++ + + - - - + - 40 ++ - + - - - - - Minutes of exposure to 10 M urea 3-7 ++ ++ ++++ ++++ ++ ++ ++ ++ 12-18 + + +++ +++ + . + - 25-32 - - ++ ++ - - - - 40 - - + + - - - - “Groups I- VII denote bands with substrate specificities typical of acetylcholinesterases (I), acetylesterases (II), carboxylesterases (III a, b, and c, IV, and VI), and arylesterases (V and VII). Nonspecific esterase activity of each group, as determined with a mixture of a- and /3-naphthyl acetate, is denoted by ++++; - indicates no detectable activity; + denotes trace activity; ++, +++ are intermediate amounts of activity; and +++++ is activity exceeding that observed toward the mixture of a- and /3-naphthyl acetate substrates. The latter mix¬ ture was used also as the substrate to test the effects of inhibitors. bInhibitor concentrations used were as follows: DPF, 1 mM; T-o-TP, 1 mM; PMSF, 5 mM; eserine, 1 mM; CMBSA, 2 mM; and acetazolamide, 20 mM. Two replicates of tripli¬ cate gels of esterases were analyzed for substrate and inhibitor specificity. were most active against esters of acetic acid but also showed some activity toward /3-naphthyl laurate and thiophenylacetate. Table I also shows results of characterization of esterases from rabbit erythrocytes on the basis of stability to heat and urea. The acetylcholi¬ nesterases (I) were stable in buffer at 55 C for 7 min and were still rela- ERYTHROCYTE ESTERASES 175 lively active after 18 min at this temperature; however, they were rapidly inactivated by 10 M urea at room temperature. Acetylesterases (II) and the slow (V) and fast (VII) migrating arylesterases revealed intermediate values for heat resistance and showed urea lability similar to the acetylcholinesterases (I). Most of the slow carboxylesterases (III a, c) were relatively stable to both heat and urea; however, the band in region 1.8 - 2.2 cm (III b) was extremely heat labile but remained active in the presence of urea. The intermediate (IV) and fast carboxylesterases (VIII) behaved similarly to the acetylesterases (II). The on-gel enzymatic activities of the multiple forms of esterases from washings and membranes of rabbit erthrocytes were essentially constant over the pH range 5. 7-7. 4. At pH 8.0, however, all of the bands were approximately one-fourth to one-half as active as those observed at the other pH values. CONCLUSIONS These data from qualitative techniques of gel electrophoresis suggest that membranes of rabbit erythrocytes contain a complex array of este¬ rases. Although some differences exist in the esterase patterns of wash¬ ings and membranes, many of the enzymes exhibited similar mobilities and had corresponding substrate specificities, susceptibilities to inhibi¬ tors, pH optima, and sensitivities to heat and urea. The similarities of the banding patterns of esterases in the two fractions suggest that cor¬ responding constituents were present in the cytoplasm and membranes of erythrocytes. This investigation was done to standarize techniques (enzyme extrac¬ tion, gel electrophoresis, detection, and identification) for examining cytoplasmic and membrane esterases of rabbit erythrocytes. Application of the techniques yielded results with good reproducibility — i.e., uni¬ formity in intensity of gel staining, and repeatable spacial arrangement and identification of esterase bands between experiments. The electro¬ phoretic patterns that were established may serve as standards to which those from physiologically altered test animals (e.g., due to nutrition¬ ally inbalanced diets) can be compared. LITERATURE CITED Augustinsson, K. B. 1961. Electrophoresis studies on blood plasma esterases. I. Mam¬ malian plasmas. Acta Chem. Scand. 13:571-592. Augustinsson, K. B., B. Axenfors, I. Anderson, and H. Eriksson. 1973. Arylesterase and acetylcholinesterase in the erythrocytes of man, cow and pig. Biochim. Biophys. Acta 293:424-433. Carter, J. R. 1973. Role of sulfhydryl groups in erythrocyte membrane structure. Bio¬ chemistry 12:171-176. 176 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 2, 1983 Cherry, J. P. 1977. Oilseed enzymes as biological indicators for food uses and applica¬ tions, p. 209-228. In R. L. Ory and A. J. St. Angelo (Eds.), Enzymes in food and bev¬ erage processing. American Chemical Society, Washington, D.C. Cherry, J. P. 1978. Enzymes as quality indicators in edible plant tissues, p. 370-399. In H. O. Hultin and M. Milner (Eds.), Postharvest biology and biotechnology. Food Nutrition Press, Inc., Westport, CT. Cherry, J. P., and F. R. H. Katterman. 1971. Nonspecific esterase isozyme polymor¬ phism in natural populations of Gossypium thurberi. Phytochemistry 10:141-147. Cherry, J. P., and R. L. Ory. 1973. Gel electrophoretic analysis of peanut proteins and enzymes. 2. Effects of thiol reagents and frozen storage. J. Agric. Fd. Chem. 21:656- 660. Cherry, J. P., and J. M. Prescott. 1974. Electrophoretic evaluation of various proce¬ dures for solubilizing erythrocyte membranes. Proc. So c. Exptl. Biol. Med. 147:418- 424. Cherry, J. P., L. R. Beuchat, and P. E. Koehler. 1978. Soluble proteins and enzymes as indicators of change in peanuts infected with Aspergillus flavus. J. Agric. Fd. Chem. 26:242-245. Ciliv, G., and P. T. Ozand. 1972. Human erythrocyte acetylcholinesterase purification, properties and kinetic behavior. Biochim. Biophys. Acta. 284:136-156. Holmes, R. S., and C. J. Masters. 1967. The developmental multiplicity and isoenzyme status of cavian esterases. Biochim. Biophys. Acta. 132:379-399. Holmes, R. S., and C. J. Masters. 1968. A comparative study of the multiplicity of mammalian esterases. Biochim. Biophys. Acta. 151:147-158. Manwell, C., and C. M. A. Baker. 1970. Molecular biology and the origin of species: Heterosis, protein polymorphism and animal breeding. University of Washington Press, Seattle, WA. 394 p. Markert, C. L., and R. L. Hunter. 1959. The distribution of esterases in mouse tissues. J. Histochem. Cytochem. 7:42-49. Ray, L. E., and J. P. Cherry. 1977. Effects of hyperoxia on glutathione reductase activ¬ ity, membrane proteins, and esterases of rabbit erythrocytes. Aviat. Space Environ. Med. 48:649-653. Shafai, T., and J. A. Conner. 1971. Human erythrocyte acetylcholinesterase. I. Resolu¬ tion of activity into two components. Biochim. Biophys. Acta. 236:612-618. Srinivasan, R., A. Karczmar, and J. Bernsohn. 1972. Activation of acetylcholinesterase by Triton X-100. Biochim. Biophys. Acta. 284:349-352. Wheeler, G. E., R. Coleman, and J. B. Finean. 1972. Cholinesterase activities in sub- cellular fractions of rat liver. Biochim. Biophys. Acta. 255:917-930. Wilkinson, J. H. 1976. Chemical enzymology: the state of the art. Lab. Manag. 14:21 - 24. Wright, D. L., and D. T. Plummer. 1972. Solubilization of acetylcholinesterase from human erythrocytes by Triton X-100 in potassium chloride solution. Biochim. Bio¬ phys. Acta. 261:398-401. OFFICERS President: President-Elect: Vice-President: Immediate Past President: Secretary-Treasurer: Editor: AAAS Council Representative: Bernard T. Young, Angelo State University Michael Carlo, Angelo State University William J. Clark, Texas A&M University Elray S. Nixon, Stephen F. Austin State University Everett D. Wilson, Sam Houston State University William H. Neill, Texas A&M University Arthur E. Hughes, Sam Houston State University DIRECTORS 1981 Richard L. Noble, Texas A&M University Bob F. Perkins, University of Texas, Arlington 1982 Billy J. Franklin, Texas A&I University Ethel W. McLemore, Dallas 1983 D. Lane Hartsock, Austin Katherine Mays, Bay City SECTIONS I — Mathematical Sciences : Philip S. Morey, Jr., Texas A&I University II — Physical Sciences: R. Charles Ivey, La Jet Corporation, Abilene III — Earth Sciences: S. Christopher Caran, University of Texas, Austin IV — Biological Sciences: Frank W. Judd, Pan American University V — Social Sciences: Rollo K. Newsom, Southwest Texas State EJniversity VI — Environmental Sciences: D. Lane Hartsock, Texas Air Control Board VII — Chemistry: John T. Moore, Stephen F. Austin State University VIII — Science Education: Rebecca Sparks, San Marcos IX — Computer Sciences: Charles N. Adams, North Texas State University X — Aquatic Sciences: G. Dan McClung, SK Engineering, San Angelo Collegiate Academy Counselors: Shirley Handler, East Texas Baptist College Helen Oujesky, University of Texas, San Antonio Junior Academy Counselors: Ruth Spear, San Marcos Peggy Carnahan, San Antonio COVER PHOTO Sediment Sampling Device by Ward, pp. 101-108 2nd CLASS POSTAGE PAID AT HUNTSVILLE TEXAS 77341 AND AT ADDITIONAL MAILING OFFICE AT LUBBOCK TEXAS 79401 LIBRARY AC SMITHS Off I A QlliSITOMS N IMS T 83 i AS HI MG TOM 20 560 DC Volume XXXV, Number 3 September 1983 PUBLISHED QUARTERLY BY THE TEXAS ACADEMY OF SCIENCE SECTION I MATHEMATICAL SCIENCES Mathematics, Statistics, Operations Research SECTION VI Economics, History, ENVIRONMENTAL Psychology, Sociology SCIENCES AFFILIATED ORGANIZATIONS Texas Section, American Association of Physics Teachers Texas Section, Mathematical Association of America Texas Section, National Association of Geology Teachers GENERAL INFORMATION MEMBERSHIP. Any person or group engaged in scientific work or interested in the pro¬ motion of science is eligible for membership in The Texas Academy of Science. Dues for members are $20.00 annually; student members, $12.00 annually; sustaining members, at least $30.00 in addition to annual dues; life members, at least $400.00 in one payment; patrons, at least $500.00 in one payment; corporate members, $250.00 annually; corporate life members, $2000.00 in one payment. Library subscription rate is $45.00 annually. Pay¬ ments should be sent to the Secretary-Treasurer, Box 2175, Huntsville, TX 77341. The Journal is a quarterly publication of The Texas Academy of Science and is sent to all members and subscribers. Inquiries regarding back issues should be sent to Dr. Fred S. Hendricks, Dept. Wildlife & Fisheries Sciences, Texas A&M University, College Station, TX 77843. The Texas Journal of Science (USPS 616740) is published quarterly at Huntsville, Texas U.S.A. Second class postage paid at Post Office, Huntsville, TX 77341, and at additional mailing office at Lubbock, TX 79401. Please send form 3579 and returned copies to Texas Tech Press, Box 4240, Lubbock, TX 79409. ^ OCT 1 9 1983 THE TEXAS JOURNAL OF SCIENCE UgfuVRUS Volume XXXV, No. 3 September 1983 CONTENTS Instructions to Authors . 179 Geology’s Heritage and Promise. By Michel T. Halbouty . 181 Translation of C Shell Scripts to C for Faster Execution of Unix Computer Programs. By Grady Early, Jane Gambill and Teresa Thomas . 189 Vegetational Analysis of a Post Oak-Black Hickory Community in Eastern Texas. By K. L. Marietta and E. S. Nixon . 197 Woody, Streamside Vegetation of Prairie Creek in East Texas. By E. S. Nixon, R. L. Ehrhart, S. A. Jasper, J. S. Neck and J. R. Ward . 205 Global Inverse Function Theorem. By John D. Miller . . .215 New Records of Invertebrate Saprovores from Barn Owl Pellets. By Kirk L. Hamilton and Annemarie B. Hamilton . 219 A New Edgeworth- type Expansion. By James G. Galloway and E. D. McCune . 221 Relationships of Sugar Maples ( Acer saccharum and A. grandidentatum ) in Texas and Oklahoma with Special Reference to Relict Populations. By Frederick R. Gehlbach and Robert C. Gardner . 231 Recent Population Trends of Cormorants (Aves: Pelicaniformes) in Texas. By Michael L. Morrison, Brenda S. Hale and R. Douglas Slack . 239 Occurrence of the Caddisfly Atopsyche erigia in Texas’ Guadalupe River below Canyon Reservoir. By Robert A. Short . 243 Herpetofauna of the Pedro Armendariz Lava Field, New Mexico. By Troy L. Best, Herman C. James, and Frank H. Best . 245 Taxonomic Status of the Brazilian Colubrid Snake, Xenodon suspectus Cope. By James R. Dixon . 257 Viscometric Measurement of the Cellulase Activity of a Soil Fungus. By J. Ortega and E. J. Baca . . . 261 New Records of the Freshwater Ectoproct Pectinatella magnijica in Eastern Texas. By Raymond W. Neck and Richard W. Fullington 269 THE TEXAS JOURNAL OF SCIENCE EDITORIAL STAFF Editor: William H. Neill, Texas A&M University Assistant to the Editor: Fred S. Hendricks, Texas A&M University Associate Editor for Chemistry: Marvin W. Rowe, Texas A&M University Associate Editor for Mathematics and Statistics: George R. Terrell, Rice University INSTRUCTIONS TO AUTHORS Scholarly papers in any field of science, natural history, or technology are eligible for publication in The Texas Journal of Science. Before a paper can be accepted for publication, it must undergo critical review by at least 2 appropriate referees and the editor. A manuscript intended for publication in the Journal should be pre¬ pared in accordance with the following instructions and then submitted to Dr. William H. Neill, TJS Editor, Department of Wildlife & Fisheries Sciences, Texas A&M University, College Station, TX 77843. The manuscript is not to have been published elsewhere. Triplicate typewritten or machine-printed copies (or the original and 2 good xero¬ graphic reproductions) must be submitted. Text, table and figure cap¬ tions, and references should be double-spaced with 2-3 cm margins (without right-justification) on 8% X 11-inch paper. The title of the arti¬ cle should be followed by the name and business or institutional address of the author(s). Be sure to include zip code with the address. If the paper has been presented at a meeting, a footnote giving the name of the society, date, and occasion should be included but should not be num¬ bered. Begin the body of the paper with a brief ABSTRACT to which is appended a list of key words (abstracting services pick this up directly), followed by the text subdivided into sections as appropriate. Use upper /lower case letters, italics (indicated by single underscore), and indenta¬ tion in a way that mimics the pattern evident in the most recent issue of the Journal. In the text, cite all references by author and date in chronological order, i.e., Jones (1971); Jones (1971, 1972); (Jones 1971); (Jones 1971, 1972); Jones and Smith (1971); (Jones and Smith 1971); (Jones 1971; Smith 1972; Beacon 1973). If there are more than 2 authors, use: Jones et al. (1971); (Jones et al. 1971). References are then to be assembled, arranged alphabetically , and placed at the end of the article under the heading LITERATURE CITED. For a PERIODICAL ARTICLE use the form: Jones, A. P., and R. J. Smith. 1971. Persistence of chlorinated hydrocarbons. J. Soil Chem. 37:116-123. For a paper published in the PROCEEDINGS OF A SYMPOSIUM, etc., use the form: Jones, A. P. 1971. Persistence of chlorinated hydrocar¬ bons, p. 155-181. In A. P. Jones (ed.), Pesticides in soils. Soc. Soil Chem., New York, NY. For a REPORT use: Jones, A. P. 1971. Persistence of chlorinated hydrocarbons. Texas Soils Institute (Austin, TX) Report No. 14, 46 p. A masters OR Ph.D. THESIS should appear as: Jones, A. P. 1971. Persistence of chlorinated hydrocarbons in blackland soils. M.S. thesis, Texas A&M Univ., College Station, TX. For a BOOK, NO EDITORS, use: Jones, A. P. 1971. Environmental effects of chlorinated hydrocarbons. Academic Books, New York, NY, 439 p. For a CHAPTER IN A BOOK WITH 180 THE TEXAS JOURNAL OF SCIENCE-VOL. XXXV, NO. 3, 1983 EDITORS: Jones, A. P. 1971. Persistence of chlorinated hydrocarbons, p. 13-39. In A. P. Jones, B. R. Smith, Jr. and T. S. Gibbs (eds.), Environ¬ mental effects of chlorinated hydrocarbons. Academic Books, New York, NY. For an IN-PRESS PERIODICAL ARTICLE use: Jones, A. P. In Press. Persistence of chlorinated hydrocarbons. J. Soil Chem. For an IN-PRESS BOOK use: Jones, A. P. In Press. Environmental effects of chlorinated hydrocarbons. Academic Books, New York, NY. References to unpublished data or personal communications should not be listed in the LITERATURE CITED section. However, they should be presented within the text as: (unpubl. data from C. J. Jones, Dept. Zoology, Univ. Texas, Austin, TX) or (pers. comm, from R. C. Smith, P.O. Box 133, Mexia, TX). Any footnotes (except those referenced in the body of a table) should appear on a separate sheet of paper, following the LITERATURE CITED. All tables are to be typed with a carbon ribbon, free of error, without handwritten notations, and ready for photographic reproduction. Each table, headed by its caption, should be placed on a separate sheet of paper. Tables must have a text reference, i.e., Table 2 shows. . .or (Table 2). Figures are to be original inked drawings or photographic prints no larger than 4Vi X 6Vi inches and mounted on standard 8^ X 1 1-inch paper. Each illustration should be marked on the back with the name of the first author and the figure number. Captions for figures are to be pro¬ vided on a separate sheet of paper. Figures must have a text reference, i.e., Figure 3 illustrates. . .or (Fig. 3). Authors will receive galley proofs plus the edited typescript and information concerning reprints and page charges. Proofs must be cor¬ rected (using ink) and returned to the editor within 5 days. Page charge payment (check or purchase voucher) or a publication-grant request must accompany return of the corrected proofs or a delay in printing the manuscript could occur. Reprint orders should be returned directly to Texas Tech Press, Box 4240, Lubbock, TX 79409. THE EDITOR SHOULD BE NOTIFIED IMMEDIATELY OF ANY CHANGE IN THE PRINCIPLE AUTHOR’S ADDRESS OR TELEPHONE NUMBER. NOTE: Authors are encouraged to contribute $35.00 per published page to defray printing costs, and authors of articles exceeding ten pages are expected to make some contribution to the publication fund. However, payment of printing costs is not a condition for publication in The Texas Journal of Science , and NO AUTHOR, WHO WOULD OTH¬ ERWISE SUBMIT A MANUSCRIPT, SHOULD HESITATE TO DO SO BECAUSE OF LACK OF FEJNDS. Members without funds may apply to the Texas Academy of Science for a grant to cover some or all costs of publication. GEOLOGY'S HERITAGE AND PROMISE1 by MICHEL T. HALBOUTY2 Chairman of the Board and Chief Executive Officer Michel T. Halbouty Energy Co. 5100 Westheimer Road Houston , TX 77056 As a geoscientist my career has been centered in geology, geophysics, and petroleum engineering. And, because of this affiliation, many of the other sciences have rubbed off on me. In reality, I have worn two hats since the day I graduated from Texas A&M University-one that of a geologist and the other that of a petroleum engineer. I have practiced diligently and studied continually so that I might add to my knowledge of those two disciplines to the best of my ability. To be more blunt, I can say that I gave my all to enhance them and add to their heritages. I will take off my engineering hat now and leave the other hat on, because what I want to share with you today is the meaning of geology — the meaning of its heritage and what the science may mean for the future. Before proceeding, I want to make it clear that what I say here today you probably know already. I just want to review the “known with the knowing” so that we may all pause and reflect on the importance of the science of geology to mankind. !Text of address presented in plenary session at the Texas Academy of Science 86th Annual Meeting, Stephen F. Austin State University, Nacogdoches, Texas, 4 March 1983. Mr. Halbouty presented the address upon the occasion of his being named “Distin¬ guished Texas Scientist” for 1983 by the Academy. He became the fourth person to be so honored; the other three are heart surgeon Michael DeBakey (1979), physicist Ilya Prigo- gine (1980), and ecologist Perry Adkisson (1982). The following synopsis of Mr. Halbouty’s credentials is condensed from information compiled by Ann Benham, past president of the Academy. 2Michel Halbouty is among the world’s foremost figures in geology and petroleum engi¬ neering. A native of Beaumont and a graduate of Texas A&M University, Mr. Halbouty not only has built one of the nation’s most successful energy companies but also has authored or coauthored 5 books and over 240 professional papers. He is on the directoral boards of ten commercial, professional, and civic organizations. Active in more than 40 professional societies, Mr. Halbouty has been elected “Fellow” of four — The Texas Academy of Science, the American Association for the Advancement of Science, the Insti¬ tute of Petroleum (London), and the Geological Society of America. He has also been awarded honorary membership in both the American Association of Petroleum Geolo¬ gists and the American Institute of Mining, Metallurgical and Petroleum Engineers. Among numerous other awards and honors Mr. Halbouty has received are election to the National Academy of Engineering (1979) and appointment as leader of President Reagan’s Transition Team on Energy. The Texas Journal of Science, Vol. XXXV, No. 3, September 1983. 182 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 The story of the earth is the science of geology. Those of us who call ourselves geologists are fortunate that we have such a rich foundation upon which to base our studies. Others who have gone before us have lighted the way in unique but effective manners. The procession of life, which for eons has passed over the earth’s sur¬ face, and a thousand closely related themes have attracted countless men and women to the realm of the science. Their efforts have pro¬ duced one of the most interesting records of human endeavor and achievement found in scientific history. Geologists have the benefit of the accumulated knowledge of centur¬ ies of studies made by dedicated men and women who were not afraid to question the unknown, who had the courage of their convictions — the courage of stand up and be counted without fear. Geologists have a grand heritage upon which to rely. I feel a close bond to and a great love for the earth. The almost unlimited facets of the geological sciences have fascinated me from my earliest boyhood. I have seen giant strides made in the understanding of the dynamics of the earth and I have witnessed a surge of scientific and technological breakthroughs once considered to be impossible or only in the realm of science fiction. From the beginning, the discipline of geology has grown and advanced on the balance-scale of probability rather than in the rigid, less flexible framework of mathematics. Thus geology always has been an inexact, speculative science. Commonly suffering from speculation beyond the limits of observation and experience, geological hypotheses and theories have been promulgated and dissipated, but not without some benefit to each succeeding generation of earth scientists. It is precisely this inexactness that makes geology such a great chal¬ lenge. There were many who labored in this science who were maligned and criticized for their observations but who courageously weathered the storm of derision to prove that they were right. Although their efforts at times were impeded by ignorance and human fallibility, their observations, failures and successes helped forge the study of the earth into a fascinating science. We can trace recorded observations of nature from those of Herodo¬ tus in the 5th century. Since that time students have searched, probed, and charted the earth to unlock her past and to record her secrets for the benefit of mankind. Our early observers of the earth were called, and even referred to themselves as, “philosophers of nature’’, and their efforts to prove and disprove their observations and beliefs are legend¬ ary. The philosophers of nature during the Middle Ages undoubtedly were influenced by the “Aristotelian elements’’ of fire, air, earth, and water. Werner and Hutton gained many of their ideas on minerology GEOLOGY’S HERITAGE AND PROMISE 183 from the published works of George Bauer, better known as Agricola. Werner and Hutton debated their respective philosophies and fought for the minds of their colleagues, each in the belief that he was right. Each of these men, whether right or wrong, had a heritage upon which he laid the foundation for his own pursuits. These men, their forebearers, their colleagues, and their successors all contributed in some measure to the heritage by continuously ferreting out the unknown and adding to the knowledge which we all share today. The names of other great men of long ago come to mind, men such as John Playfair, James Hall, Robert Jameson, Nicholas Steno, Wil¬ liam Smith, Thomas Chamberlin, William Davis, Willard Libby, Norman Bowen, James Walker, and so many more — a roll-call so long that no list could ever be completely accurate. Innumerable men and women through their discoveries, their mistakes, their confusions, and their solutions have given to us the total results of their efforts which have added immeasurably to our heritage. Simply, our heritage consists of geologic truths, and carries no obli¬ gation except that we carry on from where our predecessors left off. Thus, there must be a continuum, based on more study, exploration, curiosity, failure, success, and total effort so that we, in turn, may hand down to our geological successors a heritage greater than that which we received. We must not break the continuum. This is our responsi¬ bility to the future of the science of geology and to the peoples of the earth. Geology and its associated sciences have continued through the cen¬ turies to move forward to serve nations and their people. The rush of activity that began during the 19th century toward in-depth study of the earth heralded the beginning of various geoscience fields, and it is indeed significant to note that today geology has split into numerous scientific disciplines. The science has become so diversified that men and women working in one area may neither know nor understand those whose specialty lies in another field. This in turn has led to sig¬ nificant accomplishments for the betterment of the world’s people. Let us review some of them. In the fields of energy supply, geology was responsible for the dis¬ coveries of raw energy fuels which have been so important to the pro¬ gress and prosperity of the world. Based largely on the pioneering of Israel Charles White and a handful of others in the latter part of the 19th century, geology has been the foundation of the worldwide search for oil and gas. Petroleum is probably the most dramatic modern con¬ tribution of geology to the needs of mankind. In nuclear energy, itself based on the results of geological explora¬ tion for fissionable materials such as uranium, a whole new age of human progress has been opened. 184 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 The space program, the most conceptual field of science today, will lean more and more on geology as it progresses. We are becoming more involved in the studies of the other planets and astronaut-geologists are a regular feature of any space exploration team. Also in the realm of space, programs such as the land satellite project (LANDSAT) and the observation satellites for ocean coverage (SEASAT) have become inval¬ uable tools in the exploration for various minerals and fuels. The earliest photographic experiments in space on the Mercury, Gemini, Apollo and Skylab flights showed the value of the space per¬ spective for study of the earth. The coverage provided from these mis¬ sions, however, was never sufficient to do anything more than to tan¬ talize the prospective users of space data. The Land Satellite launched in 1972 extended the application of space remote sensing to all areas of the earth and to spectral regiohs never seen before by man. LANDSAT provided the repetitive coverage necessary to the study of dynamic phenomena on land, in the oceans and in the atmosphere. LANDSAT 4, now orbiting the earth with its Thematic Mapper, is providing the scientist new data with better resolution which will materially assist in the discovery of the world’s energy and mineral resources of the future. As a geoscientist who has used and appreciated the value of LANDSAT data, and one who has been involved in the project since its inception, I am of the opinion that in terms of benefit to the world’s people, the United States’ LANDSAT program is proba¬ bly the most significant mission ever launched by NASA. Even more sophisticated satellites, some already designed and some now on the drawing boards, will provide new and spectacular data which will aid us enormously in our further search for energy and mineral resources from the land and the seas. Oceanographers have given us valuable information of the seas and more is yet to come. We know that the seas make up one of this planet’s richest ecological units and comprise scarcely touched reser¬ voirs of resources that will absorb increasing proportions of man’s research and development energies for generations to come. These untold stores of minerals and life are already creating far-reaching chal¬ lenges to the geologists, biologists, and oceanographers. In association with the paleontologists, we have recorded the age of man and developed a fascinating story of the evolution of all past liv¬ ing things, and working with the archeologists, geologists have made untold contributions to the culture of the entire world. Geologists have also been responsible, along with engineers, for the development of major building and construction programs, such as changing the courses of rivers, locating dams, harbors, high-rise struc¬ tures, housing developments, railroads, highways, sites for new cities GEOLOGY’S HERITAGE AND PROMISE 185 and untold other taken-for-granted activities in the advancement of human progress. Geologists and seismologists currently are involved in studies of past earthquakes and are seeking criteria for the possible prediction of future earthquakes. This includes the study of the areas most vulnera¬ ble to earthquakes and could result in recommendations for the actual removal of major cities or portions of them to other locations where the likelihood of earthquakes would be negligible. The spreading deserts of the world call attention to the need for pro¬ tection of crops and grazing lands. As a result of using innovative land designs, new irrigation techniques, and methods of controlling wind damage, much desert land is now arable and habitable. The forests of many nations have been depleted by industrialization and natural disas¬ ters. This affects the overall agriculture by disrupting soil conditions and water balance, and we are now actively involved in reforestation to speed nature’s progress in renewing and reclaiming the land. Geologists and the aquatic scientists are also recycling and protecting our planet’s most precious resource — water. We have recognized that the world’s fresh water is not inexhaustible and that a problem of both the present and the future is how to meet an increasing demand with a limited supply. The problem has been approached in many ways — cloud seeding to produce rainfall, extracting fresh water from seawater, decreasing evaporation from reservoirs, building strong earthen reser¬ voirs to hold seasonal excesses, transferring water from one basin to another and storing it in permeable rocks for future use. Through the use of three-dimensional analysis of groundwater flow, subsidence of land areas, which until recently were considered unsalvageable, is being controlled. “Dead” lakes and waterways are being cleaned up and are being repopulated to provide new marine food supplies. Geologists have stud¬ ied the effect of weather on certain land areas and have established methods to control the erosion and destruction of the land. All of these activities and many, many more, too long a list to men¬ tion, are in some measure controlled by the proper applications of geology. Therefore, it is appropriate to state that there is no area of human interest where geology does not explore or participate in some manner. Our science is constantly working to understand the needs of man¬ kind and how they can be met. Through the studies of historical and physical geology, through investigations into the many branches of the earth sciences, from the deepest parts of the oceans to the heights of the atmosphere, we are finding clues to the solution of mankind’s prob¬ lems. 186 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 We are constantly examining the internal and external phenomena of nature to further adapt the environment to man to meet his needs and assure his continued presence upon the earth. Although all of our past efforts required diligent research and careful examination of detail in all areas of geology, we must strive for better understanding of man’s future needs and ways of fulfilling these needs. It is appropriate here to mention that the Geological Society of America’s Centennial Decade Study of North America will add new chapters to what has been handed down to us by our predecessors. The investigations of this continent will write remarkable new pages in the history of the geology of this landmass. The investigation of the North American continent alone is a Herculean task. Covering more than 9 million square miles and representing slightly over 16% of the earth’s land area, it poses a formidable challenge to every aspect of geoscience. The geological endowments of North America cover the spectrum of features of terrestrial continental evolution in space, time and style. Its history is a compendium of spectacularly diverse fragments of time, each punctuated by momentus events. Its landscape has been sculptured by a staggering variety of elemental forces. Its mosaic of natural monuments conveys an infinity of moods — awesome like Death Valley, turbulent like the Colorado River rapids, placid like Canada’s Athabasca Glacier, luxuriant like the Yucatan jungle, austere like the Dakota Badlands. Mountain ranges, plains, and lakes stand out as the most obvious aspects of the terrain. Large rivers drain the interior of the continent, carrying sediments to the seas that border it. The face of the continent today is only the most recent of many profiles the continent has shown since the earth took shape. Whatever its origins, North America was first a lifeless landmass in the turbulent process of being formed and shaped. Towering moun¬ tains were thrust up by volcanic action. The mountains were capped with smoldering craters which spewed torrents of lava. The crust of the continent coiled and contracted, buckled and buckled again, shifting and lifting mountain spires. Then earthquakes shattered and rear¬ ranged the continent. The primal seas washed the surface and hid the landscape. Throughout the billions of years, the forces of nature con¬ tinued in restless surges to remold and strip and lift and submerge again the land. The rainbow of rock stripes in the Grand Canyon marks the passage of time. Billions of sand particles from ancient seas became sandstone layers, mud transformed into shale, enormous masses of marine skele¬ tons and shells compressed to form limestone. Every color and every layer signifies small eternities that mock our conventional calendars. From the Canadian Shield carved by ice after milenia of folding, faulting and compression, to the Central Lowland of arches and domes, GEOLOGY’S HERITAGE AND PROMISE 187 basins and troughs, to the Appalachian Highlands uplifted by exten¬ sive moutain building, to the soft, young Coastal Plain and to the rugged Western Cordillera, the face of the continent presents endless opportunities for exploration and investigation. What happened so long ago is impossible to determine with cer¬ tainty. The sequence of events, and the events themselves, are still dis¬ puted by scholars and scientists. Time is a tease when it comes to con¬ templating these events. A thousand years is a fleeting instant, barely worth mentioning. A million years is a brief moment, leaving the bar¬ est of legacies. It is noteworthy to observe that what is visible of our continent is awesome in its grandeur, and its unsurpassed surface beauty is chal¬ lenged only by its geological history. What we have already uncovered of the once unseen has intrigued and amazed both scientist and layman alike. What is still yet to be uncovered will amaze us even more. As I stated in the beginning of this presentation, my intention was to review the “known with the knowing” and what I have just outlined about the Continent are things you already know. This audience today is comprised of scientists from many fields, but we all have the com¬ mon bond as probers who are constantly searching for better solutions to old problems and searching for new methods of unlocking the secrets of our world. Mankind today relies more than ever before on the endeavors of scientists for survival. The world within us and the world around us are the realms of science. In looking toward the future, it is vitally important that we realize that the quality of the lives of the world’s people is directly linked to the scientific and technological progress which are made day after day. This progress must be never-ending, a continuance without interruption or cessation, an everlasting hand- down procedure. This is the obligation each one of us here owes to our respective science. The scientific endeavor is the most optimistic of all human activities. It can have no end — only continual challenge and only continual amazement in what the mind of man can imagine, change, or create. The future scientific accomplishments are limited only by the imagina¬ tion of the men and women involved in the ever changing, ever chal¬ lenging world of science. Today’s science is tomorrow’s hope. t TRANSLATION OF C SHELL SCRIPTS TO C FOR FASTER EXECUTION OF UNIX COMPUTER PROGRAMS by GRADY EARLY Department of Mathematics and Computer Science Southwest Texas State University San Marcos, TX 78666 and JANE GAMBILL and TERESA THOMAS Department of Computer Science University of North Carolina Chapel Hill, NC 27514 ABSTRACT Many UNIX computer programs are, in reality, shell scripts — text files interpreted at run-time by the generalized UNIX command-language interpreter, the shell. Although this mechanism provides great flexibility, it tends to slow execution because some shell scripts are executed frequently and iteratively. In this paper, we describe a translator for one of the available UNIX shells, the C shell. Given a C shell script as input, the transla¬ tor produces a C program to accomplish the same job. The program binds C shell scripts for fast execution, avoids interpretive overhead, and performs some operations in-line that otherwise would be done by invoking a subprogram. INTRODUCTION The C shell (Joy 1979, 1980) is a generalized command-language interpreter that is somewhat more powerful and more flexible for the interactive user of UNIX1 than the regular shell (Bourne 1978; Ritchie and Thompson 1978). The C shell provides a very convenient, interac¬ tive mechanism for command execution and file manipulation. A mul¬ titude of C shell commands, UNIX system commands, and user-written programs (including shell scripts) may be invoked and executed by the C shell. Commands may be executived singly, in parallel (pipelining), or in tandem. C shell and user variables may be defined and manipu¬ lated. These variables may be used as normal program variables or may be used to specify files (either explicitly or via pattern-matching meta¬ characters) that are to be created, modified, or deleted as dictated by the commands being executed. Late binding (e.g., of file names) allows the flexibility that one expects of an interpretive system. However, the C-shell mechanism has the usual disadvantages of a purely interpretive system. One primary disadvantage is the relatively *UNIX is a trademark of Bell Laboratories. The Texas Journal of Science, Vol. XXXV, No. 3, September 1983 190 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 slow speed of execution as compared to compilation or partial compi¬ lation. Many UNIX programs are, in fact, C shell scripts that are fre¬ quently or iteratively invoked. It would be desirable to bind such sequences and thus reduce execution time by removing much of the interpretive overhead. The purpose of this project was to investigate the feasibility of producing a translator to effect early binding. DESIGN DECISIONS Target Language The design of any programming system necessitates many decisions that affect the form of the finished product. Perhaps the most impor¬ tant decision, in the present case, was the choice of language. Transla¬ tion to a high-level language is often much easier than translation to an assembly or machine language. Three considerations led to the selection of C. First, the C shell was designed with a C-like syntax. Thus, the formulation of C shell commands into corresponding C statements is nicely effected. Second, the code generation routines, being written in C, reduced the confusion inherent in writing, in one language, a translator for a second language, to produce code in yet a third language. The presence of a very powerful C compiler in the UNIX system made the decision almost foreordained. Third, the use of C throughout means that the translator is at least potentially transport¬ able. Translation Aids The spirit of UNIX programming insists that there be no “re- invention of the wheel.” In this case, there were two clear choices of preexisting ‘wheels.’ The UNIX system contains two state-of-the-art translation aids that greatly simplify the translation task. The first is ‘lex’ (Lesk and Schmidt 1979), which is a lexical analyzer generator. Use of lex requires only that one define the rules and associated actions to produce tokens that can be recognized by the parser. The function of lex is to take the rules specified by the user and generate a program (in C) that reads the input script and breaks off appropriate tokens, pass¬ ing them to the parser. The second is ‘yacc’ (Johnson 1981), which generates a parsing algo¬ rithm (also in C). The user specifies a grammar and associated actions to be performed upon recognition of a grammatical rule. The grammar may be ambiguous, but should be context-free. As we shall see, C shell constructs are not necessarily context-free. However, this difficulty can be avoided. Modularity and Information Hiding Another decision, which was almost foreordained, required that the translator be written in clearly-defined and easily-interfaced modules. TRANSLATION OF C SHELL SCRIPTS 191 This decision allowed development of the translator to proceed on three fronts — lexical analysis, parsing, and code-generating. Crisp module definition and interfacing thus accomplished two goals. First, the amount of programmer interaction was reduced because, given care¬ fully controlled interface specifications, each programmer was free to develop his part of the translator in the most efficient way. Algorithm modifications in one module had minimal effect on other modules. Second, consistent modularity resulted in a translator that is easily enhanced. Incremental Development There were actually twelve versions of the translator developed. Each version, beginning with the implementation of comments only (!), added yet another C shell feature to the translator. The decision to pro¬ ceed in this manner resulted in the attainment of three goals. First, beginning with the very simplest construct (the comment) allowed the programmers to become familiar with the use of the various translation aids and with the source and target languages. Interface specification problems were resolved at a very low level, and it was possible to achieve a working system very quickly. Second, it was possible to fix overall goals as development proceeded. Rather than attempt the implementation of a grand, predetermined goal, features were added in a fairly natural manner. And it was possible to stop at an arbitrary point — when the system was judged to be powerful enough to be useful and when it had been demonstrated that translation was feasible as well as useful. Third, the experience gained with incremental development resulted in a system that can be easily enhanced. The steps required to add yet another feature to the translator are by now somewhat stylized. Enhancement of the system can actually take the form of addition of new features or of increasing the capabilities of features already imple¬ mented. In either case, the overall system need not be redesigned; only those modules affected by the enhancement need be scrutinized. Error Handling One of the most elegant design decisions concerns the error handling capabilities of the translation system: There are none. However, the sys¬ tem does detect and report C shell constructs, or forms therof, that are not implemented within the current version of the translator. Error handling within those constructs that are implemented was deliberately avoided. The goal was to reduce the complexity of the translation sys¬ tem itself, and the goal was attained. The elegance of the decision arises from the attempt to produce C programs that faithfully mimic, insofar as possible, the results produced by the C shell as it interprets the scripts being translated. The presence of the C shell makes it very easy to require that, prior to translation, the script be executed interpre- 192 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 tively. Thus, syntactic or semantic errors will be detected during inter¬ pretation. Given an input script that has been debugged by the C shell, the translator need not concern itself with the correctness of that script. If the script is executable by the C shell, then it is by fiat correct. Binding The stage at which a particular bit of information is bound can range from very early binding of complete compilation versus very late binding of pure interpretation. The translator pursues a moderate course between these two extremes. The primary area in which binding time was a concern was in the specification of file names. On the UNIX system, there is no particular differentiation among files: At one and the same time, a specific file may contain a command which is to be executed, or it may be taken as the argument to a command. We treat these two areas separately. For example, the command cat *.c>outfile means to catenate all files, in the current directory, that have the .c suf¬ fix and to store that catenation in the specified output file. In most scripts the command itself (e.g., cat) is subject to little if any change. That is, the command to be executed is generally known and specified explicitly. Hence, command file names are bound at translation time. Command arguments, on the other hand, often are not known at trans¬ lation time. They are specified, as in the above example, with the help of pattern-matching metacharacters. The intent is that all files whose names match the pattern, including those that did not exist when the command was written, be used as arguments to the command. A run¬ time routine effects this file name expansion (globbing) at the time the translated script is actually executed. Context Sensitivity The decision to use the C shell interpreter to debug scripts before subjecting them to translation yielded yet another advantage in the implementation of the translator. Because all scripts input to the trans¬ lator are assumed to be correct, the translation of one line of a script has little or no effect on the translation of subsequent lines. For exam¬ ple, an ‘if’ statement implies that a corresponding ‘endif’ is also in the script. This arrangement simplified the design of the translator in that code could be generated for each line as it was encountered in the script. Not only did this simplify code-generation, but also parsing. In effect, the translator can proceed as if each script consists of only a sin¬ gle line. Of course, some information can be common to more than one line of a script. A crucial example of this lies in the variables typi¬ cally defined in one line, modified in others, and utilized in still others. TRANSLATION OF C SHELL SCRIPTS 193 The handling of this problem simply required the maintenance of a user symbol table for collecting the names of all variables specified by the user. No auxiliary information was required since the translator, like the C shell, maintains all variables as arrays of 0 or more strings. Thus, variable handling simply required keeping a table of variable names so that the appropriate C declarations could be produced once the entire script had been translated. Futher, the line-by-line translation of scripts allowed resolution of a conflict created by the use of yacc, which requires a context-free gram¬ mar, to parse C shell commands, which are not context-free. For exam¬ ple, in the commands set x== echo x== the *x==’ mean entirely different things. In the first command, the meaning is to store the string ‘=’ in the variable x. In the second com¬ mand, the string ,x==’ is to be displayed. However, by processing each script line separately, it is possible to handle such problems by inter¬ preting each character string in terms of the type of line in which it is encountered. Thus, the ‘set’ command is a signal that the first equal sign be taken as a replacement operator, while the ‘echo’ command is a signal that equal signs have no special meaning within words. IMPLEMENTATION The current version of the translator implements more than enough C shell features to verify the effectiveness and the feasibility of transla¬ tion. These features are variables, comments, simple commands, pipe¬ lines, input/output redirection, globbing (metacharacter pattern match¬ ing for file names), set/unset, arithmetic and string expressions, if/else if/else/endif, while/end, and goto/label. The features implemented are quite adequate for many UNIX pro¬ gramming applications. And they are adequate to demonstrate the advantages of translation through the comparison of execution times of interpreted versus translated scripts. It would be desirable to implement other C shell features; but for purposes of this project, the above list is adequate. EXAMPLES A perhaps atypical C shell script is shown in Figure 1. While a more common use of scripts is for file manipulation, this example is never¬ theless appropriate to illustrate the form of the generated code. The C code which corresponds to the example of Figure 1 is shown in Figure 2. 