GULF RESEARCH REPORTS Volume 4, Number 1 Published by GULF COAST RESEARCH LABORATORY Ocean Springs, Mississippi August 1972 Gulf Research Reports Volume 4 Issue 1 January 1972 A Study of Nektonic and Benthic Faunas of the Shallow Gulf of Mexico Off the State of Mississippi As Related to Some Physical^ Chemical^ and Geological Factors James S. Franks Gulf Coast Research Laboratory J.Y. Christmas Gulf Coast Research Laboratory Walter L. Siler Gulf Coast Research Laboratory Ralph Combs Gulf Coast Research Laboratory Richard Waller Gulf Coast Research Laboratory et al DOI: 10.18785/grr.0401.01 Follow this and additional works at; http://aquila.usm.edu/gcr Part of the Marine Biology Commons Recommended Citation Franks,}. S., J. Christmas, W. L. Siler, R. Combs, R. Waller and C. Burns. 1972. A Study of Nektonic and Benthic Faunas of the Shallow Gulf of Mexico Off the State of Mississippi As Related to Some Physical, Chemical, and Geological Factors. Gulf Research Reports 4 (1): 1-148. Retrieved from http:// aquila.usm.edu/gcr/vol4/issl/ 1 This Article is brought to you for free and open access by The Aquila Digital Community. It has been accepted for inclusion in Gulf and Caribbean Research by an authorized administrator of The Aquila Digital Community. For more information, please contact Joshua.Cromwell^usm.edu. A STUDY OF NEKTONIC AND BENTHIC FAUNAS OF THE SHALLOW GULF OF MEXICO OFF THE STATE OF MISSISSIPPI AS RELATED TO SOME PHYSICAL, CHEMICAL AND GEOLOGICAL FACTORS by James S. Franks, J.Y. Christmas, Walter L. Siler, Ralph Combs, Richard Waller and Charles Burns GULF COAST RESEARCH LABORATORY Ocean Springs, Mississippi 1972 This study was conducted in cooperation with the Department of Commerce, National Marine Fisheries Service, under Public Law 88-309, Project 2-42-R. Table of Contents Page I. List of Tables and Figures iii n. Abstract 1 III. Introduction 2 IV. Station Location and Identification 5 V. Bathymetry 8 VI. Materials and Methods 8 VII. Hydrology 10 Temperature 10 Salinity 13 Chemical Determinations 15 Transparency 15 VIII. Sedimentology 17 Background 17 Technique 18 Findings 18 Sediment Composition 20 Size 20 IX. Plankton Sampling 24 Common Plankters 27 Phytoplankton 27 Zooplankton 27 X. Dredge Sampling 37 Species Account 38 XI. Nekton Sampling 40 XII. Trawl Sampling 42 Laboratory Work on Samples 43 Systematic Account — Invertebrates . 44 Systematic Account — Fishes 66 XHI. Relative Abundance 129 Seasonal Bathymetric Distribution 132 Length" Frequency Distribution 134 XIV. Estuarine Relationships 134 XV. Summary . 136 XVI. Literature Cited 139 XVII. Index 144 ii List of Tables and Figures TABLES Page 1. Number of Monthly Hauls 7 2. Monthly Mean Temperature and Salinity 11 3. Minimum, Maximum, Range and Mean of Monthly Average Temperature 14 4. Minimum, Maximum, Range and Mean of Monthly Average Salinity 14 5. Monthly Mean Nitrate, Nitrite, Total Phosphate and Ortho-phosphate 16 6. Monthly Transparency Observations (May 1968 - May 1969) 19 7. Sediment Properties of Offshore Stations 21 8- Number of Offshore Plankton Samples Examined .... 26 9. Settled Volumes, Salinity, Temperature and Relative Abundance of Common Plankters 28 10. Total Dredge Catch from Six Offshore Stations 39 11. Surface and Benthic Nekton Hauls 41 12. Species Most Commonly Encountered in Nekton Hauls . 43 13. Distribution of Lolliguncula brevis by Bottom Salinity and Temperature Intervals 48 14. Distribution of Penaeus aztecus by Bottom Salinity and Temperature Intervals 52 15. Distribution of Penaeus fluviatilis by Bottom Salinity and Temperature Intervals 55 16. Distribution of Callinectes sapidus by Bottom Salinity and Temperature Intervals 60 17. Distribution of Callinectes similis by Bottom Salinity and Temperature Intervals 62 18. Contribution of Each Family to Total Catch of Fishes . 67 19. Percentage Distribution of Commercially Important Families 67 20. Distribution of Anchoa hepsetus by Bottom Salinity and Temperature Intervals 75 21. Distribution of Galeichthys felis by Bottom Salinity and Temperature Intervals 80 22. Distribution of Centropristes ocyurus by Bottom Salinity and Temperature Intervals 85 23. Distribution of Cynoscion arenarius by Bottom Salinity and Temperature Intervals 92 24. Distribution of Leiostomus xanthurus by Bottom Salinity and Temperature Intervals 95 25. Distribution of Micropogon undulatus by Bottom Salinity and Temperature Intervals 98 26. Distribution of Lagodon rhomboides by Bottom Salinity and Temperature Intervals 101 27. Distribution of Stenotomus caprinus by Bottom Salinity and Temperature Intervals 104 iii 28. Distribution of Peprilus burti Fowler by Bottom Salinity and Temperature Intervals 114 29. Distribution of Cyclopsetta chittendeni by Bottom Salinity and Temperature Intervals . , ......... .118 30. Distribution of Syacium gunteri by Bottom Salinity and Temperature Intervals 123 31. Relative Numbers of the Most Abundant Fishes 130 32. Relative Numbers of the 12 Most Abundant Invertebrate Species 130 FIGURES 1. The “Big House” 4 2. Location of Work 6 3. Bottom Profile 9 4. Nitrate Concentrations (May 1968 through May 1969) . 17 5. Total Phosphate Concentrations (May 1968 through May 1969) 18 6. Nomenclature for Bottom Sediments Based on Grain Size 22 7. Average Grain Size of Bottoms of Offshore Stations . . 23 8. Type of Closing Plankton Net Used in Sampling .... 26 9. Relative Abundance of Number Caught and Weight of Twenty-one Species of Trawl Caught Fishes (1967-1969) 131 10. Offshore Seasonal Bathymetric Distribution of Micropogon undulatus and Stenotomus caprinus 132 11. Offshore Seasonal Bathymetric Distribution of Cynoscion arenarius^ Peprilus burti, Leiostomus xanthurus and Penaeus aztecus 133 Acknowledgements Mr. C. E. Dawson originally served as principal investigator for this project. We sincerely acknowledge his contributions to this study. Mr, Felix Jackson worked as project staff member through- out the program. We hereby acknowledge their contribution and the work of many others who, from time to time, gave assistance. IV NEKTONIC AND BENTHIC FAUNAS 1 Abstract A seasonal study of the nektonic and benthic faunas of the shallow Gulf of Mexico off Mississippi was conducted from January 1967 through May 1969. It was planned to sample monthly six fixed offshore stations at depths ranging from 5 to 50 fathoms in the open Gulf. In general this was carried out fairly well, as shown by Table 1, Water samples were taken from surface, midwater, and bottom levels each time a station was occupied, and temperatures and salinities were recorded for each of these. Samples were tested for the presence of nitrates, nitrites, ortho-phosphates and total phosphates. Secchi disc extinction points were recorded. Grab samples were taken for the determination of bottom composition. Plankton samples were taken from surface, midwater and bottom levels. Copepods, brachyuran zoea and megalops, stomatopod larvae, Lucifer faxonU Acetes a. carolinaCy Penilia avirostris^ Voliolum sp. and fish eggs and larvae were present in greatest abundance. Surface and benthic nekton samples were obtained. Dredge samples were made quarterly and twelve invertebrate species and three species of fishes were collected. Renilla miilleri was the most abundant species taken, and the fish catch consisted of Centropristes ocyurus, Citharichthys spilopterus and Etropus crosaotus. Accounts of 50 invertebrate species (24,679 specimens) and 129 fishes (93,563 specimens) taken in trawl hauls is presented. Tem- perature and salinity data are given for all species. Relative abundance, seasonal bathymetric distributions and movements, apparent growth patterns, catch per unit of effort and various biological data are noted for the most abundant species. Station 5 (40 fathoms) produced the largest percentage of trawl catches {22.1). Jtenilla miilleri was the most abundant invertebrate taken in trawling. The brown shrimp, Penaeus aztecus, was second in abundance (10.92%). The five most abundant species comprising 80.57% numerically of the catch were croaker, longspine porgy, butterfish, spot, and seatrout. The species comprising 91.89% of the catch by weight were the croaker, longspine porgy, spot, seatrout, lizardfish, butterfish, pinfish, bank sea bass, sea catfish and black fin sea robin. The families Sciaenidae, Sparidae and Stromateidae were represented by the greatest numbers and comprised 82.9% of the total catch. Families considered to be of commercial importance contributed 92.9% to the total fish catch. 2 GULF RESEARCH REPORTS Introduction Fishery resources in the Gulf of Mexico are primarily exploited in the estuaries and shallow continental shelf waters. Although most commercial species are estuarine dependent, the adults of many are harvested in Gulf waters. Systematic studies of the fauna in northern Gulf offshore waters east of the Mississippi Delta have not been made. There have been few such studies in other areas of the Gulf. Gunter (1936 and 1945) carried out systematic sampling pro- cedures in shallow Gulf waters out to the 10-fathom (18-meter) curve off Louisiana west of the Mississippi Delta (1931-33) and off Port Aransas in Texas (1941-42). He also carried out one concurrent sampling program in Mississippi estuarine waters, which is not yet published. Moe and Martin (1965) made monthly trawl collections off Pinellas County, Florida out to the 17*fathom (31-meter) curve, but stations beyond 8 fathoms were rarely sampled successfully; their work covered a period of 8 months. Miller (1965) collected regularly for 6 months at stations from 3 to 15 fathoms (5.5 to 27 meters) off Port Aransas, Texas. Dawson (1966) carried out a 16-month ecological survey of the offshore waters of Grand Isle, Louisiana from 3.5 to 20 fathoms (6.4 to 36.6 meters). The major portion of his work is unpublished and is lost to science through a misconceived policy decision of legal advisers to the Freeport Sulphur Company. Springer and Bullis (1952 and 1956) published species catch records for exploratory fishing catches of the M/V Oregon I in Gulf offshore waters. Siebenaler (1952) gave accounts of a few of the fishes taken in Mississippi offshore waters by the M/V Oregon I. Hildebrand (1954 and 1955) reported on the fauna caught by shrimp trawlers on the brown and pink shrimp grounds off Texas Roithmayr (1965) studied the catch of the industrial bottomfish fisheries in the northern Gulf. Other works on the northern Gulf offshore fauna treat limited segments of the population. Beginning in 1952 the industrial bottomfish fishery expanded rapidly and Roithmayr (1965) completed a sampling study of the industrial bottomfish catch from 1959-63. He reported the species NEKTONIC AND BENTHIC FAUNAS 3 composition of commercial landings and areas and seasons of fishing, as well as measurements of catch, effort and bottomfish abundance. Bottomfish landings in Mississippi reached a peak of 93.7 million pounds (42.5 million kg) in 1962 and then declined to a stable average of 60 to 70 million pounds (27-32 million kg). About 64% of the shrimp catch between Mobile Bay and the Mississippi Delta is caught in Gulf offshore waters (Christmas, Gunter and Musgrave 1966). The present work was designed to acquire information about the Gulf fauna off the Mississippi barrier islands in contradistinction to inside waters, by regular sampling at fixed stations out to the 50-fathom (91-meter) curve. The need for this information has been emphasized by expanding fisheries efforts in these waters. A concurrent study of Mississippi estuarine areas was carried on. The estuarine study was incorporated in the Cooperative Gulf of Mexico Estuarine Inventory and Study (GMEI). The offshore project was amended to provide for electronic data processing of the acquired data in order to increase capability for correlation with the Cooperative program and to facilitate data analysis. This report covers 29 months of collections at six fixed stations in a transect across the continental shelf off Mississippi. Trawl data have been stored in computer files. Plans provided for monthly sampling of nektonic and benthic faunas with a 1-meter nekton net and a 40-foot (12-meter) balloon trawl. Plankton sampling was incorporated into the program later. Quarterly sampling of the sediments and associated infauna was also added later as an extension of the Cooperative GMEI sedimentology study. Current summaries of all data were maintained throughout the study. When sampling was completed a backlog of plankton and nekton samples had accumulated because of the initial lack of proficient help. Project personnel continued work on these samples and started preparation of the manuscript for final project reports. This work was well advanced when Hurricane Camille hit the Mississippi Coast. Project laboratory and offices were located in the **Big House” on the Laboratory grounds. This building, originally the residence of the owners of the property now occupied by the Laboratory, was built in 1900. The precaution of moving data files, equipment and samples to the second floor before Camille arrived was futile as is evident in Fig. 1. 4 GULF RESEARCH REPORTS NEKTONIC AND BENTHIC FAUNAS 5 Fortunately, trawl and hydrographic data were in EDP (computer) files and could be retrieved. What has been salvaged from nekton and plankton data, meager though it is, is included in this report. Through cooperative efforts at no extra cost to the project, two dissertations were completed based upon data from plankton samples collected during project cruises. Mr. C. B. Subrahmanyam studied the penaeid shrimp larvae for his doctoral dissertation which degree was conferred on him by Mississippi State University in June 1969. Mr. Danny J. Acosta studied the offshore copepod fauna from the same samples. His Ph.D. was conferred by the University of Southern Mississippi in June 1970. Consequently, excellent data is now available for the study area on these two important groups. One master’s thesis was written from data on trawl collections made during this project. Mr. Allison Perry’s study of the bottomfish collected in 1967 trawl hauls was accepted by the University of Mississippi as a Master of Science thesis. His degree was conferred in the summer of 1970. The first offshore cruise was completed in January 1967. Seventy -three cruises were completed by May 1969. Cruises were scheduled to take advantage of favorable weather insofar as possible, but rough weather occasionally prevented the occupation of some stations. This occurred more often at the distant stations. The six stations were occupied a total of 245 times during the 29-month sampling period. Station Location and Identification The study area lies along a southeasterly transect across the continental shelf east of the Chandeleur Islands and the Mississippi River delta and south of the Mississippi Sound barrier island chain (Fig. 2). Six stations reaching from just south of Dog Keys Pass out to the 50-fathom (91 -meter) curve were established. During field cruises stations were located from pre-determined co-ordinates with the aid of Loran readings. The number of day and night hauls made at each station during the study is shown in Table 1 . Station 1: 30°13’15” N. Lat., 88°47’30” W. Long. Loran: 3H1-1108, 3HO-3598 Station 1 is the northernmost station lying approximately 1 3/4 miles south of the Dog Keys Pass Buoy, which is located near the western tip of Horn Island. This station lies in 5 fathoms (9 meters) of water. Twenty-nine day hauls and eighteen night hauls were made. Over GULF RESEARCH REPORTS Fig. 2. Location of work, Project 2-42-R, showing station locations. NEKTONIC AND BENTHIC FAUNAS 7 TABLE 1 NUMBER OF MONTHLY COLLECTIONS MADE AT THE OFFSHORE STA- TIONS (1967-69) D-Day N-Night MONTH S ta 1 D-N sea 2 D-N Sta 3 D-N Sta 4 D-N Sta 5 D-N 1 1 Sta 6 D-N Total D-N Total Monthly January 3-2 3-4 ! 3-3 2-2 1-1 1-1 ! 13-13 26 February 3-2 2-1 2-2 2-1 1-1 1-1 11-8 19 March 3-1 3-2 3-2 2-2 2-2 3-2 16-11 27 April 3-1 3-1 1-2 1-1 1-1 1-1 10-7 17 May 3-3 3-3 2-3 3-2 3-2 4-2 18-15 33 June 2-1 2-1 ' 2-2 3-1 2-2 1-2 12-9 21 July 2-2 2-2 2-1 2-1 2-2 1-2 11-m 21 August 2-1 2-1 2-1 2-1 2-1 2-1 12-6 18 September 2-1 2-1 1-1 0-1 0-1 0-1 5-6 11 October 2-1 2-] 1-2 1-1 2-2 2-2 10-9 19 November 2-1 2-1 2-1 1-2 1-2 j 1-1 9-8 17 December 3-2 1-2 1-1 1-1 1-1 1 1-1 8-8 16 Total D-N 30-18 27-20 22-21 20-16 18-18 18-17 135-110 Per/Sta 48 47 43 36 36 j 35 245 21% of all animals taken in trawl hauls were encountered at this station. St ation 2: 30°02’30” N. Lat., 88° 4015^^ W. Long. Loran: 3H14220, 3HO-3580 Station 2 is located in 10 fathoms (18 meters) of water. Over 12% of the total trawl catch was taken here in twenty-seven day and nineteen night hauls. Station 3: 29°42’00” N. Lat., 88°27’30’’ W. Long. Loran: 3H1-1440, 3HO-3539 The 20-fathom (37-meter) station contributed 10.9% of the total trawl of fishes and invertebrates. A total of twenty-one day and twenty-one night hauls were made at this depth. Station 4 : 29° 2415” N. Lat., 88°17’00’’ W. Long. Loran: 3H1-1618, 3HO-3494 Over 13.2% of the total trawl catch was taken at the 30-fathom (55-meter) depth. Nineteen day hauls and sixteen night hauls were made here during the study. 8 GULF RESEARCH REPORTS Station 5: 20°19’00” N. Lat., 88°14’00” W. Long. Loran: 3H1-1657, 3HO-3480 Station 5 lies at the 40-fathom (73-meter) depth. In the course of the survey seventeen day and eighteen night hauls (Table 1) at this station produced 22.7% of the total trawl catch. Station 6 : 29“1715" N. Lat., 88‘’12’05” W. Long. Loran: 3H1-1683, 3HO-3472 Station 6 at 50 fathoms (91 meters) was the deepest station occupied. A total of seventeen day and seventeen night hauls were made here and catches comprised 19.5% of the total number of organisms collected. Bathymetry The shelf bottom along the transect is relatively smooth with a uniform slope of 3.4 feet per nautical mile for about 55 miles (101 kilometers). The slope increased to approximately 12.8 feet per nautical mile between 30 and 50 fathoms. Consequently stations located at 10-fathom intervals are closer together farther offshore. From Station 1 to Station 2 is about 12 nautical miles (22 kilometers); Station 2 to Station 3 is 23 nautical miles (43 kilometers); the distance between Stations 3 and 4 is about 22 nautical mRes (41 kilometers). The distance between Stations 4 and 5 and between 5 and 6 is reduced to about 5.5 and 2.5 miles (10.2 and 4.6 kilometers) respectively (Fig. 3). Materials and Methods An effort was made to obtain mohthly day and night trawl samples, monthly day and night nekton and plankton samples, and quarterly dredge samples from all established stations. Bad weather conditions sometimes hampered regular collecting procedure. The methods of collecting and the associated materials employed will be described separately under each phase of the collecting program . NEKTONIC AND BENTHIC FAUNAS 9 0 10 20 X s f-H 30 40 50 60 10 20 30 ^0 50 60 70 NAUTICAJ. MILES Fig. 3. Bottom profile along shelf transect, showing station location. The offshore sampling was conducted aboard the R/V Gulf Researcher, a 65- foot (19.8-meter) wooden Navy T. Boat which was equipped for oceanographic research in 1963. Information concerning individual sampling procedures and the physical data acquired was recorded on standardized field sheets on board the research vessel. Water samples were obtained from three depths (surface, midwater, and bottom) each time a station was occupied. Surface samples were taken in a bucket, while midwater, and bottom samples were taken with a Nansen bottle. Surface water temperatures were taken with a Celsius thermometer. The midwater and bottom temperatures w^ere taken by “fisheries-lype^’ reversing thermometers which were attached to the Nansen bottles. Salinities were at first determined with Gemware sea water hydrometers; however, after the program had been in progress for 10 months an American Optical Goldberg Refractometer was employed for the determination of salinities (refractive index x lO"* - then changing to parts per thousand [pptj by consulting a conversion table). This method was followed throughout the remainder of the program. Water samples were frozen on board for the purpose of chemical analysis later at the .shore laboratory. These samples were tested for the presence of nitrates, nitrites, ortho-phosphates and total phosphates. Secchi disc (300 mm 10 GULF RESEARCH REPORTS diameter, white) readings were taken during day samples. Results were recorded to the nearest foot. Wind direction and speed, sea-state and movement of the tide were all recorded. Processing of samples (measurements, weights, etc.) was carried out at the Gulf Coast Research Laboratory. All physical and trawl data were then transferred from field work sheets to GMEl formats. Hydrology There is now considerable hydrological information for the Gulf of Mexico. Galtsoff (1954) reviewed the history of systematic hydrographic studies. Important papers were first published about 1878. Lcipper (1954) reviewed the physical oceanography of the Gulf of Mexico. Collier (1968) presented extensive data from the Alaska cruises in the Gulf. Rivas (1968) gave monthly Gulf of Mexico mean surface isotherms and regional minima and maxima. Drennan showed surface circulation (1963) and sea surface temperature (1966) in the northern Gulf. Despite the long history and extent of oceanographic study in the Gulf of Mexico, information about the shelf water remains relatively sparse. This is particularly true of thx'? area considered in the present study. Temperature and salinity data were collected throughout this project. Some analyses were completed for determination of the micro-nutrient parameters studied in GMEI projects. Temperature Monthly means of surface, midwater and bottom temperature and salinity observations for each station (depth) are shown in Table 2. These averages represent day and night samples. Diurnal differences were usually minor but day and night samples were not necessarily taken on the same day; consequently, monthly averages are very close to sample determinations. Since data for all months are not available during calendar years 1967 and 1968, annual averages would not be comparable. Data are complete for the period June 1968 through May 1969, and monthly averages are shown for this period in Table 3. NEKTONIC AND BENTHIC FAUNAS 11 TABLE 2 MONTHLY MEAN TEMPERATURE AND SALINITY BY STATION (DEPTH) 1967 JAN FEB HAR APR f^AY JUU JUL AUO SEE OCT NOV QEC YEAR &UAf ACe 12. a IT. 2 IS-l 26. S 22.T 26.1 27.1 27.6 25.5 25.8 16.8 18,0 22.2 HIDAATeH 11.1 21.1 26.9 26.2 25.9 26.6 16*8 17.7 22.5 BOTTOM D.O 1A.2 13.1 21.1 22.1 21.1 26.2 25.1 26.1 20. B 17,0 17.5 20.8 SALIMIIV surface 10. T 26. 6 33.6 26,1 26. i 28.9 11.6 31.6 26.7 11.1 12.9 15.2 10.1 HICiMATeH 33.7 11. 1 12.2 32.1 21.9 12.8 11.6 31.9 51.8 dDTTON 11.2 12.1 31.7 11.9 12.7 29.8 33.0 35.9 31.0 11.3 12.6 11.9 12.6 Surface lA.S 1A.2 IS. 6 26.8 26.7 26.5 27.8 26.9 25.5 22.5 19.6 18.9 21.8 MIOWATER IS. 6 la.i 2S.6 25.7 25.7 28.7 21.8 19,6 18.2 22.7 BOTTOM IB.S 16. tt IS.B IB.l 22.7 25.1 21.7 25.1 28i9 20.2 19.5 IB.B 20.8 SAUINITV surface 31.6 16.0 31.9 za.s 3N*7 29.1 10.6 13.6 29.7 36,5 31.6 15.6 12.6 MJUWAIER 16.7 15.5 11.7 36.1 31.2 16.6 15.1 12.1 31.9 BOTTOH >4.0 36,0 3.0 IS. 2 33. B 32.5 28.0 36.7 16.5 36.6 31.7 MIOUATER 35.9 36«A 11.9 15.5 36*5 36.5 55.1 BOTTOM 16.9 36.0 16.1 37,3 35.1 16.7 16.8 36*7 36.8 36.1 SURFACE 18.9 16.9 20.7 22. C 28.8 28. T 27.6 22.6 26.7 MIOWATER 17,8 21.1 25.7 26.6 22.0 21.6 BOTTOM IB. 6 16.6 20.0 21.2 26.0 26.9 25.2 22.0 22.6 SALIMITY SURFACE 16.2 J3*6 il.r 33.8 12.7 11.5 13.8 36.8 13.5 MIOWATER 16.6 37.1 32.7 35.3 36.8 35.2 BOTTOM 36.9 3S.6 36.7 36.6 37.1 36 b 9 17.1 37.0 16.7 surface 20.2 26. 7 27.3 29.5 29.6 2*. 