194 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 //Example 2: Calculate n! where n is a command line argument, set n = $argv[1] set f = 1 loop: if($n <= 0)then goto output else @ f *= $n @ n — end if goto loop output : echo $argv[1] factorial equal $f Figure 1. C shell script example. Note that the execution of a command is effected by means of the UNIX exec command which does not return control to the calling pro¬ gram unless, for some reason, it is not possible to execute the specified command. Thus, the system fork command creates a clone, an almost exact duplicate, of the running program. The original program, called the parent, waits for the clone, called the child, to execute the specified command. When that command completes execution, the child dies with a signal to the parent that it can resume execution. Note also that two separate exec’s are generated. The reason for this is that a com¬ mand may itself be a shell script or it may be an executable binary file such as the output of the C compiler. The execv attempts command execution under the assumption that the command is an executable binary file. If this assumption is incorrect, then the execv will fail and //include loop : ; //define MAXVEC 100 if (atoi(n[ 1 ] )<=0) { //define MAXLINE 512 goto output; char •strcpy ( ) ; ) char *strcat( ) ; else { char •malloc ( ) ; tmp=atoi ( f [ 1 ] ) *atoi (n [ 1 ] ) int tmp ; if(strlen(f[ 1 ] ) < 1 0 ) char int cmdline [MAXLINE] ; execvecc ; * ex ec v ecc [ MAXVEC ] ; f[ 1 ]=malloc( 10) ; sprintf (f [ 1 ] ,"%d" ,tmp) ; char _f=1 ; int pid ; tmp=atoi (n [ 1 ] ) -1 ; int ivec ; if(strlen(n[ 1 ] ) < 1 0 ) •User-def ined variable •declarations »/ char *n [ MAXVEC ] ; int n ; char Tf [MAXVEC]; int _f ; main(_argv ,argv) int argv; char Targv[]; { argv — ; /» //Example 2: Calculate n! where n is a command line argument . */ n[ 1 ] = argv[ 1 ] ; n= 1 ; 7[ 1 ] = " 1" ; f = 1 ; sprintf(n[ 1 ] , "%d" ,tmp) ; n= 1 ; T goto loop; output : ; execvec[0]="echo" ; execvec[1]=argv[1]; execvec[2]="factorial" ; exec vec [3]= "equal"; execvect 4]=f [ 1 ] ; execvec[5]=NULL; execvecc=5 ; if((pid=fork())==0){ ex ecv( "/bin/echo" , exec vec) ; strcpy ( cmdline , "/bin/echo" ) ; for(ivec=1;ivec 0.5 cm), were recorded by species during the summer. Concur¬ rently, seedlings of woody species with dbh of less than 0.5 cm were counted in 4 m2 (2 X 2 m) plots. Herbaceous species data were recorded from 1 m2 (1 X 1 m) plots every two weeks during the growing season, from February through October. The herbaceous species rooted in each plot were identified and counted as they flowered. Shoots of rhizomat- ous plants were treated as individual plants. Plot data were used to determine importance values for each species. Importance values were based on relative frequency, relative density, and relative basal area for those woody species with measured dbh and on relative frequency and relative density for woody seedling and her¬ baceous plants. The Shannon-Weiner diversity index (Shannon and Weaver 1949) was computed for each layer of the community and for the community as a whole. Nomenclature followed Correll and John¬ ston (1970). Soil samples collected from the A horizon at three selected locations within the study site were analyzed for pH, Ca, P, K, and Mg by the Stephen F. Austin State University Soil Testing Lab. Particle size dis¬ tribution was determined by the hydrometer method (Bouyoucos 1962). OAK-HICKORY COMMUNITY ANALYSIS 199 Table 1. Physical and chemical properties of the A Horizon (0-15 cm) of the soil at the study site. Sample pH Exchangeable cations (ppm) Distribution (%) of particle size Texture Ca P K Mg sand silt clay 1 5.2 600 1.5 50 75 75.6 15.4 9.0 sandy loam 2 4.6 200 2.0 42 35 78.0 13.2 8.8 sandy loam 3 5.2 300 0.7 37 60 RESULTS AND DISCUSSION Soils The physical and chemical properties of the top soil are reported in Table 1. These results indicate the soil is low in phosphorus, a condi¬ tion often encountered in east Texas soils (Nixon et al. 1977). Such low levels of P, however, do not appear to restrict the growth of native east Texas plants. Woody Vegetation The community was well stratified with distinct overstory, shrub, woody seedling, and herbaceous layers. The overstory layer was com¬ posed of large trees up to 50 cm dbh and 25 m in height. Several of the largest Quercus stellata trees were cored and found to range in age from 85 to 100 years. The larger trees were scattered over the area, forming a relatively closed canopy with occasional openings. Quercus stellata and Cary a texana dominated this layer, along with occasional Ulmus alata and Quercus nigra (Table 2). The shrub layer of the community was quite prominent, as indicated by the presence of six shrubby species among the top- 10 dominant woody species (Table 2). Most common were Forestiera ligustrina , Cra¬ taegus marshallii, and Vaccinium arboreum. With a combined density of 13.4 plants/25 m2 plot, these species formed occasional thickets in the area and represented 98.0 % of the individuals with dbh from 1-5 cm. The woody seedling layer was dominated by small vines of Gelse- mium sempervirens and Parthenocissus quinquefolia, which together made up 40.2 % of the total importance value of this stratum. The other eight of the top- 10 dominants were seedlings of the canopy and shrub dominants. All the remaining species in this layer, except for five, were seedlings of the woody overstory and shrub layer species. The five exceptions were Rhus toxicodendron, Bignonia capreolata, Rubus trivialis, Trachelospermum dif forme, and Ascyrum hypericoides. Woody seedling species had a total density of 40.4 plants/4 m2 plot (253 plants/25 m2 plot). Gelsemium sempervirens had a density of 18.7 200 THE TEXAS JOURNAL OF SCIENCE — VOL. XXXV, NO. 3, 1983 Table 2. Data on frequency, density, basal area, and importance value for woody species in the canopy and shrub layers. Species Relative Frequency Frequency (%) (%) Density (No. /25m2) Relative Density (%) Relative Basal Area (%) Importance Value* Quercus stellata 46.3 7.1 1.0 5.5 41.3 53.9 Carya texana 48.2 7.4 0.8 4.2 24.1 35.7 Forestiera ligustrina 81.5 12.5 3.4 18.9 1.6 33.0 Crataegus marshallii 68.5 10.5 2.7 15.0 1.7 27.2 V accinium arboreum 48.2 7.4 2.2 12.3 4.4 24.1 Ilex vomitoria 59.3 9.1 1.9 10.4 1.5 21.0 Ulmus alata 29.6 4.5 0.4 2.1 13.2 19.8 Crataegus spathulata 50.0 7.7 1.9 10.3 1.3 19.3 Ilex decidua 50.0 7.7 1.4 7.5 0.8 16.0 Quercus nigra 13.0 2.0 0.2 0.8 8.0 10.8 Othersb 24.4 2.4 13.1 2.1 39.6 Total 100.3 18.3 100.1 100.0 300.4 aSum of relative frequency, relative density, and relative basal area. bOther species, listed in order of decreasing importance value, were Chionanthus virgin- ica, Viburnum rufidulum, Callicarpa americana, Vitis rotundijolia, Crataegus crus-galli, Pinus taeda, Quercus marilandica, Campsis radicans, Fraxinus americana, Bumelia lanuginosa, Gelsemium sempervirens, Smilax bona-nox, Berchemia scandens, Ilex opaca, Juniperus virginiana, Cissus incisa, Lonicera japonica, Parthenocissus quinquefolia, Smilax rotundijolia. plants/4 m2 plot (117 plants/25 m2 plot), which was three times higher than Parthencissus quinquefolia and nine times higher than any other species in the woody seedling layer. Herbaceous Vegetation The herbaceous layer of the community was completely dominated by Chasmanthium sess i l ifloru m — a caespitose, rhizomatous, shade tol¬ erant, perennial grass of sandy forests (Gould 1975). It occurred in all 54 plots and made up 53.9 % of the total importance value and 77.0 % of the total density for herbaceous species (Table 3). Including Chasmanthium sessiliflorum, 34 species, representing 18 families, flowered in the plots. Eleven of these species were represented by a single individual. An additional 10 species were represented by only two individuals. Thus 61.8 % of the species present in the com¬ munity had an importance value of less than 1.0 % of the total. A den¬ sity of 31.0 plants/m2 plot (775 plants/25 m2 plot) was tabulated (Table 3). Eighteen species (52.9 %) flowered before the trees produced mature leaves in the spring. During the late spring and summer months, 12 species, including Chasmanthium sessiliflorum, flowered. The remain¬ ing 4 species flowered in September and early October. Of the 34 spe¬ cies present, 3 were annuals and 31 perennials. Only the perennial OAK-HICKORY COMMUNITY ANALYSIS 201 Table 3. Frequency, density, and importance values for the herbaceous species. Species Relative Frequency Frequency (%) (%) Density (No./m2) Relative Density (%) Importance Value3 Chasmanthium sessiliflorum 100.0 30.9 23.9 77.0 107.9 Ranunculus fascicularis 38.9 12.0 1.6 5.1 17.1 Stipa avenacea 37.0 11.4 0.9 3.1 14.5 Carex nigromarginata 18.5 5.7 0.5 1.5 7.2 Sanicula canadensis 9.3 2.9 0.6 1.9 4.8 Aster patens 9.3 2.9 0.6 1.8 4.7 Carex flaccosperma 11.1 3.4 0.3 0.9 4.3 Vicia minutiflora 11.1 3.4 0.2 0.5 3.9 Scutellaria parvula 5.6 1.7 0.6 2.0 3.7 Galium uniflorum 7.4 2.3 0.2 0.5 2.8 Others1* 23.4 1.8 5.7 29.1 Total 100.0 31.2 100.0 200.0 “Sum of relative frequency and relative density. bOther species, listed in order of decreasing importance value, were Nothoscordum bivalve, Claytonia virginica, Galactia volubilis, Allium canadense, Oxalis violacea, Dichanthelium oligosanthes, Sporobolus asper, Carex complanata, Dichanthelium angustifolium, Asplenium platyneuron, Aristida longespica, Dichanthelium lindheimeri, Dichanthelium laxiflorum, Cardamine bulbosa, Ruellia humilis, Passiflora lutea, Oxalis dillenii, Anemone caroliniana, Spiranthes X laciniata, Cyperus globulosus, Polygala polygama, Acalypha gracilens, Panicum anceps, Cyperus ovularis. grass and sedge species such as Chasmanthium sessiliflorum, Stipa avenacea, and Carex nigromarginata were present in the vegetative form throughout the growing season. Diversity Diversity indices for each layer and a combined index were computed (Table 4). The herbaceous layer was much less diverse than the woody or woody seedling layer. This reflected the complete dominance of Chasmanthium sessiliflorum. The combined index as well as the her¬ baceous layer index is lower for this community than for more open upland communities studied in the same area (Marietta and Nixon unpublished data). Community Comparisons Dry upland sites are scattered throughout eastern Texas. They occur in Tharp’s (1939) Pine-Oak and Oak-Hickory Forest regions as well as in the Longleaf Pine Forest region. In the Oak-Hickory region, Quer- cus stellata is the universal dominant usually accompanied by Q. mari- landica and Carya texana (Tharp 1925; McBryde 1933). Quercus stellata and Carya texana were dominants in the present study. Other asso¬ ciated species listed by Tharp (1939) and McBryde (1933) were also found in this study. 202 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 Table 4. Shannon-Wiener diversity indices for the community’s layers, separately and combined. Layer Diversity index Number of species Woody 3.63 29 Woody seedling 2.95 29 Herbaceous 1.69 34 Combined 3.82 66 Our post oak-black hickory community was also similar to commun¬ ities in the Western Cross Timbers region of Texas (Dyksterhuis 1948), and to communities in the Oak-Hickory region of Oklahoma (Rice and Penfound 1959). Rice and Penfound (1959) compiled a list of species for upland forest in Oklahoma. We found all the listed woody species, plus Ilex vomitoria and Forestiera ligustrina, which are more coastal in their distribution and therefore would not be expected in Oklahoma. The paucity of quantitative studies of dry upland communities in the Pine-Oak and Longleaf Pine regions makes comparisons difficult. However, a great deal of similarity is likely. Sullivan and Nixon (1971) analyzed the vegetation of an upland site in the Pine-Oak region which was more mesic than the present site. The community was dominated by Pinus echinata, Quercus stellata, Sassafras albidum, Cornus florida, and Carya spp. The canopy layer of the more mesic community had a greater diversity of species than our post oak-black hickory community. The dominance of Chasmanthium sessiliflorum in the herbaceous layer of our community is not surprising. It is frequently encountered in the shade of east Texas forests and has been listed among the domi¬ nant species of other communities (Stransky et al. 1974; Nixon et al. 1981). LITERATURE CITED Bouyoucos, G. J. 1962. Hydrometer method improved for making particle size analyses of soil. Agron. J. 54:464-465. Braun, E. L. 1950. Deciduous forests of eastern North America. The Blakiston Company, Philadelphia, PA. 596 p. Carr, J. T. 1967. The climate and physiography of Texas. Texas Water Development Board Report 53. 27 p. Correll, D. S., and M. C. Johnston. 1970. Manual of the vascular plants of Texas. Texas Research Foundation, Renner, TX. 1881 p. Dyksterhuis, E. J. 1948. The vegetation of the Western Cross Timbers. Ecol. Monogr. 18:325-376. Geologic Atlas of Texas. 1967. Palestine sheet. Bureau of Economic Geology, University of Texas, Austin, TX. 1 p. Gould, F. W. 1975. The grasses of Texas. Texas A&M University Press, College Station, TX. 653 p. OAK-HICKORY COMMUNITY ANALYSIS 203 Langston, S. A. 1974. Woody vegetation of mesic uplands in Nacogdoches and Rusk counties, Texas. Masters thesis, Stephen F. Austin State University, Nacogdoches, TX. 40 p. McBryde, J. B. 1933. The vegetation and habitat factors of the Carrizo sands. Ecol. Monogr. 3:247-297. Nixon, E. S., R. L. Willett, M. L. Butts, and C. L. Burandt, Jr. 1981. Early serai devel¬ opment following partial dearcutting in east Texas. Texas J. Sci. 33:25-32. Nixon, E. S., R. L. Willett, and P. W. Cox. 1977. Woody vegetation of a virgin forest in an eastern Texas river bottom. Castanea 42:227-236. Rice, E. L., and W. T. Penfound. 1959. The upland forest of Oklahoma. Ecology 40:593- 608. Shannon, C. E., and W. Weaver. 1949. The mathematical theory of communication. Uni¬ versity of Illinois Press, Urbana, IL. 117 p. Stransky, J. J., E. S. Nixon, C. L. Burandt, Jr., and R. L. Willett. 1974. First year revege¬ tation following timber harvest in east Texas. USDA For. Serv. Res. Note SO- 173. Southern For. Exp. Sta., New Orleans, LA. 7 p. Sullivan, J. R., and E. S. Nixon. 1971. A vegetational analysis of an area in Nacogdoches County, Texas. Texas J. Sci. 23:67-79. Tharp, B. C. 1925. Structure of Texas vegetation east of the 98th meridian. Ph.D. disser¬ tation, University of Texas, Austin, TX. 125 p. Tharp, B. C. 1939. The vegetation of Texas. Texas Academy of Science Nontechnical Publication Series. The Anson Jones Press, Houston, TX. 74 p. WOODY, STREAMSIDE VEGETATION OF PRAIRIE CREEK IN EAST TEXAS by E. S. NIXON, R. L. EHRHART, S. A. JASPER, J. S. NECK and J. R. WARD Department of Biology Stephen F. Austin State University Nacogdoches, TX 75962-3003 ABSTRACT The woody vegetation of upper Prairie Creek in east Texas was analyzed by the plot method, with communities being sampled along a moisture gradient from wet to mesic. Dominant woody species at the creek’s origin, a wet site, were Nyssa sylvatica, Magnolia virginiana, Persea borbonia, Finns taeda, and Rhododendron canescens. Downstream, at a deeper and more clearly defined channel, Finns taeda, Rhododendron canescens, Magno¬ lia grandiflora, Quercus alba, and Fagus grandifolia emerged as dominants. The lower, mesic-site communities of Prairie Creek were dominated by Fagus grandifolia, Pinus taeda, Magnolia grandiflora, Car pinus caroliniana, and Ostrya virginiana. Shannon- Wiener species diversity indices increased down the moisture gradient. INTRODUCTION The gently rolling terrain of east Texas supports a variety of upland and bottomland communities. Variable and quite distinct from the regional forest cover is the woody vegetation along the frequent creek- bottoms (Sullivan and Nixon 1971; Nixon and Raines 1976; Nixon et ah 1980). These creek bottoms generally have been neglected and need further vegetational characterization. Understanding creek-bottom vege¬ tation requires elucidation of creekside floristic changes along the length of individual creeks. Prairie Creek — a small continuously flow¬ ing stream which begins and extends for about 3.3 km within the Angelina National Forest in east Texas — is appropriate for such a study. The area along Prairie Creek outside the National Forest could not be included because of recent clearcutting. Prairie Creek is located vegetationally within Tharp’s (1939) Longleaf Pine region near its border with the Pine-oak Forest region. It is in San Augustine County just southeast of the junction of Texas Highway 103 and FM 1277. The creek runs from north to south, generally paralleling (at approximately 0.5 km) FM 1277. The study was conducted in the fall of 1980. Except for a band of trees immediately bordering the creek, the forest associated with Prairie Creek was clearcut in 1935. Since that time, the creek-bottom forest was subjected to occasional thinning, selective cut¬ ting, prescribed burning, and wildfire (personal communication, U.S. The Texas Journal of Science, Vol. XXXV, No. 3, September 1983 206 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 Forest Service, Lufkin, Texas). It appears, however, that disturbance was minor immediately along the creek as evidenced by a rather mature forest, and the absence of stumps. Thus, the study was restricted to this creekside forest. The east Texas climate is mild, with temperatures generally ranging from 41 C to -12 C and a mean relative humidity of 73%. Precipitation, of which rainfall is the dominant form, is 119 cm annually and fairly evenly distributed throughout the year. The growing season averages about 240 days. The soil of upper Prairie Creek, at the sites of our communities 1, 2, and 3 (see below), is a Renzel loamy fine sand (Dolezel and Holt 1979). This soil generally occurs on both sides of spring-fed, flowing streams and at times marks the starting point of continuously flowing springs. The soil is somewhat poorly drained and has a high available water capacity. Just north of community 4, the Renzel soil grades into an Iuka fine sandy loam. Communities 4 and 5 were located on this rather deep, occasionally flooded Iuka soil, which is generally found on nearly level bottomlands of small streams and creeks (Dolezel and Holt 1979). Iuka soils are moderately well drained and have a high available water capacity. STUDY SITES Five segments of woody vegetation along Prairie Creek were desig¬ nated as communities. Each community was located approximately equidistant (about 0.8 km apart) along the creek channel starting at the creek’s head and ending near its exit from the National Forest. The first community (Community 1) was at the creek’s origin, where small springs and seepages feed water into a shallow channel 0.3-0.6 m deep and usually not more than a meter wide. Ferns were common at this rather wet site. At Community 2 the stream channel was 1-1.5 m deep and up to 2 m wide. Further downstream at Community 3 there was a channel depth of 2-2.5 m and a channel width to 3-3.5 m. The banks were quite steep and the creek began to meander. Communities 4 and 5, as a result, were positioned along a winding channel about 3 to 3.5 m deep, respectively. The channel bottoms in communities 4 and 5 were about 2 m wide, widening to about 5 m across at the top. Prairie Creek contained only a small amount of water at the time of this study but high levels of water and some flooding occur during heavy rains. A soil moisture gradient exists moving from the wet stream head (Community 1) to the more mesic communities of lower Prairie Creek. METHODS Woody vegetation of the 5 communities was sampled by the plot method. Fifty 5 X 5 m plots located in belt transects, 25 immediately VEGETATION OF PRAIRIE CREEK 207 paralleling each side of the creek, were analyzed in each community, giving a total of 250 plots. Where the creek meandered, some plots were irregularly shaped to contain 25 m2. All trees, shrubs and woody vines with diameters at breast height (dbh at 140 cm above ground) equal to or greater than 0.5 cm were measured to the nearest centimeter. Scien¬ tific nomenclature followed Correll and Johnston (1970). Data obtained from plots included frequency, density and basal area. By summing relative frequency, relative density, and relative basal area, an importance value for each species in each community was calculated and used in organizing composition tables and in determining com¬ munity ordination (Cox 1980). Dominance, as used in this study, is based on importance value. Pairs of communities were compared by calculating a coefficient of community (C). The formula followed was C = 2w/(a+b), where w equals the sum of the lower of the two quan¬ titative values (importance values) for species shared by the two com¬ munities, a equals the sum of all importance values for the first com¬ munity and b the sum of all importance values for the second community (Cox 1980). Shannon-Wiener diversity indices also were cal¬ culated for the 5 communities (Shannon and Weaver 1949). RESULTS A community ordination was constructed and community similarity coefficients calculated to determine if vegetation on east and west banks within each of the 5 communities was different. Results indicated a high degree of similarity; therefore each community was treated as a whole. The same ordination indicated 3 groupings involving the 5 communities. The more hydric Community 1 separated from all the downstream study sites, Communities 2 and 3 clustered together, and Communities 4 and 5 clustered together. These three groupings will be referred to as upper, middle, and lower Prairie Creek communities. Upper Prairie Creek The dominant species, based on importance value, at upper Prairie Creek (Community 1) were Nyssa sylvatica and Magnolia virginiana (Table 1). Overstory constituents were N. sylvatica, M. virginiana, Pinus taeda, and Liquidambar styraciflua. The middle layer was com¬ posed mainly of Persea borbonia, Ilex opaca, Chionanthus virginica, Acer rubrum and Fraxinus pennsylvanica. Prevalent in the shrub layer were Rhododendron canescens, Vaccinium arkansanum, Alnus serrulata and Viburnum nudum. The distribution of both P. borbonia and R. canescens was characterized by a clumping pattern as indicated by a high density to frequency ratio. The vine most frequently encountered was Smilax lauri folia. The vegetation of upper Prairie Creek was represented by fewest number of species (27) and the highest average density (10.8 plants per plot) of any of the communities studied. 208 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 Table 1. A comparison of density, basal area, species richness and species diversity and of the importance values of dominant woody species in the five communities along Prairie Creek. Community 1 2 3 4 5 Upper Middle Lower Wet Importance Value3 mesic Per sea borbonia 29.8 Vaccinium arkansanum 13.3 Alnus serrulata 10.2 S mi lax lauri folia 10.1 Ilex opaca 13.3 13.8 Magnolia virginiana 34.7 15.4 Nyssa sylvatica 46.0 16.8 20.6 Rhododendron canescens 25.8 39.9 27.9 Liquidambar styraciflua 20.0 11.4 13.8 Pinus taeda 27.9 45.0 45.9 27.2 37.7 Fagus grandifolia 25.4 35.0 50.0 35.1 Quercus alba 29.5 31.0 11.0 Magnolia grandiflora 30.7 20.6 10.9 Morus rubra Acer rubrum 20.2 15.3 11.3 Chionanthus virginica 12.3 13.9 Quercus lyrata 15.9 Fraxinus pennsylvanica Quercus phellos 14.9 26.0 Quercus nigra 12.9 Symplocos tinctoria 11.9 Ostrya virginiana 24.3 17.5 Carpinus caroliniana 20.2 26.1 Ulmus alata 14.0 11.3 Vitis rotundifolia 14.4 Styrax americana 11.4 Density (No/Plot) 10.84 8.08 6.74 7.04 7.48 Basal area (sq. m) 6.62 8.35 6.27 6.94 5.65 Species richness 27 30 34 37 38 (no. of species) Species diversity (Hr) 4.01 3.95 4.16 4.49 4.58 aSum of relative frequency, relative density and relative basal area. Middle Prairie Creek A middle Prairie Creek (Communities 2 and 3), P. taeda emerged as the dominant species, because of its high relative basal area (Tables 1 and 2). Other overstory species were Fagus grandifolia, Quercus alba , Magnolia grandiflora, Pinus echinata and M. virginiana. The middle layer was composed primarily of P. borbonia, I. opaca, C. virginica, F. pennsylvanica, A. rubrum, and Morns rubra. The dominant shrub was VEGETATION OF PRAIRIE CREEK 209 Table 2. Importance values and size-class distribution of woody plant species of Prairie Creek. : Species Importanct Value3 Size Class (cm) 1-10 11-20 21-30 31-40 41-50 51-60 >60 Pinus taeda 36.3 3 15 11 10 14 14 6 Fagus grandifolia 27.5 25 19 19 13 14 4 Rhododendron canescens 22.1 267 Nyssa sylvatica 18.2 60 23 8 5 7 Quercus alba 15.7 50 10 10 2 4 2 1 Magnolia virginiana 14.9 69 22 13 6 1 2 1 Magnolia grandiflora 14.8 28 4 6 4 5 5 1 Liquidambar styraciflua 12.4 51 14 10 1 1 1 Acer rubrum 11.4 60 19 8 Persea borbonia 9.9 117 2 1 Others'5 117.4 923 50 7 11 3 3 1 Total 300.6 1653 178 93 52 49 31 10 aSum of relative frequency, relative density and relative basal area. bOther species present, listed in order of decreasing importance value (in parentheses), were Quercus phellos (9.7), Fraxinus pennsylvanica (9.6), Ilex opaca (9.1), Chionanthus virginica (8.9), Carpinus caroliniana (8.4), Ostrya virginiana (7.5), Vitis rotundijolia (5.5), Quercus nigra (5.2), Ulmus alata (4.9), Alnus serrulata (4.5), Vaccinium arkansa- num (3.9), Symplocos tinctoria (3.8), Styrax americana (3.2), Smilax laurifolia (3.2), Vib¬ urnum dentatum (2.8), Callicarpa americana (2.8), Cornus florida (2.7), Myrica cerifera (2.4), Viburnum nudum (2.2), Pinus echinata (1.9), Acer saccharum (1.6), Vaccinium arboream (1.6), Quercus falcata (1.6), Ilex decidua (1.4), Hamamelis sp. (.9), Arundinaria gigantea (.8), Pinus palustris (.7), Prunus serotina (.6), Gelsemium sempervirens (.6), Viburnum rufidulum (.5), Castanea spp. (.4), Crataegus marshallii (.4), Bignonia capreo- lata (.4), Sassafras albidum (.4), Quercus prinus (.4), Tilia americana (.3), Rhamnus caro¬ liniana (.3), Morus rubra (.3), Ilex montana (.3), Vaccinium amoenum (.3), Smilax rotundijolia (.3), Berchemia scandens (.3), Campsis radicans (.2), Ulmus americana (.1), Bumelia lanuginosa (.1), Ulmus rubra (.1), Euonymous americanus (.1), Juniperus virgi¬ niana (.1), Celtis laevigata (.1). R. canescens, which again displayed a clumping pattern of distribution like that observed at upper Prairie Creek. A. serrulata, Symplocos tinc¬ toria, Callicarpa americana, V. arkansanum and Ilex decidua also were present in the shrub layer. The middle portion of Prairie Creek con¬ tained a total of 42 woody species with an average density of 7.41 plants per plot. Lower Prairie Creek Lower Prairie Creek (Communities 4 and 5) was dominated by F. grandifolia and P. taeda. These species, along with Quercus phellos, L. styraciflua, Quercus nigra, and M. grandiflora characterized the over¬ story. The midlayer consisted chiefly of Carpinus caroliniana, Ostrya virginiana, A. ruhrum, Ulmus alata, and C. virginica. Acer saccharum also was encountered occasionally in that stratum. The shrub layer was 210 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 composed primarily of Styrax americana, Viburnum dentatum, S. tinc- toria, and R. canescens. The vine, Vitis rotundifolia, was among the dominants because of its high frequency and density. A total of 49 spe¬ cies of woody plants was recorded, with an average density of 7.26 plants per plot. Combined Prairie Creek Communities When one considers the woody creekside vegetation of Prairie Creek as a single community, the following species emerge as dominants in order of importance value: P. taeda, F. grandifolia, R. canescens, N. sylvatica, Q. alba, M. virginiana, M. grandiflora, L. styraciflua, A. rubrum, and P. borbonia (Table 2). The presence among the dominants of R. canescens, a shrub, is due to its high relative frequency and den¬ sity. All 267 plants of this species were in the 1-10 cm size class (Table 2). A well represented size class distribution existed for the other domi¬ nant species with the exception of P. taeda, which had only 3 individu¬ als in the 1-10 cm size class. Comparative Analysis A total of 59 woody species was recorded in plots at Prairie Creek. On average, there were 8.1 plants per plot. Upper Prairie Creek contained 27 species, the middle portion 42 and the lower portion 49. This increase in species richness from the wet habitat to mesic habitat was reflected in an accompanying increase in species diversity (Shannon- Wiener indices increased from 3.95 to 4.58 — Table 1). The more hydric species common to upper Prairie Creek occurred less frequently with distance downstream and were confined to seepages or to the creek bank. Conversely, 16 species were found only at lower Prairie Creek. An ordination was made of other east Texas creek-side and creek- bottom communities to compare them with creek-side communities of this study (Fig. 1). Three general groupings occurred — those associated with very wet creek bottoms, wet to somewhat wet creek bottoms and mesic creek bottoms. The very wet creek-bottom site was wide and flat with much running water. It was dominated by Nyssa aquatica and Taxodium distichum (Nixon and Willett 1974). The wet to somewhat wet grouping included communities 1, 2 and 3 of the present study and a wet creek-branch community analyzed by Nixon et al. (1980). The wet creek branch community consisted chiefly of M. virginiana and N. syl¬ vatica. The 2 communities of lower Prairie Creek clustered with other mesic area communities. C. caroliniana, L. styraciflua, Q. alba and O. virginiana generally dominated these communities (Sullivan and Nixon 1971; Nixon and Raines 1976). VEGETATION OF PRAIRIE CREEK 211 7n 6- 5- 4- Y 3- 13 VERY WET 2- ;8 iu° i MES'C* Jl6 4.* ?2%™ T 3 iaWET "T*3-! - 5 6 T 7 8 9 Figure 1. Ordination of 18 east Texas creek-side and creek- bottom communities (com¬ munities 1-5, present study; 6-10 and 14-15, Nixon and Raines 1976; community 11, Nixon et al. 1980; community 12, Sullivan and Nixon 1971; community 13, Nixon and Willett 1974; communities 16-18, Nixon unpublished data). DISCUSSION The wet area associated with the origin of Prairie Creek was domi¬ nated by N. sylvatica , M. virginiana, P. borbonia, P. taeda and R. canescens. The designation of a Sweetbay-Swamp tupelo-Redbay Forest Cover type by the Society of American Foresters (Eyre 1980) indicates the high frequency with which this kind of community occurs. This aggregation of species mainly occurs at branch heads (Nixon et al. 1980), creek heads, wet creek bottoms and seepages in eastern Texas and then may be found eastward and northeastward in these same kinds of habitats throughout the southern Coastal Plain to Maryland and Virgi¬ nia (Eyre 1980). Downstream on mesic sites of Prairie Creek, P. taeda and F. grandifolia dominate the streamside vegetation in association with Q. alba, M. grandiflora and L. styraciflua. At the lower communi¬ ties C. caroliniana and O. virginiana become prevalent. With the excep¬ tion of M. grandiflora, these are the principal species associated with creeks in Nacogdoches County, Texas (Sullivan and Nixon 1971; Nixon and Raines 1976). Although Glascock and Ware (1979) observed numerous floristic and vegetational differences among bottom-land communities of the eastern U.S., they concluded that A. rubrum, Fraxinus spp., N. sylvatica, L. styraciflua, M. virginiana, and Ulmus spp. are the most consistently important species of small stream bottoms in Alabama, Florida, Virgi- 212 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 nia, and New Jersey. This remarkable floristic uniformity appears to extend into eastern Texas, as evidenced in this study, and also north¬ ward to some extent. Upwards to 40% of the species in streamside forests of Illinois were in common with Prairie Creek vegetation, with taxa such as Q. alba, O. virginiana, F. pennsylvanica, U. rubra, and U. americana occurring at times among the dominants (Boggess and Geis 1967; Bell and del Moral 1977; Johnson et al. 1978). As a part of Gemborys and Hodgkins’ (1971) analyses of forests of small stream bottoms in the Coastal Plain of southwestern Alabama, they associated taxa with a moisture gradient. The following selected species occurred along a gradient from drier to wet: Cornus florida, Pinus palustris, S. tinctoria, Q. nigra, L styraciflua, M. grandiflora, I. opaca, N. sylvatica, M. virginiana, and A. serrulata. These species gen¬ erally followed the same pattern at Prairie Creek. Oftentimes there is an increase in species diversity associated with a decrease in stress (Barbour et al. 1980). Assuming that the water- saturated soils of upper Prairie Creek provide a more stressful environ¬ ment than those of mesic sites, species diversity should increase, at least for some distance, with distance from the creek’s headwaters. This was demonstrated in that both species richness and diversity increased as apparent soil moisture decreased. Bell (1974) and Bell and del Moral (1977) found that species richness and diversity tended to increase with decreasing flood stress. LITERATURE CITED Barbour, M. G., J. H. Burk, and W. P. Pitts. 1980. Terrestrial plant ecology. The Benja¬ min/Cummings Publishing Company, Inc., Menlo Park, CA. 604 p. Bell, D. T. 1974. Tree stratum composition and distribution in the streamside forest. Amer. Midi. Nat. 92:35-45. Bell, D. T., and R. del Moral. 1977. Vegetation gradients in the streamside forest of Hick¬ ory Creek, Will County, Illinois. Bull. Torrey Bot. Club 104:127-135. Boggess, W. R., and J. W. Geis. 1967. Composition of an upland, streamside forest in Piatt County, Illinois. Amer. Midi. Nat. 78:89-97. Correll, D. S., and M. C. Johnston. 1970. Manual of the vascular plants of Texas. Tex. Res. Found., Renner, TX 1881 p. Cox, G. W. 1980. Laboratory manual of general ecology. William C. Brown Co., Dubuque, IA. 195 p. Dolezel, R., and T. Holt. 1979. Angelina National Forest study area soil survey in San Augustine Co., Texas. U.S. Department of Agriculture Soil Conservation Service, Nacogdoches, TX 68 p. Eyre, F. H. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, D.C. 148 p. Gemborys, S. R., and E. J. Hodgkins. 1971. Forests of small stream bottoms in the Coas¬ tal Plain of southwestern Alabama. Ecology 52:70-84. Glascock, S., and S. Ware. 1979. Forests of small stream bottoms in the Peninsula of Vir¬ ginia. Virginia J. Sci. 30:17-21. VEGETATION OF PRAIRIE CREEK 213 Johnson, G. R., D. R. Pelz, and G. L. Rolfe. 1978. Woody vegetation of a streamside forest in Illinois. Trans. Ill. State Acad. Sci. 71:41 2-4 1 9. Nixon, E. S., and J. A. Raines. 1976. Woody creekside vegetation of Nacogdoches County, Texas. Tex. J. Sci. 27:443-452. Nixon, E. S., and R. L. Willett. 1974. Vegetative analysis of the floodplain of the Trinity River, Texas. U.S. Army Corps of Engineers, Fort Worth District, Fort Worth, TX. 267 P- Nixon, E. S., J. W. Higgins, P. L. Blanchette, and F. A. Roth. 1980. Woody vegetation of a wet creek branch in east Texas. Tex. J. Sci. 32:337-341. Shannon, C. E., and W. Weaver. 1949. The mathematical theory of communication. Uni¬ versity of Illinois Press, Urbana, IL. 117 p. Sullivan, J. R., and E. S. Nixon. 1971. A vegetational analysis of an area in Nacogdoches County, Texas. Tex. J. Sci. 23:67-79. Tharp, B. C. 1939. The vegetation of Texas. The Anson Jones Press, Houston, TX. 74 p. GLOBAL INVERSE FUNCTION THEOREM by JOHN D. MILLER Department of Mathematics Texas Tech University Lubbock , TX 79409 ABSTRACT A global inverse function theorem is obtained here which is equivalent to one due to Hadamard. INTRODUCTION Let f: Rn— Rn be a differentiable function of n-dimensional Euclidean space into itself. The classical Inverse Function Theorem states that, at points x in Rn where f'(x) is nonsingular, the function f maps a suffi¬ ciently small open set U about x diffeomorphically onto an open set f(U)\ It is well known that even if f'(x) is nonsingular for each x in Rn, f may fail to be either one-one or onto (e.g., take f(x)— ex for x e R, R the reals, in one case and x e C, C the complex numbers, in the other). That is to say, even if f'(x) is everywhere nonsingular, f may fail to be a global diffeomorphism. The purpose of this paper is to provide a short proof of a global inverse function theorem that is equivalent to a version of one due to Hadamard (1968). Whereas in Hadamard’s theorem the given function is required to be proper, I require the seemingly stronger but equivalent condition of having a homotopy associated with the given function to be proper. DEFINITIONS Before stating and proving the theorem, I establish some definitions: A differentiable map f on Rn into Rn is a diffeomorphism if it is one- one, onto, and has a differentiable inverse. A continuous map f is proper if f”1 (K) is compact whenever K is compact. Continuous maps f and g between spaces X and Y are homotopic if there is a continuous map H, called a homotopy, defined on I x X into Y, I the unit interval, such that H(0,x) = f(x) and H(l,x) = g(x) for all x in X. Let f:Rn-*Rn be a C2 map with f(0) = 0. A homotopy H can be defined between f and f'(0) by the rule The Texas Journal of Science, Vol. XXXV, No. 3, September 1983 216 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 H(t,x) f(tx) 0 1, similar equations may be written. Now En(x;A) may be difficult to obtain if the cumulants associated with F( ;A) and if/ are dif¬ ficult to calculate. This approximation also can take on negative values for certain values of x and A (Table 1). EDGEWORTH TYPE EXPANSION 223 Table 1. Approximations of the probability distribution function F(x;A), for various values of A and x, given by the Edgeworth expansion Ei(x;A), the Gray-Coberly-Lewis expansion Ci(x;A), and our expansion Gi(x;A). A X F(x;A) E^x;!) (x ; A ) G1(x;A) 15 -3.5 .000000 -.000612 -.000071 .000000 25 -3.5 .000000 - . 000422 -.000069 .000000 50 -3.5 .000009 -.000230 -.000048 .000008 100 -3.5 . 000034 -.000095 -.000005 .000032 15 -3.0 .000003 -.001702 -.000603 .000001 25 -3.0 .000047 -.001014 -.000457 .00003.5 50 -3.0 .000211 -.000321 -.000105 .000190 100 -3.0 .000430 .000168 .000255 .000413 15 -2.5 .000420 - . 001710 -.003081 .000268 25 -2.5 .001193 .000075 -.001007 .000971 50 -2.5 .002348 .001872 .001251 .002100 100 -2.5 .003353 .003142 . 002814 .003238 15 -2.0 .007703 . 008810 -.005579 .004829 25 -2.0 .011105 .011952 .004012 .008847 50 -2.0 .014602 .015115 .011464 .013297 100 -2.0 .017111 .017351 . 015629 .016375 15 -1.5 .047908 .052873 .056274 .057332 25 -1.5 .053176 .050014 .057684 .058487 50 -1.5 .057808 .059175 .059864 .000337 100 -1.5 .000740 . 001411 .061712 .061971 15 - .5 .331368 .331203 .333184 .332195 25 - .5 .320208 .320141 .327257 .320680 50 - .5 .321020 .320985 .321520 .321245 100 - .5 .317305 .317339 .317604 .317400 15 .5 .714000 . 714188 .712694 .713490 25 .5 .708989 .709006 .708147 .708638 50 .5 .703871 .703910 .703438 .703689 100 .5 .700233 .700264 .700024 .700151 15 1.5 .922877 .919259 .918588 .910045 25 1.5 .924039 . 922400 . 921917 .920449 50 1.5 . 920717 .925501 . 925273 .924571 100 1.5 .928380 .927796 .927633 .927294 15 2.0 .905281 . 963310 .970750 .970082 25 2.0 .907625 . 960452 . 971204 .970628 50 2.0 . 970192 . 969614 .972152 .971745 100 2.0 . 972129 . 971851 .973183 .972924 15 2.5 . 985570 .985870 .988057 .980923 25 2.5 .987403 .987655 .988998 .988201 50 2.5 .989283 . 989452 . 990137 .989670 100 2.5 .990620 . 990723 .991008 .990807 15 3.0 .994410 .995599 . 995748 .994950 25 3.0 .995517 .990286 .996337 .995812 50 3.0 .996503 . 996979 .996979 . 996695 100 3.0 .997249 .997468 . 997458 .997308 15 3.5 .997909 . 998922 .998603 .998184 25 3.5 .998528 . 999112 .998893 .998637 50 3.5 . 999009 .999305 .999179 . 999052 100 3.5 .999292 . 999440 . 999372 .999310 15 4..0 .999301 . 999796 . 999567 .999386 25 4.0 . 999551 .999834 .999691 .999590 50 4.0 .999741 . 999874 .999799 .999754 100 4.0 .999839 . 999901 .999864 .999844 224 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 GRAY-COBERLY-LEWIS EXPANSION The Gray-Coberly-Lewis expansion is another representation of F( ;X) in terms of i/r, but in this case it is not necessary to know the cumulants. Only the first-order expansion will be derived, but higher orders can be derived in a similar fashion. Using the Edgeworth expan¬ sion for n = 1, it follows that (see Coberly 1972) F(y;A) = .//(y)+ "ft! /^(X) +Q(X~h (8) 3! and F'(x;\) = i/t'(x) + /?3i/>(4|(x) + Q(x~'). 3! (9) This implies that i/f(x) = (l)F(x;\) + _ _ - 0(\"‘) 3! (10) and iA'(x) - F'(x;A) = (0)F(x;X) + /WV) _ p^1). (11) 3! Now in equations (10) and (11), treating F(x;A) and §1 as unknowns, 3! and ignoring order terms, application of Cramer’s Rule gives the Gray- Coberly-Lewis expansion Ci(x;A) = (i/d(x) - F'(x;X)) (x) (13) and for the case in which if/ is the standard normal distribution, EDGEWORTH-TYPE EXPANSION 225 C,(x;X) = i «x) + tW) (f(v) - F' (x;X)) (14) H3(x) where H2(x) ” x2 - 1 and Hs(x) = x3 — 3x are so-called Hermite poly¬ nomials. Higher order approximations Cn can be derived in a similar manner. Gray, Coberly and Lewis (1975) show that F(x;A) - Cn(x;A) = 0(A'(n+1)/2), (15) which is the same asymptotic property as that in (5). Note that the Gray-Coberly-Lewis expansion does not require the cumulants; instead only derivatives of i /r(x) and F(x;A) are needed. As with the Edgeworth expansion, the Gray-Coberly-Lewis expansion can take on negative values (Table 1). A NEW EXPANSION A new Edgeworth- type expansion in which it is not necessary to know the cumulants can be derived as follows: Rewrite (8) as F(x:X) = ■//(y){1 + ,/'l3>(x) +Q(X~')} (16) 3! t/f(x) and 1 — F(x;X) = (1 — «A(x)){l + ll _ ^'3> - lng 1 ~ *fr(x) + ^l3>(x) + Q(X~'). (18) F(x;X) i A(x) 3! i/»(x){1 - i/i(x)} In a similar manner, we rewrite (9) as = Zlh ^(4>(x) + Q(X~')} (19) 3! tfr'(x) log F(x-X> = i^_jA^_ + 0(x-1). i h’{x) 3! (x) . n(X-i? (21) (x) + '(x) Gi(x;X) ij/(x) (X) , f F'(x;X) |M|X| Gi(x;X) tjj(x) * 1 (23) (24) where M(x) = - ^(3>(x)^(x) (25) l 1 (26) L l/((x) l l/f'(x) J J for all values of x for which 0 < i fj(x) < 1, i If' (x) > 0, F'(x;A)>0, and i A(4)(x) ^ 0. Also, M(x) is defined in (25). At this point a few remarks are in order concerning the new approx¬ imation. It is not necessary to know the cumulants of the distributions involved in order to use Gi; and, unlike the Edgeworth and Gray- Coberly-Lewis expansions, this new expansion will never give negative EDGEWORTH-TYPE EXPANSION 227 values as approximations for F(x;A). In fact, for all x in the domain of Gi, we have 0 < Gi(x;A) < 1, the required range for approximation of a probability value. In most applications the limiting distribution if/ is the standard nor¬ mal distribution, for which if/(4\x) = (3x — x3)if/'(x). When this is the case and when F'(x;A) > 0, Ci and Gi are defined for all real x except where if/{4)(x) = 0, that is except for x e {— \/~3, 0, \/3}. Hence, when if/ is the standard normal Ci and Gi will be defined at all values of x in the left and right tails of the distribution; however, when selecting values “near” — \/~3, 0, or \f 3, some numerical problems in calculating Ci or Gi may arise. Thus, in these regions the user should use some caution. We will return to this matter later in an example of numerical calculations comparing Ei, Ci, and Gi. We would hope that Gi has the same asymptotic property as Ci; this turns out to be the case. Substituting (21) and (22) into (23) we obtain log1 _ Gl = log ! _ F 0 (35) Note that F( ;A) is the standard Gamma distribution, for which it can be shown that F(x;A) — if/(x) as A — 00 for all real x in the support of F( ;A). 