1 22.8 26.3 MIDUATER 20.3 26.1 28.1 21.6 20.0 26.1 nOTXQH 19.0 19.5 20.6 21.9 21.7 20.1 19.5 20.9 SALIMITY surface 12.7 16.0 36.0 27.6 3^bT 37.1 36.6 31.5 HtOWATER 37.5 10.7 15.6 37.2 36.7 16.1 bottom 36.2 36.6 35.7 16.9 37.0 37.6 3&*fel 36. b SURFACE 20.5 23.8 29.2 29.2 29.6 26.6 26.6 MIDUATER 20.6 18.1 26,2 26.1 21.6 bottom 20.0 19.7 19.6 19.7 25.0 22.6 20*9 SAL I9ITY SURFACE 11.9 16.2 12.5 29.2 16.1 17.3 11.7 MIDUATER 37.8 36,7 12.7 37.0 37,1 15.9 BOTTOM 17.8 16.3 35.3 16.9 36.9 37.0 16.5 1968 JAN FEtt HAK APR PAY JUN JUL AUO SEP QCT NOV DEC YEAR surface 12.3 11-5 15.9 21.2 25.5 29.9 10.3 2Q.0 26,5 21.7 17.2 16.0 20. V hiouatEr 12-6 11.7 15.6 25.0 25,0 31.0 29.7 29,0 26.0 22.7 17.3 16.2 20.8 BOTTOM 16.9 16.5 15.5 21.7 26. T 29.5 29.0 29.0 26.6 20.6 17.6 16.5 20.7 Salinity surface 26.2 28. q 25.9 IJ«1 11.0 26.0 1 7. f 22.6 27.6 36. S 36-1 32.0 29,1 MIDUATER 30.0 16.0 25.8 IT.B 34*3 27.8 24.0 22.6 30.7 L7.3 35.7 32.6 27,6 bottom 27.1 28.5 25.0 3Z.4 3b«7 28.8 26.9 29.2 26*6 16.2 16.1 16.3 31. 5 surface 13.9 16.6 22.6 25.1 29.5 2V,9 29.6 28.9 25. 1 19.5 16.2 22.7 MIOUATER 16.2 16.8 22.2 26.1 29.5 26.9 30.0 28.0 25.6 17,5 16.1 22.0 sorroH 16.0 17.1 20.2 20.6 26.0 27.0 29.0 27.6 26.9 22.2 16.1 21. H 5Ai INTT t Surface 29-2 2b. 0 18.6 2b«4 29,4 24.4 29.9 31.5 33.7 16.5 32.3 29,1 MIOUATER 26.2 21.6 26.2 27.3 21.6 25.2 29.9 12.6 33.7 36.5 13.2 29.1 BOTTOM 27.6 76.6 27.0 10.7 27.8 26.9 10-8 12.6 35.8 36.9 31*3 30.8 surface 15.7 U.S 20.9 26.2 29.6 ID. 6 30.6 26.2 27.0 19.0 16.8 22.8 MIOUATER 17.5 16.5 19.0 21.5 JO. 6 Jl.O 27.9 29.1 19.7 17.2 22.7 eOTlOH 18.5 17.0 U.S 22.0 25.0 27.1 29.0 28.0 27.1 ir.o 17. d 22.2 SALINITY surface 10.0 26.0 19.6 26-2 ir.7 29.0 21.6 34. 4 34. T 36.1 13.1 30.9 MIDUATER 16. B 26.6 2J.6 15.6 19. 8 16.0 26.9 35.7 35.6 36.5 15.1 11.5 BOTTOM 30.4 26.6 25.2 34.4 37,0 zv.a 29.9 11.6 37,3 37.6 36,6 12.9 12 GULF RESEARCH REPORTS TABLE 2 MONTHLY MEAN TEMPERATURE AND SALINITY BY STATION (DEPTH) 1968 (Cont’d) J*N FEB H*R *PR H*y JUN JOL *0C SEP OCT NOV CLC TEAR station a ‘-TENPERAIURE SURFACE 1A.3 17, A JC.l 32.0 28.8 29,0 27.6 27.6 21 .S 20.2 2A.2 mOWATER l/.T IT.B 23.0 ^R-A ‘D 26.0 26. A 18.1 20.5 22.5 bottom 15.2 17. « 21.0 27.0 20.1 21.0 21.0 22.3 20.0 21.6 20.9 SALINITY SURFACE 33.2 25,8 27.0 *6.6 29,0 2A.9 35.7 27.9 32.3 32.6 30.6 MIOWATER 25.0 27.0 27.2 »A-’ 27, A 30.7 35.7 29.2 37. A 3A.1 31.6 BOTTOM 33.0 3A.6 28.8 3T.9 2A.9 32. A 36.5 21.2 3A,A 32.5 32.0 STATION 5 TEMPERATURE--- SURFACE 18.0 25.3 28.5 29.9 JO. A 27.1 27.7 23.0 21.6 25.5 MIOUAIER 19.0 20.3 23.3 25.2 29.2 25.0 2a.7 21. A 21.6 23.2 bottom IB.O IT. 8 23.7 19.2 20. A 19,3 22,3 21-3 22.0 21,3 salinity SURFACE 28.6 27.5 36.0 IT. A 20.8 20.2 27. A 36.9 32.8 30,0 MIOWATER 25.6 29,6 37.2 23.2 23.2 JA.O 27.7 36.1 33.2 31.1 BOTTQH 3A.0 32.A 37.8 23.2 29.9 2A.9 29.0 36.5 36.5 32.6 STATIOm 6 lEMPERAfuRE- Surface is. 3 25.5 29. a so. a so.a ti.o 27.5 22.9 21.6 2A.e MIOWATER 15.6 25.0 25.3 25.3 29.8 23.0 22-8 73.6 21. A 22.7 BOTTOM IS. A 20.5 18.2 IT. 6 21.9 18.9 20.5 21.1 21.5 19.5 salinity surface 23.9 28.8 35.1 73.2 28.2 35.7 27.1 3T.A 3A.I 30.5 MIOWATER 21.2 25.5 36.1 21.6 35.7 12. A 27.0 37.8 35.6 30.6 bottom 3A.6 27.0 36. A 33.2 33.2 37. A 27.2 35.3 3A.e 33.1 1969 JAN FE8 mar APR MAY JUN JUL AOS SEP OCT NOV OEC YEAR STATION 1 TEMPERATURE SURFACE 12.9 lA.l 16.7 20.6 2A.2 MIOWATER II. B 13.7 15.7 20. A 22. A bottom 12, a 13.6 IA.7 20.2 21.0 SALINITY Surface 2T.9 2A.9 29, O 11.6 20.7 MIOWATER 32.6 29.8 10.2 31.1 21.1 BOTTOM 32.6 29. A 30.2 33.6 25.2 STATION 2 - — ■ — TEMPERATURE SURFACE TA.A 13.9 16.5 21.1 2A,0 MIOWATER lA.B 13.7 15. A 20.9 23.5 aOTIOM IA.2 13 . a 1A,9 19.5 20.3 salinity SURFACE 33.3 28. A 31.9 33.2 27.7 midwater 28,7 31.9 32.1 32.8 26.1 BOTTOM 31.3 31.6 33.6 35.3 33.2 station 3 TEMPERATURE SURFACE 16.7 15. A IT. I 21.3 26.5 MIOWATER 15.7 15.1 17.0 22.6 2A.7 BOTTOM 16.0 15.0 lo.A 17.6 19.1 SALINITY Surface 3a.9 20 . a sa.o 33 . t 27.0 MIOWATER 33.0 28.7 35.3 36,1 23.2 BOTTOM 33.6 30.0 3A.9 37.3 28.6 STATION A TEMPERATURE surface 15.2 15.6 IT. 2 21.7 25.9 MIOWATER 15.0 15.2 16.7 19. A 23.6 BOTTOM ]A.r 1A.6 16.6 19.0 20.3 SALINITY SURFACE 32.9 33.5 35.3 36.1 29.0 MIOWATER 3A.8 26.1 35.3 37. A 36.0 BOTTOM 33.9 20.2 36.1 37. A 30. T STATION S — TEMPERATURE SURFACE l6.A 16.3 17.2 22.1 26.0 MIOWATER IT. 5 15.7 17. T 20.6 22.3 eOTTOH l6.S 16.0 16.6 18.9 20. A SALINITY SURFACE 35.3 36.3 35.3 36.9 29.8 MIOWATER 36.0 38.0 35. 3 36.9 32.8 bottom >6,1 31.3 15.7 37. A 11,1 STATION 6 temperature SU8FACE 16, a 16. A is.l 22.0 26.6 MIOWATER 17.6 16.0 IT. 9 19.9 23.8 BOTTOM 16.9 16.3 16.9 17.9 19.3 SALINITY SURFACE 3a,a 33.3 35.3 36.9 31.2 MIOWATER 36.1 3A,1 36.1 36.9 35. T BOTTOM 36.5 3A.7 36.5 37.8 28.2 NEKTONIC AND BENTHIC FAUNAS 13 Average temperature decreased from surface to bottom at all stations (Table 3). The greatest differences occurred at Stations 1 and 6. Differences increased with depth from 10 to 50 fathoms. Surface temperature averaged 2.1° C higher at Station 6 than at Station 2, but Station 1, with the greatest estuarine influence, showed an average temperature 1.6° C higher than Station 2. Average bottom temperature showed a maximum difference of 2.4° C between Station 3 and Station 6. There was only 0.1° C difference in the average bottom temperature at Stations 1 and 6. Minimum temperature averages occurred in January at Stations 1 and 4 and in February at other stations (Table 3). The maximum average temperature (32° C) was found in June at Station 4. Maximum averages were found in July and August at other stations except for bottom observations at Station 5 where maxima occurred in August at the surface and in June at the bottom. Seasonal differences (Table 3) were highest (17.4°C surface and 17.1° C bottom) at Station 1 and decreased with increasing depth. Seasonal temperature variations at the bottom were less than they were at the surface. The temperature at subsurface levels was often higher than at the surface. Salinity In Table 4 monthly average salinities are shown for surface, mid water and bottom samples. These averages were determined by the same calculations used for temperature. Average salinities (Table 4) clearly indicate that water in the study area is mixed with estuarine water much of the time. The highest annual average (34.3 ppt) occurred at the bottom in 50 fathoms of water. During the study period, monthly average salinities ranged from 13,1 to 38.8 ppt (Table 4), a difference of 25.7 ppt. The maximum observation occurred at midwater (Station 3, June 1969). The lowest seasonal variation at any station was 10.3 ppt for bottom salinities at Station 2. At Station 1 the range of surface sjalinity was 23.4 ppt (Table 4). Minimum and maximum salinities, with one exception, did not occur in December, January and February at the surface or bottom. Apparently salinity in the study area was more stable in the colder months. Minimum salinity had a range of 11.8 ppt at the surface and decreased to 6.8 ppt at the bottom. The range of maximum salinities varied from 1.2 at the surface and bottom to 3.1 at midwater. The surface salinity range decreased from 23.4 ppt at Station 1 to 14.2 ppt 14 GULF RESEARCH REPORTS :2: o CO < w o t-H W o < > Eh iz; O S O :z: i 0.19 0.2«> 0.32 0.29 0<2O 0.2fl 0.2] NITAHI SuAFACt OtOO O.liO 0.00 0.00 O.CO 0.09 9.09 0.00 0.00 mIdnAICR 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 BOTTOM 0.00 0.00 O.OC O.OD Q.OO 0.00 O.OU 0.00 O.OO STATION 2 Ni TaaIE. — S9AFACC 0.32 0.24 0.2S 2.)4 1.12 U.2b 0*29 0.31 NlUWAffcA 0*41 0*23 0.26 O.tA Q.2d 0.29 0.2V 0.31 ttOirOM 1.7S 0.2V 0.24 0,44 0.26 O.tO 0.2h U.il NITRITE SUBAACE 0.00 0.00 0.00 0.00 0.00 0,00 0.00 0.00 HlOwATER 0.00 0.00 0.00 0*00 O.OO 0.00 0.00 O.vO OUTTtiH O.OO 0.00 0.00 0,00 0.00 t/.QU O.UO O.OU station 3 NITRATE- — - SURFACE 0.41 0.31 0.19 I i42 0.31 0. 10 0.31 N10NATER 2.44 0.)1 O.IS 2.S(» 0.31 O.ll O.fV BOTTOM 0.41 0.4] D.IO 2.JT 0.24 C,3l 0.2c NllAITf SURFACE 0.00 0*00 0.00 0.00 0.00 0.00 0.00 MIOnaTIR 0*00 0.00 0.00 0.00 C.OO CrOO Q.OO bottom O.CO O.OU 0.00 0.00 0.00 O.JO 0.00 STATION A NTTOATE* - SuNFaCC 0>B6 0.63 0.33 0.22 0,l3 2,24 O.SI 0.2S 0.29 MIONATEA 0.91 0.93 0.29 U.29 O.tS 2.24 0. 31 0.2B O./a BUTIOM O.W 0.84 0.21 Ct22 0.18 2.40 0. M 0.2tt 0.4.9 NllnlU Surface o.oo q.oo o.co o.oo o.oo o.oo o.oo o.oo o.vu HtOwATCR 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 BOTtOM 0,00 O.po O.oo 0.00 0,00 0.00 0.00 0,00 0.00 ST A HON > — - — — - .Si 7 A ATE ... Surface o.it 0,47 o.iv 0.29 0.33 ii.4(i 0.11 0,29 ci .29 KtOUATFR 0.1s 0,47 O.IH 0.29 0.2R 1.96 0.31 0.11 0.29 bOTIGn 0.17 0.43 0.14 0,>1 0.22 2.42 0.29 0,31 V.4^ NITRIIE SURFACI Q.OO 0,00 0.00 0.00 0,00 0.00 U.UU Cl, CO O.CO niOWAIER 0.00 0,00 0,00 0.00 0.00 0.00 Q,JO 0.00 u.£/0 bottom O.OCi 0,00 0.00 O.CO 0.00 0.00 o.no O.QO o.uo StATlOM 4 NITRAfl- - Surface o.4> o >21 0.24 2,4p 0.29 0,31 0.29 HIDWAfCA 0.»3 0.22 0.24 1,73 0.11 O.ll U.2V BOTTUM 0.B4 U,16 0.24 2.14 0.31 0.31 0.2V NiTftirs SliRTaCF a. O n A.nA 0.00 0.00 0.00 0.00 O.OO MiOwAISR 0.00 0,00 O.OU 0*00 0.00 O.OU U.uU BUMnn O.OO 0.00 0.00 0*00 A.ou 0.00 0.00 MONTHLY MEAN TOTAL PHOSPHATE AND ORTHOPHOSPHATE BY DEPTH MAY 1968 TO MAY 1969 Concentrations given as microgram atoms per liter (jUga/1) iuN 4UL AUC OCT r*Ov OCC JAN FEB ma« APk r.At SI AT ION 1 — — . —QRIMOAHOSAHAI SURFACE 1.03 0*44 L.LO 1,0S O.SO U*40 0.40 O.SO C.-aO mIOUATIR I.T7 0.<,4 l.ll 0.7S O.SO O.BC U.3U O.SO 0.«2 BOTTOM 1.06 0.44 1.21 0.50 0.50 O.iO 0.50 0.50 0.50 total R^'OSAmATC SURPACe l.ll 1.26 1,11 J.UO l.OU 1.25 2.00 2.50 2.50 MIOWAIEK 1.26 1.26 1.22 3.02 1,00 1*25 2,2!i 2.50 3.25 BOTTOM k.OV 1.26 1.33 1.03 1.00 1.2S 2,00 2.50 .',?5 station 2 ORIMDPMOSPkATL SuRFACC 0.44 1.04 l.W 0.50 0.30 0.>U U.VO 0.42 HIDhATAR 0.33 |.0& l.U 0.50 0.50 0.50 0.J7 0.62 BUnOM D,44 i.U 1,30 0.50 O.SO O.'iO 0.3r 0.5Q TOTAL PMOSPHATt SDRFACF U33 1,16 2.35 V.OO l.OO 1.5U 2. 7> 3.00 MIOhaTCR 1.17 k.io 2.15 1.00 l.QO 2.00 2, 75 BOTTOM l.OT 1.24 2,72 l.OU l.OO UTS 2.TS 2.50 MAI I UN 3 L‘RTHOPMUSP>«ATe i— — SuAFaCI O.ST I. it 0.50 0.50 0.50 0.62 0.b2 MIONATCR 0.74 1.29 0.50 rt.50 0.50 0*62 0.62 BOTTOM 0.17 1.13 0.42 0.50 0.50 0.62 O.-Xi TOTAL P'’OSPMATf SURFACE I.U 1.2r 2,00 1.00 2.0U I.OQ l.r.2 nIUMAIER 1,11 L.Jd U 75 UOQ 2.50 3.UU ;.LK1 eOTTOM I.U 1.46 I.T5 1.00 2.00 3.00 ? . SO station 4 — ORTMOPhOLPmaTE-* — SURFACE 0.V4 0.S2 l,4i 0.50 UOO 0.50 U,5U 0.->0 U.62 nIOVaTLR 0.9» 0.52 l.*>3 1,00 UOO 0.50 0.50 0*VO 0.50 BOTTOM 1.96 0*52 1.62 l.OO l.UO U.50 O.jO 0.50 U.5U total PhOSPMArt Surface uu l*C4 U4r 2.00 2.00 1.30 2. so 2. so 2.74 mIOMATEA 1,09 l,C4 1.59 2.00 2.00 1.5G 2,2> 1.00 2.75 BOTTOM 2.31 1.04 i.bl 2,00 2.00 l.OU 2,>U 2.50 J.UU 51 AT ION 5 j^PMA I E — Surface UB2 o.s; uu 0.75 0,50 0.50 0.;? 0.53 o.5u NlQyAUB L.B6 0,52 l.LT 0.50 0.5U 0.50 UOO O.nO 0.50 BOTTOM 1.93 0.52 1 . iH 0-50 0.50 U.>U 0.7^ 0.50 total ruCSPf'ATL 5URFACC 2.06 1,04 l.bA 2,50 3.00 1.00 3.00 ).0U ),UQ MIOUATER 2.01 1.09 Un 2.5U 2.UU l.OQ }.2> 1.00 2.75 BOTTOM 2,96 UIV I, BO 2.50 2.U0 1.00 3,00 ).00 2.75 station 4 DilTMDPMUSPMftf k SURFACE 0.V2 1.06 0.50 O.VO O.Tn 0.42 U.5U NlUMATeR 0.52 U13 0.50 0.50 0.75 0.62 0.5C BOTTUM 0,52 UlB 0.50 0.50 0,15 0.50 0,5C TOTAL PHOSPhATt SUrtFACt UlO 1.10 1.75 UOO 2 , 3,00 2. 75 HIOUATER 1.56 1,24 UTS U25 2.50 T.Uu 3.00 BOTTOM 1,56 1.24 1.75 UOO 2*75 l.OU l.OD NEKTONIC AND BENTHIC FAUNAS 17 Fig. 4. Nitrate concentrations expressed in microgram atoms per liter for six offshore stations (May 1968 through May 1969). Sedimentology Background; Sediments of the Mississippi and Louisiana coasts and in shallow offshore areas originally were derived from the Appalachian Mountains, the Rockies and the mid-continental U. S. Many of these sediments have undergone multiple cycles of erosion-deposition which cause the chemical and mechanictil destruction of most poorly-resistant mineral grains. Debris eroded from the Appalachian Mountains is usually distinctive because it has been reworked more often and residual grains are the most resistant of minerals, e.g., quartz, rutile, zircon, staurolite, etc. The Rockies, a much younger mountain complex, contributed 18 GULF RESEARCH REPORTS Fig. 5. Total phosphate concentrations expressed in microgram atoms per liter for six offshore stations (May 1968 through May 1969). sediments that show less destructive breakdown. Sediments from the mid-continent are a mixture of debris ranging in age from ancient Precambrian to Pleistocene and Holocene with a varied mineral content. The heavy mineral content, i.e., minerals more dense than quartz (SG=2.65), renders the Appalachian suite distinctive. Technique: Samples of the bottom were taken by a Poerst grab at quarterly intervals four times during the project. Qualitative and quantitative analyses were performed in the laboratory. Findings: The qualitative analysis was made by binocular microscope and NEKTONIC AND BENTHIC FAUNAS 19 shows the following; Station 1. Silty mud with shell debris; fecal pellets; much organic matter; and a few foraminiferal tests. Station 2. Sandy silt with some shell debris; many and varied foraminifer^ tests; much organic matter; and some mica. Station 3. Silty mud with little shell debris; much organic matter; many foraminiferal tests including pelagic forms; few echinoid spines; and some mica. Station 4. Muddy, fine, well rounded sand; much shell debris with some fragments of gravel size; little organic debris; many foraminiferal tests; few echinoid spines; and mineral grains are polished . Station 5. Variable bottom, at times a medium sand and at others a sandy mud; much shell debris; many and varied foraminiferal tests including pelagic forms; and few echinoid spines. Station 6. Sandy clay with much shell debris; many and varied foraminiferal tests; few fecal pellets; and a trace of mica. TABLE 6 MONTHLY TRANSPARENCY OBSERVATIONS AT OFFSHORE STATIONS Observations are secchi disc extinction points In feet Sta. May June July 1968 Aug. Sept. Oct . Nov. Dec . 1 28 9 10 10 25 12 18 2 39 39 12 20 15 25 22 25 3 61 54 24 48 17 16 4 90 4 80 64 43 95 51 5 110 115 118 56 70 99 81 6 98 124 112 130 71 65 Sta. Jan. 1969 Feb. Mar . Apr. May 1 12 12 18 9 2 37 25 21 21 14 3 57 22 22 24 51 4 84 61 32 23 50 5 74 87 24 61 64 6 98 20 30 51 59 20 GULF RESEARCH REPORTS Quantitative analysis was made by pipette and sieve. The results may be seen in Table 7 and Fig. 6. The size name of sediments is shown in Fig. 6. Some terms used in Table 7 are: 0 mean - average grain size in 0 units. M mean - average grain size in microns. sand mean - average size in microns of the sand particles only. o 0 - standard deviation in 0 units, which is a measure of sorting. The terms sand, silt, etc., are a designation of size only. These sizes are: gravel > 2mm diameter sand <2mm and > 62,5m diameter silt <62,5 and >3,9 diameter clay <3.9 Sediment composition: In offshore samples all the coarsest grains (<500 m) were bio-authigenic, i.e. recently formed in or near the northern Gulf by biotic processes. In the coarser sand samples (125-500/i) most of the grains had the same origin, either molluscan debris, small bryozoan colonies or foraminiferal tests. Allogenic mineral grains were small (<260 m) and consisted largely of quartz fragments, mica, and minute traces of heavy minerals. Size: Theoretical expectations place coarsest sediments at Station 1 with a decreasing size gradient to Station 6; in situ samples do not conform with the theory (see Fig. 7). Stations 1, 2 and 3, closest to the mainland, show the finest sediments. Station 4 showed a consistently high percentage of sand throughout the sampling period. Station 5 was most variable; the sand content ranging from 12% to 90%; Station 6, the most distant from land, contained particles similar in size to Stations 1, 2 and 3. The variations in grain size at the several stations may be attributed to Quaternary sea level changes, modified by recent depositional patterns. Continental glaciation, in the past, bound considerable quantities of water on land as ice, thereby lowering sea level. Estimates vary but maximum lowering may be conservatively estimated at 300-350 feet below today’s sea level. NEKTONIC AND BENTHIC FAUNAS 21 The presence of a sand body at Station 4 may indicate the presence of an ancient shoreline, covered so rapidly by rising water during the interglacial stage that the usual erosional processes did not destroy or disperse the sand body. Stations 1, 2 and 3 probably represent once emergent lands later covered by water and sediments brought in by rivers. In particular the Mississippi River appears to have contributed to this sediment cover; in the recent past (approximately 5000 yrs. B.C.) the Mississippi River flowed in an easterly direction, TABLE 7 SEDIMENT PROPERTIES OF OFFSHORE STATIONS Date % Sand % Silt % Clay Mean y Mean u Sand Mean a Sorting 7/31/68 61 11 Station 5.6 1 19.2 101 2 Very poor 11/20/68 44 26 30 5.6 19.2 100 2.6 Very poor 2/13/69 27.9 34.3 37.8 6.3 12.9 94 2.6 Very poor 5/15/69 19 43.8 37.2 6.45 11.5 91 2.5 Very poor 7/18/68 13 83 3 Station 5.6 2 20 95 1.56 Poor 11/13/68 13 60 27 5.98 16.7 98 2.24 Very poor 2/13/69 5.4 57.5 37.1 6.69 9.8 93 2.21 Very poor 5/15/69 12.9 54.4 32.7 6. 34 12.4 96 2.36 Very poor 7/30/68 18 78 4 Station 6.14 3 14.2 101 1.81 Poor 11/13/68 20 34 46 6.66 9 112 2.4 Very poor 2/26/69 16.9 29 54.1 7.19 6.9 102 2.56 Very poor 5/29/69 20.5 35.5 44 6,74 9.4 97 2.58 Very poor 7/25/68 85 12 3 Station 3.02 _4 123 204 1.93 Poor 11/21/68 78 8 13 3.68 79 177 2.52 Very poor 2/26/69 84.2 2.9 12.9 3.63 81 156 2.5 Very poor 5/29/69 83.2 3.2 13.6 3.26 104 226 2.66 Very poor 7/25/68 89.8 5 5 Station 2.49 5 178 267 1.92 Poor 11/21/68 12.9 30.1 57 7.2 6.1 109 2.1 Very poor 2/26/69 71.3 7.6 21.1 7.45 140 2.83 Very poor 5/28/69 55.4 11.8 32.8 5.36 24,4 138 3.07 Very poor 7/2A/68 16 77 7 Station 6.64 _6 10 129 1.88 Poor 11/21/68 21.9 26 56.5 7.12 7.2 134 2.7 Very poor 2/26/69 25 20.2 54.8 7.11 7.2 125 2.8 Very poor 5/29/69 20.2 18.6 61.2 7.52 5.5 125 2 . 66 Very poor NEKTONIC AND BENTHIC FAUNAS 23 _ 180 Fig. 7. Average grain size of bottoms of offshore stations. 24 GULF RESEARCH REPORTS building the St. Bernard delta complex. Today this complex is partially submergent, and its edge makes up the Chandeleur Islands. Downslope migration of mud and silt on the old delta front is filling the shallow offshore basin. The extreme variability of sediments at Station 5 may be explained in one of two ways. Either navigational errors prohibited repeated return to the same spot, or the samples were taken at nearly the same spot and bottom conditions vary because of the downslope migration of sand waves. The bottom at Station 6 was the most consistent. Foraminiferal populations followed expected trends with shallow-water forms found at Stations 1, 2 and 3, and deeper-water and pelagic forms found at 4, 5 and 6. At Stations 5 and 6 the presence of reef-dwelling foraminifera indicated presence of nearby reefs, and trawling produced dead corals and concretionary masses of mudstone. Many of the foraminiferal forms at these two stations seemed to be fossilized. Plankton Sampling A plankton sampling program was added early in 1968 and continued through May 1969. An effort was made to obtain monthly day and night plankton samples from all stations. Samples were collected from three depths (surface, midwater and bottom). Collections were made with nets measuring 50 cm across the mouth and the length reaching from the mouth (including canvas) to the bucket was 200 cm. Number 3 nylon netting (mesh of 0,33 mm) was used. The nets were fixed with underwater closing devices and were similar in design to that given by Hardy (1956), The net and associated closing device are shown in Fig, 8. A surface net with a long nylon rope attached was towed from the stern of the boat. A bathythermograph winch (Model No. 1216 - BTW, Tacoma Boatbuilding Company) was used in hauling operations of the midwater and bottom nets which were secured on the same cable. A 60-lb. lead weight was shackled to the end of the towing cable before the nets were attached. This was done in order to increase stabilization of cable and nets, as well as to decrease the cable angle from the winch boom when the boat was underway and nets were open and “fishing”. All nets were towed simultaneously at 600 rpm (approximately 2 knots) for a period of 20 min. In order to prevent a movement off cm Type of closing plankton net used in offshore sampling. 26 GULF -RESEARCH REPORTS station, a circular towing course was always maintained. The required cable angle was determined at the beginning of each tow period and the calculated amount of cable was let out (cable length = depth x cosecant of wire angle). Then, immediately after the wire angle became rather constant, the length of cable was adjusted (depth = sine of wire angle x cable angle) to maintain the wire angle that would keep the bottom net approximately one meter off the bottom. Occasionally heavy seas or swift tidal movements altered the cable angle and compensations in cable length were made accordingly. Closing of sub-surface nets was accomplished by using cable messengers (Fig. 8). When these nets were closed and were being hauled in the surface net was also brought aboard. Samples were labeled and preserved separately in 10% formalin. As was previously mentioned in the introduction, progress had been made in the processing of the backlog of plankton samples by the summer of 1969. \^en the investigators were informed of the approach of Hurricane Camille, the majority of plankton samples and all TABLE 8 NUMBER OF OFFSHORE PLANKTON SAMPLES EXAMINED Station Day Night Total 1: Surface 6 3 9 Mid-water 6 4 10 Bottom 5 4 9 2: Surface 9 1 10 3: Surface 3 4 7 4: Mid-water 4 - 4 Bottom 3 2 5 5: Surface 3 5 8 6: Surface 3 3 6 Bottom 3 _ 3 _ Totals 45 26 71 NEKTON IC AND BENTHIC FAUNAS 27 plankton data forms were moved from the ground floor of the “Big House” to the second floor. This structure had weathered numerous severe hurricanes in the past -and, for all practical purposes, the second floor of this building was considered to be safe storage area. Unfortunately, these samples and all data were destroyed during the storm. A small number of plankton samples (71) had been placed in another building which received little damage and when laboratory facilities were partially restored the samples were examined. These few samples had previously been worked for penaeid shrimp larvae (Subrahamanyam 1971) and samples were checked only for abundant plankters. All salvaged samples had been collected in 1968 (March through December, Table 8). Samples were allowed to settle and settled volumes were recorded. Entire samples were examined for commonly occurring forms and such forms were noted as being either few in occurrence, several or abundant. The relative abundance of the common plankters, the months of their occurrence, corresponding temperatures and salinities at time of collection and settled volumes of samples are presented in Table 9. Common Plankters Phytoplankton Phytoplankters were noted as abundant in four samples ranging from 5 to 40 fathoms. The majority were diatoms and on one occasion (Station 3 - October) a species of Chrysophyta was noted. Zooplankton COELENTERATA This phylum was represented only by members of the class Hydrozoa. HYDROZOA The only identified species of this class was Liriope tetraphyla. Siphonophores occurred at the 5-, 10-, 20-, 40- and 50-fathom stations and were taken with only one exception (50 fathoms: bottom - night sample) in surface hauls. Siphonophorans were coUected in several months (Table 9). 