228 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 Table 2. Extension of Table 1 for values of x near zero. X X F(x;X) Ex(x;X) C1(x;X) G1(x;X) 15 -.10 .494221 .493995 .487416 .487228 -.09 .498210 .498063 .490569 .490408 -.08 . 502312 . 502125 .493510 .493376 -.07 . 506347 . 506180 .496152 .496046 - . 06 . 510373 .510228 .498347 .498268 -.05 .514390 . 514268 .499834 .499781 -.04 .518400 . 518300 . 500084 .500056 -.03 .522401 . 522323 .497870 .497863 -.02 .526394 . 526337 .489510 .489509 -.01 .530376 . 530341 .456585 .456633 .01 .538307 . 538320 .611695 .610298 .02 .542258 . 542293 . 578742 .578486 . 03 . 546199 . 546256 . 570332 .570287 .04 .550129 .550207 . 568050 .568096 .05 . 554046 . 554146 . 568212 . 568315 .06 .557952 . 558072 . 569591 .569737 .07 . 561846 . 561987 . 571660 .571842 .08 . 565726 . 565888 .574156 .574369 .09 . 569596 . 569776 .576931 .577174 The cumulants of (F ;A) are and those for i (/ are «i = Therefore, 0 i = 1,2 A 1 “ i/2 (i- 1)! i = 3,4, ••• (36) (37) (38) The Edgeworth expansion can easily be calculated from (38). Like¬ wise, the Gray-Coberly-Lewis expansion and the new expansion can readily be found. Selected results for first order calculations (n = 1) are shown in Table 1. The accuracy of the new expansion seems to be quite satisfactory, especially for negative values of x. In fact, this point is clearly made by observing in Table 1 that for x = -3.0 and A = 50, we have F(x;A) = .000211, Ei(x;A) = -.000321, Ci(x;A) = -.000105, and EDGEWORTH-TYPE EXPANSION 229 Gi(x;X) = .000190. Also, by observing Table 1, it appears that for this example Gi is uniformly better than Ei or Ci for x < -3.0 and x > 3.0, which seems to support its application in approximating tail probabil¬ ities. Since in this example the limiting distribution is the standard nor¬ mal, the approximations are not defined at points where t /r(4)(x) = (3x — x3)i Jj'(x) = 0, that is at x = -\/3,0, or >/~3. In fact, as mentioned earlier, when selecting values of x “near” these points we might expect numer¬ ical problems to arise. In Table 2 we have selected values of x near 0 in order to illustrate the erratic behavior of Ci amd Gi. Similar behavior also exists for x values near -\/~S or Hence in small neighborhoods about these points, we again emphasize that caution should be taken by the user. Fortunately, the expansion Gi is defined at all points in the tails of the distribution. ACKNOWLEDGEMENTS This research was supported by a Stephen F. Austin State University Faculty Research Grant. The authors would like to thank the referees for their detailed criticisms and helpful comments on an earlier version of the paper. LITERATURE CITED Bickel, P. J. 1974. Edgeworth expansions in nonparametric statistics. The Annals of Sta¬ tistics 2(l):l-20. Coberly, W. A. 1972. On Edgeworth expansions with unknown cumulants. Ph.D. disser¬ tation, Texas Tech University, Lubbock, TX. Gotze, F. 1981. On Edgeworth expansions in Banach spaces. The Annals of Probability 9(5):852-859. Gray, H. L., W. A. Coberly, and T. O. Lewis. 1975. On Edgeworth expansions with unknown cumulants. The Annals of Statistics 3(3):741-746. McCune, E. D., and J. E. Adams. 1979. The practitioner’s approach to obtaining general¬ ized Cornish-Fisher expansions. The Texas Journal of Science. 31(4):303-308. McCune, E. D., and H. L. Gray. 1982. Cornish-Fisher and Edgeworth expansions. Encyc¬ lopedia of Statistics 2:188-193. Singh, K. 1981. On the asymptotic accuracy of Efron’s bootstrap. The Annals of Statistics 9(6) 1 187-1 195. Terrell, R., and D. W. Scott. 1980. On improving convergency rates for nonnegative ker¬ nel density estimators. The Annals of Statistics 8(5): 1 160-1 163. RELATIONSHIPS OF SUGAR MAPLES (ACER SACCHARUM AND A. GRANDIDENTA TUM) IN TEXAS AND OKLAHOMA WITH SPECIAL REFERENCE TO RELICT POPULATIONS by FREDERICK R. GEHLBACH and ROBERT C. GARDNER1 Department of Biology Baylor University Waco, TX 76798 ABSTRACT Leaf shape and leaf flavonoid compounds suggest that southwestern sugar maples ( Acer saccharum complex) have a common gene pool. A. s. floridanum (mature leaves larger than 50 mm in mid-vein length and with fewer than 14 blade points on the aver¬ age) occurs in Arkansas, eastern Oklahoma and across Texas; whereas, A. s. grandidenta¬ tum (smaller leaves with 14 or more blade points) is present in Arizona, western New Mexico, and the Wichita Mountains, Oklahoma. An intermediate population lives in the Caddo Canyons, Oklahoma. The leaf features vary environmentally but remain diagnos¬ tic in McKittrick Canyon, Guadalupe Mountains, Texas, where A. s. floridanum is tem¬ porally and spatially diverse. INTRODUCTION Relict maple populations in central Texas are called Acer saccharum var. grandidentatum (Nutt.) Sarg., var. sinuosum (Rhed.) Little, var. brachypterum (Woot. and Standi.) E. J. Palm., or simply A. grandiden¬ tatum (Correll and Johnston 1970). Similar isolates in western Okla¬ homa are referred to A. saccharum March or A. grandidentatum Nutt., usually without varietal or subspecific epithets (Dent 1969). All live in restricted, comparatively mesic habitats (Rice 1962) between the range of A. saccharum floridanum (Chapm.) Small and Heller (sugar maple) in the forests of eastern Texas and Oklahoma and montane popula¬ tions of A. grandidentatum (bigtooth maple) in trans-Pecos Texas and westward. Desmans’ (1952) revision of sugar maples in the eastern U. S. and Canada designated grandidentatum as a western subspecies of saccha¬ rum, relegating sinuosum and brachypterum to its synonymy, although the bigtooth maple was not studied quantitatively. Leaf characteristics were used to combine all named taxa of the sugar maple complex with A. saccharum, but southwestern floras do not concur taxonomically (Kearney and Peebles 1960; Correll and Johnston 1970; Martin and deceased 2 October 1981 The Texas Journal of Science, Vol. XXXV, No. 3, September 1983 232 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 Hutchins 1981). Confusion results, in part, from using qualitative leaf features that may be modified temporally and spatially by local envir¬ onments (Fig. 1). A newly discovered population of the sugar maple complex at Owl Creek Mountain, Coryell County, Texas (U.S. Army’s Fort Hood) is of special interest, because it is isolated between the range of the sugar maple in east Texas and the presumed bigtooth maples of Bandera, Kendall, and Uvalde counties in central Texas. So that we might iden¬ tify it and provide a quantitative appraisal of southwestern popula¬ tions, the senior author analyzed leaf features (Anderson and Hubricht 1938; Desmaris 1952) with multivariate statistics, while the junior author compared flavonoid compounds from leaves of the same sam¬ ples from Arkansas, Oklahoma, Texas, and Arizona. EASTERN SUGAR MAPLES Preliminary to our study of southwestern sugar maples, we used a principal components analysis (BMDP4M, Dixon and Brown 1979) to reexamine Desmaris’ (1952) extensive information on eastern sugar maples. His table-3 data, appropriately transformed, on 22 populations containing 5,254 specimens in a transect from Arkansas through Ohio to Maine provided a test of critical leaf characteristics. Shape (florida- num and saccharum outline classes 1 and 3, respectively, with correla¬ tion coefficients of 0.91 and -0.88) plus number of teeth (r = 0.86) and size (r = 0.83) were the highly significant (P < 0.001) features compris¬ ing PC I, which explained 31 percent of the variance; hence these fea¬ tures were selected for examination in our southwestern samples. Also, the principal components analysis suggested that A. nigrum Michx. is a distinct species that hybridizes with A. saccharum, rather than a non-geographic subspecies as postulated by Desmaris (1952). Midwestern populations, most influenced by nigrum ( fide Desmaris and pers. observ.), fall between and overlap Arkansas-Tennessee sam¬ ples (A. s. floridanum) and those from Pennsylvania through New Eng¬ land (A. s. saccharum) on PC I but segregate completely on PC II, defined by erect leaf hairs (r = 0.80) and a pubescent, nigrum-type leaf (Desmaris outline class 5, r = 0.85, P < 0.001). PC II explains 27 per¬ cent additional variance. SOUTHWESTERN SUGAR MAPLES Methods Following Desmaris (1952), two stands from Arkansas (Benton and Randolph counties, N = 62) and two from Arizona (Chiricahua and Huachuca mountains, Cochise Co., N = 83) were chosen to represent sugar maple versus bigtooth maple influence, respectively. Unbiased SUGAR MAPLE RELATIONSHIPS 233 Figure 1. Extreme variation in the mature leaf shape of Acer saccharum from 1560-1650 m in McKittrick Canyon, Guadalupe Mountains, Culberson County, Texas, 1981. Specimen (A) resembles A. s. saccharum; (B) A. grandidentatum; (C), var. sinuosum; and, (D), A. barbatum Michx. (Leaves have 17, 10, 9, and 7 blade points, respectively, and are 61-70 mm in mid-vein length; all are from the outer twigs of trees at least 10 cm dbh.) samples of leaves from McCurtain Co., Oklahoma (N = 30) and Nacogdoches Co., Texas (N = 42) represented sugar maple features near the western limit of range; whereas, a sample from McKittrick Canyon, Guadalupe Mountains, Culberson Co., Texas (N = 55) presumably represented bigtooth features near their eastern limit. Relict maples of the complex from Owl Creek Mountain (N = 60); Sabinal Canyon, Bandera Co., Texas (N = 65); Caddo Canyon, Canadian Co., Oklahoma (N = 30); and the Wichita Mountains, Comanche Co., Oklahoma (N = 30). Stratified random samples of mature, undamaged leaves, larger than 40 mm in mid-vein length, were taken from the outer twigs of trees at least 10 cm in diameter at breast height (dbh) in Texas and Arizona (vouchers in Baylor University herbarium). Data for Arkansas and Oklahoma trees were obtained by measuring presumably unbiased samples of mature leaves in the Robert Bebb Herbarium, University of Oklahoma. A minimum of 10 leaves from each of 3 trees per locale provided data on number of blade points (teeth), mid-vein length (size), maximum middle and right lateral lobe widths, distance from edge of blade in the right lateral sinus to petiole insertion, and angle of the right lateral vein relative to the mid-vein. These six features were sub¬ jected to a discriminant function analysis with BMDP7M (Dixon and Brown 1979), using the Arkansas and Arizona samples for reference. 234 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 Flavonoids from 3-5 leaves of at least 2 trees per locale were extracted. Paper chromatography methods followed Mabry et al. (1970). Eleven compounds were located by means of their Rf values and color in ultraviolet light with and without ammonia vapor. A single linkage cluster analysis of the leaves was based on the simple matching coeffi¬ cient of their compounds (Sneath and Sokal 1973). Results and Discussion Number of blade points was the only feature of leaf shape that dif¬ fered significantly among the nine populations (F = 36, P < 0.001). Mid-vein length, a criterion of leaf size, was significant (F = 9, P < 0.001) when considered together with number of blade points but did not distinguish the samples by itself. None of the remaining measure¬ ments differed significantly among the samples (F = 0. 1-1.9, P > 0.05). Arizona and Oklahoma trees had smaller leaves with more blade points in comparison with Arkansas and Texas populations (Table 1). The discriminant function analysis separated Arizona maples from all other (F = 8-52, P < 0.05) except those in Comanche Co., Oklahoma (F = 5, P > 0.05). Arkansas samples differed significantly from those of Arizona, and Comanche and Canadian counties, Oklahoma (F = 11-36, P < 0.05). When individual leaves were classed according to reference sample, Arizona and Arkansas were 90 percent distinct; all Texas sam¬ ples fell with those from Arkansas, as did those from McCurtain Co., Oklahoma (55-100% of leaves); the Canadian Co., Oklahoma sample was exactly intermediate; and, Comanche Co., Oklahoma, leaves fit largely with those from Arizona (60%). On the basis of leaf shape, therefore, Arkansas sugar maples seem distinct from Arizona bigtooth maples. Eastern Texas and Oklahoma maples resemble the sugar maple in leaf-type (larger with fewer blade points) as predicted, but the montane and canyon isolates in central and trans-Pecos Texas are also allied with this type. Western or big¬ tooth maple influence (smaller leaf with more blade points) is more apparent in the Oklahoma relicts; although, varying degrees of inter¬ mediacy exist in the Texas and Oklahoma populations we examined (Table 1), thereby uniting the sugar and bigtooth maples as suggested by Desmaris (1952). The analysis of flavonoid compounds grouped leaves within popula¬ tions and closely assembled the Texas populations. In addition, it sug¬ gested greater intermediacy among the Oklahoma samples while failing to group any of the samples convincingly with either the sugar or big¬ tooth maple-types (Table 1). One-way ANOVAs of the arcsine- transformed matching coefficients suggested that neither the Texas nor Oklahoma samples were significantly closer to those of Arkansas (F = 1.0, P > 0.05) or Arizona (F = 2.1, P > 0.05). SUGAR MAPLE RELATIONSHIPS 235 C T3 •-< u «« c i . § § - Is M a « s g* s I o * u fe c 0 QJ 'd “o a o | c x £ tJ Si ft! ^ flj U C3 «_ c —, O .2 S c« ‘2 oj J2 c 5 a | I &“ M C O »C W5 w .2 9J C Soi a •§ 3 8 d © U Q T3 * o 11- ° O ® G £ t 1§ G e 2 es O U U S >T- oj ^ c| I » uof ? 1 § 3^ u u h <0 43 u O T3 >. 5P ti id +1 +1 GO -H 00 -tf to -H +1 04 OO as os -3 id -H +1 ifs ’—' cm U — « iO r- +1 -H as o cm r- -H +1 to to so r-» CM 00 +1 +1 SO Tt« -J OS — in 00 — < o as -H -H 00 o S £ s :s S 6 ! •s bo c p S G CU !U o J T3 e cs .5 S SJ es rj a a a § ^ .a 3 a ^ O W a 3 .C G < < !§ iS ^ ^ | | | | 236 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 Table 2. Within-and between-years comparison of the diagnostic features of leaf shape (x ± SD) in Acer saccharum from McKittrick Canyon, Guadalupe Mountains, Culber¬ son Co., Texas. (N = 10 leaves from each of three trees per elevation per year.) Elevation (m ) Feature Year 1560 1567 1650 Grand Mean ± SD Mid-vein Length 1981 61.8 ± 6.8 53.6 + 3.9 63.6+7.1 1982 55.1 ± 7.1 48.0 ± 6.3 55.5 + 7.5 54.3 ± 6.4 Leaf Blade Points 1981 16.1 ± 2.5 13.8 ± 1.6 13.6 ± 1.2 1982 13.7 + 2.3 13.3+ 1.2 13.1 + 1.3 13.4 ± 1.7 The general evidence of intermediacy, yet morphologic distinctive¬ ness, of the Arizona maples requires us to consider grandidentatum as the westernmost subspecies of A. saccharum ( sensu Desmaris 1952), re¬ cognizable in southeastern Arizona and adjacent New Mexico (pers. observ.) but not widespread in Oklahoma and certainly not in Texas. Moreover, our findings do not support recognition of var. sinuosum or var. brachypterum, thus corroborating Desmaris’ (1952) synonymy of these forms with grandidentatum. The newly found relict population in Coryell Co., Texas, represents the eastern sugar maples, i.e. A. s. floridanum in eastern Texas, Okla¬ homa, and Arkansas. This too obtains for the other canyon and mon¬ tane isolates in Texas, while the Canadian Co., Oklahoma, relict must be called floridanum X grandidentatum, and the Wichita Mountains population is strictly grandidentatum. The primacy of eastern sugar maple influence in Oklahoma and Texas, undoubtedly a mixture of genetic and environmental factors (Rice 1962), agrees with the postu¬ lated Pleistocene history of temperate zone biotas in the region (Martin and Harrell 1957). As a guide for discerning the two subspecies of sugar maples in Texas and Oklahoma, we suggest that mature, outer leaves (at least 40 mm in mid- vein length) from several trees at least 10 cm dbh will aver¬ age 14 or more blade points and 50 mm or less in mid-vein length if closest to grandidentatum. If more like floridanum the leaves will be larger and have fewer than 14 blade points on the average. We empha¬ size the importance of replicated blade point (tooth) counts, especially when the key features give conflicting information. Because of the potential for environmental modifications, both within and between growing seasons, two additional year-samples from three sites in the 1560-1650 m elevational gradient of McKittrick Canyon, Texas, were studied (Fig. 1, Table 2). A two-way ANOVA revealed significant differences between years and among sites (F =4.8 —9.6, P < 0.05) except for the inter-site comparison of leaf blade points (F = 1.4, P > 0.05). No significant site by year interactions were appar¬ ent (F = 0.01-1.2, P > 0.05). SUGAR MAPLE RELATIONSHIPS 237 Despite these findings, only one measure of one sample (16.1 blade points in 1981) was at variance with our earlier designation of the McKittrick Canyon sugar maples as largely eastern in character (above and see Gehlbach 1981). Furthermore, when the grand means of 1981 - 1982 (Table 2) were compared with those of 1980 (Table 1), the result confirmed that the McKittrick Canyon trees resemble A. s. floridanum more than A. s. grandidentatum (two-way t = 1.1, 1.5, P > 0.05). Thus, we suggest that local temporal and spatial gradients do not alter the diagnostic value of our taxonomic criteria. ACKNOWLEDGEMENTS Robert Gardner extracted the flavonoids and qualitatively assessed their similarities before his untimely death. The senior author is responsible for all other aspects of this study, which benefitted from the comments of James Estes and Thomas Dent. Estes, Vincent Roth and Carroll Peabody sent specimens; Brenda Harvey and Daniel Turner helped in the laboratory; and Harold Beaty, Owen Lind, Richard Meyerhof f, Elray Nixon, and Roger Reisch aided the field work. LITERATURE CITED Anderson, E., and L. Hubricht. 1938. The American sugar maples. I. Phylogenetic rela¬ tionships as deduced from a study of leaf variation. Bot. Gaz. 100:312-323. Correll, D. S.» and M. C. Johnston. 1970. Manual of the vascular plants of Texas. Texas Research Foundation, Renner. 1881 p. Desmaris, Y. 1952. Dynamics of leaf variation in the sugar maples. Brittonia 7:347-387. Dent, T. C. 1969. Relationships of two isolated groups of sugar maples in central Okla¬ homa to eastern and western species. Ph.D. dissert., Univ. Oklahoma, Norman, OK. 50 p. Dixon, W. J., and M. B. Brown. 1979. Biomedical computer programs: P-series. Univ. California Press, Berkeley, CA. 880 p. Gehlbach, F. R. 1981. Mountain islands and desert seas: A natural history of the U.S.- Mexican borderlands. Texas A&M University Press, College Station, TX. 298 p. Kearney, T. H., and R. H. Peebles. 1960. Arizona flora. Univ. California Press, Berkeley, CA. 1085 p. Mabry, T. S., K. R. Markham, and M. B. Thomas. 1970. The systematic identification of flavonoids. Springer-Verlag Publ. Co., New York, N.Y. 354 p. Martin, P. s., and B. H. Harrell. 1957. The Pleistocene history of temperate biotas in Mexico and eastern United States. Ecology 38:468-480. Martin, W. C.» and C. R. Hutchins. 1981. A flora of New Mexico, vol. 1. J. Cramer, W. Germany. 1276 p. Rice, E. L. 1962. The microclimate of sugar maple stands in Oklahoma. Ecology 43:19- 25. Sneath, P. H., and R. R. Sokal. 1973. Numerical taxonomy; the principles and practice of numerical classification. W. A. Freeman Publ. Co., San Francisco, CA. 573 p. RECENT POPULATION TRENDS OF CORMORANTS (AYES: PELICANIFORMES) IN TEXAS by MICHAEL L. MORRISON Department of Forestry and Resource Management University of California Berkeley , CA 94720 and BRENDA S. HALE1 Department of Fisheries and Wildlife Oregon State University Corvallis , OR 97331 and R. DOUGLAS SLACK Department of Wildlife and Fisheries Sciences Texas A&M University College Station, TX 77843 ABSTRACT Data from Christmas Bird Counts and statewide nest surveys suggest that cormorants have maintained relatively high numbers in Texas during the late 1970’s, 1980, and 1981. Cormorant populations in Texas underwent an apparent decline dur¬ ing the early 1960’s (Oberholser 1974), followed by a fluctuating but generally increasing trend in numbers by the end of the decade (Morri¬ son and Slack 1977). However, data presented by Morrison and Slack (1977) indicated that numbers of Olivaceous Cormorants ( Phalacro - corax olivaceus ) might have been entering another period of decline as recently as the winter of 1973-74. This note examines population trends of Olivaceous and Double-crested ( P . auritus ) Cormorants in Texas through 1981. Specific methods are given in Morrison and Slack (1977). Briefly, data were recorded from nine Texas coastal areas in which Audubon Christmas Bird Counts (CBCs) consistently have been conducted since 1949 (Morrison and Slack 1977: Table 1). (CBCs are 1-day counts con¬ ducted by volunteers in 15-mile-radius areas throughout much of North America sometime during late December and early January each year. CBC data are published annually in American Birds.) Data transcribed 'Present Address: Arizona Cooperative Wildlife Research Unit, University of Arizona, Tucson, Arizona 85721. The Texas Journal of Science, Vol. XXXV, No. 3, September 1983. 240 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 from each count were number of parties, total party-hours, total party- miles, and numbers of Olivaeous and Double-crested Cormorants seen. Although Raynor (1975) has cautioned that varying levels of observer effort over time can make interpretation of CBC data difficult, we felt justified in using the acutal numbers of birds counted in the nine areas for trend analysis because (1) count effort has remained relatively con¬ stant from 1975 to 1981 in the nine CBC areas used, and (2) the general trends shown for cormorants in Texas are similar for both standardized and raw data (Morrison and Slack 1977). Numbers of birds were reported by 3-year means to smooth the data series (Raynor 1975). To supplement wintering data for Olivaceous Cormorants, nesting colony surveys of the Texas Colonial Waterbird Society (TCWS) through 1981 were analyzed in the same way as the CBC data. (Double-crested Cor¬ morants wintering in Texas nest primarily outside of the state.) The TCWS has conducted a formal census of colonial nesting waterbirds in Texas since 1967. Data by colony are made available to the public annually and have been compiled for the period 1973-1980 (Texas Colonial Waterbird Society 1982). Although numbers of wintering Olivaceous Cormorants declined during the first half of the 1970’s, they rose to a historic high by the end of the decade (1979-81; Table 1). The decline in the early 1970’s was not as severe in magnitude nor duration as that noted during the 1960’s. Although the total number of Olivaceous Cormorants (for the nine areas analyzed) prior to 1970 often dropped below 100 individuals per winter (range = 14-1682), total numbers since 1970 have remained above 100 birds (range = 125-1807). After nesting Olivaceous Cormorants attained a mean population of more than 900 pairs in 1973-75, they apparently declined slightly through 1981 (Table 1). However, the number of nesting pairs still is considerably higher than that recorded during the 1960’s. The data given for 1979-81 should be considered a minimum number of nesting pairs; coverage (survey) of nesting colonies during 1980 was incom¬ plete, with several colonies not included in the count. After wintering (coastal) Double-crested Cormorant populations reached a historic maximum in the mid-1970’s, they declined during the latter part of the decade (Table 1). However, numbers of Double- crested Cormorants in the mid-1970’s still were about twice as great as population levels previously reported. Numbers of this species were never above 1000 individuals/winter (for the nine count areas) until 1968 (range = 8-937). During the 1970’s numbers usually were greater than 2000 individuals/winter (range = 572-7872), with a historic high of 7872 birds recorded during the winter of 1977-78. Morrison and Slack (1977) summarized possible factors responsible for the fluctuations in populations of cormorants in Texas. Although CORMORANT POPULATION TRENDS 241 Table 1. Mean number of Olivaceous and Double-crested Cormorants wintering (data from nine Christmas Bird Count areas) and nesting (Texas Colonial Waterbird Society 1982) in Texas8. Mean number of Mean number of Olivaceous Cormorants Double-crested Cormorants Period nesting wintering wintering 1949-51 b 188 15 1952-54 — 101 45 1955-57 — 190 134 1958-60 — 773 449 1961-63 — 78 64 1964-66 oc 153 301 1967-69 99 116 1560 1970-72 435 750 794 1973-75 943 351 4365 1976-78 648 424 3860 1979-81 607 994 2549 “Data for 1949-51 to 1973-75 adapted from Morrison and Slack (1977). bSurvey not conducted. 'Data for 1966 only; surveys not conducted prior to 1966. further speculation is not appropriate, apparently populations of cor¬ morants in Texas maintained (on the average) high numbers during the 1970’s. For Olivaceous Cormorants, a nesting population of at least 500 pairs and a wintering population of about 500 individuals (for the nine CBC areas) should be considered average. For Double-crested Cormorants, a winter total of more than 2000 individuals (for the nine areas) should be expected. Continued monitoring of winter (CBC) and nesting (TCWS) cormorants will allow early detection of significant departures from expected population sizes. Wintering Double-crested Cormorants in the coastal regions analyzed herein deserve special atten¬ tion, given the probable decline in their numbers during the late 1970’s. Double-crested Cormorants also winter in inland Texas. There¬ fore, monitoring of inland populations of Double-crested Cormorants is especially important because it is possible that a certain segment of their population may shift between coastal and inland wintering areas among years. Such shifting between wintering areas, if it occurs, could have resulted in an under- or overestimate of populations of this spe¬ cies in the coastal areas monitored in this study. LITERATURE CITED Morrison, M. L., and R. D. Slack. 1977. Population trends and status of the Olivaceous Cormorant. American Birds 31:954-959. Oberholser, H. C. 1974. The bird life of Texas. Vol. 1. University of Texas Press, Austin. 530 p. 242 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 Raynor, G. S. 1975. Techniques for evaluating and analyzing Christmas birds count data. American Birds 29:626-633. Texas Colonial Waterbird Society. 1982. An atlas and census of Texas waterbird colonies 1973-1980. Caesar Kleberg Wildlife Research Institute, Kingsville, Texas. 358 p. OCCURRENCE OF THE CADDISFLY ATOPSYCHE ERIGIA IN TEXAS" GUADALUPE RIVER BELOW CANYON RESERVOIR by ROBERT A. SHORT Aquatic Station Southwest Texas State University San Marcos , TX 78666 ABSTRACT Larvae of the caddisfly Atopsyche erigia, which previously had been reported in south- central Texas only from spring-fed streams, were collected from the Guadalupe River below Canyon Reservoir. Recent colonization of the Guadalupe River by A. erigia appar¬ ently has been enabled by hypolimnial flow from the reservoir, which causes the tailwat- er’s thermal regime to resemble that of a spring-fed stream. The caddisfly (Trichoptera) genus Atopsyche Banks contains about 30 mostly South and Central American species (Ross 1953). Atopsyche erigia Ross occurs in the southwestern United States and has been col¬ lected in several Texas counties (Edwards 1973). All previous larval col¬ lections in Texas have been from spring-fed streams emanating from the Edwards Aquifer in the south-central part of the state, most notably the San Marcos River. Adults always have been taken in areas near a spring-fed stream (Edwards 1973). During 1981, I collected larvae of A. erigia from the Guadalupe River, Comal County, Texas. Larvae were first collected during Sep¬ tember, about 24 km downstream of Canyon Dam, a hypolimnial- release reservoir constructed in 1964. Occurrence of A. erigia at this site is interesting for several reasons. Kent (1971) collected extensively at the same site during 1969-70, some five years after Canyon Dam was closed, but did not report finding any A. erigia. Furthermore, collections by Kent (1971) and myself from the Guadalupe River above Canyon Reservoir did not yield any A. erigia. Apparently, the hypolimnial release has modified environmental conditions such that A. erigia has been able to colonize the Guadalupe River below the dam. Further¬ more, this colonization has occurred within the past ten years, probably from the Comal River some 20 km downstream or from a smaller spring-fed tributary of the Guadalupe River. Streams below hypolimnial-release reservoirs may exhibit thermal and flow characteristics similar to those of springbrooks (Ward and Short 1978). When compared to upstream sections, reservoir tailwaters The Texas Journal of Science, Vol. XXXV, No. 3, September 1983 244 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 tend to have a more constant thermal regime, with winter-warm and summer-cool conditions. Kent (1971) reported an annual range of 8.0- 29.5 C for the Guadalupe River above Canyon Reservoir and 12.5-17.7 C for the section below the dam. The restriction of A. erigia to spring-fed streams may reflect their need for relatively low summer temperatures (Edwards 1973); the family to which it belongs, Rhyacophilidae, is said to be cool-adapted (Wig¬ gins 1977). Thus, the establishment of A. erigia in the Guadalupe River below Canyon Dam may have been in response to the lower water temperatures provided by the hypolimnial release during summer. However, the winter-warm conditions below Canyon Reservoir and in spring-fed streams may also be of importance, considering that A. eri¬ gia belongs to a caddisfly genus with tropical affinities. Edwards (1973) reported collecting adult A. erigia from January through May, indicat¬ ing that growth and/or pupal development continues through the win¬ ter, which might require winter-warm conditions. Life history studies of A. erigia are needed to more fully establish its habitat requirements. I thank Steve Canton and James Ward for helpful suggestions regarding the manuscript. LITERATURE CITED Edwards, S. W. 1973. Texas caddisflies. Tex. J. Sci. 24:491-516. Kent, D. H. 1971. The effects of a deep-storage reservoir on the benthic macroinvertebrate community of the Guadalupe River, Texas. M.S. thesis, Southwest Texas State Uni¬ versity, San Marcos, Texas. Ross, H. H. 1953. Additional material on the phylogeny and dispersal of Atopsyche (Tri- choptera: Rhyacophilidae). J. Wash. Acad. Sci. 43:287-293. Ward, J. V., and R. A. Short. 1978. Macroinvertebrate community structure of four spe¬ cial lotic habitats in Colorado, U.S.A. Verh. Int. Verein. Limnol. 20:1382-1387. Wiggins, G. B. 1977. Larvae of the North American caddisfly genera (Trichoptera). Uni¬ versity of Toronto Press, Toronto, Ontario, Canada. HERPETOFAUNA OF THE PEDRO ARMENDARIZ LAVA FIELD, NEW MEXICO by TROY L. BEST1, HERMAN C. JAMES Llano Estacado Center for Advanced Professional Studies and Research Eastern New Mexico University P or tales, NM 88130 and FRANK H. BEST P.O. Box 4371 Eastern New Mexico University Portales, NM 88130 ABSTRACT Notes on the distribution, relative abundance, habitat, and the relative degree of mela¬ nism are presented for 26 species of amphibians and reptiles collected at the Pedro Armendariz lava field, New Mexico. Crotaphytus collaris, Sceloporus undulatus, Uta stansburiana, Phrynosoma cornutum, P. modestum, Crotalus atrox, and C. molossus exhibited noticeable melanism. The 718 specimens analyzed represent the first compre¬ hensive herpetofaunal study of the lava field. INTRODUCTION Three large basaltic lava fields occur in south-central New Mexico — the Tularosa malpais in Lincoln and Otero Counties, the Afton lava flows in Dona Ana County, and the Pedro Armendariz lava field in Socorro and Sierra Counties. Several authors (e.g., Dice 1929, 1930, 1942; Benson 1932, 1933; Bradt 1932; Dice and Blossom 1937; Burt 1939; Blair 1941, 1943; Lewis 1949; Shields and Crispin 1956) have investi¬ gated the biota of the Tularosa malpais. Lewis (1951), Prieto and Ja¬ cobson (1968), Koschmann (1972), and Elder (1977) have studied reptiles and mammals on the Afton flows. However, no biological investiga¬ tions of the Pedro Armendariz lava field have been published. The earliest account of collecting activities on the Pedro Armendariz lava field was that of Seth Benson of the University of California at Berkeley (unpublished); according to his field notes, Dr. Benson and his wife spent a few days there in July 1933. These field notes contain references to nearly black forms of Phrynosoma, Crotalus, and Crota¬ phytus, as well as dark forms of mammals such as Peromyscus eremi- ^resent address: Department of Biology and Museum of Southwestern Biology, The University of New Mexico, Albuquerque, NM 87131. The Texas Journal of Science, Vol. XXXV, No. 3, September 1983 246 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 cus and Perognathus intermedins. It was not until the late 1970s that additional collecting was done; mammals were collected by Melvin and Felecia Beard of Eastern New Mexico University under a contract with the New Mexico Department of Game and Fish. Our study is the first comprehensive survey of the amphibians and reptiles of the Pedro Armendariz lava field. The purposes of our study were to determine which amphibian and reptile species occur on and near the lava field, the relative abundance of these, the habitats occu¬ pied by each, and the relative degree of melanism within the popula¬ tions. MATERIALS AND METHODS A map of the Pedro Armendariz lava field, including place names mentioned in the text, is presented in Figure 1. The age of the field is approximately 760,000 years (Bachman and Mehnert 1978). It is 15 to 20 km in diameter, and there is a large crater near its center (elevation 1,566 m). The lava abruptly meets the plains on all sides. However, on the west and southwest sides there is a great deal of sandy soil on the lava. The edge of the lava is 3 to 5 m high and rises gradually toward the crater in a series of low hills. Between the low hills are soil-filled flats that hold water following heavy rains (Dr. S. Altenbach, Univer- LAVA-FIELD HERPETOFAUNA 247 sity of New Mexico, Albuquerque, pers. comm. 1982). The soil here is mostly sandy although there is enough clay to make passage of vehicles difficult after rain showers. The surface of the lava field consists of broken pieces of lava embedded in soil. Much of the field is well vege¬ tated with shrubs and grasses. Small lava pebbles form desert pavement between shrubs in many areas. The mosaic of lava and soil areas is extensive, especially near the edges of the lava field, and extends into the crater itself. During April, July, and August of 1981 and May and June of 1982, 718 specimens of amphibians and reptiles were collected on or within 300 m of the lava field. Specimens were collected by hand, by rubber bands (launched ballistically from the collector’s finger), and with .22 caliber no. 12 shot. All specimens were preserved in 10% formalin in the field, stored in 40% isopropyl alcohol, and permanently deposited in the Eastern New Mexico University Natural History Museum. Although we might have been more successful in capturing some species had rocks been overturned systematically, rock- turning was avoided to minimize disturbance of the lava habitat. Unless stated, the species listed below did not exhibit melanism. ACCOUNTS OF SPECIES Ambystomidae, Mole Salamanders Amby stoma tigrinum, Tiger Salmander Specimen examined, 1 — Socorro Co.: Antelope Well. Sight records — Socorro Co.: Lambing Tank. Sierra Co.: Malpais Well. Remarks — Tiger salamanders (larvae and adults) occurred regularly in small numbers in earthen stock tanks. All specimens were observed at night. Pelobatidae, Spadefoot Toads Scaphiopus couchi, Couch’s Spadefoot Specimens examined, 12— Socorro Co.: Lambing Tank. Remarks— Couch’s spadefoots were locally abundant at only one of the four tem¬ porary rainwater ponds where we collected in August 1981. Scaphiopus multiplicatus , Western Spadefoot Specimens examined, 32 — Socorro Co.: Harriet Well; North Well; Lambing Tank; T9S R2E NE 1/4 Sec 20; Sec 29 Windmill. Sierra Co.: Chavez Ranch. Remarks — We have followed Brown (1976) in assigning the species name to this taxon. Western spadefoots occurred regularly in small numbers at earthen stock tanks and abundantly in temporary rainwater ponds. Scaphiopus bombifrons, Plains Spadefoot Specimens examined, 21— Socorro Co.: Harriet Well; Lambing Tank; T9S R2E NE 1/4 Sec 20. Remarks — These spadefoots were locally 248 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 abundant following heavy rains, and were found in three of the four temporary rainwater ponds where we collected in August 1981. Bufonidae, Toads Bufo cognatus, Great Plains Toad Specimens examined, 26 — Socorro Co.: North Well; 2.4 km (1.5 mi) S North Well; Antelope Well; T9S R2E NE 1/4 Sec 20; Sec 29 Windmill. Sierra Co.: Malpais Well; Chavez Ranch. Remarks — The Great Plains toad occurred regularly in small numbers at earthen stock tanks and temporary rainwater ponds throughout the region. One specimen was found under a 20 cm diameter lava boulder 2.4 km (1.5 mi) south of North Well, the nearest water. The soil under the rock was moist from a recent rain. This was the only specimen of Bufo or Scaphiophus actually collected on the lava field proper. Bufo debilis, Green Toad Specimens examined, 12 — Socorro Co.: Lambing Tank; T9S R2E NE 1/4 Sec 20. Remarks — Green toads were locally abundant following heavy rains, and were found in two of four temporary rainwater ponds in August 1981. Testudinidae, Box and Water Turtles, Tortoises Terrapene ornata, Box Turtle Specimens examined, 13 — Socorro Co.: North Well; 0.8 km (0.5 mi) W Antelope Well; Antelope Well; 7.7 km (4.8 mi) NE Lava; Santa Fe Well; 4.2 km (2.6 mi) S Hackberry Well; 1.9 km (1.2 mi) SW Baca Well; Lava. Sierra Co.: 1.0 km (0.6 mi) NE Casa Grande Ranch; Malpais Well; 0.5 km (0.3 mi) NW Windmill, T10S R1E NW 1/4 Sec 14; 3.2 km (2 mi) N Chavez Well. Remarks — Box turtles were common, especially in sand-filled lava areas on the south and west side of the lava field. They were present on the lava field proper in smaller numbers, and were most common in periods following rainfall. During late May and early June 1982, when it was very dry, no box turtles were observed. Iguanidae, Iguanid Lizards Holbrookia maculata, Lesser Earless Lizard Specimens examined, 34 — Socorro Co.: Harriet Well; 2.4 km (1.5 mi) S North Well; Antelope Well; Lambing Tank; 0.6 km (0.4 mi) N Mal¬ pais Well; Lava. Sierra Co.: Malpais Well; 1.0 km (0.6 mi) NE Casa Grande Ranch; 6.4 km (4 mi) SW Casa Grande Ranch; 2.9 km (1.8 mi) SW Casa Grande Ranch; 4.8 km (3 mi) SW Casa Grande Ranch; 3.2 km (2 mi) N Chavez Well. Remarks — Individuals of this species were locally abundant near the edge of the lava field, but were not common on the lava field proper. They preferred sandy soils with sparse vegeta- LAVA-FIELD HERPETOFAUNA 249 tion, and were often observed at entrances to banner-tailed kangaroo rat (Dipodomys spectabilis) burrows. Within the lava field, lesser earless lizards were found only on the flat, sandy-soiled areas. They were most active during the warmest part of the day. Crotaphytus collar is, Collared Lizard Specimens examed, 145— Socorro Co.: Harriet Well; 0.8 km (0.5 mi) W North Well; 2.4 km (1.5 mi) S North Well; 2.9 km (1.8 mi) SW North Well; Antelope Well; T9S R1E NE 1/4 Sec 1; T9S R2E N 1/2 Sec 5; Lambing Tank; Santa Fe Well; 0.2 km (0.1 mi) SE Crater Well; Ruins, 1.1 km (0.7 mi) SE Crater Well, 1.6 km (1 mi) SW Crater Well; 1.9 km (1.2 mi) SW Crater well; 3.1 km (1.9 mi) NE Hackberry Well; 2.4 km (1.5 mi) NE Hackberry Well; 1.8 km (1.1 mi) NE Hackberry Well; 2.1 km (1.3 mi) E Hackberry Well; 2.9 km (1.8 mi) E. Hackberry Well; Hackberry Well; Sec 29 Windmill; 1.1 km (0.7 mi) SE Hackberry Well; 1.4 km (0.9 mi) SE Hackberry Well; 3.1 km (1.9 mi) SSW Hack¬ berry Well; 7.6 km (4.7 mi) SSW Hackberry Well; 50.7 km (31.5 mi) N, 18.5 km (11.5 mi) E Engle; T9S R2E S 1/2 Sec 19; T9S R2E N 1/2 Sec 29; T9S R2E N 1/2 Sec 33; 1.9 km (1.2 mi) SW Baca Well; Sec 36 Windmill; 3.9 km (2.4 mi) NNW Malpais Well; 3.4 km (2.1 mi) NNW Malpais Well; 3.2 km (2 mi) NNW Malpais Well; 3.1 km (1.9 mi) NNW Malpais Well; 2.9 km (1.8 mi) NNW Malpais Well; 0.6 km (0.4 mi) N Malpais Well; Lava. Sierra Co.: 1.9 km (1.2 mi) E Casa Grande Ranch; T10S R2E NW 1/4 Sec 6; T10S R2E SW 1/4 Sec 6; T10S R2E SE 1/4 Sec 6; T10S R2E NW 1/4 Sec 7; 0.5 km (0.3 mi) NW Windmill, T10S R1E NW 1/4 Sec 14; 6.4 km (4 mi) SW Casa Grande Ranch; T10S R1E W 1/2 Sec 15; 3.2 km (2 mi) N Chavez Well. Remarks — The collared lizard was probably the most abundant reptile on the lava field; most lava outcrops had one or more individuals present. Collared lizards also were found perched in tops of Rhus and A triplex, and on man-made objects such as cement blocks, corrals, and old boards. This species was restricted mostly to the lava field, although specimens were collected 50 to 80 m from the lava border. They were most active dur¬ ing the warmest part of the day. Specimens ranged from almost black dorsally to pale green. The majority of specimens was dark and many were approximately the same color as the lava. Ventrally, all specimens were pale. Crotaphytus wislizenii, Leopard Lizard Specimens examined, 7 — Socorro Co.: Antelope Well; Santa Fe Well. Sierra Co.: 1.9 km (1.2 mi) E Casa Grande Ranch; Malpais Well; 0.5 km (0.3 mi) NW Windmill, T10S R1E NW 1/4 Sec 14. Remarks— Leopard lizards were not common. They seemed to prefer sandy soils and were most active during the warmest portion of the day. This spe- 250 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 cies was never found on the lava field, but was collected within 20 m of lava at all localities. Sceloporus undulatus, Fence Lizard Specimens examined, 13 — Socorro Co.: Harriet Well; T9S R2E N 1/2 Sec 5. Sierra Co.: 3.2 km (2 mi) N Chavez Well. Remarks — These lizards were found in only three localities. Fence lizards were common on the sides and tops of large lava boulders at the Harriet Well and Chavez Well sites, and their absence at other localities is puzzling. Although specimens at the lava field were all found on or near the lava, one specimen was collected from the top of a fence post in a sandy soiled area several miles north of the lava field (Socorro Co., T7S R2E SW 1/4 Sec 21). Specimens from the lava field were dark. How¬ ever, the two light colored dorsolateral stripes were visible. Uta stansburiana, Side-blotched Lizard Specimens examined, 185 — Socorro Co.: Harriet Well; North Well; 2.1 km (1.3 mi) SW North Well; 2.4 km (1.5 mi) S North Well; 2.1 km (1.3 mi) N Harriet Ranch Hdqts.; T9S R2E N 1/2 Sec 5; Antelope Well; Santa Fe Well; Lava; Malpais Well. Sierra Co.: 1.9 km (1.2 mi) E Casa Grande Ranch; Malpais Well; 2.9 km (1.8 mi) SW Casa Grande Ranch; 0.5 km (0.3 mi) NW Windmill, T10S R1E NW 1/4 Sec 14; 6.4 km (4 mi) SW Casa Grande Ranch; 3.2 km (2 mi) N Chavez Well. Remarks — Side-blotched lizards were locally abundant, especially in areas with considerable sand on the lava. The area on the east side of the lava field had relatively little sand, and no U. stansburiana was col¬ lected there. Since U. stansburiana is relatively dark colored, it was dif¬ ficult to assess the degree of melanism in this species. Specimens ex¬ hibited some melanism, but were extremely variable. In collecting specimens we qualitatively observed that darker specimens came from areas with less sand on the lava, and vice versa. We believe this species would be valuable in studying color variation between populations occurring on and off the lava field. Phrynosoma cornutum, Texas Horned Lizard Specimens examined, 7 — Socorro Co.: 2.4 km (1.5 mi) S North Well; 0.8 km (0.5 mi) W Antelope Well; Santa Fe Well; Sec 29 Windmill; Lava. Sierra Co.: 3.2 km (2 mi) S Lava. Sight record — Socorro Co.: 2.1 km (1.3 mi) N Harriet Ranch Hdqts. (eviscerated and mummified body on Rhus ; not saved). Remarks — Texas horned lizards were common only on the west and northwest portions of the lava field in both lava and sand covered areas. The species seemed most common on sandy sites, and many were observed in sandy habitat north of the lava field. Some of the specimens exhibited a slight degree of melanism. LAVA-FIELD HERPETOFAUNA 251 Phrynosoma modestum , Round-tailed Homed Lizard Specimens examined, 15— Socorro Co.: Harriet Well; 2.4 km (1.5 mi) S North Well; T9S R1E NE 1/4 Sec 1; Antelope Well; T9S R2E N 1/2 Sec 5; Hackberry Well; Sec 29 Windmill; 41.0 km (25.5 mi) N, 8.9 km (5.5 mi) E Engle; 1.9 km (1.2 mi) SW Baca Well. Sierra Co.: 6.4 km (4 mi) SW Casa Grande Ranch; 3.2 km (2 mi) N Chavez Well. Sight record — Sierra Co.: 0.5 km (0.3 mi) NW Windmill, T10S R1E NW 1/4 Sec 14 (eviscerated and mummified body on Prosopis ; not saved). Remarks— This was one of the most abundant reptiles on the lava field proper. It occupied lava flats and sandy flats next to lava outcrops. Some specimens were nearly black and others were paler, but all of them exhibited some melanism. Teiidae, Whiptails Cnemidophorus neomexicanus, New Mexico Whiptail Specimens examined, 48— Socorro Co.: Harriet Well; North Well; 2.1 km (1.3 mi) N Harriet Ranch Hdqts.; 2.4 km (1.5 mi) S North Well; Antelope Well; 2.3 km (1.4 mi) NNE Santa Fe Well; Santa Fe Well; T9S R2E N 1/2 Sec 29; 1.9 km (1.2 mi) SW Baca Well; Lava. Sierra Co.: 1.9 km (1.2 mi) E Casa Grande Ranch; T10S R2E NW 1/4 Sec 7; 0.5 km (0.3 mi) NW Windmill, T10S R1E NW 1/4 Sec 14; 4.8 km (3 mi) SSW Lava; 6.4 km (4 mi) SW Casa Grande Ranch. Remarks— New Mexico whiptails were most abundant on the extreme north side of the lava field near Harriet Well and North Well. The species was common throughout the rest of the region, but in lesser numbers. It occurred on both lava and soiled sites, but seemed to prefer soil-covered areas. Cnemidophorus