28 GULF RESEARCH REPORTS TABLE 9 SETTLED VOLUME, SALINITY, TEMPERATURE, AND RELATIVE ABUNDANCE OF COMMON PLANKTERS March to December 1968 (Nunbcre Indicate total in sooflc; F-fcv; S-aeveral; A-abundant; 0-not observed; D-day; K-nlght; S-surface; M-niduater; B-bottom) STATION 1. Day Night 1968 Mar Apr Hay Jun Jul Sep Oct Dec Hay Jul Nov Dec Settled Volume ml Surface 100 18 50 100 170 40 — 30 50 8 Hldvratei 100 40 100 100 — 40 50 — 150 40 8 Bottom 50 70 — 180 70 — 40 150 40 110 Salinity ppt Surface 25.8 13.1 31.6 26.0 15.7 — 36.5 — 34.3 19.9 — 33.2 Hldwater 25,8 17.8 31.6 27.8 — — 18.0 33,2 28.2 35 ./ 28.9 Bottom — 32.4 33,6 19.9 26.6 ~ 33.2 34.4 29.0 37 .4 33.2 Temperature C* Surface 15.9 23.2 26.0 29.9 30.4 — 23.5 25.0 30.3 — 13.9 Mldwacer 15.4 25.0 25.2 31.0 25.0 — 1 L4.1 — 29.4 18.6 14.4 Bottom — 21.7 24.0 29.5 26.4 ~ 14.5 20.3 26.4 19 .4 16.3 Mar Apr May Jun Jul Sep Oct Noy Dec D N D N DM D N D N D N D N D N D N SMB SMB SMB SMB S.MB SMB S.MB SMB S.MB S.MB SMB SMB SMB SMB SMB SMB SHB SMB PHOTOPLANK'TON 00- 000 000 0-0 00- 0-0 000 — 0 00- -OA -AO 000 COEIENTERATA SlphoDophora 00- 000 000 0-0 00- 0-0 000 — 0 -00 -00 SOO holLusca Gastropoda LAR 00- 000 000 4-0 00- 0-0 ooo — 0 00- -00 -00 000 ANNELIDA Polychata LAH 00- 000 004 0-0 00- 0-0 000 — 0 00- -FO -00 000 ARTHROPOD A Copepode AA- FAO AAA A-A AA- A-A AAA — A AA- -AA -AA AAA Stomatopoda 00- 000 000 4-0 00- 0-0 000 — 0 00- -00 -00 000 Stonatopode LAR 00- -AA 004 0-8 00- 0-0 040 — 0 00- -00 -00 000 CarJdea LAR 00- 000 000 0-0 00- 0-0 000 — 0 OS- -00 -00 OOO Lucifef fitKMi 00- 000 000 F-S AO- .’'-0 SSO — s FF- -00 -00 OOF Aaetea a. aarolinaeOO- OFO 000 F-O 00- 0-? OSS — 0 OS- -SS -SO FOO Anoaura LAR 00- S40 000 0-0 00- 0-0 OOF — 0 00- -00 -00 FOO Porcellanldae 00- OSO OAO O-F 00- 0-0 OOF — 0 00- -00 -00 000 Porcellanldae L.VR 00- 00 S 004 0-0 00- 0-0 000 «-0 00- -00 -00 OFO Porcell anldac ZOE 00- SOO 000 0-0 00- 0-0 000 — 0 00- -00 -00 000 Pagurlda* MEG OS- 000 000 0-4 00- 0-0 OSO — 0 00- -00 -00 ooo Braebyura ZOE 00- 00 S SSO S-S SF- 0-S SOA — 0 FA- -00 -AF SSF Brachyura MEG so- 000 FAF 3-0 80- 0-0 SOO “S QO- -00 -00 000 Ponilia aviiroatrio 00- FFO FOO S-0 00- 0-0 000 — F OA- -00 -FS 000 chaetocnatha So^itta spp. AA- FOO AAA S-0 AA- A-A AAO — s FF- -PO -AA OAO XUNICATA 00- 000 000 0-0 00- F-F 000 — 0 00- -00 -00 000 Oikoplura ap. 00- 000 SOO 0-0 00- 0-0 000 — 0 00- -00 -00 000 Doliotun sp. 00- FOO 000 0-0 00- 0-0 000 — 0 00- -00 -00 ooo CEPHALOCRORDATA 00- 000 000 0-0 00- 0-0 000 —0 00- -00 -00 010 CHORDATA Ostelcnthyea EGG 00- AOO 00 S 0-S 00- F-0 000 — 0 00- -00 -00 070 Ostelclithyes lAR 00- 500 OOS 0-0 00- 4-0 ooo — 0 00- -00 -00 OFS Clupelfoi-aea LAR 00- 040 000 0-0 00- 0-0 ooo — 0 00- -00 -00 800 Clupeldae LAR 00- 000 000 0-8 00- 0-0 ooo ~0 00- -00 -00 000 Angullltforaea LAR 50- 000 000 0-0 00- 0-0 out! — 0 00- -00 -00 800 Ferclformea LAR 00- 040 000 0-0 00- 0-0 OQA ~0 00- -00 -00 800 Botbldac LAR 00- 000 000 0-0 00- 0-0 OOS — 0 00- -00 -00 000 STATION 2. Day Night 1968 Mar Apr Hay Jun Jul Aug Sep Nov Dec July Volume Surface 140 40 300 50 400 21 3 3 18 40 Salinity Surface 26.0 27 .0 21.3 29.6 19.0 29.9 31.5 16.5 31.5 29.8 Temperature Surface 16.6 20 .2 24.8 29.5 29.8 29.6 28.9 20,6 16.2 30.1 Mar Apr Hay Juu Jul Aug Sep Nov Dec D N D N D N D N D N D N DM D N D N S S S S S S S S S S S S S S s s S S DOtLENTERArA lArippe tetraphylla 0 - 0 - 0 - 0 - 0 F 0 - Q - a - a ^ M)LLUSCA Gastropod LAR 0 - 0 - 0 - 0 - 0 F Q - Q - 0 - Q - P teropoda 0 - 0 - 0 - 0 - 0 F 0 - 0 - a - 0 - ARTHROPODA Copepoda A - A - A - A - A A A - A - A - r - Stomatopoda LAR 0 - F - 0 - 8 - 0 F 0 - F - 0 - 0 - NEKTONIC AND BENTHIC FAUNAS 29 TABLE 9 (Continued) Mar Apr May Jun Jill Aug Sep Mov Dec Luisifer 0 0 0 0 A - 0 0 0 0 '.farolinae 0 d F 0 0 S 0 F 0 0 Hrarhytira ZOE 0 s 0 F 0 S s 0 A 0 Btachyura MEG s s 0 F 0 A 0 F 0 0 F.0HINODEBMATA 0 0 0 0 0 - 0 0 0 0 Ophlurnliiea 0 0 0 0 1 - 0 0 0 0 CUAETiJGNAIMA 0 0 0 0 0 0 0 0 0 SaoitVi app- F A A A 0 A A A A A IWUCATA LAR 0 0 0 4 0 - 0 0 0 0 'Jikapl^ura ap . 0 0 F 0 0 0 0 0 0 CHORDAIA 0 0 0 0 0 - 0 0 0 0 OstolchthyeB ECO 0 0 0 0 0 - 0 0 0 0 »p- A 0 ■ 0 0 0 - 0 0 0 0 Percl formes LAR 0 0 0 0 0 - 0 0 0 0 STATION 3. Day Night J968 Mar Jul Sep Hay Jun Oct Dac Volume ml Surface 80 40 150 100 70 50 100 Salinity ppc Surface 24.0 29.0 35.7 24,2 37.7 34.7 33.2 Temperature Surface 16.5 30.4 28.5 24.2 29.4 27.1 17.3 Mar May Jun Jul Sep Oct Dec D N D N D N D N D N D N D H S S S S S S S S S S S S S S THALLOPHYTA iSirysophyCa 0 0 0 0 0 0 0 F 0 0 CXJELtNTEKATA SiphoRoptiura HlauSCA 0 A 0 0 0 0 s 0 0 A CaPtrupodu LAA s 0 0 0 F F 0 0 0 0 Pternpoda 0 0 0 0 F S 0 0 0 0 AATJELlDA Polychaeca LAR A 0 0 0 0 0 0 0 0 0 ARTHROPOD A Copepoda A 0 0 A A 0 0 0 A 0 Caridea LAR F 0 0 0 0 0 0 0 0 0 Luoifer fazoni AveWa flr 0 0 0 F A F 0 0 A 0 (2c2r'£;Ztrtae 0 0 0 0 0 0 0 0 0 A BracJiyurn ZOE 0 0 A F A 0 0 0 0 A Braehyura MEG 0 0 A F 0 S 0 0 A 0 CtlAETOGNATWA SiiQitia app. S 0 A S A 0 0 0 A A TUNICATA Peliolwi sp. 0 0 0 0 0 0 0 0 0 A CHORDATA OsCelchthyes EGG 0 0 S 0 0 F 0 0 0 0 Ostelchchyes LAR 0 0 4 0 0 0 0 0 0 0 Synodontidae LAR 0 0 S 0 0 (1 0 0 0 0 Balistldac LAR 0 0 - 0 0 1 0 0 0 0 STATION 4. Day Night 1968 Jun Jul Oct Nov Sep Oct Voliuae inl JUdwttter 100 50 — 50 — — Bettoa 31 4 — 40 60 6 Salinity .Midwater 36.7 27.4 28.9 37 .4 — — Bo Ltoin 37.9 24.9 — 31 .5 36.5 26,5 Temperature KldwaCer 26.4 25. 3 27.5 20 .3 — — Bottom 27.0 20-1 — 20 .9 21,0 21.7 Jun Jul Sep Oct Nov D N D N D N D N D S MB MB MB KB MB MB KB MB KB MB MOLLUSCA Gastropoda LAR 00 00 -0 0- -S OF Pceropoda 00 00 -A 0- -F 00 ARTHROPODA Copepoda AA AA -A 0- -F AA Stomacopoda LAR 00 00 -0 0- -0 OA £u£»i/Vr faxoni Acetes a. OS OF -0 0- -0 00 caroUme 00 OF -s 0- -F OA Porcellaiiidae ZOE 00 AO -0 0- -0 00 Brachyura zOE SS OS -s 0- -0 00 Brachyura LAR Feni Lia 00 00 -0 0- OS 00 aidrcs tris so 00 -0 0- -0 00 30 GULF RESEARCH REPORTS TABLE 9 (Continued) Jun Jul Sep Oct Nov CM>£TOCaiATHA Sagitta sp. AS AA -S 0- OF AA TUHICAIA Doliolun up. FO AS -0 0- -F 00 CUORMTA Oateichthyea EGG 00 00 -0 4- -F 00 Oateichchyea LAR 00 SO -0 0- -0 00 A)iiiuXlllfonui» LAS 00 00 -0 80 -0 00 Pareiforuea LAR 00 00 -0 4- -0 00 Cynovaian ap. 00 00 -0 3- -0 00 rhtjt.'iboidee LAR 00 00 -0 0- -0 00 TrtgUilae LAR 00 00 -0 4- “O 00 HecaroaoBAta LAR 00 00 -0 0- -0 00 Sothldae LAR 00 00 -0 3- -1 00 STAriW 5. Day Night 1968 Jun Aug Dec Mar Jul Sep Oct Dec VoluM al Surface 50 15 17 200 150 21 19 8 Sallivity ppt Surface 35.4 20.8 37.4 28.6 17,4 28.2 24.9 28.2 leopcracura Surface 29.1 30.4 21,6 18.0 29.9 27.1 27.7 21.7 Mar Jun Jul Aug Sep Oct Dec D N D H D K D N D N D N D N S S S S S 3 S S S S S S S S PmrOPLANKTOR 0 0 0 0 A 0 0 0 COELENTERATA Hydroaoa 0 0 0 0 0 0 0 0 Siphonophora F 0 0 0 0 0 A 0 MOauSCA Oaacropoda LAR 0 4 0 0 0 0 0 F Pteropoda F 0 0 S 0 1 S F ANNELIDA Polychata LAR F 0 0 F 0 0 0 0 AJtTRROPODA Cop«pOda A A A S A A A A Stromatopo^da lAR 0 0 F 0 0 0 0 0 tophlpoda 0 0 0 0 0 0 A 0 faxani 0 0 0 s s F 1 0 Acetea a. (XuvlinoB 0 0 S 0 s 0 0 0 Brachyura 20E F 4 0 0 0 0 0 S Bracdiyura MEG 0 0 S 0 0 F 0 0 CHAR70CNATHA 5^Sta spp. s A A A A F 0 A TUNICAIA Dclielt^ sp , 0 0 0 0 0 F A F CHORDATA Oateldithyes EGG 0 0 0 A 0 0 0 0 Osteichthyes LAR 0 0 4 0 0 0 0 0 Clupclfaimea LAR 0 0 A 0 0 0 0 0 AMofupa ftapeetue LAR 0 0 4 0 0 0 0 0 Aagullliformes LAR 0 0 0 0 8 0 0 0 Perct formes LAR 0 0 0 8 0 0 0 0 Sallacldae 0 0 0 0 8 0 0 0 STATIOS 6. Day Night 1963 Mar May Aug Mar Jun Dec Volume ml Surface 60 71 5 140 22 21 liottoo 20 4 30 — — Salinity Surface 24.4 28.8 28.2 23.4 36.1 36.5 Bottom 34.6 27-0 33.2 — — — Temperature Sur face 18.8 25.5 30.4 17.8 25.3 20.8 Bottom 15.6 20.5 21.9 — — Mar May Jun Aug Dec D N D N D N D N D S SB SB S SB 5 SB S SB S COELENTERATA SLphonophora AF S 00 0 FO 0 M0LLU3CA Pteropoda OF 0 00 0 OF 0 WNELIDA Polychaeta LAR FA 0 40 0 OS 0 NEKTONIC AND BENTHIC FAUNAS 31 TABLE 9 (Continued) Mar May Jun Aug Dec ARTHROPODA Copepoda AA A AA S AA S Stoma capoda LAR 00 0 OA 0 SO 0 Amphipoda 00 0 00 0 02 0 Isopoda 00 0 00 0 00 1 liuaiiyer faxoni 00 F 00 s FO s Aaetes a. (XLt'olinati 00 0 00 s 00 s Brachyura Z0£ 00 0 FO 0 OF 0 Brachyura HEC 00 F 05 0 00 0 Penitia avix>o&txn.9 00 F OF 0 OF 0 CHAETOGNAIHA CagiUa spp. FF A AA A AA A TUNICATA Voliolm sp. 00 0 FO 0 OA 0 (HORDATA Oatetchthyea HOG 00 0 OO 0 00 0 Oatltlchthyea LAR OA 0 00 4 00 0 Clupeiformea LAR 00 0 03 0 00 0 Carane ohrysoe 00 0 00 1 00 0 TrlgUdae LAR 00 F 00 0 00 0 MOLLUSCA GASTROPODA Pteropods occurred at all stations except Station 1 (Table 9), Only pteropods of the order Thecosomata were collected. Temperatures and salinities ranged from 15.6® to 30.4® C and from 17.4 to 37.4 ppt respectively. Pteropods were taken only in surface and bottom samples. Unidentified gastropod larvae appeared often at most stations but never in abundance. ANNELIDA The only representatives of the phylum were polychaete larvae which appeared at temperatures ranging from 14.4° to 30.4° C and salinities from 20.8 to 35.7 ppt. Larvae were collected from all three levels of sampling (surface, midwater and bottom). ARTHROPODA The Crustacea was the only group of arthropods found in samples. Crustaceans were found to be the major components of plankton samples in both abundance and species diversification. The majority of specimens were identified only to higher taxa. COPEPODA Copepods were the major zooplankters in practically all samples examined, always being present in large numbers. Identifications were made only to the taxon Copepoda. Temperatures and salinities of collections in which copepods appeared ranged from 14.1® to 33.6® C 32 GULF RESEARCH REPORTS and from 13.1 to 37.9 ppt. Acosta (1970) studied the abundance, distribution and seasonal variation of copepods collected at our stations and the effects of salinity and temperature on selected species. Amphipoda Four small specimens appeared in a Station 5 surface (day) tow in December. The temperature and salinity were 21.6° C and 37.4 ppt. Two specimens were taken in an August tow (bottom -day) from 50 fathoms. The temperature was 21.9° C, and the salinity was 33.2 ppt. ISOPODA A single specimen was noted in a December surface sample taken at night at Station 6. The temperature and salinity were 20.8° C and 36.5 ppt respectively. Stomatopoda Stomatopod larvae occurred in many samples at all stations and from all sampling levels (Table 9). Larvae were taken at temperatures and salinities from 17.0° to 30.4° C and from 17.4 to 34.4 ppt respectively. Caridea Caridean shrimp larvae were noted in two samples; one from Station 1 (mid water-day) and the other from Station 3 (surface-day). The Station 1 specimens were taken in October at a temperature of 25.0° C and a salinity of 18.0 ppt. The Station 3 larvae were collected at a temperature of 16.5° C and a salinity of 24.0 ppt during the month of March. Sergestidae Two sergestid shrimp, Lucifer faxoni and Acetes americanus carolinae, occurred together occasionally in the same samples. Lucifer was present in greater abundance than was Acetes and appeared at all three vertical sampling levels. Lucifer faxoni was taken at temperatures and salinities ranging from 14.5° to 30.4° C and 15.7 to 37.9 ppt respectively, Hopkins (1966) and Kelly and Dragovich (1968) noted that L, faxoni was more abundant at temperatures between 25.0° and 34.9° C in Florida. The majority of specimens observed in this study occurred from 28.0° to 30.4°C. Woodmansee (1966) reported on the vertical migration of Lucifer off Mississippi in relation to the solar and tidal cycles. Acetes was taken at temperatures ranging from 13.9° to NEKTONIC AND BENTHIC FAUNAS 33 30.1° C and salinities from 21,3 to 37.4 ppt and appeared in samples obtained from all three sampling levels. Anomura Porcellanid larvae were taken seasonally from the three vertical levels and at the majority of stations (Table 9). These larvae were found in greatest abundance at the midwater and bottom depths. Tem- peratures and salinities ranged from 14.4° to 26.4° C and from 17.8 to 34.4 ppt respectively. Pagurid megalops (four specimens) were encountered at 5 fathoms in a May sample (bottom-night). The temperature was 20.3° C, and the salinity was 34.4 ppt. Other unidentified larvae were assigned to the taxon Anomura. BRACHYURA Brachyurans encountered were identified only to the taxon - Brachyura. Zoea and megalops were taken in the majority of samples and were considered to be abundant plankters in the examined samples. Zoea and megalops were found together on numerous occasions: isolated occurences of both were noted (Table 9)* Brachyuran zoea and