inornatus , Seven-striped Whiptail Specimens examined, 62 — Socorro Co.: Harriet Well; North Well; 2.1 km (1.3 mi) N Harriet Ranch Hdqts.; 2.4 km (1.5 mi) S North Well; T9S R1E NE 1/4 Sec 1; Antelope Well; T9S R2E N 1/2 Sec 5; Lambing Tank; Santa Fe Well; Hackberry Well; Sec 29 Windmill; 2.3 km (1.4 mi) SW Hackberry Well; 5.3 km (3.3 mi) SW Hackberry Well. Sierra Co.: Malpais Well; T105 R2E SE 1/4 Sec 6; T10S R2E NW 1/4 Sec 7; 2.9 km (1.8 mi) SW Casa Grande Ranch; 0.5 km (0.3 mi) NW Wind¬ mill, T10S R1E NW 1/4 Sec 14; 6.4 km (4 mi) SW Casa Grande Ranch; 3.2 km (2 mi) N Chavez Well. Remarks— This lizard was one of the most common species on the lava field; it was also common in adjacent areas. Cnemidophorus tigris, Marbled Whiptail Specimens examined, 2— Socorro Co.: 2.1 km (1.3 mi) N Harriet Ranch Hdqts.; Santa Fe Well. Remarks — Marbled whiptails were rare, and were never found on the lava field. The specimen from near Har¬ riet Ranch was collected on top of a banner-tailed kangaroo rat mound, 252 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 near some broomweed ( Xanthocephalum ) and grass; the substrate was sandy with desert pavement of caliche and lava. The Santa Fe Well specimen was collected in creosote bush ( Larrea ) habitat north of the lava field, again with caliche desert pavement. Cnemidophorus tesselatus, Checkered Whiptail Specimens examined, 51 — Socorro Co.: Harriet Well; 2.1 km (1.3 mi) N Harriet Ranch Hdqts.; 2.4 km (1.5 mi) S North Well; Lambing Tank; Santa Fe Well; Hackberry Well; T9S R2E N 1/2 Sec 29; Sec 36 Windmill; 1.9 km (1.2 mi) SW Baca Well; Malpais Well. Sierra Co.: 1.9 km (1.2 mi) E Casa Grande Ranch; Malpais Well; T10S R2E SE 1/4 Sec 6; T10S R2E NW 1/4 Sec 7; 0.5 km (0.3 mi) NW Windmill, T10S R1E NW 1/4 Sec 14; 3.2 km (2 mi) N Chavez Well. Remarks— This species was common, especially on soil-covered areas in and near the lava field. It seemed to prefer areas with sand and at least some lava nearby, but several were collected on sandy soils away from the lava. Colubridae, Colubrid Snakes Sonora semiannulata, Ground Snake Specimens examined, 2 — Socorro Co.: T9S R2E N 1/2 Sec 33. Sierra Co.: T10S R2E NW 1/4 Sec 7. Remarks — Because we elected not to sys¬ tematically overturn rocks, this species may have been more common than was indicated by our observations. One specimen was collected from under a 20 cm diameter lava rock on a lava outcrop; the other was collected as it crawled across the desert pavement on a soil-filled lava flat. Heterodon nasicus, Western Hognose Snake Specimen examined, 1 — Socorro Co.: North Well. Remarks — These snakes are common in the general region, but they probably are not abundant on the lava field. Our specimen was collected as it crawled along the cement base of the large stock tank at North Well. Masticophis flagellum, Coachwhip Specimens examined, 5 — Socorro Co.: North Well; 2.1 km (1.3 mi) N Harriet Ranch Hdqts.; 2.4 km (1.5 mi) S North Well. Sierra Co.: 4.0 km (2.5 mi) SW Casa Grande Ranch; T10S R1E NE 1/4 Sec 13. Remarks— Coachwhips were common on the lava field and throughout the region. They seemed to prefer sandy-soiled areas. Pituophis melanoleucus, Gopher Snake Specimens examined, 3 — Socorro Co.: 0.8 km (0.5 mi) W Antelope Well. Sierra Co.: Malpais Well; T10S R2E NW 1/4 Sec 7. Remarks— Gopher snakes were common on the lava field and throughout the region. LAVA-FIELD HERPETOFAUNA 253 V iperidae, Pit Vipers Crotalus atrox, Western Diamondback Rattlesnake Specimens examined, 14 — Socorro Co.: Harriet Well; 2.1 km (1.3 mi) N Harriet Ranch Hdqts.; Hackberry Well; T9S R2E N 1/2 Sec 33; Sec 29 Windmill; 41.0 km (25.5 mi) N, 8.9 km (5.5 mi) E Engle; Sec 36 Windmill. Sierra Co.: 0.5 km (0.3 mi) NW Windmill, T10S R1E NW 1/4 Sec 14. Remarks — This is probably the most common snake species on the lava field. Lava outcrops and soil-covered areas next to lava were preferred, but some western diamondbacks occurred in adjacent sandy areas at dusk. All specimens exhibited melanism. The variation ranged from nearly black to moderately dusky. The diamond-shaped dorsal markings were visible on all specimens. Often the ventral sides were pinkish rather than cream colored. Crotalus molossus, Black-tailed Rattlesnake Specimen examined, 1 — Socorro Co.: 50.7 km (31.5 mi) N, 18.5 km (11.5 mi) E Engle (=Ruins). Remarks— Our specimen was coiled in a rockpile in the mining ruins near the center of the lava field, and was darker than those examined from adjacent areas in New Mexico. Crotalus viridis, Prairie Rattlesnake Specimens examined, 6 — Socorro Co.: Harriet Well; Antelope Well; Santa Fe Well; T9S R2E NE 1/4 Sec 20; Lava. Remarks — Prairie rat¬ tlesnakes were common, especially on sandy areas, throughout the region. They preferred sandy soils away from the lava, but the speci¬ men from Antelope Well was collected from the top of a large lava out¬ crop where it was coiled on the sand in a lava crevice. MELANISM IN REPTILES FROM NEW MEXICO LAVA FLOWS Coloration of reptiles on New Mexico lava fields has received little attention. Lewis (1949) briefly reported on the coloration of reptiles from the Tularosa malpais, and Lewis (1951) and Prieto and Jacobson (1968) provided comments on specimens they collected on the Afton lava flows. These studies provide a basis for comparisons of coloration between the three southern New Mexico lava fields. We observed some degree of melanism in seven reptile species on the Pedro Armendariz lava field; these were Crotaphytus collaris, Scelopo- rus undulatus, Uta stansburiana, Phrynosoma cornutum, P. modestum, Crotalus atrox , and C. molossus. Of these species, Lewis (1951) col¬ lected U. stansburiana and C. collaris on the Afton lava flows and also found them to be malanistic. However, his C. atrox was not melanistic. Prieto and Jacobson (1968) subsequently collected additional non- melanistic specimens of C. atrox from the Afton lava flows, but their C. molossus were melanistic. For the Tularosa malpais, Lewis (1949) col- 254 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 lected specimens of U. stansburiana, S. undulatus, C. co llaris, and C. molossus; all exhibited melanism. Thus, C. collaris, U. stansburiana, and C. molossus were darker on all three fields, S. undulatus was darker on both lava fields where they occurred (the Pedro Armendariz field and the Tularosa malpais), and the only darkly pigmented popu¬ lations of P. cornutum, P. modestum, and C. atrox were on the Pedro Armendariz field. ACKNOWLEDGEMENTS We are grateful to Dr. G. Sanchez, Dean of Graduate Studies and Research, Llano Estacado Center for Advanced Professional Studies and Research, Eastern New Mexico University, who provided a major por¬ tion of the financial support for this project. N. J. Scott verified our identifications of specimens, A. L. Gennaro provided some of the equipment, and W. R. Barber, D. G. Beard, H. F. Pearson, and F. W. Weckerly provided valuable assistance in the field. Joe Williams and Johnnie Mounyo allowed us to collect specimens on the land in their care; we sincerely appreciate their assistance. L. L. DeVries typed the manuscript, D. J. Hafner helped prepare the figure, S. A. Reza assisted in proofreading, and N. J. Scott provided valuable criticism and con¬ sultation throughout the study. LITERATURE CITED Bachman, G. O., and H. H. Mehnert. 1978. New K-Ar dates and the late Pliocene to Holocene geomorphic history of the central Rio Grande region, New Mexico. Geol. Soc. Amer. Bull. 89:283-292. Benson, S. B. 1932. Three new rodents from lava beds of southern New Mexico. Univ. California Publ. Zool. 38:335-345. Benson, S. B. 1933. Concealing coloration among some desert rodents of the southwestern United States. Univ. California Publ. Zool. 40:1-69. Blair, W. F. 1941. Annotated list of mammals of the Tularosa Basin, New Mexico. Amer. Midi. Nat. 26:218-229. Blair, W. F. 1943. Ecological distribution of mammals in the Tularosa Basin, New Mex¬ ico. Contrib. Lab. Vert. Biol., Univ. Michigan No. 20, 24 p. Bradt, G. W. 1932. The mammals of the malpais, an area of black lava rock in the Tula¬ rosa Basin, New Mexico. J. Mammal. 13: 321-328. Brown, H. A. 1976. The status of California and Arizona populations of the western spadefoot toads (genus Scaphiopus ). Nat. Hist. Mus. Los Angeles Co., Contrib. Sci. No. 286, 15 p. Burt, W. H. 1939. A new woodrat ( Neotoma mexiana) from the lava beds of southern New Mexico. Occas. Pap. Mus. Zool., Univ. Michigan No. 400, 3 p. Dice, L. R. 1929. Description of two new pocket mice and a new woodrat from New Mex¬ ico. Occas. Pap. Mus. Zool., Univ. Michigan No. 203, 4 p. Dice, L. R. 1930. Mammal distribution in the Alamogordo region, New Mexico. Occas. Pap. Mus. Zool., Univ. Michigan No. 213, 32 p. Dice, L. R. 1942. Ecological distribution of Peromyscus and Neotoma in parts of south¬ ern New Mexico. Ecology 23: 199-208. LAVA-FIELD HERPETOFAUNA 255 Dice, L. R., and P. M. Blossom. 1937. Studies of mammalian ecology in southwestern North America with special attention to the colors of desert mammals. Carnegie Inst. Washington Publ. No. 485, 129 p. Elder, F. F. B. 1977. The ecological distribution of the rock pocket mouse Perognathus intermedius Merriam, in the Afton lava flows of southern New Mexico. Stud. Nat. Sci., Eastern N. Mex. Univ. 2(3): 1-23. Koschmann, J. R. 1972. Melanism in rodents of the Afton lava flows, Dona Ana County, New Mexico. M.S. Thesis, Univ. Texas El Paso, 50 p. Lewis, T. H. 1949. Dark coloration in the reptiles of the Tularosa malpais, New Mexico. Copeia 1949:181-184. Lewis, T. H. 1951. Dark coloration in the reptiles of the malpais of the Mexican border. Copeia 1951:311-312. Prieto, A. A., and E. R. Jacobson. 1968. A new locality for melanistic Crotalus molossus molossus in southern New Mexico. Herpetologica 24:339-340. Shields, L. M., and J. Crispin. 1956. Vascular vegetation of a recent volcanic area in New Mexico. Ecology 37:341-351. TAXONOMIC STATUS OF THE BRAZILIAN COLUBRID SNAKE, XENODON SUSPECTUS COPE by JAMES R. DIXON Department of Wildlife and Fisheries Sciences Texas A^M University College Station, TX 77843 ABSTRACT Xenodon suspectus is proposed to be conspecific and synonymous with X. rhabdoce- phalus. In 1968 Cope questioned the relationship of several species of Xenodon and agreed with Gunther (1863) that the species in British India belonged to another genus. However, Cope argued that Jan’s (1863) removal of Xenodon gigas to a separate genus was in error. When Cope (1868) described the single known specimen of Xenodon suspectus, he had before him two specimens of X. gigas (= Hydrody- nastes gigas), five of X. sever us, one of X. neovidii (= X. neuwiedii ), three of X. colubrinus (= X. rhabdocephalus), and four of X. angusti- rostris (= X. rhabdocephalus ). Cope stated that the type locality of X. suspectus was Lake Jose Azzu, Brazil. Amaral (1929), in his list of neo¬ tropical snakes, gave the distribution of X. suspectus as “eastern Peru’’, and this suggestion was followed by Peters and Orejas-Miranda (1970). A review of the literature indicates that only one specimen of X. sus¬ pectus, other than the holotype, has been recorded. This specimen was reported by Boulenger (1894) from Moyobamba, N.E. Peru. Dick (1977), in his account of the stations of the Thayer Expedition to Brazil during 1865-1866, states that Agazziz, Burkhardt, Thayer, and Coutinho traveled to Lago Jose Assu (=Acu), Brazil, during August 27- 30, 1865. This locality is approximately 02°51'S — 57°00'W. It is no longer named Lago Jose Assu on modern maps and gazetteers for Brazil. The locality now may be recognized as the body of water formed at the confluences of Igarape Acu, Rio Ariau, and Rio Andira, on the extreme eastern edge of the Brazilian state of Amazonas. This lake is located just west and south of the confluence of the Rio Ramos and Rio Andira. The Peruvian locality is either the town or province of Moyobamba. The town lies at 854 meters and the lowest part of the province is at an The Texas Journal of Science, Vol. XXXV, No. 3, September 1983 258 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 10 mm Figure I. Dorsal and lateral views of the heads of three Xenodon rhabdocephalus from Iquitos region, Peru, and of the holotype of X. suspectus. A) TCWC 38213, female; B) MCZ 362, female (holotype of X. suspectus)-, C) TCWC 42103, male; D) TCWC 42100, male. elevation of approximately 200 meters, well within the known altitudi¬ nal distribution of Xenodon. Boulenger (1894) diagnosed X. suspectus and separated it from X. columbrinus (= rhabdocephalus) only on the basis of the width and depth of the rostral scale, i.e., one and one-third as broad as deep in X. suspectus versus one and one-half to one and two-thirds as broad as deep in X. rhabdocephalus. The two species are essentially identical in scutellation and color pattern. The only other species of Xenodon STATUS OF XENODON SUSPECTUS 259 Table 1. Range of variation in external characters of Xenodon rhabdocephalus and X. suspectus, taken from specimens. Number in parenthesis below name represents sam¬ ple size. X. r. rhabdocephalus (40) suspectus (2) r. mexicanus (10) Scale Rows 19-19-15 19-19-15 19-19-17 Ventrals 135-155 132-140 124-144 Subcaudals 36-50 36-41 35-42 Supralabials 8 8 8 Infralabials 9-11 9 9-10 Infral. Chin Shield Contact 5-7 6 5-6 Preoculars 1-3 1 1 Postoculars 2-3 2 2 Temporals 1 + 2/2 + 3 1 +2 1 + 2 Max. Teeth 14-19 16 15-16 Blotches 13-18 14 13-15 Tail/Total Length Ratio .132- .152 .134 .138 - .168 Supral/Orbit 4 + 5 4+- 5 4 + 5 Anal Plate E E E Rostral Width/Height 1.32- 1.80 1.33 1.40- 1.60 (sensu stricto) that have the essential external characters of X. suspectus are X. bertholdi and X. guentheri. Of these, X. guentheri has a higher number of ventrals (170) and subcaudals (57), and a divided anal plate. Xenodon bertholdi has, on each side of the trunk, a series of large oval spots that are separated from each other medially. A sample of 28 Xenodon rhabdocephalus that I examined from a 100 km radius of Iquitos, Peru, exhibited several color patterns. The dor¬ sum ranged from a very light ground color with dark blotches to a uni¬ form blackish brown. The venter was almost immaculate yellow to dusky dark brown. The dorsum of the head varied from light brown freckles and mixed dark spots to uniform brown. The side of the head was almost completely black to almost completely light tan or yellow. Of the 28 specimens, 21.4% had wide (Fig. 1A), 28.6% medium (Fig. 1C), and 50.0% narrow (Fig. ID) temporal dark stripes from the snout to the temporal region of the head. The dorsum of the head was dense¬ ly freckled (Fig. 1A) in 60.7%, had a spear-shaped mark (Fig. 1C) in 14.3%, and an ill-defined spear with freckles (Fig. ID) in 25.0% of the individuals. The infralabials and supralabials were scored as freckled (light on dark or dark on light), streaked (black edging), or unmarked. The labials were freckled in 25.0%, streaked in 64.3%, and unmarked in 10.7% of the sample. The ventral color was dark in 14.3%, moderately dark in 21.4%, moderately light in 17.9%, and light in 46.4% of the sample. Twenty-seven of the 28 individuals contained 13-18 (mean = 14.7) body blotches; one individual was unicolored. 260 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 The single specimen in the British Museum identified as X. suspec¬ tus from Moyobamba, Peru, and the holotype of X. suspectus (Fig. IB), appear very similar to the dark phase color pattern of X. rhabdocepha - lus (Fig. 1A). This — together with the broad overlap of count-data from the two forms (Table 1) — leads me to propose that Xenodon suspectus be considered a junior subjective synonym of X. rhabdocephalus. I thank E. E. Williams for the loan of the type specimen of X. sus¬ pectus. I also thank W. W. Lamar for data on Colombian Xenodon and R. Dean, H. McCrystal and E. Michaud for reviewing the manuscript. LITERATURE CITED Amaral, A., do. 1929. Estudos sobre ophidios Neotropicos XVII. Valor systematico de varias formas de ophidios neotropicos. Mem. Inst. Butantan 4:1-68. Boulenger, A. G. 1894. Catalogue of the snakes in the British Museum (Natural History). Vol 2. Trustees of the Museum, London, England, xi + 382 p. Cope, E. D. 1868. An examination of the Reptilia and Batrachia obtained by the Orton Expedition to Ecuador and the upper Amazon, with notes on other species. Proc. Acad. Nat. Sci. 20:96-140. Dick, M. M. 1977. Stations of the Thayer expedition to Brazil 1865-1866. Brevoria 444:1- 37. Gunther, A. 1863. Third account of new species of snakes in the collection of the British Museum. Ann. Mag. Nat. Hist. (3)12:348-365. Jan, G. 1863. Enumerazione sistematica degli ofidi appartenenti al gruppo Coronellidae. Arch. Zool. Anat. Fisiol. 2(2):213-330. Peters, J. A., and B. Orejas-Miranda. 1970. Catalogue of the neotropical Squamata. Part 1. Snakes. Bull. U.S. Natl. Mus. 297:v-347. VISCOMETRIC MEASUREMENT OF THE CELLULASE ACTIVITY OF A SOIL FUNGUS by J. ORTEGA and E. J. BACA School of Sciences and Mathematics Pan American University Edinburg , TX 78539 ABSTRACT A simple viscometric technique for the determination of the cellulase activity of fluids from liquid cultures of fungi was developed. Because results were expected to follow Michaelis-Menten kinetics for enzyme activity, the data obtained from the viscosity tests were fitted to an exponential function. Significantly high coefficients of correlation were obtained. The inital rates of the reactions were calculated from these functions. The Michaelis-Menten constant (Km) of the test fungus was estimated from a Lineweaver- Burk plot. INTRODUCTION Fungi vary greatly in their ability to decompose cellulosic materials (Mandels and Weber 1969; Mandels 1975; Rosenberg 1978). Because the number of species of fungi found in most agricultural soils tends to be large, there is a need for a simple and direct method that will permit the screening of large numbers of fungal isolates for cellulolytic activity with a minimum of laboratory equipment and time. This work is an attempt to develop such a method. Several methods based on viscometric techniques have been proposed for the evaluation of cellulase activity of fungi and other microorga¬ nisms. One of these mehtods (Levinson and Reese 1950) relates cellu¬ lase activity to the changes in fluidity of a cellulose-derivative test solu¬ tion. This method does not seem to equate cellulase activity with the rate at which depolymerization of the substrate occurs. Another method (Almin and Eriksson 1967; Almin et al. 1967) is complicated by the cal¬ culation and introduction of an exponent (a) based on the empirical relationship between the intrinsic viscosity of the test solution and time. A final method (Hulme 1971) offers a somewhat similar approach to that described here. It relates cellulase activity to specific viscosity of a test solution and to the average molecular weight of the substrate; Lineweaver-Burk plots for the velocity of depolymerization of the sub¬ strate are calculated as the reciprocals of the units of cellulase activity versus concentration of the substrate. In this work, the proposed method for measuring cellulase activity is based on the Michaelis-Menten equation as described by Laidler (1965). The Texas Journal of Science, Vol. XXXV, No. 3, September 1983 262 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 With the use of this equation and the Lineweaver-Burk plot as des¬ cribed by Williams and William (1973), the maximum velocity of sub¬ strate degradation (a measure of enzyme activity) for a given enzyme concentration can be calculated. Furthermore, the Michaelis-Menten constant, which is an approximate measure of the enzyme-substrate bonding affinity, can be evaluated. THEORY In the study of reactions affected by enzymes, it is necessary to mea¬ sure the initial rate of the reaction at variable substrate concentrations while the concentration of the enzyme is kept constant. The initial rate of the reation can be determined by fitting the concentration and time data for each experiment to the exponential function. Cs = a • ebt where Cs represents the concentration of the substrate, a and b are the constants fo the function, e is the base of natural logarithms and t is the time. The inital rate, VQ, then can be evaluated by computing dCs/dt at time = 0, which is, Vo = dCs(0)/dt = a • b. The Michaelis-Menten equation can be used to relate the initial rate to the concentration of the substrate. This equation leads to the follow¬ ing expression for the rate: Vo = Vm • Cs/(Km + Cs) where VD is the initial rate, Vm the maximum reaction velocity, Cs the concentration of the substrate and Km the Michaelis-Menten constant. This expression can be rearranged to obtain 1/Vo = Km/(Vm • Cs) + 1/Vm. The Michaelis-Menten constant (Km) can be determined from the slope and the intercept of the linear regression of 1/VQ versus 1/CS. The specific viscosity (Nsp) determined experimentally for each of the test solutions can be used to determine the average molecular weight (Mn) and the concentration (Cs) of the substrate using the method pro¬ posed by Hulme (1971). CELLULASE ACTIVITY OF SOIL FUNGUS 263 MATERIALS AND METHODS The fungus Fusarium roseum was isolated from soil taken from an agricultural field near Edinburg, Texas, in March of 1982. The initial culture was purified and identified following the methods of Toussoun and Nelson (1976). The liquid culture medium had the following composition: (NH4)2S04, 4.5 g; KH2P04, 2.0 g; MgS04*7H20, 0.8 g; Ca(N03)2-4H20, 0.5 g; Fe(N03)3-9H20, 1.44 mg; ZnS04*7H20, 0.88 mg; MnS04*4H20, 0.40 mg; Neo Peptone (Difco), 5.0 g; powdered cellulose (Sigma 50), 20.0 g; distilled water, 1000 ml. The pH of the medium was adjusted to 5.0 with 0.01 M K2HP04 buffer. The medium was dispensed in 500-ml flasks, 250 ml per flask, and sterilized for 15 minutes at 121 C and 15 psi. Solid medium for the inoculum was prepared by adding 15 g of agar to the ingredients listed above. Seven-day-old cultures of the test fungus grown in petri dishes on solid medium were used as sources of inocu¬ lum. Each culture flask was inoculated as described before (Ortega 1980) by aseptically transferring four 5 mm inoculum disks carrying hyphae and spores. All cultures were incubated at 25 C. Samples from the fungus cultures were taken after eight days of cul¬ tivation by pipetting 15 ml of the fluid into sterile test tubes. The sam¬ ples were centrifuged at 6000 g for 15 minutes at 20 C. After centrifuga¬ tion, the clear supernatant was carefully pipetted into sterile test tubes and frozen until the cellulase assays were made. Samples of the culture fluids were assayed for carboxymethyl cellu¬ lase (CM cellulase; EC 3.2. 1.4) as described before (Ortega 1980), by measuring the change in the viscosity of a buffered solution of sodium carboxymethyl cellulose, when the fluid from the test fungus was mixed with it and the reaction mixture was kept at constant tempera¬ ture. The test solution consisted of 7.0 g of sodium carboxymethyl cel¬ lulose (CMC, type 7HF with a D.S. of 0.7, by Hercules, Inc.) dissolved in 1000 ml of 0.055 M sodium citrate buffer with a pH of 5.0. A series of test solutions with different CMC concentrations (0.2% to 0.8%) was also prepared for the determination of the Michaelis-Menten constant. The reaction mixture consisted of 9 ml of CMC test solution and 1 ml of a 50% dilution of the fungus fluid in 0.055 M sodium citrate buffer. The changes in the viscosity of the reaction mixture were determined with a Cannon-Fenske routine viscometer. All tests were made at 37 C, at intervals of 1 to 3 minutes for 25 to 30 minutes. The efflux time of the viscometer was determined in seconds. The data obtained from the viscosity tests were used to determine the specific viscosity of the sub¬ strate, the rate of the reaction and the activity of the enzyme. Specific viscosity (Nsp) was determined as suggested by Levinson and Reese 264 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 (1950). Reaction rates were determined as the time-derivatives of the exponential functions of the substrate concentrations versus the incuba¬ tion time. The measurement of the cellulase activity was based on the amount of substrate hydrolyzed as inferred from viscosity reduction, not on the formation of any intermediate or end product of the reaction. The unit of enzyme activity was that amount of cellulase that produces a 0.1 mg per ml decrease in the substrate concentration per minute at 37 C, under the conditions described for the assay. The Michaelis-Menten constant was estimated from a Lineweaver- Burk plot of the reciprocals of substrate concentrations against the reciprocals of the reaction rates at different substrate concentrations and constant amount of enzyme, at the start of the reaction. RESULTS AND DISCUSSION The data presented in Table 1 show the changes in viscosity and inferred substrate concentration with respect to time for a typical exper¬ iment in which the initial substrate concentration was 4.71 g per liter. The viscosity of the reaction mixture was reduced 23.5 % during the first 90 seconds of incubation. A plot of substrate concentration (Cs) versus time for this experiment is shown in Figure 1. This plot, as well as those obtained for other experiments with different initial substrate concentrations, resulted in a good fit to the exponential model. The units of cellulase activity shown in Table 1 can be determined directly from this plot or from the data of Table 1. Initial reaction rates (Vo) were determined from the plots of a series of tests with different initial substrate concentrations and con¬ stant amount of enzyme (Table 2). The relationship between the reciprocal of Vo and substrate concen¬ tration (Cs) is shown in Figure 2. This Lineweaver-Burk plot illustrates that the reaction followed the Michaelis-Menten model for enzyme activity. The Michaelis-Menten constant (Km = 2.84 X 10~2) for the test fungus was determined from the resulting slope and intercept of a lin¬ ear regression of the plot. Maximum velocity (77.9 units per ml per minute) of substrate degradation was determined from the intercept of the plot. The method described above permits one to determine the activity of fungal cellulases from simple viscometric measurements and a few cal¬ culations. The present method is more precise than that of Levinson and Reese (1950) and less cumbersome than that of Almin and Eriksson (1967) and Almin et al. (1967). Its advantage over the method of Hulme (1971) is that the initial reaction rate can be estimated directly, by fit¬ ting experimental viscosity data to an exponential model. CELLULASE ACTIVITY OF SOIL FUNGUS 265 Table 1. Decline in viscosity of a solution of sodium carboxymethyl cellulose due to cel- lulase activity of Fusarium roseum. Time in minutes Efflux, seconds Specific viscosity8 Cs, g per liter xlO 1 Activity Units'5 0.00 281 55.88 4.71 1.49 216 42.72 4.04 45 5.58 192 37.87 3.76 17 9.35 173 34.02 3.54 13 12.78 159 31.19 3.36 11 16.02 147 28.76 3.20 10 18.89 138 26.94 3.08 9 21.79 130 25.32 2.97 8 24.51 124 24.10 2.88 7 27.05 118 22.89 2.79 7 29.48 114 22.08 2.73 7 32.10 109 21.06 2.66 6 “Centistokes bEach unit equals a 0.1 mg per ml decrease in the substrate concentration per minute, as described in the text. Figure 1. Substrate concentration (Cs, in g per liter) versus time (t, in minutes). Equation of the line is Cs = 0.404-e"° °136 t; r2 = 0.99. 266 THE TEXAS JOURNAL OF SCIENCE-VOL. XXXV, NO. 3, 1983 Table 2. Data for a Lineweaver-Burk plot of the cellulase activity of Fusarium roseum. Nspa Cs.g per liter 1/C., (g per liter) 1 Vo, (g per liter per minute) 1/Vo, (g per liter per minute)-1 2.6 0.64 1.56 1.45 0.69 5.9 1.16 0.86 2.22 0.45 11.5 1.82 0.55 3.09 0.32 19.4 2.53 0.40 3.83 0.26 27.7 3.13 0.32 4.67 0.21 33.9 3.53 0.28 4.03 0.25 44.4 4.13 0.24 4.99 0.20 56.0 4.71 0.21 5.49 0.18 68.7 5.29 0.19 5.31 0.19 54.7 4.65 0.22 3.72 0.27 “Specific viscosity in Centistokes. Figure 2. Lineweaver-Burk plot of the reciprocals of the initial reaction rate (V0, in g per liter per minute) and substrate concentration (Cs, in g per liter). Equation of the line is 1/Vo = 0.128 + 0.360*(1/Cs); r2 = 0.97. CELLULASE ACTIVITY OF SOIL FUNGUS 267 LITERATURE CITED Almin, K. E., and K. E. Eriksson. 1967. Enzymic degradation of polymers. I. Viscometric method for the determination of enzymic activity. Biochim. Biophys. Acta 139:238-247. Almin, K. E., K. E. Eriksson, and C. Jansson. 1967. Enzymic degradation of polymers. II. Viscometric determination of cellulase activity in absolute terms. Biochim. Biophys. Acta 139:248-253. Hulme, M. A. 1971. Viscometric determination of carboxymethyl cellulase in standard international units. Arch. Biochem. Biophys. 147:49-54. Laidler, K. J. 1965. Chemical kinetics. McGraw-Hill Book Co., New York, N.Y., p. 475- 478. Levinson, H. E., and E. T. Reese. 1950. Enzymatic hydrolysis of soluble cellulose deriva¬ tives as measured by changes in viscosity. J. Gen. Physiol. 33:601-628. Mandels, M., and J. Weber. 1969. The production of cellulases, p. 391-413. In R. F. Gould (Ed.), Cellulases and their applications. Advances in chemistry series 95. Am. Chem. Soc., Washington, D.C. Mandels, M. 1975. Microbial sources of cellulase, p. 81-105. In Biotechnol. Bioeng. Symp. No. 5. John Wiley and Sons, Inc. New York, N.Y. Ortega, J. 1980. Cellulase activities of soil fungi. Texas J. Sci. 32:241-246. Rosenberg, S. L. 1978. Cellulose and lignocellulose degradation by thermophilic and thermotolerant fungi. Mycologia 70:1-13. Toussoun, T. A., and P. E. Nelson. 1976. Fusarium. A pictorial guid to the identification of Fusarium species according to the taxonomic system of Snyder and Hanson. Second Edition. The Pennsylvania State University Press, University Park, PA. Williams, V. R., and H. R. Williams. 1973. Basic physical chemistry for the life sciences. W. H. Freeman and Co., San Francisco, CA. p. 299-302. NEW RECORDS OF THE FRESHWATER ECTOPROCT PECTIN ATELLA MAGNIFICA IN EASTERN TEXAS by RAYMOND W. NECK Texas Parks and Wildlife Department 4200 Smith School Road Austin, TX 78744 and RICHARD W. FULLINGTON Dallas Museum of Natural History P.O. Box 26193, Fair Park Station Dallas, TX 73205 ABSTRACT We present additional records of the freshwater ectoproct, Pectinatella magnified, from the eastern part of Texas. Apparent proliferation of this animal in Texas may have resulted from an increase in suitable habitat comprised by numerous artificial impound¬ ments constructed since 1932. The lophophorate phylum Ectoprocta largely consists of marine forms, although the class Phylactolaemata contains approximately 50 freshwater species (Ryland 1970). Many ectoprocts live as loosely- developed, mat-like colonies. However, Pectinatella magnifica (Leidy) forms large gelatinous masses with maximum diameters as great as one meter. Only limited records of P. magnifica in Texas have been pub¬ lished. The first Texas report seems to be one by Geiser (1934), who had specimens from Caddo Lake near Jefferson, Marion and Harrison counties (collected by E. P. Cheatum and W. M. Longnecker in 1933) and from a locality in Lake Worth, Tarrant County (collected by B. B. Harris on 29 October 1933). Everitt (1975) also reported colonies in “Caddo Lake, Texas.” More recently, Casto and Johnson (1982) reported a population in Belton Lake, Bell County, in the Brazos River drainage. Here we report additional localities and speculate on what may be an increase in abundance of this species in Texas waters. On 23 September 1982, one of us (RWN) encountered several colonies of Pectinatella magnifica on small tree- branches floating in the water and on bald cypress (Taxodium distichum) knees in a slough of Lake Houston off Caney Creek south of the fork known as Peach Creek, San Jacinto River drainage, Montgomery County. Water level was approx¬ imately one meter below normal due to severe drought conditions. Col¬ onies were variable in size; the largest was 28 cm by 11 cm. The Texas Journal of Science, Vol. XXXV, No. 3, September 1983 270 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 3, 1983 Over the past several years the other of us (RWF) has encountered colonies of Pectinatella magnified in a number of localities as follows (with date of collection): Lake Murvaul, Murvaul Creek, Sabine River drainage, Panola County, 1968; Lake Tawakoni, Sabine River, Hunt County, 1974; Toledo Bend Reservoir, Sabine River, Shelby County, 1976; Lake Palestine, Neches River, Henderson County, 1977; Cedar Creek Lake, Cedar Creek, Trinity River drainage, Kaufman County, 1978; Lake Hawkins, Little Sandy Creek, Sabine River drainage, Wood County, 1980; and Beaver Lake (private lake on Patton farm), Sabine River drainage, Wood County, 1982. These observations of Pectinatella magnified in widely separated por¬ tions of Texas may reflect a recent increase in suitable microhabitat due to the large number of reservoirs now present in Texas. Records now exist for all major Texas drainages from the Sabine west to the Brazos. The large globular colonies are conspicuous and certainly evince inter¬ est and curiosity among biologists and non-biologists alike. Several environmental factors have been implicated as controlling agents in distribution of Pectinatella magnifica. The most comprehen¬ sive study of this species is by Brown (1933), who found it in warm, well-lighted waters of less than 3 meters depth in quiet, protected areas. In seeming contradiction of Brown’s (1933) findings, Davenport (1904) reported that P. magnifica prefers shady conditions and running water. Williams (1921) reported that young colonies in aquarium jars prefer dark areas. Brown (1933) observed that P. magnifica was not found in acidic waters and that colonies planted in bogs soon died because organic debris accumulated in the region of the mouth and tentacles. However, Everitt (1975) found no P. magnifica in waters with pH over 7.1. Marcus (1925) reported that a temperature of 20 C was required for proper colony development; destruction of colonies observed by Marcus (1925) occurred when temperature declined to 16-17 C. Bushnell (1974) stated that P. magnifica “is known only from uncontaminated water.’’ Hubschman (1970) investigated substrate discrimination and demon¬ strated that P. magnifica prefers pebbles over glass which is preferred over sand. While the Caddo Lake and Lake Houston localities are both in east¬ ern Texas, which is characterized by acidic waters, the Belton Lake locality is located in the limestone region of central Texas with alka¬ line waters. The key habitat factor in Texas appears to be a permanent body of quiescent water. Such habitats were relatively rare in Texas until the construction of numerous reservoirs beginning in the 1930’s. Dispersal mechanisms employed by Pectinatella magnifica are not well understood. Asexual reproduction of freshwater ectoprocts involves production of resistant bodies known as statoblasts which may float, sink to the bottom or adhere to the parent colony. Statoblast viability is NEW RECORDS OF PECTIN ATELLA MAGNIFICA 271 reduced following ingestion by various vertebrates, but significant numbers survive (Brown 1933). Introductions into Germany (Schacha- nowskaja 1929) probably involved transport by ships (Hyman 1959). Dried statoblasts are able to survive for several years (Rogick 1940). Fluctuations in population density and sudden appearances at new localities are typical for Pectinatella magnified (Geiser 1937). A dra¬ matic appearance of this species in Iowa was associated with low water levels during the cool season (Geiser 1937). Lack of overflow Iowa ponds during winter resulted in a larger than normal percentage of the statoblasts remaining in the pond at the intiation of the spring grow¬ ing season. Nutrients similarly retained in the pond allowed maximum production of suitable food organisms. LITERATURED CITED Brown, C J. D. 1933. A limnological study of certain fresh-water Polyzoa. Trans. Amer. Micros. Soc. 52:271-313. Bushnell, J. H. 1974. Bryozoans (Ectoprocta), p. 157-194. In C. W. Hart. Jr. and S. L. H. Fuller (Eds.), Pollution ecology of freshwater invertebrates. Academic Press, New York, N.Y. Casto, S. D., and K. W. Johnson. 1982. A second record of the ectoproct Pectinatella magnifica in Texas. Texas J. Sci. 34:192. Davenport, C. B. 1904. Fresh-water Bryozoa of the United States. Proc. U.S. Natl. Mus. 27:211-221. Everitt, B. 1975. Freshwater Ectoprocta: Distribution and ecology of five species in sou¬ theastern Louisiana. Trans. Amer. Micros. Soc. 94:130-134. Geiser, S. W. 1937. Pectinatella an occasional river pest in Iowa. Field and Laboratory 5(2):65-76. Hubschman, J. H. 1970. Substrate discrimination in Pectinatella magnifica Leidy (Bry¬ ozoa). J. Exp. Biol. 52:603-607. Hyman, L. H. 1959. The invertebrates: Smaller coelomate groups. Vol. V. McGraw-Hill, New York, N.Y. 783 p. Marcus, E. 1925. Bryozoa, p. 1-46. In P. Schulze (Ed.), Biologie der Tiere Deutschlands, Lief. 14, Teil 25. Rogick, M. D. 1940. Studies of freshwater Bryozoa. XI. The viability of dried statoblasts of several species. Growth 4:315-322. Ryland, J. S. 1970. Bryozoans. Hutchinson Univ. Library, London, England. 175 p. Schachanowskaja, M. 1929. Pectinatella magnifica Leidy in Bohmen. Zool. Anzeiger 80:296-297. Williams, S. R. 1921. Concerning ‘ larval” colonies of Pectinatella. Ohio J. Sci. 21:123- 127. THE TEXAS ACADEMY OF SCIENCE, 1983-84 OFFICERS President: President-Elect: Vice-President: Immediate Past President: Secretary- T reasurer: Editor: AAAS Council Representative: Bernard T. Young, Angelo State University Michael J. Carlo, Angelo State University William J. Clark, Texas A&M University Elray S. Nixon, Stephen F. Austin State University Everett D. Wilson, Sam Houston State University William H. Neill, Texas A&M University Arthur E. Hughes, Sam Houston State University DIRECTORS 1981 Richard L. Noble, Texas A&M University Bob F. Perkins, University of Texas, Arlington 1982 Billy J. Franklin, Texas A&I University Ethel W. McLemore, Dallas 1983 D. Lane Hartsock, Austin Katherine Mays, Bay City SECTIONAL CHAIRPERSONS I — Mathematical Sciences : Barbara Schreur, Texas A&I University II — Physical Sciences : Virginia L. Rawlins, North Texas State University III — Earth Sciences : James C. Grenda, Angelo State University IV — Biological Sciences : Edward Schenider, Southwest Texas State University V — Social Sciences : James O. Standley, Stephen F. Austin State University VI — Environmental Sciences : Robert D. Larsen, Southwest Texas State University VII — Chemistry. John T. Moore, Stephen F. Austin State University VIII — Science Education-. Fred L. Fifer, University of Texas, Dallas IX — Computer Sciences : H. P. 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Please send form 3579 and returned copies to Texas Tech Press, Box 4240, Lubbock, TX 79409. THE TEXAS JOURNAL OF SCIENCE Volume XXXV, No. 4 January 1984 CONTENTS Instructions to Authors . . . 275 Toric Sections. By Ali R. Amir-Moez and Gregory A. Fredricks . . . 277 Use of Fissiogenic Stable Ruthenium Versus Xenon Isotopes in the Determination of Induced Fission in Uranium Ores. By Moses Attrep, Jr., and Kung Hsing-Tung . .283 The Death Dip Among Ordinary Folks: A Study of the Dip/Peak Phenomenon for Texans Dying in 1979. By Rollo K. Newsom, Alvin P. Short, Louis M. Tanner, and T. C. Borelli . 293 Cattle Egrets ( Ardeola ibis = Bubulcus ibis) in Texas. By Raymond C. Telfair II and Larry E. Marcy . 303 Swim Bladder Stress Syndrome in Largemouth Bass. By Gary J. Carmichael and J. R. Tomasso . 315 Distributional Records and Notes for Nine Species of Mammals in Eastern Texas. By Arthur G. Cleveland, John T. Baccus, and Earl G. Zimmerman . 323 Development of Tensile Strength in Compatible Autografts of Eggplant ( Solanum pennellii) and Tomato ( Lycopersicon esculentum). By Mary T. McGarry and Randy Moore . 327 Abstracts of the Ninth North American Physarum Conference . 333 Index to Volume XXXV . 349 Reviewers 362 THE TEXAS JOURNAL OF SCIENCE EDITORIAL STAFF Editor: William H. Neill, Texas A&M University Assistant to the Editor: Fred S. Hendricks, Texas A&M University Associate Editor for Chemistry: Marvin W. Rowe, Texas A&M University Associate Editor for Mathematics and Statistics: George R. Terrell, Rice University INSTRUCTIONS TO AUTHORS Scholarly papers in any field of science, natural history, or technology are eligible for publication in The Texas Journal of Science. Before a paper can be accepted for publication, it must undergo critical review by at least 2 appropriate referees and the editor. A manuscript intended for publication in the Journal should be pre¬ pared in accordance with the following instructions and then submitted to Dr. William H. Neill, TJS Editor, Department of Wildlife & Fisheries Sciences, Texas A&M University, College Station, TX 77843. The manuscript is not to have been published elsewhere. Triplicate typewritten or machine-printed copies (or the original and 2 good xero¬ graphic reproductions) must be submitted. Text, table and figure cap¬ tions, and references should be double-spaced with 2-3 cm margins (without right-justification) on 81/ X 1 1-inch paper. The title of the arti¬ cle should be followed by the name and business or institutional address of the author(s). Be sure to include zip code with the address. If the paper has been presented at a meeting, a footnote giving the name of the society, date, and occasion should be included but should not be num¬ bered. 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For a paper published in the PROCEEDINGS OF A SYMPOSIUM, etc., use the form: Jones, A. P. 1971. Persistence of chlorinated hydrocar¬ bons, p. 155-181. In A. P. Jones (ed.), Pesticides in soils. Soc. Soil Chem., New York, NY. For a REPORT use: Jones, A. P. 1971. Persistence of chlorinated hydrocarbons. Texas Soils Institute (Austin, TX) Report No. 14, 46 p. A MASTERS OR Ph.D. THESIS should appear as: Jones, A. P. 1971. Persistence of chlorinated hydrocarbons in blackland soils. M.S. thesis, Texas A&M Univ., College Station, TX. For a BOOK, NO EDITORS, use: Jones, A. P. 1971. Environmental effects of chlorinated hydrocarbons Academic Books, New York, NY, 439 p. For a CHAPTER IN A BOOK WI TH 276 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 EDITORS: Jones, A. P. 1971. Persistence of chlorinated hydrocarbons, p. 13-39. In A. P. Jones, B. R. Smith, Jr. and T. S. Gibbs (eds.), Environ¬ mental effects of chlorinated hydrocarbons. Academic Books, New York, NY. For an IN-PRESS PERIODICAL ARTICLE use: Jones, A. P. In Press. Persistence of chlorinated hydrocarbons. J. Soil Chem. For an IN-PRESS BOOK use: Jones, A. P. In Press. Environmental effects of chlorinated hydrocarbons. Academic Books, New York, NY. References to unpublished data or personal communications should not be listed in the LITERATURE CITED section. However, they should be presented within the text as: (unpubl. data from C. J. Jones, Dept. Zoology, Univ. Texas, Austin, TX) or (pers. comm, from R. C. Smith, P.O. Box 133, Mexia, TX). Any footnotes (except those referenced in the body of a table) should appear on a separate sheet of paper, following the LITERATURE CITED. All tables are to be typed with a carbon ribbon, free of error, without handwritten notations, and ready for photographic reproduction. Each table, headed by its caption, should be placed on a separate sheet of paper. Tables must have a text reference, i.e., Table 2 shows. . .or (Table 2). Figures are to be original inked drawings or photographic prints no larger than 4Zi X 6Zi inches and mounted on standard 8^2 X 1 1-inch paper. Each illustration should be marked on the back with the name of the first author and the figure number. Captions for figures are to be pro¬ vided on a separate sheet of paper. Figures must have a text reference, i.e., Figure 3 illustrates. . .or (Fig. 3). Authors will receive galley proofs plus the edited typescript and information concerning reprints and page charges. Proofs must be cor¬ rected (using ink) and returned to the editor within 5 days. Page charge payment (check or purchase voucher) or a publication-grant request must accompany return of the corrected proofs or a delay in printing the manuscript could occur. Reprint orders should be returned directly to Texas Tech Press, Box 4240, Lubbock, TX 79409. THE EDITOR SHOULD BE NOTIFIED IMMEDIATELY OF ANY CHANGE IN THE PRINCIPLE AUTHOR’S ADDRESS OR TELEPHONE NUMBER. NOTE: Authors are encouraged to contribute $35.00 per published page to defray printing costs, and authors of articles exceeding ten pages are expected to make some contribution to the publication fund. However, payment of printing costs is not a condition for publication in The Texas Journal of Science , and NO AUTHOR, WHO WOULD OTH¬ ERWISE SUBMIT A MANUSCRIPT, SHOULD HESITATE TO DO SO BECAUSE OF LACK OF FUNDS. Members without funds may apply to the Texas Academy of Science for a grant to cover some or all costs of publication. TORIC SECTIONS by ALI R. AMIR-MOEZ and GREGORY A. FREDRICKS Department of Mathematics Texas Tech University Lubbock, TX 79409 ABSTRACT Plane sections of a torus are described with techniques of vector algebra. Then, the result is generalized to an n-dimensional Euclidean space. INTRODUCTION The study of plane sections of a torus is relevant to both pure and applied mathematics and suggests, through vector algebra, many generalizations. Yeates (1947) states, without proof, that certain sec¬ tions of tori are Cassini ovals. In this note we explore this idea for R3 and give a generalization to Rn. NOTATION We employ standard notation. Vectors are denoted by Greek letters and scalars by Latin letters. The inner product of o and (3 is denoted by (o, (3) and the norm of o is denoted by || o ||. The subspace spanned by the set {01, . . . ,Ok} is indicated by [01, . . . ,Ok]. TORIC SECTIONS Suppose that T is a torus in R3. Then there exists an orthonormal basis {01,02,03} of R3 for which the leading circle S of T lies in [011,0:2] and has its center r on the 02-axis (Fig. 1). Let a>0 be the radius of S and suppose that r = po2. The equation of S is 7 — hoi + ko2, II7 — t||— a. The generating circle of T lies in the plane which is parallel to 03 and passes through the endpoints of r and 7. If the endpoint of f is on T, then {$; f = m(y — r) + sou + r llf-7ll=-b >0, (1) The Texas Journal of Science, Vol. XXXV, No. 4, January 1984 278 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 where b is the radius of the generating circle of T. One can write (1) as r f = mhai + [mk + (1 — m)p] ai + sc*3 \ h2 + (k — p)2 = a2 (2) t (m — l)2 a2 + s2 — b2. Note that p,a and b are fixed, while m,s,h and k are parameters. It suffices to consider the intersection of T with planes of the form [on, (3], where f3e[oL2,OL?,] and || || = 1. Let t denote the angle between (3 and 0L2. The intersection of the torus and such a plane is given by r f = mhai + [mk + (1 — m)p] a 2 + sa3 s f = xai + (y cost) 012 + (y sin t) «3 (3) ^ h2 + (k — p)2 = a2, a2(m — l)2 + s2 = b2, where (x,y) is the set of components of f with respect to the orthonormal set {co, (3}. Eliminating the parameters, we obtain (x2 + y2)2 + 2[p2 — (a2 + b2)-2 (p cos t)y] (x2 + y2) + (p2 — a2 — b2)2 — 4 (p2 — a2 — b2) (p cos t)y + 4 p2(cos2t) y2 = 4a2(b2 — y2 sin2t). (4) TORIC SECTIONS 279 Thus, toric sections in R3 are curves which satisfy equations of the form (4). We will discuss only some simple cases. When t = 7t/2 and p = b we obtain the equation (x2 + y2)2 = 2a2(x2 — y2) + 4a2b2 — a4, (5) which is a Cassini oval (Fig. 2). When the shape of the torus changes, the shape of the Cassini oval given by (5) also changes. For example, when a — 2b the Cassini oval is a Bernoulli lemniscate (Fig. 3). For those interested in convexity, we remark that it can be shown by elementary techniques that the Cassini oval (5) is the boundary of a convex set when b > a. HYPERTORIC SECTIONS We now generalize the study of the previous section to Rn. Let T be a torus in Rn, i.e., T is as in the previous section except that the “leading circle” of T is a sphere of dimension n-2. Then there exists an orthonormal basis {an, . . . ,an} of Rn for which the leading sphere S of T has center at r e[ai] and is given by S — {yeRn| • • • ,«n-i] and \\y — t\\ = a > 0}. Figure 3. Lemniscate of Bernoulli. 