megalops were taken at temperatures and salinities of 13.9° to 31.0°C and 17.4 to 37.9 ppt and were found at the surface^ midwater and bottom sampling levels. Clodocera Penilia avirostris appeared in samples from 5, 30 and 50 fathoms and occurred at all sampling levels. Bigelow and Sears (1939) noted Penilia about 60 km off the New Jersey coast, and Marukawa (1921) found the species offshore east of Japan (230 to 310 km). These apparently constitute the greatest offshore distances recorded. Lock- head (1954) discussed the distribution of P. avirostris and noted its occurrence in larger numbers in coastal waters. Penilia avirostris is the only marine representative of the cladoceran tribe, Ctenopoda, and Lockhead (1954) discussed various life history aspects of the species. Penilia has usually been reported from salinities higher than 32.0 ppt. A record from fresh water (Kramer 1895) is of notable interest. Penilia occurred in our samples at temperatures and salinities from 17.8° to 27.0°C and from 21.9 to 36.7 ppt. The majority of specimens were from salinities higher than 33.4 ppt. 34 GULF RESEARCH REPORTS ECHINODERMATA OPHIUROIDEA A single larval form was obtained in a July sample (Station 2, surface-day). The salinity was 19.0 ppt and the temperature was 29.8° C. CHAETOGNATHA Chaetognaths were second to copepods in general abundance. Unidentified species of Sagitta were noted and recorded. Sagitta was found in the majority of samples examined, and appeared at all levels. Temperatures were from 13.3° to 30.4° C and salinities ranged from 18.0 to 37.7 ppt. UROCHORDATA Doliolum was noted in numerous samples from 5 and 20 to 50 fathoms. Species identification was not made. Doliolum was found in various samples from all levels of collecting. Temperatures and salinities were 17.3° to 27.7° C and 13.1 to 37.4 ppt. The other tunicate collected, Oikopleura^ was not as abundant as Doliolum and occurred in only two of the examined samples (Station 1, surface-day; Station 2, surface-day). The Station 1 sample was taken in May, and the temperature and salinity were 26.0°C and 31.6 ppt. The specimens from 10 fathoms were collected also in May at a temperature of 24.8° C and a salinity of 21.3 ppt. CEPHALOCHORDATA In a midwater sample (night) in December at a temperature and salinity of 14.4° C and 29.9 ppt one cephalochordate was collected. The entire sample was examined, but only one specimen was found. This is an interesting record in the offshore plankton. CHORDATA OSTEICHTHYES Larval fishes and fish eggs were found at all stations (5 to 50 fathoms). Identification of larvae has been carried out to the specific level when possible; however, the majority of larvae have been placed in higher taxa. NEKTONIC AND BENTHIC FAUNAS 35 OSTEICHTHYES eggs The majority of eggs were found in samples taken from May through October, with some eggs being taken in December. OSTEICHTHYES larvae Numerous larvae were identified only to class level. Larvae were quite abundant in several samples (Table 9). CLUPEIFORMES Several clupeiform larvae appeared at Stations 1, 5 and 6 and were taken from the three levels of sampling (surface, mid water and bottom) at these stations. Clupeidae Clupeid larvae were encountered only in one of the examined samples (May, bottom-night). The temperature and salinity were 20.3'’ C and 34.4 ppt. ENGRAULIDAE Anchoa hepsetus (Linnaeus) appeared in one sample (40 fathoms, surface-night). The temperature was 29.9*^ C and the salinity was 17.3 ppt. Gunter (1945) noted a spring spawning season in Texas for A. hepsetus. Anchoa sp. Anchovy larvae were taken from Station 2 in March and July. March temperature and salinity were 16.6® C and 26.0 ppt. The temperature and salinity during the July period were 30.1® C and 29.8 ppt. anguilliformes Leptocephalus larvae were found in samples from the 5-, 30- and 40-fathom stations. Temperatures and salinities ranged from 13.9® to 27.5® C and 25.8 to 33.2 ppt. These were presumed to be Anguilliformes but they were not critically examined. Myctophiformes SYNODONTIDAE Myctophiform larvae appeared in a surface (night) tow at Station 3 during May. The temperature was 24 .2° C and the salinity was 24.2 ppt. These specimens were classified only as far as family. 36 GULF RESEARCH REPORTS PERCIFORMES A number of larvae were not classified further than the major taxon - Perciformes. These larvae appeared in samples from Stations 1, 2, 4 and 5 (Table 9). Carangidae A single young specimen of Caranx crysos (Mitch ill) occurred in a June sample (Station 6, surface-night). The temperature was 17.8°C and the salinity was 23.4 ppt. SCIAENIDAE Cynoscion sp. Small larvae (three specimens) of Cynoscion appeared in mid water (day tow) in October from Station 4 (Table 9). The temperature was 27. 5° C and the salinity was 28.9 ppt. Seatrout (local species) probably spawn from spring through fall seasons (Pearson 1929, Gunter 1938a and 1945). Identification was carried only to the generic level on these small individuals. Micropogon undulatus (Linnaeus) A small number of M. undulatus larvae were taken in December at a temperature of 13.9''C and a salinity of 33.2 ppt. The sample was a surface (night) tow from Station 1 (Table 9). Pearson (1929) noted a spawning season from October to February in Texas for M. undulatus. Roithmayr (1965) suggested a spawning period from September to November in the northern Gulf. SPARIDAE A single larval specimen of Lagodon rhomboides was found in an October bottom (night) sample from 30 fathoms. Spawning in the Gulf from fall through winter has been suggested by several workers. Among these are Gunter (1945), Caldwell (1957), Springer and Woodburn (1960) and Cameron (1969). Spawning L. rhomboides were en- countered in March during this study, and this is discussed in the trawl species account. The present occurrence of a larval form in October would indicate aii early fall spawning of this individual. The tem- perature and salinity at the time of capture were 21.0^ C and 36.5 ppt respectively (Table 9). Larvae were abundant in some GMEI samples during the winter and early spring. NEKTONIC AND BENTHIC FAUNAS 37 TRIGLIDAE Triglid larvae (four specimens) were encountered only in an October sample at a temperature and salinity of 27.5° C and 28.9 ppt. The sample was a mid water tow (day) from Station 4. Bothidae Flounder larvae were found in July and October samples from Stations 1 (twelve specimens) and 4 (three specimens), respectively, at temperatures ranging from 21.7° to 26.4° C and salinities from 26.5 to 29.0 ppt (Table 9). Balistidae Larvae of this family appeared only in two September samples. At Station 3 a surface (day) sample (one specimen) was taken at a temperature of 28.5° C and a salinity of 35.7 ppt. The other sample, a surface (night) tow at Station 5 (eight specimens) was made at a temperature of 27.1° C and a salinity of 28.2 ppt (Table 9). Dredge Sampling After 10 months of offshore sampling had been completed a dredging operation was added to the collection program in order to gain information concerning the infauna at the established stations. The first dredge hauls were made on 11 November 1967 and efforts were made to continue on a quarterly basis at all stations until the termination of the sampling period in May 1969. Two vessels, the Oregon I and the Silver Bay (Bureau of Commercial Fisheries) have made only a limited number of dredge hauls in the area investigated during the offshore survey. The literature shows that information concerning dredging in Mississippi offshore waters is practically non-existent. The dredge employed was a Peterson Biological Dredge. The dredge consisted of a nylon catch bag (mesh, 1 inch stretched) attached to a metal frame. The catch bag was covered by a sleeve of canvas to protect the webbing. The dredge weighed approximately 25 lbs. and measured 42 inches in length and 24 inches in width across the mouth. During periods of dredging the engine speed was maintained at 800 rpm, (approximately 2 knots) for a period of 20 minutes. This speed appeared to be the most practical for the biological dredge. 38 GULF RESEARCH REPORTS After bringing the dredge aboard, the catch was carefully sorted and preserved for shore identification. All samples were labeled as to station and sample number. In terms of both species diversification and abundance the infauna was quite sparse. The catches were primarily composed of species which do not burrow. This dredge apparently did not dig into the bottom very much, A total of forty-three hauls were made. Only twenty-seven of these contained specimens. Those hauls devoid of living specimens were usually composed of mud, sand and shell fragments. Twelve in- vertebrate and three vertebrate species were collected. Table 10 presents all collected species with the respective dates of capture, station, number taken, temperature and salinity. Species Account 1. Renilla mulleri was the most abundant species encountered in dredge samples. It occurred only at Stations 1 and 2 (a trawl record from Station 6 is discussed in the trawl species account) and appeared on twelve occasions (Table 10). Renilla was present during all seasons and was taken at temperatures and salinities ranging from 14.1° to 29.5°C and 24.9 to 36.5 ppt. Gunter (1950) found this species at temperatures ranging from 13.7° to 28.3° C and salinities ranging from 26.7 to 36.7 ppt. He indicated that these soft corals extended out to a depth of only 15 fathoms, which corresponds to the findings here. 2. Three species of polychaetes, Branchioasychis americanus, Clymenella torquata and Dlopatra cuprea, were collected. Branchioasychis arnericanus was the most abundant of these. Polychaetes appeared only in February and September from 5 to 20 fathoms (Table 10). Bottom temperatures and salinities ranged from 14.5° to 26,4°C and from 26.6 to 28.5 ppt. 3. One mollusk, Pecten papyraceuSy was taken in June from 60 fathoms at a temperature of 18.2° C and a salinity of 36.4 ppt. 4. The mantis shrimp, Squilla empusa appeared on three occasions, twice at Station 1 and once at Station 2. Twelve specimens w'ere taken at a mean temperature and salinity of 22.5° C and 34.0 ppt. Another Stomatopod, Squilla chydaea, was collected from 50 fathoms in June at a temperature and salinity of 18.2° C and 36.4 ppt respectively. 5. Callinectes similis (eighteen specimens) was taken in all seasons at a mean temperature of 23.7° C and a mean s^inity of 32.4 ppt. In addition to C. similis four other decapod crustaceans (Portunus NEKTONIC AND BENTHIC FAUNAS 39 TABLE 10 TOTAL DREDGE CATCH FROM SIX OFFSHORE STATIONS Species Date Sta- tion Salinity ppt Temp, “C No. Caught Anthozoa Renitla mulleri Nov 1967 2 35.4 19.5 18 Jan 1968 1 28.5 14.8 34 Feb 1968 1 28.5 14,5 50 Apr 1968 1 32.4 21,7 50 Jun 1966 1 28.8 29.5 100 Jul 1968 1 34.0 28.5 25 Aug 1968 1 28,2 29.0 54 Nev 1958 1 36.5 16.4 68 Huv 1968 2 26.5 14.6 68 Jan 1969 1 32.1 14.1 100 Apr 1969 1 34.9 19.5 85 May 1969 1 24.9 22.0 300 Mean. . . . . .. 31,7 .. . ... 21.2 TOTAL 884 Polychaeta Bracnffhioaaijchia ameriocxnus Feb 1968 1 28.5 14.5 12 Sep 1968 3 26.6 26.4 1 Mean. . . . ... 27.6 ... ... 20.5 TOTAL 13 Clijmenella borquata Feb 1968 1 28.5 14.5 8 D-iovatra auprsa Feb 1968 1 28.5 14.5 5 Pelecypods Peaten papyraasus Jun 1968 6 36.4 18.2 1 Crustacea Stomatopoda Squilla ahydaea Jun 1968 6 36.4 18.2 1 SquzlZa empuaa Nov 1967 2 35.4 19.5 6 Jul 1968 1 34.0 28,5 3 Aug 1968 1 34.9 19.5 3 Mean. . . . ... "34.0 ... ... 22.5 TOTAL 12 Decapoda Callinectea aimilis Nov 1967 2 1 Jan 1968 4 3.1,5 20.9 2 Apr 1968 1 32.4 21.7 1 Jul 1968 2 27.7 24,9 1 Jul 1968 1 34.0 28.5 3 Aug 1968 1 29.0 28.2 3 Sep 1968 3 35.7 28.0 3 Nov 1968 4 37.4 18.2 1 Apr 1969 4 36. A 18.2 3 Mean. . . . ... 32.4 ... ... 23.7 TOTAL 18 Por'tt4nu0 gibbeai Mar I960 6 34.6 15.6 3 Portunuo ap. Nov 1968 2 36,5 25.2 L Pagurus op. Sep 1968 3 35.7 28.0 1 Siagonia bvevirostris Nov 1960 5 38.2 21.6 3 Jan 1969 5 34.9 16.1 1 Feb 1969 5 33,5 16.9 1 Mean. . . . 