280 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 The torus T is given by T — {feRnlf er + [7 — r ,an], ||f — 7|| = b > 0 for some yeS}. Let r = pa2 for a fixed p eR and let f = m(7 — t) + san + t eT for some yeS and m,s€R. Since f - 7 = (m - 1) (7 - t) + S a. LITERATURE CITED Yates, R.C. 1947. A handbook on curves and their properties. J. W. Edwards, Ann Arbor, MI. (Republished by National Council of Teachers of Mathematics, Washing¬ ton, DC, 1952.) USE OF FISSIOGENIC STABLE RUTHENIUM VERSUS XENON ISOTOPES IN THE DETERMINATION OF INDUCED FISSION IN URANIUM ORES by MOSES ATTREP, JR., and RUNG HSING-TUNG Department of Chemistry East Texas State University Commerce , TX 75428 ABSTRACT We compare the use of fissiogenic stable isotopes of the inert gas, xenon, to those of the transition metal, ruthenium, as an indication of the ratio of thermal-neutron- induced fission of 235U to the spontaneous fission of 238U. Xenon isotopes provided an internally consistent ratio from different sets of xenon isotopes that was not observed when different ruthenium isotope pairs were used. The range of the ratios deduced from the xenon isotopes was from aproximately 0 (no induced fission) to a value of 0.47 (about 45% induced fission); values derived from ruthenium isotopes ranged from negative values to 0.93. Other, graphic analyses also indicated that xenon isotopes probably provide a more accurate picture of the nuclear geo-fission history of the ores. INTRODUCTION Uranium ores are unique in geological deposits: they represent chemical-physical phenomena as well as nuclear events in nature. Uranium-238, the most abundant isotope of uranium, undergoes both a decay and spontaneous fission, with half-lives of 4.5 X 109 years and 1.0 X 1016 years, respectively. The result is a complex, natural uranium-decay series produced by a and (3 emissions, and a wide variety of nuclides produced from the fission process. The other, less abundant isotope of uranium, 235U, also decays by a emission. Another nuclear phenomenon is observed under certain conditions, namely neutron capture by 235U, leading to fission. The cross-section for capture of thermalized neutrons is large, leading to a fission rate in many instances as great as that of spontaneous fission of 238U. The fission yield curves for the spontaneous fission of 238U and neutron induced fission of 235U are both primarily asymmetric. The fission yield curves are not superimposable because of differences in the yields of the fission products. Although neutron-induced fission is of great importance, we con¬ sider the origin of the neutrons causing that fission to be equally important. Alteration of uranium assemblies by certain elements causes changes in the amount of neutron-induced fission of 235U: (a,n) The Texas Journal of Science, Vol. XXXV, No. 4, January 1984 284 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 reaction on low Z elements increases the neutron flux and hence the amount of neutron-induced fission of 235U (Attrep and Sherwood 1972; Attrep et al. 1979; Raut and Attrep 1975; Attrep et al. 1981). The inverse effect operates when neutron absorbing elements are added, in which case the neutron-induced fission component is eliminated, leaving only spontaneous fission of 238U (Attrep et al. 1981). The Oklo phenomenon marks the only known occurrence of a uranium deposit having functioned successfully as a self-sustaining reactor (Baudin et al. 1972). Obviously, in this case, the amount of induced fission must have exceeded the amount of spontaneous fission. Patterns of isotopic fission products identified in the deposit confirm reaction status. For the reactor to have operated it would have had certain physical and nuclear requirements — sufficient moderator (proba¬ bly water), enriched fuel, a mechanism to remove the heat generated, and a suitable chemical composition. This combination existed some 1.2 billion years ago. One must consider the possibility both of uranium assemblies with no induced fission and others which could have undergone reactor status as in the case of the Oklo mine. We focus on cases in which induced fission rate is of the same order as the spontaneous fission rate of 238U. For these, 0.42 fissions per minute per gram of uranium occur. To elucidate these conditions, we have taken a two-fold approach. The first is to simulate uranium assemblies in the laboratory, controlling the chemical-physical parameters. These experiments have led to the conclusion that elements such as lithium, boron, beryllium, and carbon can undergo (a,n) reactions, leading to increased neutron- induced fission of 235U. Conversely, the introduction of samarium, a neutron absorber, reduced the total neutron flux by reduction of neutrons from (a,n) reactions and neutrons from neutron-induced fission of 235U. The other line of investigation centers around the use of stable isotopes of fissiogenically produced elements. Earlier we showed that xenon extracted from uranium minerals and analyzed mass spectrometrically provides the basis for the development of a model that could be used to measure the amount of induced fission in the system (Attrep et al. 1977). Maeck et al. (1978 a,b) used stable fissiogenic ruthenium isotopes as a means of dating uranium ores and of determining if a uranium deposit had undergone nuclear reactor status. The ruthenium analysis has been described by Delmore (1980). Mass spectrometry of ruthenium is difficult, requiring extreme caution during the separation procedure; otherwise interferences result from other elements. Here we compare xenon isotopes to ruthenium isotopes as indicators of neutron-induced fission of 235U. Fissiogenic products accumulated FISSION IN URANIUM ORES 285 and analysis of these provide an understanding of the nuclear dynamics of the uranium ores. METHODS AND EQUATIONS To calculate the ratio of thermal-neutron-induced fission of 235U to the spontaneous fission of 238U, we assume only these two fission sources. Tasa and Attrep (1974) indicated that fast-neutron fission of 238U existed at ~6% when conditions were adjusted to a large fast- neutron flux. Attrep et al. (1977) derived equations which related the experimen¬ tally observed ratios of fissiogenic nuclides, fission yields, both spontaneous and thermal-neutron induced, and R, the ratio of induced to spontaneous fission. Here we give only the equations essential to understanding the relationships between these factors. The total number of fission-produced atoms in the geological sample, Nt, is a sum of those atoms coming from the spontaneous fission process, Ns, and those coming from the thermal-neutron- induced process, N*; hence, Nt = Ns + N*. The overall ratio (R), the thermal-neutron-induced fission of 235U to the spontaneous fission of 238U in the ore, is expressed in terms of the accumulated atoms from one process divided by the atoms accumulated from the other process. Specifically, the ratio for two fissiogenic isotopes of a given element are conveniently expressed as Nt' = (Y' + RY') NT (YT + RY'') where Nt' is the number of atoms determined experimentally in the uranium sample for one fissiogenic isotope; NT is that observed for another fissiogenic isotope; Ys' and Y[, and YT and YT are the spontaneous fission yield and induced fission yield for the two respective fissiogenic isotopes. This equation will be used to indicate the sensitivity of the method of ruthenium isotopes to measure R. Fissiogenic ruthenium isotopes used in this study are mass 99, 101, 102, and 104. The fission yields for these are given in Table 1 as reported by Maeck et al. (1978a). RESULTS AND DISCUSSION Of the six possible ratios of ruthenium isotopes, the three which indicated the most significant change in the isotopic ratio over the R values from 0 to 1.0 are 101/99, 102/99, and 104/99 (Fig. 1). Consequently, these three sets of values are the best indicators of R. 286 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 Table 1. Percent fission yields of stable ruthenium isotopes from spontaneous fission of 238U and from thermal-neutron-induced fission of 235U. (Reported in Maeck et al. 1978a.) Ruthenium Mass Number 238U Spontaneous Fission Yield (Percent) 235U Neutron Induced Fission (Percent) 99 6.0 6.10 101 7.25 5.08 102 8.01 4.23 104 4.21 1.83 The slopes for ruthenium 104/102, 104/101 and 102/101 are nearly zero; thus, these are poor indicators of induced fission. We chose 101/ 99, 102/99, and 104/99 for determining values of R. A small variation in R is reflected much more significantly in the xenon isotopes where a change from 0 to 0.1 gives rise to a change of N'/N" ratio from 12 to 7 for the 134/131 xenon isotope pair (Attrep et al. 1977). A comparable R value change in ruthenium 102/99, the most promising of the ruthenium isotopes, produces a change of only 1.34 to 1.28. The xenon system changes —42% compared to 4.5% for the ruthenium system. Clearly, the xenon system is more sensitive and therefore more valuable for detecting variations in the values of R. _ i _ i _ i _ i _ i_ 0 0.1 0.3 0.5 0 7 0.9 R Figure 1. Ruthenium isotope ratios as functions of the ratio of induced fission of 235U to spontaneous fission of 238U (R). FISSION IN URANIUM ORES 287 Points on the graphs of the plots101Ru/99Ru versus 102Ru/99Ru, 102 t) /^^T> 1 04 /99t-\ i 102t) /IOItj 104t> /IOIttj /T7* Ru/ Ru versus Ru/ Ru, and Ru/ Ru versus Ru/ Ru (Fig. 2, 3, 4, respectively) generally lie between the induced-fission point (marked by I) and the spontaneous fission point (marked by S). Scatter of the points on these graphs arises from the reported values of abundances of the ruthenium isotopes. A similar plot of 134Xe/131Xe versus 136Xe/131Xe yields a well-defined spontaneous fission system; however, the 134Xe/132Xe versus136Xe/132Xe plot exhibits as much scatter as those of the ruthenium plots (Attrep et al. 1977). The trends in Figures 2, 3, and 4 indicate that accumulated fissiogenic ruthenium isotopes in the uranium ores originate primarily from spontaneous fission of 238U and thermal-neutron-induced fission of 235U. Table 2 shows calculated values of R for the three selected ruthe¬ nium pairs. The samples used were those analyzed by Maeck et al. (1978a). Listed below each pair are the calculated R values using the fission yields in Table 2. The average of the three sets of data is given in the last column. The R values vary considerably when calculated from the ruthenium 101 99 ratio, 102/99 ratio, or the 104/99 ratio. Use of the ruthenium isotopes is apparently not accurate enough. In contrast, the xenon system provides R values that varied insignificantly. Ru/ U Ru (atom/atom) 288 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 J U _ | _ i _ i _ i _ i _ 0.200 0300 0.400 0.500 0.600 0.700 0.800 ^^Ru /^Ru (atom/atom) Figure 3. 102Ru/99Ru versus 104Ru/99Ru plot for uranium ores. Figure 4. 102Ru/l01Ru versus104Ru /101Ru plot for uranium ores. FISSION IN URANIUM ORES 289 Table 2. Derived values for the ratio of thermal-neutron-induced fission of 235U to the spontaneous fission of 238 et al. 1978b.) U in uranium samples. (Ru isotopic data reported in Maeck Sample R from Ruthenium Isotope Ratio 101/99 102/99 104/99 Average ± s.d. Wilberforce, Ont.# -0.03 -0.04 -0.06 -0.04 ± 0.02 Rio Grande do Norte, Brazil4 * 0.03 0.04 0.06 0.05 ± 0.02 Shinkolbwe, Zaire 0.32 0.24 0.16 0.27 ± 0.08 Kasolo, Zaire 0.41 0.31 0.26 0.33 ± 0.08 Gordonia, SWA 0.12 0.34 0.34 0.26 + 0.13 NT, Australia a 0.31 0.36 0.37 0.35 ± 0.03 b 0.70 0.84 0.57 0.70 + 0.13 Jabiluka, Australia a 0.56 0.53 0.52 0.54 ± 0.02 b 1.01 0.95 0.83 0.93 ± 0.09 c 1.03 0.87 0.76 0.89 + 0.14 Nabarlek, Australia 0.51 0.36 0.28 0.38 + 0.12 Wilberforce, Ont. -0.07 -0.03 -0.08 -0.01 ± 0.08 Fay Mine, Sask. 0.70 0.61 0.59 0.63 ± 0.06 Cluff Lake, Sask. a 0.61 0.48 0.36 0.48 + 0.13 b 0.44 0.43 0.31 0.39 ± 0.07 Rabbit Lake, Sask. a 0.19 0.09 0.15 0.14 + 0.05 b 0.49 0.51 0.44 0.48 ± 0.04 c 0.53 0.54 0.44 0.51 ± 0.06 d 0.13 0.17 0.14 0.15 ± 0.02 e 0.16 0.08 0.17 0.14 + 0.05 f 0.43 0.13 0.10 0.21 ±0.18 Port Radium, NWT a 0.12 0.07 0.11 0.10 + 0.02 b 0.09 0.10 0.17 0.12 + 0.05 c 0.10 0.12 0.18 0.13 ± 0.04 ^Reference Samples indicated by Maeck et al. 1978a. Use of ruthenium isotopes yielded negative values of R in samples 1 and 12, which is physically unrealistic. By definition these samples are near zero since sample 1 was used to define the spontaneous-fission yield. The negative values reflect error associated with values used in the equation, the fission yields assigned to the spontaneous fission process, or the ratio of ruthenium isotopes. Jabiluka, Australia, samples b and c show unusually high values— 0.93 and 0.89, respectively. These are the highest values yet observed for the ratio of neutron-induced fission of 235U to the spontaneous fission of 238U, except for the Oklo samples which had experienced self-sustaining nuclear reactor status (R»l). Because slight variations in the ruthenium yield can cause large variations in R, these high values may simply represent error. For non-Oklo samples, xenon isotopes yielded R values from ~0 to 0.47. This is significantly different from that of the ruthenium isotopes (~0 to 0.93). Because so few R values are available from other methods, 290 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 Figure 5. (a) R(101/99) versus R(102/99), (b) R(101/99) versus R(104/99), and (c) R(101/ 99) versus R( 104/99) for uranium samples. it is extremely difficult to compare one method with another. There is only one case in which two separate methods were used to determine R for a single sample. For the African pitchblende sample, R was reported from radio-chemical data using "Tc and 36C1 (Kenna and Attrep 1966) and the xenon method by Attrep et al. (1977) with R = 0.33 and R~ 0.45, respectively. Different samples were analyzed which may account for the discrepancy. A xenon analysis of the identical African pitchblende, where R was determined to be 0.33 radio-chemically, yielded R of 0.38 (Sumerlin and Kuroda 1978). Although a single agreement does not provide conclusive evidence as to the validity of the xenon approach, it gives credence to the method. FISSION IN URANIUM ORES 291 To check the validity of the two-fission system for ruthenium isotopes, R values were plotted for different sets of ruthenium isotopes versus the R values from other sets. These are shown in Figure 5 for the R values originating from the following ruthenium isotope pairs: (a) R( 102/99) versus R(101/99), (b) R(101/99) versus R( 104/99), and (c) R( 102/99) versus R( 104/99). Least-squares analysis was used to find the line best fitting each set of data. If the scatter were due to random error a straight line, slope = 1, would be expected. The plot of R( 101/99) versus R( 102/99) had a slope of 1.04, which supports our original assumption of a simple two-component system of spontaneous fission of 238U and thermal-neutron-induced fission of 235U. The slopes of the lines in figures 5b and 5c are 1.56 and 1.59, respectively. CONCLUSIONS Although it is possible to measure neutron-induced fission in uranium ores by using ruthenium isotopes that are produced in the fission process, this method does not provide the precision observed when xenon isotopes are used. This does not, however, eliminate the usefulness of ruthenium isotopes as indicators of other nuclear geochemical events. As pointed out earlier, the age of the ore can be estimated using the fissiogenic ruthenium isotope abundance. Ruthenium is attractive because it is a non-volatile metal as compared to xenon, a gas. However, the radio-precursor in the mass 99-chain, technetium-99, has been shown to be environmentally mobile (Ehrhardt and Attrep 1979). This fact, along with the observa¬ tion that there are anomalous amounts of "Ru involving the migra¬ tion of "Tc in the Oklo Mine samples (Gancarz et al. 1979), provides an additional uncertainty in using the ruthenium isotopes to calculate R. The fractional loss of isotopes of xenon cannot be measured easily. Funk et al. (1967) showed that xenon loss in an ore occurs almost equally among all the fissiogenic isotopes with no significant isotopic fractionation. Since ratios are being used in measures of this type, the absolute amounts are inconsequential. In conclusion, the use of xenon isotopes to measure small amounts of thermal-neutron-induced fission is easier and more reliable than that of ruthenium isotopes. However, it is reassuring that the model first established for the xenon isotopes also holds, in principle, for the case of ruthenium isotopes. ACKNOWLEDGEMENT This research was supported by the Robert A. Welch Foundation, grant number T-291. 292 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 LITERATURE CITED Attrep, M., Jr., C. A. Ao, A. I. Safa, and J. G. Griffin. 1981. Induced fission factors in natural uranium assemblies. J. Inorg. Nucl. Chem. 43:2623-2627. Attrep, M., Jr., W. B. Ledbetter, and D. K. Riddle. 1979. The effects of boron and lithium on the ratio of induced to spontaneous fission in natural uranium. J. Inorg. Nucl. Chem. 41:1-3. Attrep, M., and J. D. Sherwood. 1972. The effect of (a,n) reactions on the ratio of induced to spontaneous fission in natural uranium. J. Inorg. Nucl. Chem. 34:435-438. Attrep, M., Jr., K. S. Tasa, and J. D. Sherwood. 1977. Estimations of the ratio of induced to spontaneous fission in uranium ores. Texas J. Sci. 29:109-120. Baudin, C., C. Bain, R. Hagemann, M. Kremer, M. Lucas, L. Merlivat, R. Molina, C. Nief, F. Prost-Marcehal, F. Regnaud, and E. Roth. 1972. Quelques donnees nouvelles sur les reactions nucleaires en chain que se sont produites dan le gisement d’Oklo. C. R. Acad. Sci. Paris 275:2291-2297. Delmore, J. E. 1980. The mass spectrometric analysis of nanogram levels of ruthenium. Proceedings of the Twenty-Third Conference on Analytical Chemistry in Energy Technology, Ann Arbor Science Publishers, Inc., Ann Arbor, MI. p. 51-356. Ehrhardt, K. C. , and M. Attrep, Jr. 1978. Technedum-99 in the atmosphere. Environ. Sci. Tech. 12:55-57. Funk, H., F. Podosek, and M. W. Rowe. 1967. Fisssiogenic xenon in the Renazzo and Murray meteorites. Geochim. Cosmochim. Acta 31:1721-1732. Gancarz, A. J., G. A. Cowan, D. B. Curtis, and W. J. Maeck. 1979. "Tc, Pb and Ru migration around the Oklo natural fission reactors. International Symposium on the Scientific Basis for Nuclear Waste Management, Boston, MA. Kenna, B. T., and M. Attrep, Jr. 1966. The ratio of induced fission vs. spontaneous fission and the trace element analysis in pitchblende. J. Inorg. Nucl. Chem. 28:1491- 1500. Maeck, W. J., J. E. Delmore, R. L. Eggleston, and F. W. Spraktes. 1978a. The measurement of ruthenium in uranium ores and 238U fission yields. Proceedings of a meeting of the Technical Committee on Natural Fission Reactors, International Atomic Energy Agency, Vienna, Austria, p. 521-533. Maeck, W. J., K. E. Apt, and G. A. Cowan. 1978b. A possible uranium-ruthenium method for measurement of ore age. Proceedings of a meeting of the technical committee on natural fission reactors, International Atomic Energy Agency, Vienna, Austria, p. 535-541. Raut, M. K. , and M. Attrep, Jr. 1975. (a,n) Reactions in uranium solutions. J. Inorg. Nucl. Chem. 37:274-275. Sumerlin, N. G., and P. K. Kuroda. 1978. Isotopic compositions of xenon and krypton in Belgian Congo pitchblende. Geochem. J. 12:279-285. Tasa, K. S., and M. Attrep, Jr. 1974. Fast neutron studies in uranium. J. Inorg. Nucl. Chem. 36:1699-1703. THE DEATH DIP AMONG ORDINARY FOLKS: A STUDY OF THE DIP/PEAK PHENOMENON FOR TEXANS DYING IN 1979 by ROLLO K. NEWSOM, ALVIN P. SHORT, LOUIS M. TANNER, and T. C. BORELLI Department of Sociology and Anthropology Southwest Texas State University San Marcos , TX 78666 ABSTRACT This paper explores the death dip/death peak phenomenon as it may have applied to ordinary persons dying in the State of Texas during 1979. Thirteen comparisons were made using conventional probability techniques. A death dip was not found for the overall group of Texans, but significant dips occurred for Black females and Spanish- surnamed males. In the case of Spanish-surnamed males, a death peak also was associated with the death dip. Speculations are made as to why the dip occurred in some subgroups but not in the total group. In addition, we consider the overall importance of this phenomenon to ordinary persons in view of our general findings. INTRODUCTION In 1973 a curious concept known as the death dip was introduced to sociologists (Phillips and Feldman 1973). With the usual obligatory accolades to E. Durkheim, it was argued that differing degrees of integration into one’s group and society are accompanied by differing degrees of obligation to participate in the celebrations considered important by that society. Phillips and Feldman “extended” Durk- heim’s argument to suggest that more integrated persons may be able to postpone their deaths in order to experience significant social events. Birthdays, presidential elections and the Jewish Day of Atone¬ ment were examined for association with a death dip among various populations. In particular, Phillips and Feldman examined deaths of the famous to see if fewer than the expected number of these people have died immediately before some significant social event. Using birth and death dates of several groups of “famous persons” in the United States and Europe, Phillips and Feldman (1973) found not only a death dip before the month of birth, but also a rise in the number of deaths in the month of birth and the three following months. The researchers used only “famous persons” because their birth and death dates were readily available in various biographical sources and because, as they stated, “The famous may be more likely The Texas Journal of Science, Vol. XXXV, No. 4, January 1984 294 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 than the non-famous to produce a death dip.” (Phillips and Feldman 1973; see also Phillips 1970:7). Here we report our efforts to determine whether the death dip-peak phenomenon may occur among “ordinary” people. THE DATA Recent developments in the application of computer technology at the Texas Department of Health1 have made data traditionally recorded only on death certificates available on tape for any given year since 1979. These data include the dates of birth and death for all 101,196 resident deaths in Texas during the year 1979. In addition, the tapes are coded for the sex, race, and ethnicity of the individual decedent. These data permit one to address the question as to whether or not the death dip occurs in ordinary people. Before beginning analysis, individual cases involving death before the twenty-fifth birthday were eliminated in order to better replicate the Phillips and Feldman (1973) analysis. Phillips (1970) was unable to find the death dip for infants and children even in samples where the dip was present for adults. A preliminary analysis of the Texas data (Tanner and Newsom 1981) had indicated that an extraordinary number of persons die during the month of actual birth. This was, of course, due to infant mortality. Further, as has been indicated by Short and Borelli (1981), the suggested sentiments that may influence somatic functions in adults have not likely had the chance to fully develop in the very young. Also, deaths from the chronic diseases amenable to somatic control account for only a small portion of deaths among young people and children. For the above reasons the authors decided to exclude from the analysis those persons who died prior to their twenty-fifth birthday. This resulted in a total sample of 96,093 Texans who were over twenty-five years of age when they died in 1979. MEASURING THE DIP AND PEAK The Dip To identify a death dip before bithdays, it is necessary to know the number of deaths by the month of birth and by the month of death. Also, one must determine the number of deaths expected probabilisti¬ cally if in fact there were really no association between the individual’s month of birth and month of death. These expected deaths may be computed by use of contingency table techniques, or by a much ‘The authors wish to thank the Texas Department of Health and Mr. W. D. Carroll, Chief of the Bureau of Vital Statistics, as well as others in the Department who assisted us in obtaining these data. DEATH DIP/PEAK PHENOMENON 295 simpler and more straightforward procedure in which one simply makes the assumption that the probability of dying in any given month is roughly 0.0833, or 1 in 12. We found that results obtained from the simple 1/12 assumption and by the more involved contin¬ gency table technique were virtually indistinguishable as was the case in the study by Phillips and Feldman (1973) on the death patterns of notable people. Using the assumption stated above, one would expect that 8,005 of the deaths in the total sample of 96,093 should have occurred in the month prior to the birth month.2 Actually, the number of deaths in the month prior to birth was 8,019 (Table 1). This is almost identical to what one would expect (z test, P = 0.44). There clearly is no death dip indicated for the total group of Texans dying in 1979. The Peak Phillips and Feldman (1973) also found that the existence of a death dip may lead to another phenomena known as the “death peak.” That is, if people were to “hang on” long enough to experience a significant social event like the birthday, then we might expect them to die shortly after the event. Since there was no death dip in our Texas population, we would not expect a death peak. The test for a death peak was made using the same types of probability assumptions as for the death dip; however, in the case of the peak we assumed that any peak might occur in the month of birth and persist for three months thereafter. After eliminating the data from the month prior to birth (to minimize dependence of any peak on a preceding dip), we computed the probability of dying in an eleven-month year (dip month removed) as roughly 1 chance in 11 in any given month. The expected chances of dying in the birth month and the three following months was therefore simply 4/11. The expected frequency was then compared with that observed (Table 1) and a z score computed in the usual manner. There was no significant death peak (P = 0.25). THE DIP AND PEAK BY SEX, RACE, AND ETHNICITY Table 2 provides z scores for death dips and peaks associated with sex, race, and ethnicity. We divided the total number of Texans dying in 1979 into groups according to sex, race, and ethnicity to ascertain 2Different calendar months have different numbers of days and hence either more or fewer opportunities (days) on which one can die. We, therefore, computed “expected deaths” on a 1/13 assumption dividing the year into 13 twenty-eight day months. These adjustments made no difference in results; so, the data in this paper are reported by calendar month. 296 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 © © a Q © t'- © c be _c © fl 03 X -O o © C M § d s> a. 03 _• Qj O 2 I' O N s- -X 03 -Q ■ O- c-» r- oo oo © o © # u © CM ■'3H © © © r-~ •^r © © UJ in © © © 00 CM © © © © Q !>• © © © © © © © © © r-~ © oo # > CM © © © © 0 on © © on © © 00 ■'f © M © Z © © © © © © © © © © © C"- © * © © © © © 00 © O- !>• oo oo bb # CM © TtH CM CM © GO M © © OO © 3 © © CM on © GO © © M © < © t" t-- !>• © o- © © oo © © CM © © © # M © © © © f-* © CM © © © M © © © QJ G © © © © © © © © © © © oo r-~ i^_i o x qj # c g on © © © © M © on Tj-I © o © © © © © © 00 S fJ © © © © © © © © © © © © © © >- 03 © © © © © # CM CM T)-1 o- !>■ © © © r-~ © © r" ■'f o- t'' © © © © © © © © © © © © © © * S_< © © © © CM © -'f © M o- a © on © © 00 © © CM © on < © © © © © © © © © © © © on # CM © © © © © t" 00 © © © C3 © © © on © © o* © M © M S © © © © © © © l>- © OO * © -Q © © ■'f © © o- — i— i f—i qj © © © © © © GO © oo © oo oo Uh © © © © © © © © © © © © 00 # d © © on © © © © !>■ M © © M © 03 © © © rf © C" © © © 00 Tf © © © © © © © © © © r- © r- on oo X ' w c c s ; « ! o Jan. Feb. Mar. Apr. May June 3 >-n Aug. Sep. Oct. Nov. Dec. 3 h *Month prior to birth month DEATH DIP/PEAK PHENOMENON 297 Table 2. Number of deaths and z scores for the death dip and death peak by sex, race and ethnicity. Population Number of Deaths Death Dip z Scores Death Peak Sex Male 52,946 .84 .57 Female 43,147 -.17 .88 Angloa 73,711 1.57 .09 Male 40,069 1.58 -.48 Female 33,642 1.16 1.65* Black 12,480 -.90 1.14 Male 7,029 1.21 1.33 Female 5,451 —2.63** .93 Spanish-surnamed 9,753 -2.91** 1.12 Male 5,772 -3.19*** 1.91* Female 3,981 -.80 -.50 Other" 149 .77 1.29 * P < 0.05; ** P < 0.01; *** P< 0.001. aThe term Anglo is used in a general sense here and throughout the discussion to indicate those formally coded as white, non-Spanish-surnamed persons. bThe Texas Department of Health uses the term “other” with no explanation. whether a death dip and/or a death peak was present for the individual group. As before, the z scores for real dips and peaks should be in the correct direction and of significant magnitude.3 Five of the twenty-four comparisons reported in Table 2 were in the right direction and of sufficient magnitude to be declared statistically significant. Comparison by Sex Looking first at the male-female comparisons for the total popula¬ tion, it may be observed that the z score for males was in the wrong direction for a dip, and even though the score for females was in the correct direction, it was still far from being statistically significant. The scores for the peaks for both males and females were in the right direction, but neither score was high enough to have an associated level of probability less than 0.05. It begins to become clear that we were unable to replicate Phillips and Feldman’s (1973) findings in this much larger group. 3It is appropriate to make these comparisons since these variables are routine in specifying the operation of social relationships in almost all aspects of society. We are aware of the fact that computing enough scores for various sub-divisions of the population may yield some significant scores with little real meaning. We believe, however, that these are the minimal comparisons necessary to examine possible variations among important sub-groupings in the population. 298 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 Racial and Ethnic Comparisons With reference to racial and ethnic comparisons, it can be seen that the death dip scores for Anglos were in the wrong direction. This reverse dip pattern was slightly more accentuated for the Anglo males. The small death-peak score for the Anglo male sub-sample was also in the wrong (negative) direction. Although the dip score for Anglo females was in the wrong direction, the peak score was in the correct direction and was significant. However, a peak alone is not indicative of a death dip. Apparently, there was no marked dip/peak pheno¬ menon for the larger Anglo sub-sample of Texans dying in 1979. Another interesting phenomena is found in the data concerning Black females. The Black females show a significant death dip, but there is no associated peak with the dip. Blacks overall, however, show insignificant relationships, or in the case of Black males, a relation¬ ship in the wrong direction. The one significant relationship for Blacks is the dip relationship for Black females. More significant relationships appear for Spanish-surnamed persons than for any other group. Computations for Spanish-surnamed females do not show significant relationships and the peak computation for Spanish-surnamed females is in the wrong direction. A significant dip is observed for the entire Spanish-surnamed group, but the peak computation (even though in the right direction) is not significant. Overall, three of the computations for the Spanish-surnamed group are significant. It is the Spanish-surnamed males that show the dip. There is only one set of computations in the entire table where one can observe both a significant dip and peak for the same group. Spanish-surnamed males, who in Texas would be primarily of Mexican and/or Mexican- American origin, do show the death dip/ peak phenomenon at a level that is statistically impressive. Certainly, the findings shown in Table 2 are contrary to the idea that the death dip/peak phenomenon is associated only with notability. The birthday appears to be a more important event for Black women and Spanish- surnamed men, particularly for Spanish-surnamed men, since a signifi¬ cant death peak can also be demonstrated for this group. Searching for a Pattern Examination of the comparisons within the race/ethnicity categories reveals an interesting pattern. Two computations based on factors of race, sex, and ethnicity may really be considered significant statistically in terms of the death dip. In the order of magnitude of the relationships, male Spanish-surnamed persons show the greatest dip and Black females a slightly lower dip. DEATH DIP/PEAK PHENOMENON 299 As Staples (1981:234) has indicated, “As a result of the declining fertility rate among Blacks, the elderly represent a larger proportion of the total Black population than in previous times.” This population is also becoming more disproportionately female than is the case with Anglos. In spite of the observation that poverty falls disproportionately upon Blacks in general, the Black elderly have more often than the Anglo elderly described themselves as happy because of their role in the extended family and community (Staples 1981:235). For example, elderly women often take care of children who have no other place to go. The fact that these women are vitally enmeshed in the community rather than in isolated retirement or home settings may influence attitudes about age and the significance of certain social events. Perhaps feelings about birthdays are accentuated by the family and neighborhood position of the older Black woman. This in turn could be translated into the phenomenon that we are calling a death dip prior to the birthday month. The data for the Spanish-surnamed population show both the dip and the peak. The partriarchy of the traditional Mexican-American family has been widely noted (Alvirez et al. 1981:274-277). And, as we have speculated for Black females, the status of the Mexican-American husband/father is such that some individuals may manage to “hang on” to receive birthday compliments “one more time.” CONCLUSIONS There are two possible ways to conclude this report. The first is obvious: We could state that the death dip was not manifest for a sample composed of 96,093 Texans who died in 1979 after their twenty-fifth birthday. We could, of course, emphasize the presumptive death dip for Black females in the same year and one that was definitely present (at least statistically) for Spanish-surnamed males during 1979. While the latter conclusion is important in terms of the implications for further inquiry into the effects of ethnicity on social and even biological behavior, the former conclusion has at least hidden implica¬ tions for research endeavors in sociology, social demography, and death and dying research. Data like those in this report have been available in county courthouses across the United States for many years. Data collection would be tedious and time consuming, but certainly not impossible. Also, we suspect that other states have records of birth and death on tape ancL probably have had this information available for the past several years. Why then have we not seen more published on the applicability of the death dip/peak phenomenon to various populations? The phenomenon is often mentioned in the 300 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 literature on death and dying and is alluded to in other sociologically relevant literature. In short, the research is feasible and the topic is certainly relevant to sociologists. Why then has not more been written? We suspect that much more research has been done than meets the eye and that small papers such as our own works cited in the reference section have been presented and written as tentative reports; however, few if any of these works — aside from the original Phillips and Feldman (1973) investigation of notables — have apparently been pub¬ lished in widely read journals in the field. We suggest that the findings may not have been published because the findings were either consistently negative, or mixed and somewhat ambiguous as in the case of our own Texas data. We have completed preliminary analysis for the death dip in association with specific causes of death and also using social events other than the birthday of the individual. We can merely state that the results of these analyses were consistently negative, and we suspect that may have been the result with other investigations. It seems that sociologists may be reluctant to submit important research that has a negative outcome and we, of course, cannot ascertain to what degree this feeling is shared totally or partially by editors and referees for various professional publications. Let us now return to our first conclusion emphasizing the positive findings. Spanish-surnamed males in Texas who died in 1979 do show the death dip/peak phenomenon. Perhaps we need to further investi¬ gate how patterns of ethnicity and social class may influence dying behavior in general and the specific timing of death. Perhaps the death dip does not apply to the majority of urban Americans, in these modern times, but can be found among ordinary people in more traditional societies under certain circumstances. Until we have better death reporting in more traditional societies, and better socio-economic indicators for American mortality data, some important relationships may remain only tentatively explored. LITERATURE CITED Alvirez, D., F. D. Bean, and D. Williams. 1981. The Mexican-American family, p. 269- 292. In C. H. Mindel and R. W. Habenstein (eds.), Ethnic families in America: Patterns and variations, 2nd edition. Elsenier, New York, NY. Phillips, D. P. 1970. Dying as a form of social behavior. Ph.D. dissertation, University of Michigan, Ann Arbor, MI. Phillips, D. P., and K. A. Feldman. 1973. A dip in death before ceremonial occasions: Some new relationships between social integration and mortality. American Sociologi¬ cal Review 38:678-696. Short, A. P., and T. C. Borelli. 1981. The death dip in selected Texas counties. Unpublished paper presented at the Texas Academy of Science Meetings, Austin, TX. DEATH DIP/PEAK PHENOMENON 301 Staples, R. 1981. The Black-American family, p. 217-244. In C. H. Mindel and R. W. Habenstein (eds.), Ethnic families in America: Patterns and variations, 2nd edition. Elsenier, New York, NY. Tanner, L. M., and R. K. Newsom. 1981. Do Texans really die with their boots on? Unpublished paper presented at the Southwestern Sociological Association Meetings, Dallas, TX. . CATTLE EGRETS {ARDEOLA IBIS = BUBULCUS IBIS) IN TEXAS by RAYMOND C. TELFAIR II and LARRY E. MARCY Department of Wildlife and Fisheries Sciences Texas A&M University College Station , TX 77843 ABSTRACT African Cattle Egrets reached Texas by 1954, via South America and the southeastern U.S. By 1979, there were about 300,000 breeding pairs in Texas, mostly east of the Balcones Escarpment. These birds use heronries established by native egrets and herons, but there appears to be little competition between the newcomers and their relatives. Cattle Egrets arrive at the heronries later in the spring (mid-April) and are less selective of nest sites and materials than native ardeids. Furthermore, Cattle Egrets feed primarily on terrestrial organisms, particularly grasshoppers and crickets, and consume few fish and crayfish. Consistent with their food habits, Cattle Egrets are vulnerable to agricultural pesticides. Cattle Egrets benefit cattle, with which they often associate, by preying on competing herbivorous insects and on such biting pests as horseflies (but not ticks). Cattle Egrets seem to pose little threat as vectors of disease and, by eating tabanid flies, may even help to control bovine anaplasmosis. On balance, Cattle Egrets are beneficial birds, but their heronries can be a serious nuisance to nearby human communities. INTRODUCTION The phenomenal, almost worldwide range expansion of the Cattle Egret ( Ardeola ibis — Bubulcus ibis) has been of interest to scientists and laymen alike. Cattle Egrets were first seen in Texas in 1954; today, their breeding population in the state is about 300,000 pairs. As this exotic bird has proliferated, so have questions about its orgin, rapid range expansion, population dynamics, food habits, competition with native herons and egrets, and economic importance. Our purpose here is to provide basic information about this unique bird, and to dispel some of the common misbeliefs concerning it— e.g., that the Cattle Egret consumes ticks, spreads livestock diseases, out-competes native herons and egrets, and feeds in pastures that are relatively free of pesticides. More complete treatment of these subjects is provided in Telfair (1979) and Telfair (1983). DISTINGUISHING CHARACTERISTICS The Cattle Egret is gregarious and usually associates with grazing cattle. Compared to similar-sized herons and egrets, it is short-legged and thick-necked, the throat appearing swollen. Adults are about 17 The Texas Journal of Science, Vol. XXXV, No. 4, January 1984 304 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 inches (43.2 cm) in length, have a wingspan of about 37 inches (94.0 cm) and weigh about 0.6 to 1.0 pounds (0.27-0.45 kg). At rest, whether standing or perched, the Cattle Egret has a “hunched” posture. Plumage of the Cattle Egret is generally white; but, during the breeding season, orange-buff plumes appear on the breast, forehead, nape, and mantle. In non-breeding birds, the bill, lores, and irises are yellow, and the legs are very dark green, appearing black at a distance. In breeding birds, the legs become more yellow-green and the iris darker yellow; for a brief period during the peak of the breeding season, the bill, legs, and irises turn bright red, and the lores turn purple-pink. GLOBAL RANGE EXPANSION During the last 100 years, the Cattle Egret has spread from centers of distribution in Africa and southern Asia to many parts of the world, including places as remote as Australia (by 1948), Tierra del Fuego (by 1977), and Alaska (by 1981). Although details of the Cattle Egret’s expansion to the New World are not known, the African subspecies (A. i. ibis) apparently spread from the west coast of Africa across the Atlantic to coastal areas of northeastern South America. They were noted between 1877 and 1882 in Surinam (Dutch Guiana) and in 1911-1912 in British Guiana. Several were seen and collected in this region during 1937-1947; they were common in 1947 and 1948; and by 1950, were well established. The first sight records of Cattle Egrets in North America were in Florida in 1941 or 1942, but proof via photographs was not established until 1952, and the first nest was not found until 1953. Cattle Egrets were well established in the United States by 1954, even before they were first reported from the West Indies. They may have flown to Florida directly from South America, rather than island-hopping through the Carribbean. Band recovery data suggest that Texas originally received Cattle Egrets from the eastern Gulf Coast states, probably as a result of west- south westward coastal wanderings and/or migrations, rather than via routes through Central America and Mexico. Cattle Egrets spread into Texas in 1954 (Fig. 1) and established breeding populations by 1959. Along the Texas coast, they increased from 10 pairs in 1959 to more than 20,000 pairs by 1965. The 1970 population in Texas was at least 35,500 pairs and by 1979 there were about 300,000 breeding pairs in the state. Today, in North America, Cattle Egrets are found nesting in most eastern states, throughout the Gulf Coast states, along the west coast of California, and inland as far north as Saskatchewan. They now nest in CATTLE EGRETS IN TEXAS 305 Figure 1. Locations of the first confirmed occurrences of Cattle Egrets in Texas and the subsequent breeding distribution of Cattle Egrets in relation to other ardeids. The dot-dash line marks location of the Balcones Escarpment. Only 208 of the 302 known heronries (68.9%) are represented because of the small scale of the map. Most of the omitted heronries are coastal, especially in bay systems. Data are from Mullins et al. (1982). Map updated from Telfair (1979). all but 14 of the United States (Alaska, Arizona, Indiana, Iowa, Maine, Massachusetts, Michigan, Montana, Nebraska, New Hampshire, Oregon, Washington, West Virginia, and Wyoming). DISTRIBUTION IN TEXAS The current breeding range of Cattle Egrets in Texas is largely east of the Balcones Escarpment (Fig. 1). Breeding distribution and the western inland boundary of the breeding range correspond with those of Little Blue Herons (Egretta caerules) and Snowy Egrets (E. thula). In fact, Cattle Egrets are attracted to inland heronries already estab¬ lished by native species, primarily Little Blue Herons and Snowy Egrets; the latter species, in turn, are limited by the distribution and abundance of crayfish upon which they feed (Telfair 1981). Data assembled by Mullins et al. (1982), and plotted in Figure 2, indicate that Texas Cattle Egrets nest mostly along the Gulf Coast and 306 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 Figure 2. Distribution and density of Cattle Egrets per county in Texas (black dots). The dot-dash line marks location of the Balcones Escarpment. Data are from Mullins et al. (1982). Map copied from Telfair (1983). coastal drainages (31.8% of the breeding population), and inland in the Trinity River system (40.5%). A smaller fraction of the population occupies heronries in the Sabine, Neches, Brazos, and Red River systems (27.8% combined). FOOD HABITS The diet of Cattle Egret chicks reflects that of adult birds. Telfair (1979) analyzed 500 undigested boluses regurgitated by chicks at 10 heronries to determine the diet during the nesting season. Analyses of prey items included occurrence (frequency), total numbers, average number per bolus, maximum number per bolus, total volume, and average volume per bolus. Diet composition was as follows: by frequency of occurrence — 93.6% invertebrates, 53.8% vertebrates; by total number of food items — 94.9% invertebrates, 5.1% vertebrates; and by total volume— 69.2% inverte¬ brates, 30.0% vertebrates. Most prominent in the diet were grasshoppers and crickets (78.6% by number). With the exception of aquatic organisms (4.5% by number), almost all prey items are common CATTLE EGRETS IN TEXAS 307 inhabitants of farm pastures and ranches (94.7% by number). Ticks, earthworms, crayfish, and fish were rare. During the breeding season, aquatic habitats (often away from cattle) provide vertebrate food, especially frogs and toads. These items are important during the critical period of maximum growth and energy requirement of chicks. Cattle Egrets, especially during the fall, often feed away from cattle in cotton and grain fields and follow cutting machines and tractors plowing under harvested crops. OCCURRENCE OF PESTICIDES IN EGGS AND TISSUES Egg-shell thinning and toxicosis of breeding birds are important factors related to successful reproduction (Telfair 1979). In several heronries, I found thin-shelled eggs and breeding birds that exhibited symptoms of chlorinated hydrocarbon toxicosis. For analyses, 4 eggs were randomly selected from a sample of 185 eggs lost from nests during storms, and 12 adult birds were randomly selected from a sample of 59 birds exhibiting signs of pesticide toxicosis. The most significant pesticide residues in eggs were DDE (0.20-12.45 ppm) and DDT (0.02-0.04 ppm). Lindane was found in all four eggs, but concentrations were small (0.006-0.02 ppm). Tissues from adult birds contained DDE in amounts varying from 0.01 to 297.32 ppm. Some brain tissue contained more DDE than did livers. Residues of PCB’s (trace to 8.0 ppm) were found in only 2 birds. Trace amounts of 2, 4, 5-T occurred in livers. Two apparently normal adults obtained in the field were almost devoid of pesticide residues; viz., DDE, dieldrin, and DDT occurred in amounts from trace to 0.01 ppm, and no other residues were found. These observations suggest that some Cattle Egrets feed regularly in areas that have been treated with chlorinated-hydrocarbon pesticides. The presence of greater than trace amounts of DDT residues in brain and liver tissues of some adult birds and in eggs indicates intake of the pesticide was recent since it had not been metabolized into DDE or DDD. Presence of lindane in tissues and eggs suggests feeding by Cattle Egrets in cotton-producing areas. NESTING AND REPRODUCTION The following account relies mainly on observations of Telfair (1979, 1983), who studied the breeding biology of Texas Cattle Egrets from 1972 through 1982. Most field work was conducted during the breeding seasons of 1972-1975, front the arrival of birds at the heronries in late February and March to their departure in October and November. The study area encompassed most parts of Texas in which Cattle Egrets breed (Fig. 1). Data were taken from 29 heronries. 