35.5 ... ... 18.2 TOTAL 5 Ostelchthyes Serranidae Centropr'iatea oayurus Jun 1968 6 34,6 16.6 1 Feb 1968 6 36.4 18.2 2 Mean. . . . . . . 35.5 . , . ... 17.4 TOTAL 3 Bothldae Ci bhariahthya api toptems Jun 1968 5 38.7 26.5 4 Jun 1968 6 36.4 18.2 1 Jul 1968 2 24.9 27.7 1 Apr 1969 5 37.4 19.5 1 Mean. . . . ... 34.4 ... . . . 23.0. TOTAL 7 Eti'opue crooootua Jan 1968 4 33.0 13.2 1 40 GULF RESEARCH REPORTS gibbesi, Sicyonia brevirostris^ and unidentified specimens of Portunus and Pagurus) were collected (Table 10). Sicyonia brevirostris was taken from 40 fathoms, Portunus gibbesi from 50 fathoms, and the unidentified specimens of Portunus and Pagurus were from 10 and 20 fathoms respectively. 6. Two species of flatfish, Citharichthys spilopterus and Etropus crossotus, and three specimens of the sea bass, Centropristes ocyurus, were the only fishes represented in dredge hauls. Citharichthys spilopterus (seven specimens), was taken at 10, 40 and 50 fathoms. The temperatures ranged from 18.2° to 27.7° C, and the salinities ranged from 24.9 to 38.7 ppt. Etropus crossotus occurred only once (one specimen) at a temperature and salinity of 15.2° C and 33.0 ppt respectively. This fish was taken from 30 fathoms. Centropristes ocyurus was taken in June and February and only at 50 fathoms. The mean temperature was 17.4° C, and the mean salinity was 35.5 ppt. Nekton Sampling An investigation of the free-swimming marine animals which could be categorized as nekton was considered pertinent. In view of this, a nekton sampling program was established. Collections of surface nekton began at the onset of the project. Sampling of benthic nekton was added in December 1967. Surface and benthic sampling were both accomplished using the same net. The net consisted of a stainless steel hoop one meter in diameter, with netting (1 1/2 inches stretched) attached to the hoop and trailing for a distance of 5 feet. The last 2 feet of the net near the cod end were made of fine mesh netting (1/8 inch stretched) to retain extremely small specimens. The net was attached to a winch cable and towed on both occasions (surface and benthic) at an engine speed of 1,000 rpm (4 knots) for a period of 30 min. By knowing the towing cable angle and the depth of the water, the benthic nets were calculated to be “working” just above the bottom at the respective stations. Specimens were removed from the net and preserved for later identification. Each sample was labeled according to station and sample number. An effort was made to obtain monthly day and night collections of surface and benthic nekton from all stations. A total of 245 surface and 152 benthic hauls were made. Haul information is presented in Table 11. A total of 2,478 specimens representing thirty-one species from nekton hauls were included in the final report on this project for the NEKTONIC AND BENTHIC FAUNAS 41 TABLE 11 a. SURFACE NEKTON HAULS Station Time Number of Hauls 1967 1968 1969 1 Day ! 12 13 6 Night 7 6 4 Total 19 19 10 2 Day 11 12 5 Night 9_ 5 3 Total 20 17 10 3 Day 9 8 5 Night 8 8 5 Total. . . . . i 17 16 10 A Day 8 6 5 Night 5 7 5 Total 13 13 10 5 ! Day 7 6 5 Night 6 7 5 Total 13 13 10 6 Day 6 6 5 Night 6 7 5 Total 12 13 10 Total Day Hauls 135 Total Night hauls 110 245 b, BENTHIC NEKTON HAULS Station Time j Number of Hauls 1967 1968 1969 1 Day 1 13 6 Night 0 6 4 Total 1 19 10 2 Day - 12 5 Night 5 5 Total - 17 10 3 Day - 8 5 Night 8 5 Total - 16 10 4 Day - 6 5 1 Night - 7 5 Total - 13 10 5 Day - 6 5 Night - 7 5 Total “ 13 10 6 Day - 6 5 Night - 7 5 Total ..... - 13 10 Total Day Hauls 83 Total Night Hauls 69 152 42 GULF RESEARCH REPORTS period ending 30 June 1968. A number of larval and postlarval specimens had been backlogged for identification at this time. All offshore nekton (surface and benthic) work, as well as the laboratory in which the data were filed, was destroyed during Hurricane Camille. It should be noted, however, that familiarity with the records gained from their processing previous to the hurricane (arrangement of species by stations, depth, time and month) in preparation for analyses of species catch data, as well as field observations, make possible a legitimate listing only of species which were commonly encountered and appeared to be in abundance. These species are presented in Table 12 . Trawl Sampling Trawl samples were obtained with a balloon (otter) trawl measuring 40 feet in length and 4 feet from the cork line to the lead line. The netting was 17/8 in. stretched. Trawl boards measured 7 feet (length) by 4 feet (height). The trawl was worked through rigging on the forward starboard side, and a forward deck winch (Hydrographic Trawl Winch, Model No. 1216-HTW, Tacoma Boatbuilding Company) was employed in this operation. Each trawling operation lasted for a period of 30 minutes (from the time the trawl winch was locked to prevent any further payout of cable until the commencement of “hauling-in’*). Usually the SO-minute trawling time allowed for two, occasionally three, circular passes at the station area. The boat speed was maintained at 1,100 rpm (approx- imately 3 knots). At the end of the 30-minute period the catch was hauled aboard and all captured specimens were taken from the net and sorted on the forward deck. Upon examination of the catch, if a species was represented by more than 100 specimens, selected members of this group totaling 100 were kept for shore laboratory work, and the remaining individuals were counted on board the vessel and usually discarded. If the total specimens of a particular species numbered 100 or less, all of these were retained. The majority of each catch was preserved in a separate barrel or plastic bags in 10.0% formalin and labeled with station and sample number. Barrels were lashed to the deck to prevent overturning during rough seas. Delicate invertebrates were preserved in individual bottles, and commercially important invertebrates were generally frozen. After specimens had been properly sorted, the deck was thoroughly washed in order to prevent con- tamination of the next sample with specimens of the previous catch. NEKTONIC AND BENTHIC FAUNAS 43 TABLE 12 SPECIES MOST COMMONLY ENCOUNTERED IN NEKTON HAULS Decapoda Sergescidae A.aetes a/mricanus carolinae Lufiifer faxoni Portun Idae Calliyieotes sapidus Cailin&ates similes PortunuQ gihheaii Port/unus sayi Ova apes ocellatua Osteicththyes Engraulidae Anchoa hepsetus Exocoetidae Gadidae Urophyaia megius Syngnathidae Syngnathue floridae Syngnathus saovelli Osteichthyes (continued) Mullidae htullus a'uratus Stromateidae Pepvilus hurti Fowler Mugilidae Mug-il aephalus Atherinidae f4em dia beryl It na Balistidae Alutera sovipta Tetradontidae SpJiaeroidee parvus Leptocephali - Abundant Laboratory Work on Samples At the termination of a cruise all samples were taken off the boat and transported to the laboratory. Each trawl sample was treated separately. Individual species were sorted and then measurements and weights were recorded on a standard work sheet. A measuring board marked in millimeters was used, and both standard and total lengths of fishes were recorded. Total length measurements are presented in species accounts with a few exceptions for badly damaged specimens. Measurements on certain invertebrates were not made. The majority of specimens were weighed and weights are presented in either grams or kilograms (large catches). Large specimens were weighed on Howe heavy-weight scales; however, most weights were recorded from a Precision Mettler Balance to the nearest tenth of a gram. For those species which were not taken in large numbers (100 or fewer per sample) an accurate total weight is presented. When a species appeared in large numbers per haul (100 or more), as was previously mentioned, only 100 representative specimens 44 GULF RESEARCH REPORTS were chosen, and the others were only counted. This method appeared to be practical since sizing every individual would have been quite time consuming. For those species taken in great abundance, an estimated total mass has been calculated using the formula: total number caught estimated total mass = X mass of weighed individuals. number weighed Data for the following accounts were taken from detailed tables computed by EDP. A reference collection was made during the study period. After a sample had been processed the majority of specimens were discarded. Reference material which had not been accessioned to the Gulf Coast Research Laboratory Museum was destroyed by hurricane Camille. Comparisons of data from this survey with that of the Mississippi GMEI (Cooperative Gulf of Mexico Estuarine Inventory and Study) program were made and have been noted in the species account. Systematic Account - Invertebrates A total of 50 species (24,666 specimens) representing 40 genera and 27 families was collected. A phylogentically arranged account is presented. COELENTERATA SCYPHOZOA ULMARIDAE Aurellia aurita Lamarck Two hundred fifty large A. aurita were taken in one trawl haul at 10 fathoms in September. The temperature was 28.9° C and the salinity was 33.4 ppt. This species was occasionally observed in large numbers at the surface in the study area, but they were not seen at the surface when caught in the trawl. Aurellia aurita was not found in the GMEI samples and apparently is limited to high salinity water. These findings differ considerably from those of Gunter (1950) who took specimens in the back bays at salinities as low as 16.0 ppt. NEKTONIC AND BENTHIC FAUNAS 45 ANTHOZOA Renillidae Renilla millleri Kolliker - Sea Pansy There were 16,808 sea pansies taken at temperatures between 10.8° and 29.5° C and salinities between 24.9 and 39.8 ppt. Sea pansies were taken all year at GMEI stations in and near the passes into Mississippi Sound. Gunter (1950) stated that there are no indications of any abundant populations beyond 15 fathoms. The majority of our samples showed major concentrations at 5 and 10 fathoms, with a small number taken in 1968 at 50 fathoms. Hormathiidae Calliactis polypus - Anemone Forty-nine individuals were caught at temperatures and salinities between 16.5° and 26.4° C and 23.2 and 34.9 ppt respectively. The depth was between 5 and 20 fathoms. Calliactis polypus, associated with hermit crabs, is common in Mississippi Sound neeir the barrier islands. Actinidae Bunodactis sp. A single unidentified specimen was taken in September at 50 fathoms in 1968. The temperature was 18.9° C and the salinity was 37.4 ppt. Additional Observation - Coelenterata Occasionally throughout each year Physalia physalis, Man-O-War, was observed offshore. These individuals were usually more abundant during and shortly after strong south winds. Sizes generally ranged from 25 to 250 mm (gas bladder length). Concentrations were commonly comprised of individuals of similar size. When southerly winds persist, the Man-O-War enters the adjacent estuary and often strands on the beach. Phillips, Burke and Keener (1969) indicated that this species feeds on small fishes, mainly anchovies. 46 GULF RESEARCH REPORTS MOLLUSCA GASTROPODA Melongenidae Busycon perversum Linne - Conch Only one conch was acquired during the study. The rather large specimen appeared at 10 fathoms in July of 1967 at a temperature of 23. 