308 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 EA1 FC1 FH1 LC1 I - 1 - 1 - 1 - Louisiana Heron EA2AA2 FC1 FH1 LC1 LN1 H - H - H - 1 - —I FC2 FH2 Snowy Egret EA2 AA2 FC1 FH1 LC1 LN1 Little Blue Heron LN2 — i — i — i — I — l — i — i — I — i — l — i — I — l — i — l — ] — l — l — l — I — i — I — I — | — i — i — i — | — i — i — i — | — | — l — i — | March April May June July ' August ^September! October * November ' DATE Figure 3. Average phenologies and sequences of major events during the breeding seasons of Cattle Egrets, Little Blue Herons, Snowy Egrets, and Louisiana Herons in Texas heronries. EA = early arrival, AA = average arrival, FC = first clutches, FH = first hatchlings, LC = last clutches, and LN — last nestlings. Data are from (1) Oberholser (1974) and from (2) this study. Figure from Telfair (1979). Beginning at the time of nest construction, nests were marked individually. When feasible, the condition and contents of nests were recorded each day during egg laying and at the time of hatching, and on alternate days at other times. To facilitate study of stick-stealing activity, foundation and protruding sticks of occupied nests were spray-painted from beneath, and entire unoccupied nests were lightly sprayed with the same bright-orange paint. Since 1963, over 18,000 Cattle Egret chicks have been banded or banded and color-marked in Texas. In May 1974, the Texas Parks and Wildlife Department initiated a large-scale banding and color-marking program to investigate movements and population dynamics of colon¬ ial water birds in 3 coastal and 3 inland regions of eastern Texas. Methods were described by Swepston et al. (1978). The Saflag leg tag used to color-mark birds was described by Frentress (1975). Of a total of 15,765 chicks banded and color-marked, 8,143 were Cattle Egrets. Since 1975, I have marked 9,976 additional Cattle Egrets, using a more durable tagging material, Herculite “80”. Cattle Egrets are usually the last species to arrive in Texas heronries, about 1 month after the mid- to late March return of native species (Fig. 3). By the time Cattle Egrets appear, most native species have already established nests and laid eggs. Early arrival and breeding of EA2 AA2FC’ FH1 LC2 Cattle Egret CATTLE EGRETS IN TEXAS 309 native species in inland heronries appears to be synchronized with the average of maximum spring rains during May and the subsequent availability of aquatic prey. The later arrival and subsequent nesting of Cattle Egrets is apparently synchronized with the cumulative increase of pasture-dwelling insect populations, especially gras¬ shoppers and crickets, during mid- to late summer. Cattle Egrets use a wide variety of sites and substrates for nesting. Preferred nest sites are old platforms of nests from the previous year. In swamp heronries, nests often are built in basket-like growths of limbs of common buttonbush (Cephalanthus occidentalis), water elm (Plan- era aquatica), and swampprivet ( Forestiera acuminata ); the basketlike growths result from pruning of therminal shoots by nesting birds in previous years. Cattle Egrets select unused nest sites or, in the case of late arrivals, nests vacated by native species. In coastal island heronries, Cattle Egrets prefer shrubs and tall herbaceous plants; whereas, native species generally nest lower, preferring sites in low herbs, in grasses, and on the ground. Precariously sited nests are often destroyed in wind gusts of 25 to 60 mph (40.2-96.5 kph) that occur during spring-summer thunderstorms. Since most Cattle Egrets nest several weeks later than native herons and egrets, nests of the native species are more subject to storm destruction. However, both Cattle Egrets and native species usually renest and thus replace early nest losses. Cattle Egrets usually build their nests in living vegetation about 1 m below the highest part of the nest-site plant, but they are less selective of nest sites than are native species. Consistent with the Cattle Egret’s late arrival, many live twigs bearing leaves are often incorporated into their nests. Both Cattle Egrets and native species build nests resem¬ bling shallow saucers or bowls, but there is much variation. Cattle Egrets spend about 2 more days in nest construction than native species of similar size, and Cattle Egret nests are more complete when the first egg is laid. Thus, Cattle Egrets seldom lose their first egg through the nest floor. The average clutch size of Cattle Egrets in heronries monitored by Telfair (1979) was 3.6; the average interval between laying of successive eggs was 2.0 days; and average incubation period was 24.0 days. The highest hatching success occurred on coastal islands (90.0%); in descending order, lesser success occurred on wooded inland islands (84.1%), in swamps (82.1%), and in woodlands (79.6%). Success for 26 heronries over a period of 5 breeding seasons (1970 through 1974) averaged 83.4%. Fledging success for Texas Cattle Egrets (percentage of chicks fledged in relation to the number of eggs hatched) also was highest in 310 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 The graph of composite data corresponds with that of in- Completed Eggs Young Alive at Young Clutch Hatched End of First 3 Fledged Weeks After Hatching The Three Critical Reproductive Stages Figure 4. Comparison of the breeding success of Cattle Egrets in 4 types of heronries. The composite graph is the average of all data. Figure from Telfair (1979). heronries on coastal islands (98.4%), and somewhat less in woodlands (94.7%), wooded islands (93.3%), and swamps (90.0%) (Fig. 4). Fledging success for 18 heronries over the period of 1970 through 1974 averaged 93.6%. Differences in hatching and fledging success among the 4 types of heronries could be related to the type of nest-site vegetation and the differential effects of weather. In woodland heronries, strong winds accompanying spring thunderstorms can dislodge eggs and chicks from their nests and chicks from their perches; or, eggs and chicks can be dislodged by falling dead limbs. In swamps, eggs and chicks in low, shrubby vegetation may be lost during floods associated with spring- summer thunderstorms and prolonged rains. Despite these weather-related losses, breeding success of Texas Cattle Egrets is high relative to that of native herons and egrets. In part, this is because Cattle Egrets are particularly attentive toward their young. Indeed, one parent is in constant attendance of the young during the first 2 or 3 weeks after hatching of the first chick. The incidence of 24 mixed clutches (1.4% of a sample of 1,707 clutches) and the resultant 3 mixed broods (0.2%) observed by Telfair (1979) does not indicate that the presence of Cattle Egrets has or will result in increasing nesting competition via usurped nests of native species. Interbreeding between Cattle Egrets and native species has not been observed. CATTLE EGRETS IN TEXAS 311 POPULATION DYNAMICS Breeding and winter censuses of Texas Cattle Egrets reveal an exponential growth pattern expected of a species expanding into an essentially “unlimited” environment. However, the estimated finite rate of population increase for breeding Cattle Egrets in Texas decreased from 1.86/year during 1959-1972, to 1.20/year during 1972- 1976. These data suggest that Cattle Egrets may be approaching the carrying capacity of suitable habitats in Texas. Mortality among breeding adult Cattle Egrets in Texas heronries was about 1.1%. Causes of death were pesticides, avian pedators, and shooting. Based upon band recoveries, mortality among juvenile Cattle Egrets occurred mainly in late fall and winter. The percent recovery of banded birds is greatest among juveniles banded late in the breeding season (71.0%). Most recoveries of juvenile Texas Cattle Egrets have come from 4 Mexican states — Sinaloa (25.6%), Michoacan (11.6%), Tamaulipas (10.5%), and Jalisco (7.0%). Compared to juveniles, few yearlings and adults banded in Texas as chicks have been recovered (61.7% versus 38.3%). During the fall, flocks of Cattle Egrets migrate southward along barrier islands off the Texas coast. At this time, they are subject to predation by Arctic Peregrine Falcons ( Falco peregrinus tundrius) also migrating southward along these islands. INTERACTIONS WITH NATIVE HERONS AND EGRETS Nest establishment by Cattle Egrets in Texas is mostly noncompeti¬ tive with native species, and interspecific aggression is relatively low for the following reasons: Cattle Egrets (1) arrive at the heronries later in the spring than native species; (2) are less selective of nest sites and utilize unoccupied sites; (3) make use of abundant materials to build nests in an orderly manner, thus causing little disturbance to estab¬ lished nesters; and (4) reuse abandoned nests or take them apart for materials for their own nests. The latter behavior is also common among native species. There is some evidence that the white-plumaged juvenile Little Blue Herons may associate with Cattle Egrets and thereby learn to feed in a similar manner, in close association with grazing cattle. However, at the present time, there is no evidence that typical feeding behavior of Little Blue Herons has been modified by imitative-learning from Cattle Egrets. 312 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 ASSOCIATION WITH CATTLE Cattle Egrets do not associate with all cattle within a herd, nor with all herds within a specific area even in the vicinity of a large heronry, nor do they feed within the total area of a specific pasture or range. Between 1968-1976, within 44 counties in which or adjoining which Cattle Egrets nested, the ratio of grazing cattle/egret varied widely (6:1 — 122:1) with an average of 37:1. In herds accompanied by egrets, the ratio of associated egrets/bovine usually varied from 1:1 to 5:1 with an average of 3:1. There is in Texas, at the present time, no correlation between distribution and density of grazing cattle and the breeding range and density of Cattle Egrets or location of heronries (cf. Figs. 2 and 5). Within the Cattle Egret’s breeding range, there are counties containing large numbers of grazing cattle, but with no heronries in the vicinity containing Cattle Egrets; conversly, there are many counties (especially in coastal and coastal-prairie areas) containing small numbers of grazing cattle, but with 1 to 5 heronries containing large numbers of Cattle Egrets. ECONOMIC IMPORTANCE AND HEALTH ASPECTS Because of their feeding habits, diet, and population size, Cattle Egrets are economically among the most beneficial animals to Texas cattlemen and farmers. Consumption of grasshoppers by Cattle Egrets may indirectly benefit cattle since these herbivorous insects may be the primary food competitors of cattle. Cattle benefit directly from Cattle Egrets feeding on flies. In Texas, these egrets consume large numbers of livestock-associated flies (4.3% of prey items). Fly-eating by Cattle Egrets benefits cattle because these insects are not only disease carriers, but also annoy livestock by inflicting painful bites and cause considerable loss of blood, weight, and meat and milk production. Some larval flies can cause extensive, fatal wounds. Experimental data are lacking, but there is consensus among some veterinarians and cattlemen that the fly-eating ability of Cattle Egrets reduces the number of tabanid flies in herds and, thereby, the incidence of bovine anaplasmosis. If Cattle Egrets, via their fly-eating activities among cattle herds, can help control or at least lessen the effects of this important, costly disease, they are indeed of positive benefit to the cattle industry. Unlike other methods of fly control, predation by Cattle Egrets is without cost and occurs many hours daily among some herds during the summer to fall season when vectors are most numerous. CATTLE EGRETS IN TEXAS 313 Figure 5. Distribution and density of cattle per county in Texas (black dots). The dot- dash line marks location of the Balcones Escarpment. Distribution and density of cattle populations are from the Texas Crop and Livestock Reporting Service (1979). Map updated from Telfair (1979). The close association of Cattle Egrets with livestock, especially cattle, has caused veterinary entomologists and pathologists to specu¬ late that these egrets may be involved as reservoirs in transmission of cattle diseases. In Texas and apparently elsewhere, little research has been conducted, implicative data and publications are lacking, and thus, the question of disease association with Cattle Egrets is moot. However, laboratory tests in Texas have shown that Cattle Egrets are not carriers of brucellosis. Furthermore, there is no evidence that Cattle Egrets pose a disease threat to humans (except those who enter heronries). Materials dropped within heronries comprise large quantities of highly concentrated nutrients that eventually enter the soil, water impoundments, and river systems. These wastes may add substantially to the nutrient supply at the base of the soil and aquatic food webs. Although native herons, egrets, and ibises feed primarily in aquatic systems and thereby recycle nutrients and energy within those systems, Cattle Egrets transfer nutrients and energy from terrestrial to aquatic systems. 314 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 Heronries are not desirable when located adjacent to human habita¬ tion because of noise, odor, and concern about possible health hazards; but, no evidence exists that Texas heronries represent health hazards to adjacent human communities. Heronries may, however, produce detri¬ mental effects upon nest and roost-site vegetation due primarily to the accumulation of excrement on the plants and in the substrate (soil and/or water). A direct relationship exists between materials deposited in heronries and increased levels of nitrogen and phosphorous in the waters beneath or in the vicinity of heronries. These heronries often stimulate production of thick mats of floating and submerged vegeta¬ tion, particularly algae and duckweed. Presently available methods for preventing establishment or use of heronries are either undesirable, expensive, or illegal. LITERATURE CITED Frentress, C. D. 1975. “Pop” rivet fasteners for color markers. Inland Bird Banding News 47:3-9. Mullins, L. M., G. W. Blacklock, D. R. Blankinship, A. H. Chaney, S. Kennedy, K. A. King, R. T. Paul, R. D. Slack, J. C. Smith, and R. C. Telfair II. 1982. An atlas and census of Texas waterbird colonies 1973-1980. (Compiled by the Texas Colonial Waterbird Soc.) Caesar Kleberg Wild. Instit. , Texas A8cl Univ., Kingsville, TX. Oberholser, H. C. 1974. The bird life of Texas (E. B. Kincaid, Jr., ed.), vol. 1. Univ. Texas Press, Austin, TX. Swepston, D. A., C. D. Frentress, and R. C. Telfair II. 1978. A method for banding and color-marking large numbers of wading birds, p. 219-225. In A. Sprunt IV, J. C. Ogden, and S. Winckler (eds.), Wading birds. National Audubon Society Research Report No. 7. Telfair, R. C. II. 1979. The African Cattle Egret in Texas and its relation to the Little Blue Heron, Snowy Egret, and Louisiana Heron. Ph.D. dissertation, Texas A&M University, College Station, TX. Telfair, R. C. II. 1981. Cattle Egrets, inland heronries, and the availability of crayfish. Southwest. Nat. 26:37-41. Telfair, R. C. II. 1983. The Cattle Egret: a Texas focus and world view. Kleberg Studies in Natural Resources. The Caesar Kleberg Research Program in Wildlife Ecology and The Department of Wildlife and Fisheries Sciences, The Texas Agricultural Experi¬ ment Station, The Texas A&M University System, College Station, TX. Texas Crop and Livestock Reporting Service. 1979. Texas county statistics. Texas Dept. Agr. and U.S. Dept. Agr. , Austin, TX. SWIM BLADDER STRESS SYNDROME IN LARGEMOUTH BASS by GARY J. CARMICHAEL National Fish Hatchery and Development Center U.S. Fish and Wildlife Service San Marcos, TX 78666 and J. R. TOMASSO Aquatic Station, Department of Biology Southwest Texas State University San Marcos, TX 78666 ABSTRACT Overinflated swim bladders were observed in largemouth bass ( Micropterus salmoides) after handling and short-term transport. The affected fish swam near the surface with their backs exposed and, in some cases, became inverted and later died. Plasma corticosteroid concentrations of these fish were above normal levels while plasma chloride concentrations and plasma osmolality were below normal levels. Changes in these plasma characteristics are indicative of acute handling-induced types of stress in largemouth bass. It is suggested that some physiological response to physical disturbance may increase the deposition of gas from the blood into the swim bladder. INTRODUCTION Swim bladder stress syndrome (SBSS) is a condition in adult fish characterized by overinflation of the swim bladder causing the animal to swim at the surface of the water with the back exposed. It is distinguished from gas bubble disease in that it involves only the swim bladder and does not involve the formation of emphysema or emboli due to gas supersaturation (Bouck 1980). The initial description (Clary and Clary 1978) of the development of SBSS in salmonids in response to environmental stressors (other than gas supersaturation) was the only reference to the syndrome that we found in the literature. During spring and summer 1982, at the San Marcos National Fish Hatchery and Development Center, SBSS developed on three occasions in groups of largemouth bass (Micropterus salmoides) immediately after they were handled and transported. Reported here are descriptions of SBSS in adult largemouth bass, the stressors applied immediately before the development of SBSS, and some hematological characteris¬ tics of the afflicted fish. The Texas Journal of Science, Vol. XXXV, No. 4, January 1984 316 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 MATERIALS AND METHODS Two groups of fish (50 in one group and 126 in the other) that later developed SBSS were moved from outdoor raceways to indoor tanks. These fish weighed approximately 400 g each. The 21-C water in both the raceways and tanks came from a common well. Both groups of fish were transported in large plastic cans containing water from the raceways. The water used to transport one group contained 50 mg/liter MS-222, a common fish anesthetic. A third group of fish that would later develop SBSS consisted of approximately 400 fish, each weighing about 100 g. They were seined from a culture pond and transported in pond water containing 50 mg/liter MS-222 to a raceway. When these fish were moved, the pond water temperature was 18 C and the raceway temperature was 21 C. Blood samples were taken by syringe from the caudal peduncle of five fish that developed stage 3 SBSS (see Results and Discussion) in the first group. Blood from an additional six fish from the same group that did not develop SBSS was also sampled. Samples were taken 3 days after the initial handling disturbance (approximately 2 days after the first cases of SBSS were observed). Three stage 4 SBSS fish were dissected. Total plasma corticosteroid concentrations were determined by the competitive protein binding method described by Murphy (1967) and modified by Fagerlund (1970). Glucose was determined by using Pierce auto-stat kits1 (Pierce Chemical Company, Rockford, IL) based on the glucose oxidase Trinder-Emerson reaction. Chloride was determined by amperometric-coulometric titration with a chlorideometer. Osmolality was measured by freezing point depression with an osmometer. RESULTS AND DISCUSSION Clary and Clary (1978) described four distinct stages of SBSS in salmonids. Stage 1 consisted of the fish swimming in a head-down position near the surface of the water, frequently with the caudal fin protruding from the water. Stage 2 consisted of fish broaching the surface with their backs out of the water. Fish in stage 3 swam erratically on their sides, and stage 4 fish swam in an inverted position. Our largemouth bass also exhibited well defined SBSS stages, although they differed from those described by Clary and Clary in salmonids (Fig. 1). At stage 1 bass swam near the surface, normally oriented. Stage 2 was similar to stage 1 in salmonids, including the head-downward orientation and protruding caudal fin. Fish in stage 3 swam at the surface with their dorsal fin out of the water, and those in •Use of trade names does not imply government endorsement of commercial products. SWIM BLADDER STRESS SYNDROME 317 Figure 1. Developmental stages 1-4 of swim bladder stress syndrome in largemouth bass. See text for a description of each stage. stage 4 swam inverted at the surface. The bass were never observed swimming on their sides as described for stage 3 salmonids. Approximately one third of the first group of fish developed stage 3 SBSS within 48 h of transfer from raceways to tanks. Of these, most seemed to recover within a few days; however, since this was the first occurrence, accurate observation of SBSS development and recovery was not made. Of the second group, 22% developed stage 4 SBSS within 96 h of transfer. All of the stage 4 fish died. Ninety percent of the third group developed stage 1 or stage 2 SBSS within 48 h of transport. However, these fish appeared normal by 96 h after they were moved, and they fed on the fifth day after transport. These observa- 318 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 tions suggest that largemouth bass can recover from stages 1,2, and 3 of SBSS but cannot recover from stage 4. All of the fish dissected had overinflated swim bladders that tended to push the other organs in the body cavity toward the sides and bottom of the cavity. No gas bubbles were observed in the membranes or fins. Hemorrhage was not apparent and no fluid was observed in the swim bladder. No microscopic examination of the gills for emboli was conducted. Slight physiological stress was indicated by plasma osmolality and concentrations of plasma chloride and corticosteroids in fish afflicted with SBSS, when compared to baseline information previously col¬ lected from healthy, undisturbed fish in our laboratory (Fig. 2). Fish that did not develop SBSS after transfer to the holding house (first group) had plasma osmolality, chloride and corticosteroid values that fell between baseline and SBSS-afflicted fish. The intermediate levels of these blood constituents in the normal-appearing fish indicated that, although these animals did not develop SBSS, they were stressed by the transfer from the raceways to the holding house. Declining plasma osmolality and chloride concentrations are characteristic of osmoregula¬ tory dysfunction in freshwater fish and sometimes follow handling and hauling (Wedemeyer 1972; Tomasso et al. 1980). Elevated corticosteroid concentrations are indicative of acute stress such as that induced by handling and hauling (Wedemeyer 1972; Barton et al. 1980; Tomasso et al. 1980). The lack of a trend in the plasma-glucose levels we observed is surprising, given that plasma-glucose levels tend to increase with increasing corticosteroid concentrations in channel cat¬ fish, Ictalurus punctatus (Strange 1980), and in largemouth bass (unpublished data of senior author). The physiological basis for SBSS is difficult to determine. An overinflated swim bladder may develop due to a rapid upward movement in the water column, causing a decrease in external pressure that occurs more rapidly than internal pressure can be reduced. Since the bass in this study were never in water more than 2 m deep, this explanation seems unlikely. An increase in temperature could also cause swim bladder inflation due to expansion of gas already in the swim bladder (Chamberlain et al. 1980). However, the small temptera- ture changes (0-3 C) to which our bass were exposed probably could not account for the large swim bladder volume changes observed. Overinflation may also be due to dysfunction of the physiological mechanisms that transfer gases into and out of the swim bladder. Gas is deposited in the swim bladder either by the gas gland which secretes gases from the blood or, in physostomous fishes, through a pneumatic duct that connects the upper digestive tract to the swim bladder (see SWIM BLADDER STRESS SYNDROME 319 Figure 2. Plasma characteristics of baseline largemouth bass (B), apparently normal fish after transport stress (N), and fish with stage 3 swim bladder stress syndrome (S). Height of column and vertical bar represent mean + standard error. review by Steen 1970). Gas is removed from the swim bladder either through the pneumatic duct or through the oval gland, a special area of the bladder wall through which gases are reabsorbed into the blood. Overinflated swim bladders have been observed in Atlantic croakers ( Micropogon undulatus ) after exposure to water supersaturated with nitrogen and oxygen (Chamberlain et al. 1980). The authors hypothe¬ sized that supersaturated water caused an increase in dissolved blood gases to the point where the partial pressure of nitrogen and oxygen in the blood was higher than the partial pressure of these gases in the swim bladder. The gases then diffused from the blood into the swim 320 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 bladder by way of the oval gland. It is doubtful that this process was involved in producing overinflated swim bladders in largemouth bass. To our knowledge, the bass were not exposed to gas-supersaturated water in any of the ponds or holding facilities. The few dissolved oxygen readings available from routine monitoring all were below saturation levels and no other fish in our holding facilities exposed to the same water source demonstrated any symptoms of gas bubble disease. Under conditions of normal gas saturation, secretion of gases into the swim bladder is a complex process that involves counter-current exchange of blood gases across the rete mirabile and drastic reduction in the hemoglobin’s capacity to carry oxygen, caused by production of lactic acid in the gas gland. Perhaps the increased activity due to struggling during capture and transport in some way causes an increase in the secretion of gas into the swim bladder by way of the rete mirabile. Unfortunately, we have been unable to identify a stressor that consistently induces SBSS. The three cases reported here that followed physical disturbance of the fish represent a very small percentage of the fish handled at our laboratory during the course of a year. The lack of a method to induce the syndrome has complicated attempts to understand its physiological basis. LITERATURE CITED Barton, B. A., R. E. Peter, and C. R. Paulencu. 1980. Plasma cortisol levels of fingerling rainbow trout ( Salmo gairdneri) at rest and subjected to handling, confinement, transport and stocking. Canadian Journal of Fisheries and Aquatic Sciences 37:805- 811. Bouck, G. R. 1980. Etiology of gas bubble disease. Transactions of the American Fisheries Society 109:703-707. Chamberlain, G. W., W. H. Neill, P. A. Romanowsky, and K. Strawn. 1980. Vertical responses of atlantic croaker to gas supersaturation and temperature change. Transactions of the American Fisheries Society 109:737-750. Clary, J. R., and S. D. Clary. 1978. Swim bladder stress syndrome. Salmonid l(6):8-9. Fagerlund, U. H. M. 1970. Determination of cortisol and cortisone simultaneously in salmonid plasma by competitive protein binding. Journal of the Fisheries Research Board of Canada 27:596-601. Murphy, B. E. P. 1967. Some studies of the protein binding of steroids and their application to the routine micro and ultramicro measurements of various steroids in body fluids by competitive protein-binding radio-assay. Journal of Clinical Endocri¬ nology 27:973-990. Steen, J. B. 1970. The swim bladder as a hydrostatic organ, p. 413-433. In W. S. Hoar and D. J. Randall (eds.), Fish physiology, Volume 4. Academic Press, New York, NY. Strange, R. J. 1980. Acclimation temperature influences cortisol and glucose concentra¬ tions in stressed channel catfish. Transactions of the American Fisheries Society. 109:298-303. SWIM BLADDER STRESS SYNDROME 321 Tomasso, J. R., K. B. Davis, and N„ C. Parker. 1980. Plasma corticosteroid and electrolyte dynamics of hybrid striped bass (white bass x striped bass) during netting and hauling. Proceedings of the World Mariculture Society 11:303-310. Wedemeyer, G. 1972. Some physiological consequences of handling stress in juvenile coho salmon ( Oncorhynchus kisutch ) and steelhead trout ( Salmo gairdneri). Journal of the Fisheries Research Board of Canada 29:1780-1783. \ DISTRIBUTIONAL RECORDS AND NOTES FOR NINE SPECIES OF MAMMALS IN EASTERN TEXAS by ARTHUR G. CLEVELAND Department of Biology Texas Wesleyan College Fort Worth, TX 76105 and JOHN T. BACCUS Department of Biology Southwest Texas State University San Marcos, TX 78666 and EARL G. ZIMMERMAN Department of Biology North Texas State University Denton, TX 76203 ABSTRACT Localities for nine species of mammals in eastern Texas are reported. Also, notes on reproduction in Reithrodontomys fulvescens, R. humulis, and Microtus pinetorum are presented. INTRODUCTION The last review of east Texas mammals was over twenty years ago (McCarley 1959). Since that review, few additional records have been published. We have compiled records on several species that should be noted, extending ranges within and into east Texas. Specimens described are deposited in the museums of North Texas State Univer¬ sity (NTSU), Southwest Texas State University (SWTS), and Texas Wesleyan College (TWC). SPECIES ACCOUNTS Tadarida brasiliensis (Saussure), Brazilian Free-tailed Bat Specimens of the free-tailed bat have been reported from Anderson, Angelina, Brazos, Cherokee, Grimes, Harris, Nacogdoches, Sabine, and Shelby counties (Schmidly et al. 1977). A single male (SWTS) was secured from a building in Marshall, Harrison County. This record The Texas Journal of Science, Vol. XXXV, No. 4, January 1984 324 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 extends the range of this species some 80 km north of its previously known Texas occurrence in Nacogdoches County (McCarley 1959). Lepus californicus melanotis Mearns, Black-tailed Jack Rabbit Packard (1963) reviewed the status of jack rabbit distribution in east Texas. Although he recorded specimens from several southeastern counties, the northeast was represented only by the report of Bailey (1905) from Bowie County and a single specimen from Wood County. We observed jack rabbits at five localities in sandy, upland savannah- grassland along the South Sulphur River in Delta County. A single specimen (TWC) was taken 1.6 km S Cooper. This record supports the contention of Packard (1963) that jack rabbits have been expanding their range eastward. Spermophilus tridecemlineatus texensis Merriam, Thirteen-lined Ground Squirrel Thirteen-lined ground squirrels have not been reported previously from east Texas (McCarley 1959). They were recorded by Davis (1974) from Grayson and Fort Bend counties. We observed this species at two localities in Delta County and one locality in Hopkins County. An adult male specimen (TWC) was taken 1.6 km N Klondike in Delta County. Three (TWC) were taken from Lamar County. These repre¬ sent definite extensions into east Texas. Eastward expansions of thirteen-lined ground squirrels and other mammals appear to parallel the continued clearing of forested areas for agriculture. Oryzomys palustris texensis Allen, Marsh Rice Rat Although the distribution of the rice rat in coastal and eastern areas of Texas is well defined, there are few records for northeastern Texas. McCarley (1952 and 1959) reported specimen localities from Oklahoma and Arkansas. Ten rice rats (SWTS) were collected in a grassy marsh adjacent to an old field near the Sabine River 11.2 km S Hallsville, Harrison County. Four additional Harrison County specimens (SWTS) were taken 8 km S Marshall. Two rice rats (SWTS) were trapped 3.2 km N Milam, Sabine County. Two (TWC) were collected along tributaries of the south Sulphur River (1.6 km S Liberty Grove; Klondike) in Delta County. A single rice rat (NTSU) was trapped in Paris, Lamar County. Two specimens each were reported by Parris (1974) from Hopkins and Hunt counties. These specimens extend the Texas range of this species (Davis 1974) 176 km north of Rusk County. Systematic napping probably would reveal its presence in additional counties where it lias not yet been collected, especially in the lowlands along the major rivers in east Texas. MAMMALS IN EASTERN TEXAS 325 Reithrodontomys humulis merriami (J. A. Allen), Eastern Harvest Mouse Three of these diminutive mice (SWTS) were trapped in a grassy old field 3.2 km S and 3.2 km E Marshall, Harrison County. All specimens were secured from tangles of blackberry vines ( Rubus ) that were surrounded by heavy stands of grass. Prominent grasses were Andro - pogon, Aristida , Panicum, Cenchrus and Sporobolus. Other rodent associates were Cryptotis parva, Reithrodontomys fulvescens and Micro- tus pinetorum. A single specimen (SWTS) was taken from Lotta, Harrison County. These locality records extend the known range of the eastern harvest mouse in east Texas some 80 km north of its previously known occurrence in Nacogdoches County (McCarley 1959). Lowery (1974) recorded specimens from Caddo Parish in Louisiana. McCarley (1959) and Davis (1974) reported no breeding information for this species in Texas. Two females (SWTS) obtained on 11 November contained three and four embryos, respectively. The average crown-rump lengths were 25 mm for the former and 3 mm for the latter. A male collected on the same day had scrotal testes. Thus, breeding probably extends well into autumn in east Texas. Reithrodontomys fulvescens aurantius J. A. Allen, Deer Mouse Hall (1981) failed to report any deer mice from east Texas. McCarley (1959) noted their presence in Brazos, Navarro, and Robertson Coun¬ ties. Deer mice were recorded by Parris (1974) from Hopkins County although no specimens were available to confirm the report. As predicted by McCarley (1959), deer mice are now confirmed along the oak-hickory belt; we took specimens (TWC) from Delta, Hopkins, and Rains counties. William Caire took four specimens (NTSU) from Lamar County. These records substantiate deer mice from the oak- hickory belt of east Texas. Peromyscus gossypinus megacephalus Rhoads, Cotton Mouse McCarley (1959) reviewed the occurrence of the cotton mouse in east Texas. Davis (1974) recorded this rodent as far west as Red River County. A specimen (NTSU) was trapped 4.8 km E and 5.6 km S Telephone, Fannin County, in a mixed pine-oak woodland along the shoreline of Coffee Mill Lake. An additional specimen (SWTS) was taken 9.6 km N and 27.2 km E Tyler, Smith County. Microtus pinetorum (Le Conte), Woodland Vole Parmalee (1954) and McCarley (1959) included Bowie, Marion, Nacogdoches, Panola and Wood counties within the east Texas distribution of the woodland vole. Thirty-four voles (SWTS) were 326 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 collected 3.2 km S 3.2 km E Marshall; 1.6 km E Marshall and 11.2 km S Hallsville in Harrison County; and, 9.6 km N and 27.2 km E Tyler in Smith County. Trapping data indicate a habitat preference for transition areas at the interface of old field communities with pine stands. A single specimen (TWC) (adult female) was taken by the senior author 22.4 km W Hillsoboro in Hill County. This capture (200 km west of the Smith County specimens) provides the first interme¬ diate locality between east Texas and central Texas reports (Gillespie and Kerr counties) of Davis (1974). Additional trapping in similar habitats should reveal the presence of woodland voles in other eastern and central Texas counties. Davis (1974) reported a breeding season extending from February to October and suggested the possibility of a winter period. Specimens collected in November and January confirm the winter breeding hypothesis. Two females (SWTS) secured on 11 November contained two and three embryos respectively. The advanced state of embryonic development indicated a parturition date near the end of November. A juvenile female (SWTS) was trapped on 20 January. Based upon size measurements, we concluded a parturiation date in December. Males (SWTS) examined in December and January had scrotal testes. LITERATURE CITED Bailey, V. 1905. Biological survey of Texas. North American Fauna 25:1-222. Davis, W. B. 1974. The mammals of Texas. Bull. Texas Parks and Wildlife Dept. 41:1- 294. Hall, E. R. 1981. The mammals of North America. John Wiley and Sons, New York, NY. Lowery, Jr., G. G. 1974. The mammals of Louisiana and its adjacent waters. Louisiana State University Press. Printed by Kingsport Press, Kingsport, TN. McCarley, W. H. 1952. The ecological relationships of the mammals of Bryan County, Oklahoma. Texas J. Sci. 4:102-112. McCarley, W. H. 1959. The mammals of eastern Texas. Texas J. Sci. 11:385-426. Packard, R. R. 1963. Distribution of the black-tailed jackrabbit in eastern Texas. Texas J. Sci. 15:107-110. Parmalee, P. W. 1954. Food of the great horned owl and barn owl in east Texas. Auk 71:469-470. Parris, S. D. 1974. Habitat distribution and taxonomy of mice in the upper Sulphur River watershed. M.S. thesis. East Texas State University, Commerce, TX. Schmidly, D. J., K. T. Wilkins, R. L. Honeycutt, and B. C. Weynand. 1977. The bats of east Texas. Texas J. Sci. 28:127-143. DEVELOPMENT OF TENSILE STRENGTH IN COMPATIBLE AUTOGRAFTS OF EGGPLANT (SOLAN UM PENNELLII) AND TOMATO ( LYCOPERSICON ESCULENTUM) by MARY T. McGARRY and RANDY MOORE Department of Biology Baylor University Waco, TX 76798 ABSTRACT Three phases of cohesion between the stock and scion were observed during the devel¬ opment of compatible autografts in Solanum pennellii and Lycopersicon esculentum (Solanaceae). The first phase lasted 2 to 3 days after grafting and was characterized by an average increase in tensile strength of the graft union of approximately 2 g breaking weight (BW)/mm2 graft area (GA)/day. Phase II lasted from days 3 to 15 and was charac¬ terized by a 20-fold increase in the tensile strength of the graft union. Phase III was char¬ acterized by a leveling off of the tensile strength of the graft union at a value approximat¬ ing that of an intact (i.e., ungrafted) internode. The pattern of development of tensile strength reported here is similar to that observed for other compatible graft unions between herbaceous tissues. INTRODUCTION Recent renewal of interest in plant grafting has resulted in an increased understanding of the processes associated with graft forma¬ tion. Studies of herbaceous grafts have included structural (Stoddard and McCully 1979; Moore and Walker 1981a, 1981b, in press; Moore 1982, in press a) as well as functional (Yeoman et al. 1978; Stoddard and McCully 1980; Moore and Walker 1981c) analyses of graft forma¬ tion (see review by Moore 1981a). However, the only convincing mech¬ anism to account for graft incompatibility has resulted from investiga¬ tions using woody tissues of fruit trees. Graft incompatibility between (1) pear and quince (Gur et al. 1968; Gur et al. 1978) and (2) peach and almond (Gur and Blum 1973) appears to be due to the movement (and subsequent catabolism) of cyanogenic glycosides between tissues of the stock and scion. The diversity of incompatibility responses (Moore 1981b) makes it unlikely that this mechanism is applicable to all (or even many) incompatible grafts. Several studies have quantified the development of tensile strength in compatible (Roberts and Brown 1961; Lindsay et al. 1974; Yeoman and Brown 1976; Moore 1982, in press b) and incompatible (Yeoman and Brown 1976; Moore in Press b) grafts. However, the tensile strength of The Texas Journal of Science, Vol. XXXV, No. 4, January 1984 328 THE TEXAS JOURNAL OF SCIENCE — VOL. XXXV, NO. 4, 1984 graft unions in most of these studies (Roberts and Brown 1961; Lindsay et al. 1974; Yeoman and Brown 1976) is reported only as g breaking weight (BW), rather than g BW/unit graft area (GA). Since (1) g BW would be expected to increase with increasing GA, and (2) GA is not given in these studies (Roberts and Brown 1961; Lindsay et al. 1974; Yeoman and Brown 1976), the results reported are not comparable with those reported for most other systems (see discussion in Moore 1982). More recent studies in which tensile strength was reported as g BW/unit GA (Moore 1982, in press b) have suggested that the devel¬ opment of compatible autografts, as measured by increases in tensile strength, may be similar in different grafting systems. It has also been suggested that the tensile strength of a compatible graft union may be used to determine the stage of graft development (Moore in press b). In this study, we have quantified the development of tensile strength in compatible autografts of two members of the Solanaceae, eggplant (Solarium pennellii) and tomato ( Lycopersicon esculentum), by measur¬ ing changes in the tensile strength of graft unions over time. MATERIALS AND METHODS Clonal populations of Solarium pennellii and Lycopersicon esculen¬ tum were used for this study. Grafts were made by horizontally cutting and then reuniting young expanding internodes. Grafts were monitored for 35 days. Measurements of the tensile strength of the graft union were made in a manner similar to that described by Lindsay et al. (1974). Measurements for each species and graft age were replicated at least 12 times. Diameters of the circular areas of cohesion between the stock and scion were measured with a vernier caliper in order to calcu¬ late GA. Values for the tensile strength of the graft union are expressed as the force required to separate the two graft partners (i.e., g BW) per unit of contact area (i.e., mm2 GA). A more comprehensive discussion of plant growth conditions, grafting procedures, and techniques for determining the tensile strength of the graft union has been published previously (Moore 1982). RESULTS AND DISCUSSION Three phases of cohesion were observed during the development of compatible autografts in L. esculentum and S. pennellii (Fig. 1). Phase I cohesion lasted approximately 2 days after grafting and was character¬ ized by an average increase in tensile strength of the graft union of approximately 2 g BW/mm2 GA/day (Table 1). Phase I cohesion was positively correlated with the initial adhesion of the graft partners, and was presumably due to dictyosome-mediated deposition of cell wall materials in response to wounding (Moore and Walker 1981a, 1981b; DEVELOPMENT OF COMPATIBLE AUTOGRAFTS 329 Figure 1. The development of tensile strength in compatible autografts of Lycopersicon esculentum and Solarium pennellii. Each data point represents the mean (+ standard deviation) of at least 12 separate trials. Moore 1982). The timing and extent of Phase I cohesion in compatible autografts of L. esculentum and 5. pennellii were similar to those reported for autografts of Sedum telephoides (Moore in press b) and Kalanchoe blossfeldiana (Moore 1982). Phase II cohesion lasted from days 3 to 15 after grafting and was characterized by an increase in the tensile strength of the graft union of approximately 15 g BW/mm2 GA/day. At the end of Phase II cohesion, the tensile strength of the graft union was approximately 20 times greater than at the end of Phase I cohesion (Table 1), and approxi¬ mated that of an ungrafted internode (Fig. 1). This rate of increase in tensile strength compared favorably with that reported previously for other compatible autografts (Moore 1982, in press b) and presumably was due to (1) the interdigitation of callus cells at the graft interface, (2) continued “normal” deposition of cell wall materials, and (3) redif¬ ferentiation of a lignified strand of xylem linking the stock and scion (Moore and Walker 1981a; Moore 1982, in press b). The third phase of graft cohesion in compatible autografts of L. esculentum and S. pennellii occurred subsequent to day 15 in graft formation (Fig. 1). The tensile strength of the graft union leveled off at a value approximating that of an ungrafted internode. That is, grafts sampled during Phase III cohesion were characterized by a tensile 330 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 Table 1. Development of tensile strength in compatible autografts of Lycopersicon esculentum and Solanum pennellii. Compatible Autograft Graft Phase Lycopersicon Solanum Phase I duration3 0-2 days 0-2 days average change in tensile 2 g BW/mm2GA/day 2 g BW/mm2 GA/day strength Phase II duration3 3-15 days 3-15 days average change in tensile strength ratio of strength of graft union at end 12 g BW/mm2 GA/day 14 g BW/mm2 GA/day of Phase II cohesion: end of Phase I cohesion 19 22 Phase III duration3 subsequent to day 15 subsequent to day 15 Expressed in days after grafting strength equal to that of an intact stem. As was true for Phases I and II cohesion, these observations were consistent with previous studies of other compatible autografts (Moore 1982, in press b). The general pattern of graft development in compatible autografts of L. esculentum and S. pennellii was similar to that observed for other compatible autografts (Roberts and Brown 1961; Linday et al. 1974; Yeoman and Brown 1976; Moore 1981, in press b). In each system there was a “lag” phase (i.e., Phase I) during which the tensile strength of the graft union increased at a rate of 1 to 2 g BW/mm2 GA/day. This was followed by a pronounced increase in the cohesive strength of the union (i.e., Phase II), after which it leveled off at a value similar to that of an ungrafted internode (i.e., Phase III). The similarity of graft devel¬ opment in these systems supports the previous suggestion that this general pattern of graft development is characteristic of compatible autografts. A more comprehensive discussion of how the development of tensile strength of compatible autografts correlates with (1) structural aspects of graft development, and (2) graft formation in general is presented elsewhere (Moore 1982, in press b). ACKNOWLEDGEMENTS This research was supported by a grant from the University Research Committee of Baylor University. This manuscript is submitted in par¬ tial fulfillment of the requirements for Biology 3V90 at Baylor Univer¬ sity. The authors thank Ms. Barbara Wimpee for her excellent technical assistance in preparing Figure 1. DEVELOPMENT OF COMPATIBLE AUTOGRAFTS 331 LITERATURE CITED Gur, A., and A. Blum. 1973. The role of cyanogenic glycoside in incompatibility between peach scions and almond rootstocks. Hort. Res. 13:1-10. Gur, A., R. M. Samish, and E. Lifschitz. 1968. The role of the cyanogenic glycoside of the quince in the incompatibility between pear cultivars and quince rootstocks. Hort. Res. 8:113-134. Gur, A., D. Zamet, and E. Arad. 1978. A pear rootstock trial in Israel. Sci. Hort. 8:249- 264. Lindsay, D. W., M. M. Yeoman, and R. Brown. 1974. An analysis of the development of the graft union in Lycopersicon esculentum. Ann. Bot. 38:639-646. Moore, R. 1981a. Graft compatibility-incompatibility in higher plants. What’s New In Plant Physiol. 12:13-16. Moore, R. 1981b. Graft compatibility and incompatibility in higher plants. Dev. Compar. Immunol. 5:377-389. Moore, R. 1982. Graft development in Kalanchoe blossfeldiana. J. Exp. Bot. 33:533-540. Moore, R. In Press a. Studies of vegetative compatibility-incompatibility in higher plants. V. A morphometric analysis of the development of a compatible and an incompatible graft. Can. J. Bot. Moore, R. In Press b. Studies of vegetative compatibility in higher plants. IV. The devel¬ opment of tensile strength in a compatible and an incompatible graft. Amer. J. Bot. Moore, R., and D. B. Walker. 1981a. Studies of vegetative compatibility-incompatibility in higher plants. I. A structural study of a compatible autograft in Sedum telephoides (Crassulaceae). Amer. J. Bot. 68:820-830. Moore, R., and D. B. Walker. 1981b. Studies of vegetative compatibility-incompatibility in higher plants. II. A structural study of an incompatible heterograft between Sedum telephoides (Crassulaceae) and Solanum pennellii (Solanaceae). Amer. J. Bot. 68:831- 842. Moore, R., and D. B. Walker. 1981c. Studies of vegetative compatibility-incompatibility. III. The involvement of acid phosphatase in the lethal cell senescence associated with an incompatible heterograft. Protoplasma 109:317-334. Moore, R., and D. B. Walker. In Press. Grafting Sedum and Solanum callus tissue in vitro. Protoplasma. Roberts, J. R., and R. Brown. 1961. The development of the graft union. J. Exp. Bot. 12:294-302. Stoddard, F. L., and M. E. McCully. 1979. Histology of the development of the graft union in pea roots. Can. J. Bot. 57:1486-1501. Stoddard, F. L., and M. E. McCully. 1980. Effects of excision of stock and scion organs on the formation of the graft union in Coleus: a histological study. Bot. Gaz. 141:401- 412. Yeoman, M. M., and R. Brown. 1976. Implications of the formation of the graft union for the organization in the intact plant. Ann. Bot. 40:1265-1276. Yeoman, M. M., D. C. Kilpatrick, M. B. Miedzybrodzka, and A. R. Gould. 1978. Cellular interactions during graft formation in plants, a recognition phenomenon? Soc. Exp. Biol. Symp. 32:139-160. . 'll ABSTRACTS OF THE NINTH NORTH AMERICAN PHY S ARUM CONFERENCE Southern Methodist University Dallas, Texas June 12-15, 1983 CONFERENCE COORDINATOR Claude Nations Department of Biology Southern Methodist University Dallas, TX 75275 CONFERENCE ORGANIZING COMMITTEE Elaine King Nancy Nations Gil King Harriet Schools John Ubelaker Sponsored by the Dedman College and the Department of Biology of Southern Methodist University 334 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 CELL-TYPE DEPENDENT EXPRESSION OF TUBULINS IN PHYSARUM. T. G. Burland, K. Gull*, T. Schedl, R. Boston, and W. F. Dove, McArdle Laboratory, University of Wisconsin, Madison, WI 53706, and *The Biological Laboratories, University of Kent, Canterbury, UK. Using 2-dimensional gel electrophoresis, five species of tubulin have been resolved and identified in whole cell lysates of Physarum myxamoebae and plasmodia. The identities of these species have been established by 1 )co-electrophoresis with myxamoebal al and /31 tubulins purified by self-assembly into microtubules in vitro ; 2)peptide mapping with Staphylococcus V8 protease and with chymotrypsin; 3)hybrid selection of specific mRNAs followed by translation in vitro ; and, 4)immunoprecipitation with a monoclo¬ nal antibody specific for /3-tubulin. Differential expression of the Physarum tubulins has been observed: the al and /31 electrophoretic species are found in both myxamoebae and plasmodia; the a2 and /32 species are found only in plasmodia; and the a3 species is found only in the myxamoebal phase — it may be specific to the swarm cell. Translation in vitro of myxamoebal and plasmodial RNAs has indicated that there are distinct mRNAs, and therefore probably distinct genes, for the al, a2, /3 1, and /32 species. It is uncertain whether a3 is a product of a separate gene, or whether it arises by modification of al. There is no detectable alteration in genome organization involving the tubulin DNA sequence family in concert with these changes in patterns of gene expression. It remains possible that any of these tubulin species, no matter how electrophoretically pure, contains the products of more than one tubulin gene. GENETIC ORGANIZATION OF THE TUBULIN DNA SEQUENCE FAMILIES. T. Schedl, T. G. Burland, and W. F. Dove, McArdle Laboratory, University of Wisconsin, Madison, Wl 53706. Physarum is highly polymorphic for restriction fragment length. Even within a single diploid isolate such as Wis 1, restriction fragments containing a particular DNA sequence are commonly dimorphic. This fact permits one to assign the genetic locus of any DNA sequence for which one has a cloned probe. In our laboratory, we have previously used this approach to analyze the organization of the actin DNA sequence family in Physarum. Cloned actin sequences from Saccharomyces cerevisiae and from Drosophila melanogaster showed concordant Southern blot against Physarum DNA (T. Schedl and W. F. Dove, J. Mol. Biol. 160:41-57, 1982). A similar analysis has been possible for the DNA sequence families for a-tubulin and for /3-tubulin. The a family contains 2 pairs of polymorphic Hind III bands and at least 2 bands that still remain monomorphic. The /3 family contains 2 pairs of polymorphic Hind III bands and at least 2 monomorphic bands. The segregation of the polymorphic bands for actin, a-tubulin, and (3- tubulin has been followed in the progeny of a heterozygous plasmodium derived by the mating of mutants derived from CLd (Wis 1) crossed to MA275 (Wis 2). The only evidence for linkage yet found is at the complex actin locus, ardA (Schedl and Dove, loc cit.). Southern blots have been compared between DNA from the myxamoeba and that from the plasmodium. Even though there is a shift in expression between these two phases for both the a- and /3-tubulin families, there is no detectable change in Southern blot pattern aside from the segregation of polymorphisms. Thus, it seems that the change in gene expression in the tubulin family is not accompanied by major genome rearrange¬ ments. ABSTRACTS 335 GENETIC ANALYSIS OF MBC-RESISTANCE IN PHYSARUM. T. G. Burland, University of Tromso, Norway, and McArdle Laboratory, University of Wisconsin, Madison, WI. (Presented by W. F. Dove, McArdle Laboratory.) Physarum myxamoebae are normally sensitive to methyl benzimidazole carbamate (MBC) at levels above 5/uM. Mutants resistant to 5-100 /*M have been isolated and analyzed genetically. Eight mutants have been analyzed to date; they lie in four separate genetic loci, ben A, benB, benC, and benD. It is known that benzimidazole-derived anti-mitotic agents bind to the tubulin subunit and promote the disassembly of microtubules. It is possible that MBC-resistance could involve alterations in /3-tubulin, or indirect mechanisms, such as a decrease in permeability or an increase in detoxification. Do any of the ben loci control the structure of /3-tubulin? One allele of benD, 210, creates a new electrophoretic species in two-dimensional gels. This species has a peptide map of a /3-tubulin and is immunoprecipitated by a monoclonal antibody for /3-tubulin. The benD 210 mutation co-segregates with a (3- tubulin DNA sequence. By this evidence, benD is a locus encoding a myxamoebal 13- tubulin. Mutants at this locus are resistant to MBC in both the myxamoebal and the plasmodial phase of growth, and benD 210 shows the novel /3-tubulin polypeptide in both growth phases. Quite surprisingly, however, the BEN210 mutant also displays a (3- tubulin in the normal (31 position as a myxamoeba but not as a plasmodium. It seems then that a second locus acts in the myxamoeba to produce a /3-tubulin identical in electrophoretic mobility to the product of the benD locus. This second locus seems not to be active in the plasmodial phase. A second locus of MBC-resistance mutations that also seems to contain a structural gene for /3-tubulin is benA. An allele of benA has been shown to co-segregate with a polymorphic /3-tubulin DNA fragment in the progeny of the heterozygous plasmodium (BEN41 X MA275). However, mutations at benA appear to confer MBC resistance on plasmodia. REGULATION OF TUBULIN SYNTHESIS IN THE PHYSARUM CELL CYCLE. T. Schedl, T. B. Burland, K. Gull*, and W. F. Dove, McArdle Laboratory, University of Wisconsin, Madison, WI 53706, and *The Biological Laboratories, University of Kent, Canterbury, UK. Previous work has demonstrated that microtubular proteins are synthesized periodi¬ cally in the plasmodial cell cycle; these microtubular proteins have been charcterized further and found to comprise two a and two (3 tubulin species. A simple mechanism to establish periodic synthesis is that of autoregulation, along lines suggested by Ben-Ze’ev et al. (Cell 17:319-325, 1979): the production of tubulin message would be inhibited by elevated concentrations of unpolymerized tubulin. As mitosis approaches, tubulin would polymerize and the rate of production of tubulin message would rise. To investigate this possibility, we have analyzed the timing of tubulin synthesis in the plasmodial cell cycle in relation to the appearance of microtubules. Tubulin synthesis was estimated by pulse¬ labeling 7 mm discs of a single large parent plasmodium for 15 min with 35S- methionine, followed by lysis and resolution of tubulins on two-dimensional gels analyzed by fluorography. The appearance of microtubules was followed by electron microscopy of samples fixed at the mid-point of each methionine pulse. Twenty-two samples were taken, at 15 min intervals from 210 min before metaphase to 105 min after. Tubulin synthesis begins ca. 165 min before metaphase, reaches a peak in early prophase, and falls precipitously after telophase. Significant synthesis occurs during mitosis. By contrast, microtubules are present only from a time just prior to early prophase— ca. 120 min after the onset on tubulin synthesis — until just after telophase, when the rate of tubulin synthesis is falling precipitously. 336 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 These observations are contrary to simple expectations for an auto-regulatory mechanism switching tubulin expression ON; they do not rule out such a mechanism acting to switch expression OFF after mitosis. PHYSARUM HISTONES. Harry R. Matthews, Jaap H. Waterborg, Liane M. Mende and Reinhold D. Mueller, Department of Biological Chemistry, School of Medicine, University of California, Davis, CA 95616. Our recently published procedure (M. Mende, J. H. Waterburg, R. D. Mueller and H. R. Matthews, Biochem. 22:38-51, 1983) for isolating Physarum plasmodial histones will be reviewed. In subsequent work with Physarum histone H4, we have separated the fragments produced by acetic acid digestion and determined the complete sequence of two of them. By analogy with calf H4, these peptides are at the C-terminus and give the sequence from residue 69 to the C-terminus (residue 102). In the 34-residue sequence, there are two minor differences from calf H4; arg-77 is lys in calf; and lys-79 is partially methylated in Physarum. Agr-77 also occurs in pea H4 but the methylated lysine at position 79 has not been reported in other H4s. In the N-terminal region, amino acid compositions of chymotryptic and tryptic peptides strongly imply that Physarum H4 has the same sequence as calf H4 from residue 1 to 37. To determine the acetylation sites, Physarum H4 was labelled with 3H-acetate, digested under conditions where only arginine-X bonds were cleaved and subjected to Edman degradation. This digestion yields only two labelled peptides, 1-3 and 4-17. Peptide 1-3 is not susceptible to Edman degradation. The pattern of release of label during consecutive cycles of Edman degradation shows that acetylation occurs at positions 5, 8, 12 and 16 of the whole molecule, as in calf H4. ANALYSIS OF HISTONE ACETYLATION IN THE PHYSARUM CELL CYCLE. Harry R. Matthews and Jaap H. Waterborg, Department of Biological Chemistry, School of Medicine, University of California, Davis, CA 95616. There are three patterns of histone acetylation in the Physarum cell cycle correlated with S phase (acetate incorporation into 4 core histones) or G2 phase (incorporation into H3 and H4 only) or metaphase (no incorporation). The pattern observed in G2 is not affected by cycloheximide (10 /Ltg/rnl) or hydroxyurea (50 mM) but is reduced by cordycepin (200 /ig/ml). This strengthens the correlation of the G2 phase pattern of histone acetylation with transcription. In S phase, newly synthesized histone H4 occurs in a form different from pre-existing H4. This form is converted to the bulk form between the end of S phase and mid-G2 phase, possibly by methylation. In S phase, cycloheximide inhibits both protein and DNA synthesis, in Physarum, and converts the histone acetylation pattern to a G2 phase-like pattern. The difference between the normal S phase histone acetylation and the G2 phase histone acetylation is termed “S phase specific” acetylation. S phase specific acetylation of H4 occurs only on newly synthesized H4 and is sensitive to fluorodeoxyuridine or hydroxyurea. S phase specific acetylation of histones H2A, H2B and H3 is not sensitive to these inhibitors although it is sensitive to cycloheximide. The data fit a model of chromosome replication in which S phase specific acetylation of H4 is linked with nucleosome assembly and maturation while the other core histones are acetylated after their synthesis but independently of nucleosome assembly. ABSTRACTS 337 HISTONE GENE EXPRESSION IN PHYSARUM POLYCEPHALUM : HISTONE SYNTHESIS DURING THE CELL CYCLE AND CONFORMATIONAL CHANGES OF THE H4 HISTONE GENE. M. L. Wilhelm, F. X. Whihelm, B. Toublan and R. Jalouzot, Institut de Biologie Moleculaire et Cellulaire, 15 rue Rene Descartes, 67084 Strasbourg c'e dex, France. Synchronous cultures of Physarum polycephalum were used to detect conformational changes of the histone genes during the cell cycle and to follow the synthesis of total and nuclear proteins at various times after mitosis. To monitor the rate of protein synthesis the cultures were labeled with a mixture of I4C-lysine and 14C-arginine. In the nuclei the incorporation of radioactive precursors increases rapidly, is maintained at a high level during most of the S phase and decreases at its end. Thus the rate of nuclear protein synthesis measured in isolated nuclei follows closely the rate of DNA synthesis. By gel electrophoresis and fluorography of the gel it was shown that newly synthesized histones are present in S-phase nuclei but not in G2 or during mitosis. Histone synthesis is therefore restricted to S-phase. To correlate chromatin structure and gene activity DNase I was used as a probe to detect conformational changes of the histone genes during the cell cycle. The degradation of histone was followed by gel electrophoresis and hybridization with a probe for the H4 histone gene. It was found that even during mitosis when chromatin is condensed into chromosomes, the histone genes are preferentially degraded by DNase I. The histone genes retain a characteristic structure which is recognized by DNase I during all stages of the cell cycle and thus independently of the biosynthesis of histones. Experiments are now in progress to determine whether the histone genes can be shut off when Physarum is induced to differentiate into dormant cells (spores or spherules). ANALYSIS OF POLY A+ AND ACTIN mRNAS DURING SPHERULATION IN PHYSARUM POLYCEPHALUM. Gerald Lemieux and Vern L. Seligy, Molecular Genetic Section, National Research Council of Canada, Ottawa, Ont., K1AOR6. Total RNA was extracted from microplasmodia at different times during starvation- induced spherulation in P. polycephalum. The poly A+ fraction was prepared by chromatography on oligo-dT cellulose and translated in a rabbit reticulocyte lysate. The proteins were separated by two dimensional gel electrophoresis and detected by fluorography. Results showed that the mRNA population was relatively stable during the first 24 hours of differentiation. After 32 hours, the protein pattern revealed the diminution of some major spots and the appearance of new ones. By 48 hours, a time at which spherulation is essentially complete, the variations detected earlier were more pronounced. One of the major spots whose intensity was greatly reduced in spherules had a molecular weight of 43,000. The use of DNase-Sepharose chromatography enabled us to identify this protein as actin. At least two other minor spots, one slightly more acidic and the other slightly more basic than actin, were also detected by affinity chromatography on DNase-Sepharose. Since P. polycephalum contains at least four actin genes, these satellite spots may reflect the expression of more than one actin gene. These results definitely show that the synthesis of specific mRNA is involved in the differentiation of microplasmodia into spherules. REPLICATION-TRANSCRIPTION-COUPLING IN PHYSARUM. Gerald Pierron and Helmut W. Sauer, Department of Biology, Texas A&M University, College Station, TX 77843. EM spreads of chromatin at 15 minutes post metaphase reveal activated transcription units in newly replicated chromatin. In most cases both replicated DNA strands are symmetrically transcribed and putative replication origins reside inside the transcription 338 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 unit. Hence, in Physarum a set of genes is activated in synchrony in 108 nuclei, a situation conducive to the isolation of such genes and identification of their products. Other evidence suggests that, following mitosis, initiation of transcription by RNA polymerase B as well as elongation require newly replicated chromatin devoid of nucleosomes. Since the classical density-shift experiments suggest a temporal sequence of DNA replication, it follows that in Physarum genes may become activated in a fixed order. Replication-transcription-coupling potentially comprises a novel mechanism of gene- expression control, if not the basic program of gene regulation in the cell cycle, and allows for a new look at quantal cell cycles and cellular determination. In preliminary experiments we have 1) devised a reproducible method to separate, on a preparative scale, newly replicated from non-replicated DNA, 2) hybridized restricted total DNA of Physarum after electrophoresis and Southern blotting with nick translated probes of distinct genes (actin, histones, which cross-react with Physarum DNA) and 3) constructed a genomic library in a lambda based vector. In current experiments we ask when these marker genes are replicated during S phase and whether the order of replication is invariant in different strains and/or changing during the life cycle of Physarum. CHANGES IN THE ABUNDANCE OF mRNA SPECIES DURING THE MITOTIC CYCLE OF PHYSARUM POLYCEPHALUM. Robert A. Cox and Nadia J. Smulian, National Institute for Medical Research , Mill Hill , London NW7 1AA, UK. A partial clone bank was used to measure changes in the abundance of mRNA species at intervals during the mitotic cycle of Physarum. The bank comprised approx. 900 colonies of Escherichia coli made tetracycline sensitive by the insertion of a Physarum genomic DNA between the Hind III site and BamH\ site of the plasmid pAC184. The bank was screened with radioactive cDNA probes copied from (1) RNA of microplasmo- dia; (2) RNA isolated from a macroplasmodium harvested in S-phase, and (3) RNA isolated from a macroplasmodium harvested in late G-2 phase. Fifty-four colonies hybridized equally strongly with all three probes, suggesting that the complementary RNA species were equally abundant throughout the mitotic cycle. Five colonies hybridized most strongly with the cDNA probe copied from S-phase RNA, suggesting that the designated RNA species were more abundant in S-phase. One colony hybridized most strongly with the late G2-phase probe, as might be expected for an RNA that is more abundant in G2-phase. One colony, p5.13, was used to select its complementary RNA which was then found to direct the synthesis of a protein of approximately 25,000 daltons. This mRNA species was shown to be polyadenylated and was found to increase three-fold in abundance during late S-phase, as measured by a novel isotope-dilution technique. ASSAY OF A(5') pppp(5')A AND A(5')pppp(5')G IN PHYSARUM POLYCEPHALUM AND OTHER EUKARYOTES: AN ISOCRATIC HIGH PERFORMANCE LIQUID CHROMATOGRAPHY METHOD. Preston N. Garrison and Larry D. Barnes, Depart¬ ment of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78284. A(5')pppp(5')A has been proposed to serve as a molecular signal that triggers DNA replication. In preliminary studies, synthesis of A(5')pppp(5')A was detected in the slime mold Physarum polycephalum by labeling cells with [2-3H] adenosine and analyzing by TLC and IIPL.C a fraction which copurified with standard A(5')pppp(5')A. When published methods proved inadequate for the assay of unlabeled cellular A(5')pppp(5')A by HPLC, a set of purification procedures was developed which allowed assay of as little as 2 pmol of A(5')pppp(5')A. A(5/)pppp(5/)A was purified from cellular extract by ABSTRACTS 339 covalent boronate chromatography, treated with alkaline phosphatase to hydrolyze residual mononucleotides and analyzed by isocratic ion-exchange HPLC. The analysis was facilitated by a pre-column switching procedure which allowed early eluting species to be diverted from the analytical column. Using this procedure A(5')pppp(5')A has been detected in Physarum polycephalum (1.4 pmol/mg protein), Saccharomyces cerevisiae (3.6 pmol/mg protein), and rat liver (3.3 pmol/mg protein). In each case a minor peak was also seen, which was identified as A(5')pppp(5')G. The identity of both peaks was confirmed by coelution with standards on isocratic and gradient HPLC and treatment with enzymes, including a dinucleoside polyphosphate pyrophosphohydrolase from Physarum polycephalum. MOLECULAR STRUCTURE OF THE EXTRACHROMOSOMAL NUCLEOLUS OF PHYSARUM POLYCEPHALUM. Chen-Chen Kan and Robert Marsh, Biology Pro¬ grams, The University of Texas at Dallas, Richardson, TX 75080. Nucleoli relatively free of polysaccharide granules and containing less than 1% intact nuclei were purified from synchronous Physarum polycephalum macroplasmodia late in G2 phase. A histone-depleted rDNA-containing nucleolar complex with a standardized sedimentation coefficient around 165,000 S was obtained after treating the nucleoli with 2 N NaCl or a combination of heparin and dextran sulfate, followed by sedimenting them in a neutral sucrose gradient. The S-value of the residual nucleolar complex was not affected by RNase A digestion, but the complex was dissociated by a divalent cation chelating agent such as EDTA. Within the residual complex, 6 proteins predominated. None of these proteins appeared to any appreciable extent among the extracted proteins. Visualization of the ethidium bromide-stained residual nucleolar complex by fluores¬ cence microscopy revealed a halo of fluorescence surrounding the central spherical structure. Electron microscopic examination showed the halo to be composed of the 60 kb rDNA molecules, which are present at 600-800 copies per late G2 nucleolus and encode the ribosomal RNA. It appears that the linear rDNA molecules are attached to the scaffold at internal sites on the rDNA molecules, with ends of the rDNA molecules being free. CLONING PHYSARUM DNA IN CHARON 4A AND CHARACTERIZATION OF SOME CLONES. Cheryl Knox, Mary Jo Maher, and Robert Marsh, The University of Texas at Dallas, Richardson, TX 75080. An EcoRl partial genomic library of Physarum polycephalum M3 has been con¬ structed with bacteriophage Charon 4A as vector. Theoretically, there is a 70% chance of any sequence being present. Attempts to expand this library or to construct a library using cosmid pHC79 have been unsuccessful. The Physarum M3 genome has been probed for actin, a and )3 tubulin, and amylase sequences in gel blots of EcoRl restriction fragments hybridized with isolated DNA inserts from plasmids pDmAct ( Drosophila actin), pDTA4 ( Drosophila a tubulin), pDTB4 ( Drosophila (5 tubulin), pAmy21 and pAmyl04 (mouse amylases). Actin sequences were found in 8 EcoRl fragments in agreement with Schedl and Dove (J. Mol. Biol. 160:41-57, 1982) for Wis 1 sublines, tubulin sequences were detected in 2 fragments (2.25 and 3.2 kb), and amylase sequences in 2 other fragments (1.4 and 0.45 kb). When our partial genomic library was screened with total DNA from these plasmids, several phages exhibiting homology were isolated. However, the homology has been demon¬ strated to be to the pBR322 vector DNA. Since no actin, tubulin or amylase genes have been isolated from the library, one of the clones showing homology to pBR322 is being characterized and mapped for study of DNA replication in its vicinity. 340 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 THE EFFECTS OF GROWTH CONDITIONS ON PROTEIN KINASE ACTIVITY AND cAMP BINDING ACTIVITY IN PHYSARUM POLYCEPHALUM. Joan H. McCune, Christina L. Shoemaker and Ronald W. McCune, Department of Microbiology and Biochemistry, Idaho State University, Pocatello, ID 83209-0009. Previous studies in this laboratory on arginine metabolism in Physarum polycepha- lum have indicated that arginase is an inducible enzyme in this organism. Thus, under conditions of high arginine concentration, this enzyme will be present and active. The products of arginase action are urea and ornithine. One of the enzymes which can act on ornithine is ornithine decarboxylase, the first enzyme in the biosynthesis of polyamines. Other laboratories have shown ornithine decarboxylase to be present in Physarum. Ornithine decarboxylase in Physarum is phosphorylated by protein kinase which converts ornithine decarboxylase to an inactive form. The protein kinase in turn is apparently regulated by the level of polyamines in Physarum. In some eucaryotic systems, protein kinase is stimulated by cAMP. It was therefore of interest to examine the effects of various growth conditions, especially conditions where arginase is and is not induced, on the activity of protein kinase and cAMP binding activity. The organism was grown on semi-defined medium and OV-40 medium with either valine or arginine. Protein kinase activity and cAMP binding activity were examined. PURIFICATION OF CALMODULIN FROM PHYSARUM FLAVICOMUM AND CORRELATIVE STUDIES ON CYCLIC AMP PHOSPHODIESTERASE. Thomas J. Lynch and Mary E. Farrell, Department of Biology, University of Arkansas at Little Rock, Little Rock, AR 72204. Calmodulin, an important cellular regulatory protein, has been identified in the haploid and diploid stage of P. flavicomum. Calmodulin was purified by affinity chromatography using fluphenazine or CAPP as the binding ligand. Calmodulin binds to the ligand in the presence of calcium and is preferentially released upon the addition of the calcium chelator EGTA. Myxomycete calmodulin appears to be similar to calmodulin isolated from higher organisms. These similarities include molecular weight as determined by polyacrylamide gel electrophoresis, requirement of calcium for activity and lack of species specificity. Phosphodiesterase from both stages of the life cycle exhibited two apparent km values and showed greatest activity in the presence of Mg^ and Ca^. The enzyme from both stages was inhibited by phenothiazines, suggesting the involvement of calmodulin regulation of the enzyme. To test this hypothesis, calmo¬ dulin free phosphodiesterase was prepared by passage of a crude supernatant through DEAE-sephacel. This calmodulin free enzyme was assayed in the presence and absence of exogenous calmodulin. Repeated experiments failed to show any regulation of myxomy¬ cete phosphodiesterase by calmodulin. LOCALIZATION, PURIFICATION, AND CHARACTERIZATION OF A PROTEIN¬ ASE INVOLVED IN ENCYSTMENT OF PHYSARUM FLAVICOMUM. Hiltrud U. White and Henry R. Henney, Jr., University of Houston, Houston, TX 77004. An intracellular proteinase involved in the differentiation of Physarum flavicomum haploid cells to microcysts was localized in lysosomes, purified and characterized. The total intracellular proteinase activity, as well as specific activity, increased during encystment. Lysosomes were isolated by sucrose density gradient centrifugation. The lysosomal nature of the isolated fraction was confirmed ultrastructurally with electron microscopy and functionally with assays for typical lysosomal marker enzymes. The lysosomal proteinase was further purified by affinity chromatography followed by gel filtration chromatography. Its molecular weight was estimated to be 32,000 and it exhibited no quarternary structure. Mercaptoethanol or dithiothreitol were essential for enzyme stability. The enzyme was most stable at pH 2 to 3 and its pH optimum for ABSTRACTS 341 azocasein hydrolysis was pH 3. The enzyme was relatively stable up to 45 C and its maximal rate of activity occurred at 55 C. It was sensitive to an acid proteinase inhibitor, as well as inhibitors which react with thiol proteinases. The enzyme is classified as an acid (carboxyl) proteinase with essential thiol groups. A TANNIC ACID-METHYLAMINE TUNGSTATE CONTAINING FIXATIVE FOR MYXOMYCETE PLASMODIA. M.H. Chestnut, Department of Botany, Washington State University, Pullman, WA 99164. Macroplasmodia of Badhamia utricularis were fixed for transmission electron micros¬ copy by several methods, including (a) glutaraldehyde-osmium tetroxide, (b) osmium tetroxide-glutaraldehyde-osmium tetroxide, (c) osmium tetroxide-glutaraldehyde + tan¬ nic acid-osmium tetroxide, and (d) osmium tetroxide-glutaraldehyde + tannic acidmethy- lamine tungstate. Sclerotia were germinated on moistened filter paper circles, and the resulting starving plasmodia were processed using one of the above fixative combina¬ tions. All fixative solutions were buffered with PIPES to pH 7.0 at 300 + 20 mOsm. Segments of fixed plasmodial strands were dehydrated in a graded ethanol series, and embedded in either L. R. White acrylic resin or Medcast (Epon substitute). Silver-gray sections were cut with a diamond knife on a Sorvall MT-2B ultramicrotome, collected on formvar-coated. 100 mesh grids, stained with lead citrate and/or uranyl acetate, and examined in an Hitachi 300 electron microscope at 75Kv. Results showed that method A gave good organelle preservation, but overall strand morphology was unacceptable. Addition of a 2 minute osmium tetroxide pre-treatment in methods B, C, and D preserved strand morphology. Method B produced low contrast and some indication of cytoplasmic extraction. Methods C and D produced high contrast and good preservation, method D being preferred for detail of membranes and 50-70A filaments. High contrast was dependent on lead staining. The osmium tetroxide-glutaraldehyde + tannic acid- methylamine tungstate procedure produced the best results overall, and eliminated some of the common problems encountered in fixing myxomycete plasmodia for electron microscopy. The high contrast obtained with this method allowed routine use of silver- gray sections, thereby potentially increasing resolution. (An extended version of this presentation has been submitted for publication in the Journal of Microscopy). HOW SYNCHRONOUS IS PHYSARUM ? Gerard Pierron1 and Mannfed Kubbies2, 1 Department of Biology, Texas AirM University, College Station, TX 77843, and 2Human Genetik, University of Wurzburg, 8700 FRG. Flow-cytometric analysis of Hoechst-strained isolated nuclei provided convincing confirmation of natural synchrony in Physarum. About 99% of 108 nuclei divided in less than 5 minutes as evidenced by a shift of DNA fluorescence from 4c to 2c. Futhermore, this high degree of synchrony is maintained throughout S phase. It was shown that 1) all nuclei initiate DNA replication in synchrony, 2) DNA replication occurs at a constant rate (4*109d/min) for 80 minutes until 75% are replicated, 3) the remaining DNA is replicated in synchrony, albeit at a slower rate (l*109d/min), and 4) the DNA content in G2 phase is stable. Of the nuclei derived from liquid cultures, 27% are in S phase whereas 72% are G2+ mitosis. Less than 1% of the nuclei have a DNA fluorescence compatible to a Gi DNA content. In addition, flow-cytometry of nuclei from different strains have revealed the following facts: 1) DNA content (4c values) is variable, due to the amount of late replicating, presumably A-T rich DNA sequences, 2) one strain (derived from M3C1V) was found to contain two stable populations of nuclei (4c=1.05 and 0.87 pg.DNA). Both kinds divide and replicate DNA in synchrony in the mixoploid plasmodium. It is concluded that early replicating DNA provides sufficient information for the synchronous cell-cycle. 342 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 THE USE OF PHYSARUM IN TOXICITY TESTING. J. Mohberg and M. M. Kelly, Division of Science, Governors State University, Park Forest South, IL 60466. Toxicity of several fuels — hydrazine, straight chain hydrocarbons and ethanol — has been investigated in growing microplasmodia and sporulating plasmodia of two strains of Physarum, a derivative of ]VLb and an mti X mt2 cross, LU647 X 5001d. Effect on microplasmodial growth was determined according to Becker, Daniel and Rusch (Cancer Res. 23:1910, 1963), except that cultures were grown in conical flasks in Brewer’s medium (Biochim. biophys. Acta 402:363, 1975). Plasmodia were induced to fruit by transferring plasmodia (8-cm diameter) to niacin-salts medium (Daniel and Rusch, J. Bacteriol. 83:234, 1962), starving them for three days and illuminating for 4 h. Cultures were exposed to drugs for 2 to 6 h before melanization. Effects were assessed by microscopic examination and by counting spores per sporangium. Results are tabulated below: Test Substance Test System Hydrazine 2 HC1 Hydrocarbons (l%v/v) Ethanol Microplasmodial growth ED5o,ca C6, C8, C10, no growth ED50, ca 40/zg/ml c12, c14, c16, growth normal 1.5% Sporangial formation Cleavage 8c melanization blocked by 400 /ug/ml Not studied Stalk formation 8c cleavage inhibited with 1.5% Utilization of ethanol and the C12-C16 hydrocarbons has yet to be demonstrated directly, but all show a sparing effect on glucose. (Supported in part by Air Force Contract F33615-82-K-0514.) PRELIMINARY ANALYSIS OF AN EXTRACELLULAR INDUCER OF THE AMOE- BAL-PLASMODIAL TRANSITION FROM THE MYXOMYCETE DIDYMIUM 1R1- DIS. W. Nader and G. L. Shipley, Department of Biology, Texas A&M University, College Station, TX 77843. The differentiation of myxamoebae to plasmodia is an inducible process mediated by an extracellular pheromone, the “inducer”. Cell-free culture supernatants from Didy- mium iridis suspension cultures have proven to be a ready source of inducer activity. Concentrated supernatants (see below) were capable of accelerating differentiation (selfing) of the Colonia strain of Physarum polycephalum as well as mating in Physarum and Didymium, suggesting the inducer pheromones of these two species are structurally similar. Inducer activity in Didymium cultures reached a maximum at the end of log-phase growth. Activity was measured in a semi-quantitative bioassay based on the induction of zygote formation in suspensions of mating compatible Didymium amoebae. Culture supernatants concentrated 15-50 fold were prepared by lyophilization and ammonium sulfate precipitation followed by desalting over Biogel P-2 prior to further characterization. Activity was stable at -20 C for months, at 37 C for at least 5 h, but was destroyed at 100 C in 5 min. No significant losses in activity were observed when preparations were incubated with trypsin, proteinase K, RNAse A or DNAse. Treatment with periodate (20mM, 3 h) eliminates the activity. The activity bound to a boronate- ABSTRACTS 343 conjugated agarose column and was removed by 2 M sorbitol. The later findings suggest the presence of carbohydrate groups in the pheromone. The activity was totally excluded from Biogel P-10 (20,000 d exclusion). A Biogel P-150 column resulted in a major peak of activity of 120,000 d and a minor peak at 26-30,000 d. The relationship of these two peaks is not clear at this time. The activity will bind to DEAE-cellulose in 10 mM Imidazole, pH 7 at 24 C or in 2 mM Imidozole, PH 7 at 4 C. Elution of activity can be accomplished in 100 mM KC1. Futher attempts to purify and characterize the pheromone are in progress. REPRODUCTIVE SYSTEMS AND SPECIATION IN D1DYM1UM IR1DIS : AN EVO¬ LUTIONARY MODEL. O’Neil Ray Collins, Department of Botany, University of California, Berkeley, CA 94720. Over the last 23 years, a considerable amount of genetical information on the myxomycete life cycle has been generated and this constitutes a firm foundation for evolutionary studies. The fact that true slime molds are primitive holotrophic euka¬ ryotes, displaying a prominent amoeboflagellate stage, adds a special dimension of evolutionary interest. It is conceivable, for example, that Myxomycetes are direct descendants of the earliest sexual amoeboflagellates, which might have been the originators of isogamous eukaryotic sex. A multiple allelic mating system is the ideal one for such organisms, so its existence in present-day myxomycete amoeboflagellates is easy to explain. In Didymium iridis, this system is combined with efficient asexual (apomictic) and vegetative reproductive modes, permitting a remarkable amount of adaptability and opportunities for evolutionary studies. Here, I present data on the spontaneous conversion of apomixis to heterothallism in an isolate of D. iridis and examine the behavior of the new heterothallic convertant in intra- and interisolate crosses. Data are interpreted in the context of speciation and evolutionary relationships between the apomictic and heterothallic reproductive modes. LIFESPANS AND SENESCENCE IN THE SLIME MOLDS. J. Clark, School of Biological Sciences, University of Kentucky, Lexington, KY 40506. The diploid plasmodia of heterothallic isolates of the slime molds Physarum polycephalum and Didymium iridis, when grown as non-axenic surface cultures, have a determinate lifespan controlled by their genotypes. This study extends the report of senescence to a third heterothallic species, Physarum cinereum, and to three non- heterothallic species — Physarum pussilum, Physarum compressum and Stemonitis flavo- genita. Also five non-heterothallic isolates of Didymium iridis were found to display senescence. However, two isolates, one of Stemonitis flavogenita and one of Physarum gyrosum, did not undergo a recognizable senescence during this study. The apparent lack of a definite lifespan during axenic culture of Physarum polycephalum was also investigated. While axenic cultures have remained vigorous during more than three years of continuous growth, subcultures taken from these isolates have displayed progressively shorter lifespans when transferred to non-axenic surface cultures (i.e., older axenic cultures yield short lived non-axenic cultures). A STEREOLOGICAL ANALYSIS OF CYTOLOGICAL CHANGE DURING SPORE MATURATION IN DIDYMIUM IRIDIS. W. R. Fagerberg and C. W. Mims, Depart¬ ment of Biology, Southern Methodist University, Dallas, TX 75275, and Department of Biology, StephenT. Austin State University, Nacogdoches, TX 75962. Young and mature spores of Didymium iridis were studied using stereological analytical techniques. Changes in the Vv ratios of the nuclear, autophagic vacuole, mitochondrial, microbody, lipid and cell wall compartments, as well as actual volume 344 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 changes in these compartments were evaluated during maturation (24 h period). Vv values which describe how spore volume is apportioned to each organelle compartment show that during maturation spores change from cells where nearly all organelle compartments occupy equal cell volume to cells where the volume is dominated by the cell wall and autophagic vacuole compartments. The rest of the spore volume is unequally divided amongst the other organelles. A major event during spore maturation is a 50% decrease in spore volume. Our data support the hypothesis that this is a multi- step process. The first step involves a rapid decrease in spore size, probably due to water loss. An outer spore wall is then laid down, terminating a further decrease in spore size. Additional cell wall material is then laid down with a concomitant loss in protoplast volume. The loss in protoplast volume is the result of a decrease in the volumes of the organelle compartments as a result, presumably, of metabolic activity and/or water loss. Cytological changes during spore maturation show mature spores to be highly differentiated from earlier stages. The factors controlling changes in the organelle compartments remain to be discovered. PLASMA MEMBRANES FROM PHYSARUM POLYCEPHALUM AMOEBAE AND PLASMODIA. Dominick Pallotta, Anne Barden, Francois Bernier, Josee Kirouac Brunet and Gerald Lemieux, Departments of Biology and Biochemistry, Universite Laval, Quebec, P. Q., Canada G1K 7P4. Amoebae and plasmodia growing in liquid shaken cultures were used as starting material for plasma membrane preparations. Amoebae were collected, swollen in hypotonic buffer and then broken in a Thomas tissue grinder. The plasma membranes were collected by differential centrifugation and purifed by centrifugation in a continu¬ ous 30-50% sucrose gradient. The membranes sedimented in a single band having a density of 1.16 g/cm3. They were found by enzymatic assay and by electron microscopy to be free of lysosomes, mitochondria and nuclei and minimally contaminated by endoplasmic reticulum. Plasmodia were collected, washed and homogenized in a Waring blender. Plasmodial plasma membranes were prepared by differential and sucrose gradient centrifugation and also by the dextran polyethelene glycol 2-phase system. Enzyme assay and electron microscopy showed that these membranes were essentially free of contaminating organelles. Amoebal and plasmodial plasma membrane proteins were characterized by SDS-acrylamide gel electrophoresis. In both cases fewer than 10 major bands were seen on Commassie blue stained gels. Differences in some of these major bands were seen when amoebal and plasmodial plasma membrane proteins were compared. PLASMA MEMBRANE PROTEINS FROM GENETICALLY DIFFERENT AMOEBAL STRAINS OF PHYSARUM POLYCEPHALUM. Remi Martel, Anne Barden, Gerald Lemieux and Dominick Pallotta, Departments of Biochemistry and Biology, Universite Laval, Quebec, P. Q., Canada G1K 7P4. The MatB locus controls amoebal cell fusion in Physarum polycephalum. In an attempt to study the molecular basis of cell fusion the plasma membrane proteins of amoebae carrying different matB alleles were analysed. For this work the method of Barden et al. (B.B.A. in press) was used to prepare plasma membranes from strains carrying the matBl, matB2 or matB3 alleles. The membrane proteins for each strain were separated by SDS gel electrophoresis. When the gels were colored with Commassie blue, about 10 major and 20 minor bands were seen. More bands were revealed with the silver staining method. With both staining techniques the electrophoretic profiles were similar for all strains studied. A more detailed analysis of membrane proteins was carried out by 2-dimensional gel electrophoresis as described by O’Farrell (J.B.C. 250:4007, 1975). For amoebae growing on agar with live bacteria, minor differences were seen among strains ABSTRACTS 345 carrying different rnatB alleles. The most striking differences appeared between strains growing axenically in liquid medium and those growing on agar plates. Two major plasma membrain proteins found in all agar-grown amoebae were absent from liquid- grown amoebae. EVIDENCE FOR A FACTOR THAT ALTERS THE SURFACE PROPERTIES OF COMPATIBLE MYXAMOEBAE. E. M. Goodman, P. Tipnis and G. Hanks, Biomedical Research Institute, University of Wisconsin-Parkside, Kenosha, WI 53141. It is a well recognized phenomenon in Physarum that mixing compatible mating types will induce amoebae to differentiate after a certain as yet undefined lag period. Futher, several experiments suggest that a soluble mating factor(s) may be involved in this process. We decided to study the surface properties of myxamoebae under various conditions where compatible amoebae were in contact with the growth medium of the opposite mating type but not in direct physical contact. The basic experiments involved the use of parabiotic chambers where compatible mating types were separated by a 0.45 ju millipore membrane, and growing myxamoebae in media that previously supported the opposite mating type. An aqueous, two-phase polymer system of dextran and polyethylene glycol was used to assess alterations in cell- surface properties. Data showed that the growth medium from one mating type can alter the surface properties of the compatible mating type. SURFACE DIFFERENCES BETWEEN SEXUALLY COMPATIBLE MYXAMOEBAE OF PHYSARUM POLYCEPHALUM. Henry C. Aldrich and Julia B. Reiskind, Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611. Myxamoebae of strains RSD4 and MAI 85 were grown axenically on the same semidefined liquid medium in shake culture. Plasma membranes were isolated from both strains using Jacobson’s technique of binding the cells to Affi-Gel 731 beads, vortexing to lyse the cells, and eluting plasma membraines with SDS/EDTA/phosphate buffer at pH 8.2. The solubilized membranes were electrophoresed on polyacrylamide slab gels and the polypeptide profiles compared after both Commassie Blue and Con A-peroxidase staining. We also observed that an alcohol-precipitable, soluble fraction was recoverable from the supernate when RSD4 cells were washed with cold 40 mM KC1/50 mM potassium phosphate buffer at pH 6.2. This evidently represents a soluble component of cell coat, and it is not recoverable from MA185 cells. Binding of Con A and wheat germ agglutinins was followed using fluorescein and ferritin labels. This table illustrates the differences found between the two mating types: Native memb.: Buffer washed: Sol. coat SDS-PAGE Agglut. lectins bound lectins bound present? results sheep RBC? RSD4 None Con A, WGA Yes 1 unique polypep. No MAI 85 Con A Con A, WGA No 5 unique polypeps. Yes Both strains contain polypeptides which bind Con A, but none of these is common to both strains. These results demonstrate clear differences between the cell surfaces of myxamoebae of the two mating types, differences which are distinct enough to function in sexual recognition. 346 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 PHYSARUM STRAINS TEMPERATURE SENSITIVE IN VEGETATIVE GROWTH. Thomas E. Evans and Helen H. Evans, Division of Radiation Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106. Populations of exponentially growing LU-648 amoebae were mutagenized with either nitrosoguanidine or ethyl methanesulfonate. After outgrowth, survivors were cloned, replica-plated and screened for temperature sensitivity by growth at 22 and 30.8 C. Retesting of putative mutants was done by cloning at the two temperatures; strains that produced colonies of about 50 or fewer cells at 30.8 C by the time wild-type control colonies contained approximately 105 cells were kept for further study. Mutant strains were crossed with CW-202 (mt\, fusA\), and resulting fusion group III plasmodia (fusA\/fusAi) were starved for the induction of sporulation. Spores were germinated clonally and clones tested for temperature sensitivity (segregation patterns obtained thus far are all 1:1). Temperature sensitive clones were plated pair-wise on mating plates, and fusion group III plasmodia were then used for analysis of the temperature sensitive allele as a homozygous diploid. Growth curves of four such strains show that the markers are expressed in both haploid amoebae and diploid plasmodia. Biochemical testing as well as heterokaryon analysis indicated that each of the strains was functionally and genetically distinct. Of particular interest was amoebal strain CW-435. A feulgen analysis of amoebae showed that the population became partially binucleate after incubation for various times at the restrictive temperature; the degree of binucleation increased to about 30% after four days. The nuclei of both the uninucleate and binucleate cells were determined to be 2C in DNA content (i.e., were apprarently arrested in G2). A branched pathway model involving a single transition point is consistent with these observations. TS MUTANT ISOLATION IN PHYSARUM AXENIC MYXAMOEBAE. Thomas G. Laffler and John Carrino, Department of Microbiology-Immunology, Northwestern University Medical School, Chicago, 1L 60611. The analysis of cell-cycle regulation in Physarum would be greatly facilitated if an ample supply of cell-cycle mutants was available. Attempts at isolating these mutants by non-selective methods have not generated significant numbers of mutants, and bromo- deoxyuridine (BrdUrd) suicide selections with monoxenic cultures of myxamoebae yield mainly BrdUrd-resistant thymidine-kinase-defective (tk~) mutants. We have found that thymidylate synthesis in axenic cultures of myxamoebae is inhibited by methotrexate, and growth can be restored by adding thymidine to the medium. This provides a selection for tk+ that can be used to eliminate the tk- background in BrdUrd-suicide selections. Presently, we are developing the methodology for BrdUrd suicide selections with myxamoebae of strain 301.5 (matA3, AxE). SOME GROWTH CHARACTERISTICS OF WHITE PHYSARUM MICROPLASMO- DIA. Claude Nations, Ivan Pinon, and John L. McCarthy, Department of Biology, Southern Methodist University, Dallas, TX 75275. White microplasmodia of Physarum polycephalum, LU887xLU897, enter a wet- weight stationary phase of growth six days following the transfer of quiescent cultures to fresh nutrient medium. When growth is determined on the basis of dry weight or protein content the microplasmodia complete logarithmic growth within four days and the percent of wet weight that is protein begins to decline after three days. When microplasmodia are subcultured from log-phase cultures, wet growth plateaus within five days; dry weight and protein content peak after four days of culture and the magnitude of the growth obtained exceeds that of reanimated quiescent cultures by more than 40%, over the same period. The highest continuing growth rate was maintained ABSTRACTS 347 with a three-day subculture schedule when growth was measured either as dry weight or on the basis of protein. No accumulation of lactic acid was detected over a five day period of growth. Unlike yellow microplasmodia that lower the pH of their media from 4.6 to 4.0 or lower (John Daniel, 6th International Cell Cycle Conference) the white microplasmodia were observed to increase medium pH from 4.6 to 5.2 within four days of growth. . INDEX TO VOLUME XXXV (1983), THE TEXAS JOURNAL OF SCIENCE by CHARLOTTE A. NEILL Medical Sciences Library Texas A&M University College Station, TX 77843 and L. JOSEPH FOLSE Department of Wildlife and Fisheries Sciences Texas A&M University College Station, TX 77843 PREFACE This index has separate subject and author sections. The subject index is patterned after that currently used in the Pro¬ ceedings of the National Academy of Sciences: The key word or phrase is followed by the complete title and initial page of each relevant arti¬ cle and abstract. However, when the key word(s) comprises the name of a biological or chemical taxon mentioned strictly in the context of a survey, the relevant article or abstract is identified only by initial page number. In the latter case, biological species are indexed only to the generic level, except that common names of species are used in cases where corresponding scientific names did not appear in the article or abstract. Index terms were chosen both from titles and texts. Key words sup¬ plied by authors also were used. Index terms were alphabetized by a computer program that disregarded conformational prefixes, numerals, and hyphenated Greek letters. The author index includes the names of all authors, both of articles and abstracts. Each name is followed by the number of the first page of that author’s article or abstract. C.A.N. did the indexing; L.J.F. developed the microcomputer pro¬ grams (in Pascal) that assimilated the key-word information and pro¬ duced the index. The Texas Journal of Science. Vol. XXXV, No. 4, January 1984 350 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 SUBJECT INDEX A(5’)pppp(5’)A assay Assay of A(5’)pppp(5’) A and A(5’)pppp(5’)G in Physarum polycepha/um and other eukaryotes: An isocratic high performance liquid chromatography method, 338 (abstract) A(5’)pppp(5’)G assay Assay of A(5’)pppp(5’)A and A(5’)pppp(5’)G in Physarum po/ycepha/um and other eukaryotes: An isocratic high performance liquid chromatography method, 338 (abstract) Acer : 205 Acer grandidentatum Relationships of sugar maples ( Acer saccharum and A. grandidentatum) in Texas and Oklahoma with special reference to relict populations, 231 Acer saccharum Relationships of sugar maples ( Acer saccharum and A. grandidentatum) in Texas and Oklahoma with special reference to relict populations, 231 Actin Analysis of poly A+ and actin mRNAs during spherulation in Physarum po/ycepha/um, 337 (abstract) Adduct formation Thin layer chromatography of nitrogen heterocycles on a modified silica gel support, 37 Agarose drop assay In vitro analysis of transfer factor activity in guinea pig leukocyte extracts by the agarose drop assay, 129 Air pollution Heavy metal pollution in El Paso during selected time periods, 47 Alepisaurus : 109 A/nus: 205 Amby stoma-. 245 Amoebal-plasmodial transition Preliminary analysis of an extracellular inducer of the amoebal-plasmodial transition from the myxomycete Didymium iridis, 342 (abstract) Anoplogaster. 109 Aquaculture The commercial production of mudminnows {Fund ulus grand is) for live bait: A preliminary economic analysis, 51 Aquatic weeds Observations on host selection by Lysathia ludoviciana (Chrysomelidae), a beetle with potential for biological control of certain aquatic weeds, 165 Ardeola ibis Cattle egrets {Ardeola ibis Bubu/cus ibis) in Texas, 303 Ar gyro pel ecus: 109 Aristostomias : 109 Arsenic: 47 Aster : 197 Astronesthes: 109 Ataenius: 219 Atopsyche erigia Occurrence of the caddisfly Atopsyche erigia in Texas’ Guadalupe River below Canyon Reservoir, 243 Badhamia utricular is A tannic acid-methylamine tungstate containing fixative for myxomycete plasmodia, 341 (abstract) Baitfish The commercial production of mudminnows {Fund ulus grand is) for live bait: A preliminary economic analysis, 51 Barn owl New records of invertebrate saprovores from barn owl pellets, 219 Bathy/agus: 109 Beaumont Formation Paleoenvironmental significance of a nonmarine Pleistocene molluscan fauna from southern Texas, 147 Benthosema : 109 Big Bend Nat. Park, Brewster Co., TX Status of bighorn sheep in Texas, 157 Bighorn sheep Status of bighorn sheep in Texas, 157 Biological control Observations on host selection by Lysathia ludoviciana (Chrysomelidae), a beetle with potential for biological control of certain aquatic weeds, 165 Birds’ nests New records of invertebrate saprovores from barn owl pellets, 219 INDEX TO VOL. XXXV 351 Black Gap Wildlife Mgmt. Area, Brewster Co., TX Status of bighorn sheep in Texas, 157 Black hickory Vegetational analysis of a post oak- black hickory community in eastern Texas, 197 Blackjack oak Some structural aspects of a western cross timbers forest in north central Texas, 41 Bo/inichthys: 109 Bona parti a: 109 Brama: 1 09 ' Bregmaceros : 109 Bubulcus ibis Cattle egrets ( Ardeola ibis Bubulcus ibis ) in Texas, 303 Bufo : 245 C shell scripts Translation of C shell scripts to C for faster execution of UNIX computer programs, 189 Caddisfly Occurrence of the caddisfly Atopsyche erigia in Texas’ Guadalupe River below Canyon Reservoir, 243 Cadmium: 47 Calmodulin Purification of calmodulin from Physarum f/avicomum and correlative studies on cyclic AMP phosphodiesterase, 340 (abstract) Caloric value Caloric value of the liver fluke. Fasciola hepatica , 155 Canyon Reservoir, Comal Co., TX Occurrence of the caddisfly Atopsyche erigia in Texas’ Guadalupe River below Canyon Reservoir, 243 Car ex: 197 Carpinus: 205 Carya texana Vegetational analysis of a post oak- black hickory community in eastern Texas, 197 Cattle egret Cattle egrets ( Ardeola ibis Bubulcus ibis) in Texas, 303 Cell cycle Analysis of histone acetylation in the Physarum cell cycle, 336 (abstract) Histone gene expression in Physarum po/ycepha/um: Histone synthesis during the cell cycle and conformational changes of the H4 histone gene, 337 (abstract) How synchronous is Physarum ?, 341 (abstract) Preliminary analysis of an extracellular inducer of the amoebal-plasmodial transition from the myxomycete Didymium iridis, 342 (abstract) Regulation of tubulin synthesis in the Physarum cell cycle, 335 (abstract) Reproductive systems and speciation in Didymium iridis : An evolutionary model, 343 (abstract) Cell fusion Plasma membrane proteins from genetically different amoebal strains of Physarum po/ycepha/um , 344 (abstract) Cell surface Evidence for a factor that alters the surface properties of compatible myxamoebae, 345 (abstract) Surface differences between sexually compatible myxamoebae of Physarum po/ycepha/um , 345 (abstract) Cellular immunity In vitro analysis of transfer factor activity in guinea pig leukocyte extracts by the agarose drop assay, 129 Cellulase activity Viscometric measurement of the cellulase activity of a soil fungus, 261 Celt is: 41 Centrobranchus: 109 Ceratoscope/us: 109 Cervus nippon Comparative digestive efficiency of white-tailed and sika deer, 89 Channel catfish Circulating corticosteroid and leucocyte dynamics in channel catfish during net confinement, 8 3 Chasmanthium: 197 Chau Hod us: 109 Cheletomorpha: 219 Chionanthus: 205 Christmas bird counts Recent population trends of cormorants (Aves: Pelicaniformes) in Texas, 239 Chromosome replication Analysis of histone acetylation in the Physarum cell cycle, 336 (abstract) 352 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 Chrysomelid beetles Observations on host selection by Ly sat hi a iudoviciana (Chrysomelidae), a beetle with potential for biological control of certain aquatic weeds, 165 Cloned DNA Cloning Physarum DNA in Charon 4A and characterization of some clones, 339 (abstract) Cnemidophorus: 245 Coccorella: 109 Computer graphics Biological form representation by techniques developed for airfoils, 67 Computer programing in C Translation of C shell scripts to C for faster execution of UNIX computer programs, 189 Copper smelters Heavy metal pollution in El Paso during selected time periods, 47 Cormorant populations Recent population trends of cormorants (Aves: Pelicaniformes) in Texas, 239 Corticosteroids, plasma Circulating corticosteroid and leucocyte dynamics in channel catfish during net confinement, 83 Crataegus : 197 Cross -timbers forest Some structural aspects of a western cross timbers forest in north central Texas, 41 C rot at US: 245 Crotaphytus: 245 Cryptopsaras : 109 Cyclic AMP Purification of calmodulin from Physarum fiavicomum and correlative studies on cyclic AMP phosphodiesterase, 340 (abstract) The effects of growth conditions on protein kinase activity and cAMP binding activity in Physarum po/ycepha/um, 340 (abstract) Cyc lot hone: 109 Cyprinodon: 93 DNA Molecular structure of the extrachromosomal nucleolus of Physarum (abstract) po/ycepha/um. 339 DNA replication Assay of A(5’)pppp(5’)A and A(5’)pppp(5’)G in Physarum po/ycepha/um and other eukaryotes: An isocratic high performance liquid chromatography method, 338 (abstract) How synchronous is Physarum ?, 341 (abstract) Replication-transcription-coupling in Physarum , 337 (abstract) DNA sequence Genetic organization of the tubulin DNA sequence families, 334 (abstract) Death dip/peak phenomenon The death dip among ordinary folks: A study of the dip/peak phenomenon for Texans dying in 1979, 293 Dermestes: 219 Diaphus : 109 Didymium iridis A stereological analysis of cytological change during spore maturation in Didymium iridis , 343 (abstract) Lifespans and senescence in the slime molds, 343 (abstract) Preliminary analysis of an extracellular inducer of the amoebal-plasmodial transition from the myxomycete Didymium iridis , 342 (abstract) Reproductive systems and speciation in Didymium iridis: An evolutionary model, 343 (abstract) Differentiation Preliminary analysis of an extracellular inducer of the amoebal-plasmodial transition from the myxomycete Didymium iridis , 342 (abstract) Digestive efficiency Comparative digestive efficiency of white-tailed and sika deer, 89 Diogenichthys: 109 Diplophus: 109 Dipiospinus-. 109 Diretmus: 109 Distinguished Texas Scientist, 1983 Geology’s heritage and promise, 181 Ditropichthys: 109 Double -crested cormorant Recent population trends of cormorants (Aves: Pelicaniformes) in Texas, 239 Ecological assessment Heavy metal pollution in El Paso during selected time periods, 47 Economic analysis The commercial production of mudminnows (Fund ulus grand is) for live bait: A preliminary economic analysis, 51 INDEX TO VOL. XXXV 353 Ectoprocts New records of the freshwater ectoproct Pectinate! la magnifica in eastern Texas, 269 Edgeworth expansion A new Edgeworth-type expansion, 221 Eggplant Development of tensile strength in compatible autografts of eggplant ( So/anum pen net Hi) and tomato (Ly co per si con escu/entum), 327 El Paso, TX Heavy metal pollution in El Paso during selected time periods, 47 Electron microscopy A tannic acid-methylamine tungstate containing fixative for myxomycete plasmodia, 341 (abstract) Encystment Localization, purification, and characterization of a proteinase involved in encystment of Physarum f lav i comum, 340 (abstract) Erythrocytes Characterization of erythrocyte esterases on electrophoretic gels, 169 Esterases Characterization of erythrocyte esterases on electrophoretic gels, 169 Ethanol toxicity The use of Physarum in toxicity testing, 342 (abstract) Eustomias : 109 Evolution of eucaryotes Reproductive systems and speciation in Didymium i rid is: An evolutionary model, 343 (abstract) Exotic animals Comparative digestive efficiency of white-tailed and sika deer, 89 Fagus: 205 Fasciola hepatica Caloric value of the liver fluke. Fasciola hepatica, 155 Faunal boundaries Midwater fishes of the Gulf of Mexico collected from the R/V Alaminos, 1965-1973, 109 Finfish Summer diet of finfish from nearshore habitats of West Bay, Texas 93 Fishes, midwater Midwater fishes of the Gulf of Mexico collected from the R/V Alaminos, 1965-1973, 109 Fission, neutron induced Use of fissiogenic stable ruthenium versus xenon isotopes in the determination of induced fission in uranium ores, 283 Flagel/ostomias: 109 Flavonoids Relationships of sugar maples ( Acer saccharum and A. grand id entatum) in Texas and Oklahoma with special reference to relict populations, 231 Food habits Summer diet of finfish from nearshore habitats of West Bay, Texas, 93 F orest i era: 197 Form representation, biological Biological form representation by techniques developed for airfoils, 67 Fraxinus: 205 Fund ulus: 93 Fundulus grandis The commercial production of mudminnows f Fundulus grandis) for live bait: A preliminary economic analysis, 51 Fusarium roseum Viscometric measurement of the cellulase activity of a soil fungus, 261 Galium: 197 Galveston Bay system Summer diet of finfish from nearshore habitats of West Bay, Texas, 93 Gastric ulcers Effects of a high potassium diet and prostaglandin on induced gastric ulceration in rats, 61 Gel electrophoresis techniques Characterization of erythrocyte esterases on electrophoretic gels, 169 Gene expression Cell-type dependent expression of tubulins in Physarum, 334 (abstract) Histone gene expression in Physarum po/ycepha/um: Histone synthesis during the cell cycle and conformational changes of the H4 histone gene, 337 (abstract) Regulation of tubulin synthesis in the Physarum cell cycle, 335 (abstract) Genomic clone Cloning Physarum DNA in Charon 4A and characterization of some clones, 339 (abstract) 354 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 Geology Geology’s heritage and promise, 181 Gephyroberyx : 109 Gonichthys : 109 Gonostoma: 109 Grafting Development of tensile strength in compatible autografts of eggplant ( So/anum pennellii) and tomato {Ly coper si con escu/entum), 327 Gray -Coberly- Lewis expansion A new Edgeworth-type expansion, 221 Growth Some growth characteristics of white Physarum microplasmodia, 346 (abstract) Guadalupe River, Comal Co., TX Occurrence of the caddisfly Atopsyche erigia in Texas’ Guadalupe River below Canyon Reservoir, 243 Guinea pigs In vitro analysis of transfer factor activity in guinea pig leukocyte extracts by the agarose drop assay, 129 Gulf of Mexico Midwater fishes of the Gulf of Mexico collected from the R/V Alaminos , 1965-1973, 109 H4 histone gene Analysis of histone acetylation in the Physarum cell cycle, 336 (abstract) Histone gene expression in Physarum po/ycepha/um: Histone synthesis during the cell cycle and conformational changes of the H4 histone gene, 337 (abstract) Physarum histones, 336 (abstract) Hadamard’s theorem Global inverse function theorem, 215 Halbouty, Michel T. Geology’s heritage and promise, 181 Heart disease Modeling systolic mitral valve motion: A tool for clarifying mitral valve prolapse, 5 Heavy metal pollution Heavy metal pollution in El Paso during selected time periods, 47 Helicina : 147 H el i soma: 147 Heronries Cattle egrets (Ardeo/a ibis = Bubulcus ibis) in Texas, 303 Herpetofauna Herpetofauna of the Pedro Armendariz Lava Field, New Mexico, 245 Heterodon : 245 Histone synthesis Analysis of histone acetylation in the Physarum cell cycle, 336 (abstract) Histone gene expression in Physarum po/ycepha/um: Histone synthesis during the cell cycle and conformational changes of the H4 histone gene, 337 (abstract) Physarum histones, 336 (abstract) Ho/brookia: 245 Ho/tbyrnia: 109 Hydrazine toxicity The use of Physarum in toxicity testing, 342 (abstract) Hydrocarbon toxicity The use of Physarum in toxicity testing, 342 (abstract) Hygophum: 109 /chthyococcus: 109 Ictalurus punctatus Circulating corticosteroid and leucocyte dynamics in channel catfish during net confinement, 83 / di acanthus: 1 09 Hex: 197, 205 Indomethacin Effects of a high potassium diet and prostaglandin on induced gastric ulceration in rats, 61 Inverse function theorem Global inverse function theorem, 215 Invertebrate saprovores New records of invertebrate saprovores from barn owl pellets, 219 Jasper Co., TX Vegetational analysis of a post oak- black hickory community in eastern Texas, 197 Joukowski transformation Biological form representation by techniques developed for airfoils, 67 Kali: 109 La god orr. 93 Lampanyctus: 109 Lampedena: 109 Largemouth bass Swim bladder stress syndrome in largemouth bass, 315 Lead: 47 Leaf shape Relationships of sugar maples ( Acer saccharum and A. grand id entatum) in Texas and Oklahoma with special reference to relict populations, 231 INDEX TO VOL. XXXV 355 Leiostomus : 93 Lemniscate of Bernoulli Toric sections, 277 Lepidophanes : 109 Lepidopus-. 109 Leptostomias : 109 Lepus: 323 Lest id i ops: 109 Lest id i urn: 109 Leukocytes Circulating corticosteroid and leucocyte dynamics in channel catfish during net confinement, 83 In vitro analysis of transfer factor activity in guinea pig leukocyte extracts by the agarose drop assay, 129 Lifespan Lifespans and senescence in the slime molds, 343 (abstract) Liquidambar : 205 Listeria monocytogenes In vitro analysis of transfer factor activity in guinea pig leukocyte extracts by the agarose drop assay, 129 Liver fluke Caloric value of the liver fluke, Fasciola hepatica , 155 Lobianchia: 109 Ludwigia peploides Observations on host selection by Lysathia ludoviciana (Chrysomelidae), a beetle with potential for biological control of certain aquatic weeds, 165 Lycopersicon esculentum Development of tensile strength in compatible autografts of eggplant ( So/anum pennel/ii) and tomato ( Lycopersicon esculentum), 327 Lysathia ludoviciana Observations on host selection by Lysathia ludoviciana (Chrysomelidae), a beetle with potential for biological control of certain aquatic weeds, 165 MBO resistance Genetic analysis of MBC-resistance in Physarum , 335 (abstract) Magnolia : 205 Malacosteus: 109 Mammals of east Texas Distributional records and notes for nine species of mammals in eastern Texas, 323 Mammary adenocarcinoma Variation in transplantable tumor growth-parameters can be reduced, 141 Margrethia: 109 Masticophis: 245 Masticophis taeniatus schotti Eggs and young of Schott’s whipsnake, Masticophis taeniatus Schotti, 161 Maurolicus: 109 Melamphaes: 109 Melanism Herpetofauna of the Pedro Armendariz Lava Field, New Mexico, 245 Me/anocetus: 109 Melanonus: 109 Menidia : 93 Messenger RNA Analysis of poly A+ and actin mRNAs during spherulation in Physarum po/ycepha/um, 337 (abstract) Changes in the abundance of mRNA species during the mitotic cycle of Physarum polycephalum, 338 (abstract) Mice Variation in transplantable tumor growth-parameters can be reduced, 141 Michaelis- Menton enzyme kinetics Viscometric measurement of the cellulase activity of a soil fungus, 261 Micropterus salmoides Swim bladder stress' syndrome in largemouth bass, 315 Microstoma : 109 Microtis pinetorum Distributional records and notes for nine species of mammals in eastern Texas, 323 Migration inhibition factor In vitro analysis of transfer factor activity in guinea pig leukocyte extracts by the agarose drop assay, 129 Mitosis Changes in the abundance of mRNA species during the mitotic cycle of Physarum polycephalum, 338 (abstract) Mitral valve Modeling systolic mitral valve motion: A tool for clarifying mitral valve prolapse, 5 Models, biological In vitro analysis of transfer factor activity in guinea pig leukocyte 356 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 extracts by the agarose drop assay, 129 Modeling systolic mitral valve motion: A tool for clarifying mitral valve prolapse, 5 Models, economic The commercial production of mudminnows {Fund ulus grand is) for live bait: A preliminary economic analysis, 51 Molluscs Paleoenvironmental significance of a nonmarine Pleistocene molluscan fauna from southern Texas, 147 Mortality rates, human The death dip among ordinary folks: A study of the dip/peak phenomenon for Texans dying in 1979, 293 Morus: 41, 205 Mudminnows The commercial production of mudminnows {Fund ulus grand is) for live bait: A preliminary economic analysis, 51 Mugil: 93 Mussels Paleoenvironmental significance of a nonmarine Pleistocene molluscan fauna from southern Texas, 147 Mutants Physarum strains temperature sensitive in vegetative growth, 346 (abstract) Ts mutant isolation in Physarum axenic myxamoebae, 346 (abstract) Mutation Genetic analysis of MBC-resistance in Physarum , 335 (abstract) M yet op hum : 109 Myxamoebae Abstracts of the ninth North American Physarum conference, 333 NACA four-digit system Biological form representation by techniques developed for airfoils, 67 Nature Center and Refuge, Ft. Worth, TX Some structural aspects of a western cross timbers forest in north central Texas, 41 Nickel complexes Thin layer chromatography of nitrogen heterocycles on a modified silica gel support, 37 Nitrogen heterocycles Thin layer chromatography of nitrogen heterocycles on a modified silica gel support, 37 Noto/ychnus : 109 N otoscope / US: 109 Nucleolus Molecular structure of the extrachromosomal nucleolus of Physarum po/ycepha/um, 339 (abstract) Nyssa : 205 Odocoileus virginianus Comparative digestive efficiency of white- tailed and sika deer, 89 Odontostomops: 109 Oklo phenomenon Use of fissiogenic stable ruthenium versus xenon isotopes in the determination of induced fission in uranium ores, 283 Olivaceous cormorant Recent population trends of cormorants (Aves: Pelicaniformes) in Texas, 239 Omosudis : 109 Oryzomys : 323 Ostrya: 205 Ovals of Cassini Toric sections, 277 Ovis canadensis Status of bighorn sheep in Texas, 157 Par ale pis-. 109 Pectinate! la magnifica New records of the freshwater ectoproct Pectinate! la magnifica in eastern Texas, 269 Pedro Armendariz Lava Field, NM Herpetofauna of the Pedro Armendariz Lava Field, New Mexico, 245 Pel I iso I US: 109 Peromyscus : 323 Per sea: 205 Pha/acrocorax auritus Recent population trends of cormorants (Aves: Pelicaniformes) in Texas, 239 Pha/acrocorax olivaceous Recent population trends of cormorants (Aves: Pelicaniformes) in Texas, 239 Pheromones Preliminary analysis of an extracellular inducer of the amoebal-plasmodial transition from the myxomycete Didymium iridis, 342 (abstract) Phosphodiesterase Purification of calmodulin from Physarum f lav i comum and correlative studies on cyclic AMP phosphodiesterase, 340 (abstract) INDEX TO VOL. XXXV 357 Photonectes. 109 Photostomias : 109 Photostylus : 109 Phry nosoma-. 245 Physarum spp. Abstracts of the ninth North American Physarum conference, 333 Pinus : 205 Pituophis : 245 Plant grafts Development of tensile strength in compatible autografts of eggplant ( Solarium penne/lil) and tomato Uy co per si con escu/entum ), 327 Plasma membranes Plasma membrane proteins from genetically different amoebal strains of Physarum po/ycephalum, 344 (abstract) Plasma membranes from Physarum po/ycepha/um amoebae and plasmodia, 344 (abstract) Surface differences between sexually compatible myxamoebae of Physarum po/ycepha/um , 345 (abstract) Plasmodium Abstracts of the ninth North American Physarum conference, 333 Pleistocene molluscs Paleoenvironmental significance of a nonmarine Pleistocene molluscan fauna from southern Texas, 147 Pollichthys : 109 Poly A + Analysis of poly A+ and actin mRNAs during spherulation in Physarum po/ycepha/um, 337 (abstract) Polyipnus : 109 Poly met me: 109 Poromitra: 109 Post oak Some structural aspects of a western cross timbers forest in north central Texas, 41 Vegetational analysis of a post oak- black hickory community in eastern Texas, 197 Potassium Effects of a high potassium diet and prostaglandin on induced gastric ulceration in rats, 61 Prairie Creek, San Augustine Co., TX Woody, stream-side vegetation of Prairie Creek in east Texas, 205 Probability distributions A new Edgeworth-type expansion, 221 Prolapse, mitral valve Modeling systolic mitral valve motion: A tool for clarifying mitral valve prolapse, 5 Promethichthys : 109 Prostaglandin Effects of a high potassium diet and prostaglandin on induced gastric ulceration in rats, 61 Protein kinase The effects of growth conditions on protein kinase activity and cAMP binding activity in Physarum po/ycepha/um, 340 (abstract) Proteinase Localization, purification, and characterization of a proteinase involved in encystment of Physarum f/avicomum, 340 (abstract) Pterycombus : 109 Quercus : 197, 205 Clue reus mari/andica Some structural aspects of a western cross timbers forest in north central Texas, 41 Quercus ste/lata Some structural aspects of a western cross timbers forest in north central Texas, 41 Vegetational analysis of a post oak- black hickory community in eastern Texas, 197 Rabbits Characterization of erythrocyte esterases on electrophoretic gels, 169 Rabdotus : 147 Range expansion Cattle egrets ( Ardeo/a ibis = Bubu/cus ibis) in Texas, 303 Ranunculus: 197 Rats Effects of a high potassium diet and prostaglandin on induced gastric ulceration in rats, 61 Reithrodontomys humu/is Distributional records and notes for nine species of mammals in eastern Texas, 323 Reithrodontomys fulvescens Distributional records and notes for nine species of mammals in eastern Texas, 323 Relict populations Relationships of sugar maples ( Acer saccharum and A. grand id entatum) in Texas and Oklahoma with special reference to 358 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 relict populations, 231 Reproduction Evidence for a factor that alters the surface properties of compatible myxamoebae, 345 (abstract) Reproductive systems and speciation in Didymium iridis : An evolutionary model, 343 (abstract) Surface differences between sexually compatible myxamoebae of Physarum po/ycepha/um, 345 (abstract) Rhododendron : 205 Rodent tumors Variation in transplantable tumor growth-parameters can be reduced, 141 Ruthenium Use of fissiogenic stable ruthenium versus xenon isotopes in the determination of induced fission in uranium ores, 283 Sabine Pass, TX and LA Observation of episodic sedimentation in a tidal inlet (Sabine Pass, Texas and Louisiana), 101 San Augustine Co., TX Woody, stream side vegetation of Prairie Creek in east Texas, 205 Sangamon time Paleoenvironmental significance of a nonmarine Pleistocene molluscan fauna from southern Texas, 147 Sanicu/a: 197 Sea phi opus-. 245 Sceloporus: 245 Schott’s whipsnake Eggs and young of Schott’s whipsnake, Masticophis taeniatus Schotti, 161 Scopelarchus: 109 Scope! oberyx: 109 Scope! osaurus: 109 Scutellaria-. 197 Sedimentation Observation of episodic sedimentation in a tidal inlet (Sabine Pass, Texas and Louisiana), 101 Senescence Lifespans and senescence in the slime molds, 343 (abstract) Serri vomer : 109 Sika deer Comparative digestive efficiency of white-tailed and sika deer, 89 Slime mold culture Lifespans and senescence in the slime molds, 343 (abstract) 5 mi / ax: 205 Snails Paleoenvironmental significance of a nonmarine Pleistocene molluscan fauna from southern Texas, 147 Snake eggs and young Eggs and young of Schott’s whipsnake, Masticophis taeniatus Schotti, 161 Sociolog} of dying The death dip among ordinary folks: A study of the dip/peak phenomenon for Texans dying in 1979, 293 Soil fungus Viscometric measurement of the cellulase activity of a soil fungus, 261 Solanum pennellii Development of tensile strength in compatible autografts of eggplant ( Solanum pennellii) and tomato {Ly coper si con escu/entum), 327 Sonora: 245 S per mo phi I us: 323 Spherulation Analysis of poly A+ and actin mRNAs during spherulation in Physarum po/ycephalum, 337 (abstract) Spores A stereological analysis of cytological change during spore maturation in Didymium iridis, 343 (abstract) Stemonitis flavogenita Lifespans and senescence in the slime molds, 343 (abstract) Stereological analysis A stereological analysis of cytological change during spore maturation in Didymium iridis, 343 (abstract) Sternoptyz: 109 Stipa : 197 Stomach content analysis Summer diet of finfish from nearshore habitats of West Bay, Texas, 93 Stress Circulating corticosteroid and leucocyte dynamics in channel catfish during net confinement, 83 Swim bladder stress syndrome in largemouth bass, 315 Styrax: 205 Sudis: 109 Sugar maples Relationships of sugar maples ( Acer saccharum and A. grand id entatum) in Texas and Oklahoma with special reference to relict populations, 231 INDEX TO VOL. XXXV 359 Swim bladder Swim bladder stress syndrome in largemouth bass, 315 Symbol ophorus: 109 Symp/ocos: 205 Synchrony How synchronous is Physarum, 341 (abstract) Taaningichthys: 109 Tad arid a: 323 Tannic acid-methylamine tungstate fixative A tannic acid-methylamine tungstate containing fixative for myxomycete plasmodia, 341 (abstract) Taracichthys : 109 Taylor Creek mammoth site, Kleberg Co., TX Paleoenvironmental significance of a nonmarme Pleistocene molluscan fauna from southern Texas, 147 Teeth Biological form representation by techniques developed for airfoils, 67 Temperature sensitivity Physarum strains temperature sensitive in vegetative growth, 346 (abstract) Terra pene: 245 Thin -layer chromatography Thin layer chromatography of nitrogen heterocycles on a modified silica gel support, 37 Tipping- bucket sampler Observation of episodic sedimentation in a tidal inlet (Sabine Pass, Texas and Louisiana), 101 Tomato Development of tensile strength in compatible autografts of eggplant ( Solarium penne/lii) and tomato Uy co, per si con escu/entum ), 327 Torus Toric sections, 277 Toxicity bioassay The use of Physarum in toxicity testing, 342 (abstract) Transcription Replication-transcription-coupling in Physarum, 337 (abstract) Transfer factor In vitro analysis of transfer factor activity in guinea pig leukocyte extracts by the agarose drop assay, 129 Tubulins Cell-type dependent expression of tubulins in Physarum , 334 (abstract) Genetic analysis of MBC-resistance in Physarum, 335 (abstract) Genetic organization of the tubulin DNA sequence families, 334 (abstract) Regulation of tubulin synthesis in the Physarum cell cycle, 335 (abstract) Tumor transplantation Variation in transplantable tumor growth parameters can be reduced, 141 Tydeus : 219 Tyto alba New records of invertebrate saprovores from barn owl pellets, 219 UNIX computer programs Translation of C shell scripts to C for faster execution of UNIX computer programs, 189 Ulmus : 41, 197, 205 Uniomerus: 147 Uranium ores Use of fissiogenic stable ruthenium versus xenon isotopes in the determination of induced fission in uranium ores, 283 Uta\ 245 Vacc/nium: 197, 205 Va/encienne/lus: 109 Vector algebra Toric sections, 277 Vegetational analysis Vegetational analysis of a post oak- black hickory community in eastern Texas, 197 Woody, stream-side vegetation of Prairie Creek in east Texas, 205 Vicia: 197 Vinciguerria : 109 Viscometry Viscometric measurement of the cellulase activity of a soil fungus, 261 Vitis: 205 West Bay, TX Summer diet of finfish from nearshore habitats of West Bay, Texas, 93 White -tailed deer Comparative digestive efficiency of white-tailed and sika deer, 89 Wildlife management Comparative digestive efficiency of white-tailed and sika deer, 89 Status of bighorn sheep in Texas, 157 Xenodon suspect us Taxonomic status of the Brazilian colubrid snake, Xenodon suspectus 360 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 Cope, 257 determination of induced fission Xenon uranium ores, 283 Use of fissiogenic stable ruthenium Zinc: 47 versus xenon isotopes in the in INDEX TO VOL. XXXV 361 AUTHOR INDEX Aldrich, H.C. 345 Alexander, S.K. 93 Amir-Moez, A.R. 277 Applegate, H.G. 47 Attrep, M., Jr. 283 Baca, E.J. 261 Baccus, J.T. 323 Barden, A. 344, 344 Barnes, L.D. 338 Bernier, F. 344 Best, F.H. 245 Best, T.L. 245 Borelli, T.C. 293 Boston, R. .334 Brown, R.D. 89 Brunet, J.K. 344 Burland, T.G. 334, 334, 335, 335 Campbell, J.M. 165 Carmichael, G.J. 315 Carrino, J. 346 Cherry, J.P. 169 Chestnut, M.H. 341 Clark, J. 343 Clark, WJ. 165 Cleveland, A.C. 323 Collins, O.R. 343 Cox, R.A. 338 Daniel, J.C. 141 Davis, K.B. 83 Dixon, J.R. 161, 257 Dove, W.F. 334, 334, 335 Dronen, N.O. 155 Drube, C.G. 129 Early, G. 189 Eaves, K.L. 67 Ehrhart, R.L. 205 Evans, H.H. 346 Evans, T.E. 346 Fagerberg, W.R. 343 Farrell, M.E. 340 Fechhelm, J.D. 109 Fredricks, G.A. 277 Fullington, R.W. 269 Galloway, J.G. 221 Gambill, J. 189 Gardner, R.C. 231 Garrison, P.N. 338 Gehlbach, F.R. 231 Goodman, E.M. 345 Griffin, W. 51 Gull, K. 334, 335 Halbouty, M.T. 181 Hale, B.S. 239 Hamilton, A.B. 219 Hamilton, K.L. 219 Hanks, G. 345 Heffington, W.M. 67 Henney, H.R., Jr. 340 Hsing-Tung, K. 283 Hunter, J.F. 5 Jalouzot, R. 337 James, H.C. 245 Jasper, S.A. 205 Jay, J.M. 155 Johns, M. 51 Kan, C.-C. 339 Kelly, M.M. 342 Knox, C. 339 Krausman, P.R. 157 Kroh, G.C. 41 Kubbies, M. 341 Laffler, T.G. 346 Lemieux, G. 337, 344, 344 Leopold, B.D. T57 Lively, W.M. 5 Lynch, T.J. 340 Maher, M.J. 339 Mann, M.J. 61 Marcy, L.E. 303 Marietta, K.L. 197 Marsh, R. 339, 339 Martel, R. 344 Matheson, R.E., Jr. 109 Matthews, H.R. 336, 336 McCarthy, J.L. 346 McCoid, M.J. 109 McCrystal, H.K. 161 McCune, E.D. 221 McCune, J.H. 340 McCune, R.W. 340 McGarry, M.T. 327 Mende, L.M. 336 Miller, G.E. 5 Miller, J.D. 215 Mims, C.W. 343 Mohberg, J. 342 Moore, R. 327 Morrison, D.G. 141 Morrison, M.L. 239 Moyer, M.P. 141 Moyer, R.C. 141 Mueller, R.D. 336 Murdy, E.O. 109 Nader, W. 342 Nations, C. 333, 346 Neck, J.S. 205 Neck, R.W. 147, 269 Newsom, R.K. 293 Nisbet, J. 41 Nixon, E.S. 197, 205 Olson, G.B. 129 Ortega, J. 261 Pallotta, D. 344, 344 Paquet, A., Jr. 129 Pierron, G. 337, 341 Pinon, I. 346 Redetzke, K. 47 Reiskind, J.B. 345 Rogers, W. 141 Rudzinski, W.E. 37 Sauer, H.W. 337 Schedl, T. 334, 334, 335 Seaton, D.P. 5 Seligy, V.L. 337 Shepherd, D.P. 61 Shipley, G.L. 342 Shoemaker, C.L. 340 Short, A.P. 293 Short, R.A. 243 Sim.co, B.A. 83 Slack, R.D. 239 Smulian, N.J. 338 Stoner, D.L. 5 Strawn, K. 51 Tanner, L.M. 293 Telfair, R.C. II 303 Thomas, T. 189 Tipnis, P. 345 Tomasso, J.R. 83, 315 Toublan, B. 337 Waas, B.P. 51 Ward, G.H., Jr. 101 Ward, J.R. 205 Waterborg, J.H. 336, 336 Wheaton, C. 89 White, H.U. 340 Wilhelm, F.X. 337 Wilhelm, M.L. 337 Zimmerman, E.G. 323 362 THE TEXAS JOURNAL OF SCIENCE— VOL. XXXV, NO. 4, 1984 REVIEWERS The persons listed below have reviewed manuscripts for the Texas Journal of Science within the past two years. The Academy is very grateful for their help. Aldrich, D.V. Amoss, M.S. Arnold, K.A. Baccus, J.T. Baker, R. Belial, F.T. Bickham, J.W. Bilyeu, R.G. Binderim, G.E. Bragg, L.H. Bratton, G. Brown, P.K. Brown, R.F. Bullin, J. Burch, R. Buzan, D. Cameron, G.N. Campbell, J.M. Casto, S.D. Chamberlain, G.C. Chapman, B.R. Choate, J.R. Clark, D.R. Clark, K.A. Clark, W.J. Coburn, D. Cole, C.J. Cox, R.A. Crick, R.E. Cunningham, J. Dalquest, W.M. Davies, F. Dial, B.E. Dillin, D.R. Ditton, R.B. Dockweiler, C.J. Doctor, V.M. Dolbeer, R.A. Ebrey, T. Etheridge, R. Ezell, A.W. Fares, Y. Finlay, B. Fleharty, E.D. Flowers, A. I. Folse, L.J. Foster, B.G. Foster, D.M. Frentress, C. Fullmgton, R.W. Gary, H.E., Jr. Giovanella, B.C. Gorsline, D.S. Gray, J. Greenbaum, I.F. Guthery, F.S. Harrel, R.C. Harry, H.W. Hartley, C.J. Hatch, S.L. Huffman, D.G. Jee, R. Johnson, J.D. Judd, F.W. Kelsch, S.W. Kimber, C. Koenig, H.J. Kofron, C.P. Kroh, G.C. Kyba, E.P. Landry, A.M., Jr. Leeper, P.W. Leonard, J.E. Lestrade, J.P. Lieb, C.S. Lind, O.T. Linder, L.E. Longley, G. Longnecker, M. Lovell, R.T. Lueking, D.R. Lundelius, E.L. Marcum, J.P. Martin, S.F. Martyn, R.D. McCarley, H. McCullough, J.D. McCune, E.D. McIntosh, W.A. McKinley, C.R. McLemore, E.W. McWilliams, E. Meyers, D.G. Morrison, D.G. Moyer, R.C. Namkoong, G. Naugle, N.W. Neal, J. Nix, J.F. Nixon, E.S. Norton, S.J. Odell, P.L. Owen, J.G. Pace, C.N. Pearson, B.J. Pearson, W.D. Phinney, H.K. Poole, C.F. Potempa, T. Powell, E. Powell, G.L. Pulich, W.M., Jr. Rezak, R. Richardson, A. Rutledge, J.T. Sauer, H.W. Schmidly, D.J. Scudday, J.F. Sealander, J.A. Siehr, D.J. Silvy, N.J. Smeins, F.E. Srinivasan, V.K. Stewart, K.W. Stipanovic, R.D. Strange, R.J. Stubbs, G.G. Thompson, G.A., Jr. Thompson, P.B. Thummel, R.P. Tizard, I. Turner, C. Van Horn, D.E. Vincent, J. Waldrop, J.E. Warner, I.M. Watkins, J. Weller, M.W. Wellman, P.J. Whiteside, B.G. Whitmore, D.H. Wicksten, M.K. Wilkins, K.W. Williges, G.G. Wilson, F. Wilson, L.D. Wilson, R.P. Winfree, B. Winston, A.J. Wormuth, J.H. Yancey, T.E. Yates, S. Yuen, T.S. THE TEXAS ACADEMY OF SCIENCE, 1983-84 OFFICERS Bernard T. Young, Angelo State University Michael J. Carlo, Angelo State University William J. Clark, Texas A&M University Elray S. Nixon, Stephen F. Austin State University Everett D. Wilson, Sam Houston State University William H. Neill, Texas A&M University Arthur E. Hughes, Sam Houston State University DIRECTORS 1981 Richard L. Noble, Texas A&M University Bob F. Perkins, University of Texas, Arlington 1982 Billy J. Franklin, Texas A&I University Ethel W. McLemore, Dallas 1983 D. Lane Hartsock, Austin Katherine Mays, Bay City President: President-Elect: Vice-President: Immediate Past President: Secretary- T reasurer: Editor: AAAS Council Representative: SECTIONAL CHAIRPERSONS I —Mathematical Sciences: Barbara Schreur, Texas A&I University II— Physical Sciences: Virginia L. Rawlins, North Texas State University III —Earth Sciences: James C. Grenda, Angelo State University IV — Biological Sciences: Edward Schenider, Southwest Texas State University V — Social Sciences: James O. Standley, Stephen F. Austin State University VI— Environmental Sciences: Robert D. Larsen, Southwest Texas State University VII— Chemistry: John T. Moore, Stephen F. Austin State University VIII —Science Education: Fred L. Fifer, University of Texas, Dallas IX— Computer Sciences: H. P. Haiduk, Amarillo College X— Aquatic Sciences: Fred L. Rainwater, Stephen F. 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