2^*0 and a salinity of 36.8 ppt. Moore (1961) noted that this species is the largest gastropod in Mississippi coastal waters. Abbott (1954) noted that Busycon perversum is an uncommon species found at depths from 4 to 10 fathoms. Gunter (1950) took three at 10 fathoms off the south Texas coast during 23 months of offshore trawling. SCYLLAEIDAE Scyllaea pelagica Scyllaea pelagica was represented by two specimens. Both were taken in June of 1968 at 5 fathoms. The temperature was 29.5° C and the salinity was 28.8 ppt. 5. pelagica was abundant in patches of Sargassum floating in the study area. PELECYPODA Pectinidae Pecten papyraceus Gabb - Scallop Two hundred twelve Pecten papyraceus were collected over the 3-year sampling period. These specimens were taken from depths of 30, 40 and 50 fathoms, with greatest concentrations at the 50-fathom station. Hildebrand (1954) noted that this species is commonly reported from 31 to 45 fathoms. CEPHALOPODA Loliginidae Doryteuthis plei (Blainville) - Squid Seventy-six specimens were caught at depths of 5 and 10 fathoms. Temperature and salinity ranges were 18.3° to 25.2° C and 27.0 to 37.4 ppt respectively. Lengths ranged from 95 to 189 mm (mantle length). Lollinguncula brevis (Blainville) - Squid A total of 926 individuals of this species was taken. Specimens were taken in all months and at depths ranging from 5 to 50 fathoms. The greatest numbers were obtained at the 5- and 10-fathom stations. NEKTONIC AND BENTHIC FAUNAS 47 Gunter (1950) took 179 specimens from the Gulf at depths out to 10 fathoms. He noted that this squid is more common in the shallow Gulf than in the bays of Texas. However, this squid is abundant, in inshore waters in Mississippi (GMEI data). Hildebrand (1954) made his largest catches of this species in depths out to 15 fathoms and noted an offshore movement during colder temperatures as evidenced by a large catch in January at 20 and 21 fathoms. Our data show an increase in numbers from December through April. Gunter (1950) took no specimens in bay waters during December and January. The squid ranged in size from 20 to 160 mm (mantle length). Specimens under 40 mm were taken from October to April. The temperatures and salinities of collections ranged from 10.8“ to 29.5° C and 24,9 to 39.8 ppt respectively (Table 13). Gunter’s (1950) figures were 11.1° to 30,3'^C and 17.7 to 37.2 ppt. Loligo pealei Le Sueur * Squid A total of 294 individuals was taken. They were collected in all months and in greatest numbers during March and April. Specimens were encountered from 6 to 50 fathoms and were in greatest numbers at 20 fathoms. Gunter (1950) found this species only in the Gulf. Hildebrand (1954) found this squid quite abundant, and his largest hauls were from 14 to 18 fathoms in hauls completed at dawn. His catch per unit of effort was small at night, and our data are in agreement with this. Our specimens ranged from 43 to 318 mm (mantle length) and the temperatures and salinities ranged from 12.0° to 29.0°C and’ 16.6 to 39.8 ppt respectively. Great numbers of this squid were occasionally seen around the boat at night and were apparently attracted by the lights. Sepiolidae Rossia tenera (Verrill) - Squid We collected one specimen of Rossia tenera at 5 fathoms in June at a temperature of 20.0° C and a salinity of 37.8 ppt. Hildebrand (1964) captured a single specimen at 23 fathoms. OCTOPODIDAE Octopus vulgaris Lamarck - Octopus Octopus vulgaris was uncommon and appeared only twice, once in June of 1967 (30 fathoms) and again in July of 1968 (40 fathoms). The June temperature and salinity were 20.4° C and 37.8 ppt respectively. 48 GULF RESEARCH REPORTS TABLE 13 DISTRIBUTION OF LOLLIGUNCULA BREVIS BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAI^ TOTAL LENGTH (MM). 1967 SAtlNirv INT6«V*t PfI [NT. 16*6 1 T.O 20.0 23.0 26.0 29.0 32.0 38.0 38.0 16,6 C 16*9 19.9 22.9 25.9 28.9 31.9 34,9 37.9 39.6 39.6 shpls. 0 0 0 0 0 0 0 0 0 0 10. S catch 17.9 HIN>MAX hcan SHPLS. 0 0 0 0 0 1 6 1 0 . 13.0 CATCM 14.000 3.666 0.000 6.500 19.9 niN^HAX 27- 88 35- 108 27- 10. HE am 60.1 66.3 86.4 &HPL5. 0 0 0 0 1 1 4 11 0 19 16.0 CATCH 0.000 16.000 13.250 1.923 4.947 18.9 MIN-MAX 80- 93 27- 64 44- 76 27- 9J MEAN 62.8 66.8 59,0 52.8 iHPCS. 0 0 0 0 0 2 4 21 0 27 19.0 CATCH 1. 800 8.000 3,238 1.170 21.9 HIN-MAX 72- 83 50- 93 20- 84 20- 91 MCAN 78.6 Ti.a 37.7 46*7 SHPLS. 0 0 0 0 0 1 1 12 0 16 22.0 CATCH 68.000 0.000 0.863 5.157 2*. 9 HiN-HAX 40- 87 38- 91 JS- 91 M6An 62.5 89,1 62.1 SMPLS. 0 0 0 0 0 4 2 IB 0 26 25.0 CATCH 6.750 0.000 3.S88 6.061 27.9 MIN-MAX 46- 90 80- 98 46- 98 hcan 76.1 69* 7 71.5 SHPLS. 0 0 0 0 0 0 2 0 0 2 28.0 catch 4.0U0 4.000 29.5 HIN-HAX 65- 85 68- 88 HEAn 76,6 76,6 SHPLS. 0 0 0 0 1 9 19 68 0 94 10.8 catch 0,000 16.222 5.621 2.618 4.268 29.5 HIN-HA* 2 7- 9J 27- 108 20- 95 20- lOB mean 63.3 58.2 55.0 88.8 1968 SALINITY INTERVAL PPT TEMP INTp 16.6 IT.O 20.0 23.0 26.0 29.0 32.0 35.0 38.0 16.6 C 16.9 19.9 22.9 25.9 28.9 31.9 34,9 37.9 39.8 39.8 &MPL&. 0 0 0 0 0 0 0 0 0 0 10. e CATCH 12.9 HIM-HA* MEAN SHPLS. 0 0 0 1 0 6 0 0 11 ii*0 CATCH 6.000 2J.750 8.800 13*636 15.9 HIN-HAX 51- Tl J2- 98 39- 83 32- 98 HEAN 87-7 86.2 89,1 57.2 SHPLS. 0 0 0 2 2 3 6 8 0 21 16.0 CATCH 0.000 23.000 0.000 0.333 3.628 3.666 ia.9 HIN-HAA 80- 86 84- 84 35- 95 35- 95 HEAN 65.3 86,0 66.1 65.1 SHPLS. 0 0 0 1 8 3 e 5 1 26 19.0 CATCH 0.000 0.000 0.000 1.800 0.000 0,000 0.628 21.9 HIN-HAX 41 - 72 61- 72 MEAN 60.3 60.1 SHPLS. 0 0 0 0 2 0 2 4 0 6 22.0 CATCH 0.800 1.800 5.750 3,375 26.9 HIN-HAX 56- 56 56- 77 28- 78 28- TB MEAN 84.0 70,0 81.6 51.7 SHPLS. 0 0 0 1 1 3 1 6 3 15 25.0 Catch 0.000 0.000 20.333 0.000 1.800 0.000 4.666 27.9 MIN-MAX 52- 160 80- 80 82- 160 HEAN 95.2 67.8 86.5 SHPLS. 0 1 0 0 2 3 1 1 0 8 28. 0 CAICH 0.000 9.500 3.666 0.000 0.000 1.750 29.5 HIN-HAX 57- 87 50- lOb 50- 100 hcan 70.6 75.8 72.8 SHPLS. 0 1 0 7 19 12 24 24 4 91 10.8 CATCH 0.000 0.5T1 8.675 6.000 2.833 2*841 0.000 4,021 29,8 MIN-MAX 51- n 32- 98 50- 160 39- 84 28- 95 28- 160 HEAN 5T.T 60.5 86.7 60*1 59,9 62.1 NEKTONIC AND BENTHIC FAUNAS 49 TABLE 13 (Continued) 1969 SALINITY PPT INT. C I6a6 I6h9 17.0 19.9 20.0 22.9 2>.0 2>.9 26.0 26.9 29.0 31.9 32.0 34,9 35.0 37.9 18.0 J9.8 16.6 19.9 SXPL5. 10. a CATcn 12. « nIN-MAX HEAM 0 0 0 0 0 0 1 4.000 24- 54 41.0 1 6.000 53- 78 60.6 0 2 5.000 28- 78 52.0 SMFlS. IJ.O catch IT. <3 NIN-AAA HEAN 1 O.QQO 0 0 2 S.dOO SO- 96 67.2 1 14.000 44- 60 SO. 3 7 4.571 22- 80 57,4 6 1.000 52- 70 59. S 1 0.000 0 18 3.500 22- 9b 57.8 SHPCS. lA.O CATCH ia.9 HIN'HAX KEAN 0 0 1 0.000 0 0 i 0.000 7 0.000 13 0.000 2 0.500 80- 80 ao.Q 24 0.041 80- 80 50.0 iHFli, lO.O CATCH 21. .0 CATCH 2T.9 HIN-haa HE AH 0 0 0 0 0 0 0 U 0 0 SMPLS. Z6.0 CATth 19*^ "IN-NAA MIAN 0 0 0 0 0 0 0 0 0 0 SHPIS. 10.* CATCH 19. i HIN-HAX HEAN i 0.000 i 0.000 L Q.QOO 4 s.soo so- 96 69. S i 14.000 44- 60 SO*) 8 A. 000 22- BO Sl.i 19 3.473 28- 88 66.6 21 O.OISI SI- 8J 88.1 2 0.500 80- 80 80.0 60 2.650 22- 96 64.1 In July the temperature was 19.2° C and the salinity was 23.2 ppt* A weight of 51.5 grams was recorded for the July specimen. Both specimens were small. ARTHROPODA CRUSTACEA STOMATOPODA Squiludae Squilla chydaea Manning - Mantis shrimp There were 126 specimens taken within a temperature range of 14.9° to 27.3° C and within a salinity range of 19.9 to 39.8 ppt. The depth range was from 20 to 50 fathoms. Individual total lengths ranged from 69 to 118 ram. Squilla empusa say - Mantis shrimp There were 628 Squilla empusa taken within a temperature range of 13.3° to 29.5° C and a salinity range of 23.2 to 39.8 ppt. Gunter’s (1950) studies showed limits of 13.7° C to 25.4° C and 16.5 to 34.2 ppt. 50 GULF RESEARCH REPORTS The depth range of the specimens was from 5 to 50 fathoms, with the majority being caught in waters up to 40 fathoms. Only five were caught in 50 fathoms of water. Hildebrand (1954) founds, empusa to be more abundant in waters shallower than 30 fathoms. Squilla empusa is common in Mississippi Sound when the salinity is above 15.0 ppt (GMEl data). Decapoda Penaeidae Penaeus aztecus Ives - Brown shrimp During the 3-year study period, 2,964 brown shrimp were collected. They were taken in aU months and in all years. This species was collected at depths of 5 to 50 fathoms with the largest numbers obtained from 5 to 20 fathoms. The largest catch per unit of effort was consistently encountered in night trawling. Osbum, Maghan and Drummond (1969) reported that the brown shrimp are caught at night by commercial trawlers with the largest catches made between 11 and 20 fathoms. Young shrimp (under 100 mm) entered our catch in June, July, September, November and December. November produced the smallest individuals. This was probably due to the efflux of young shrimp from Mississippi Sound because of cooler water temperatures. Spawning of this species occurs throughout the year at temperatures above 17.0° C (Su(;)rahraanyam 1971). Shrimp capable of spawning (above 140 mm, Berry and Kimsey 1964) were acquired in all months and the temperature requirements were met at some station during each month. Subrahmanyam (1971), whose study was run simultaneously with ours, found larval forms of this species throughout the year with peak concentrations in the spring and fall. Christmas, Gunter and Musgrave (1966) studied the seasonal occurrence and relative abundance of penaeid postlarvae in Mississippi Sound and adjacent waters, and discussed the prediction of future adult shrimp abundance from the numbers of juveniles in the bays following their larval immigration. Length-frequency distribution shows a great deal of overlapping with only one size group distinct enough to allow an estimation of gro'wtli rate. A mode determined in November of 1967 was followed to March of 1968. This group was 56 mm in November and had reached 145 mm by March. Only one individual was taken in February of 1968; however, the minimum size range in February of 1969 was 115 mm. These data indicate a growth rate of 90 to 100 mm for 150 days. The growth rate was fastest during November of 1969 (from 55 to 85 mm) and diminished each succeeding month. This slowing of growth NEKTONIC AND BENTHIC FAUNAS 51 probably is a result of the cooler water temperatures of December through March. Christmas and Gunter (1967) estimated the growth rate of postlarval and juvenile penaeids in Mississippi Sound and adjacent estuaries to be approximately 1.5 mm/day during the summer months. Data concerning the growth rate of penaeid shrimp in offshore waters is lacking. Our data show an average growth rate of 19 mm/month during the cooler months. The temperatures and salinities of collections varied from 14.3° to 29.5° C and 24.6 to 39.8 ppt respectively. The salinity range that produced the greatest yield was 26.0 to 31.9 ppt, however, the majority of the individuals were taken at a salinity range of 35.0 to 37.9 ppt (Table 14). The total weight of brown shrimp collected was 715 kilograms. July yielded the largest catch and the corresponding greatest monthly weight of 134.6 kilograms. The brown shrimp is by far the most abundant shrimp in the Gulf of Mexico fishery. Osburn, Maghan and Drummond (1969) state thatP. aztecus makes up 52% of the offshore shrimp fishery. Christmas and Gunter (1967) state that 5,276,000 pounds of brown shrimp were taken in 1963 from the offshore fishing grounds of Mississippi and southeastern Louisiana. In our samples the brown shrimp catch made up 80.8% of the total catch of commercial species of shrimp {P. aztecuSy P, fliwiatilis and P. duoramm) with white shrimp comprising 13.4% and pink shrimp comprising 5.8%. These percentages follow closely those reported by Christmas and Gunter (1967). Penaeus duorarum Burkenroad - Pink shrimp A total of 195 pink shrimp were collected. This species was taken at depths of 6 to 20 fathoms with the largest numbers taken in 5 fathoms. The catch per unit of effort was greatest at Stations 1 and 2 in night trawling. This shrimp was taken in May, June, August and October through January, with May showing the greatest catches. Pink shrimp were not collected in 1969. Pink shrimp were encountered at temperatures and salinities ranging from 15.1° to 27.0° C and 26.2 to 39.8 ppt respectively. These shrimp ranged from 84 to 187 mm in length. Christmas and Gunter (1967) reported that 499,000 pounds of pink shrimp were landed from the offshore fishing grounds of Mississippi and Southeastern Louisiana. Osbum, Maghan and Drummond (1969) state that the pink shrimp makes up 22% of the total shrimp catch of the Gulf of Mexico with the 52 GULF RESEARCH REPORTS TABLE 14 DISTRIBUTION OF PENAEUS AZTECUS BY BOTTOM SALlNFfY AND TEMPERATURE INTERVALS SHOWING NUMBER .OF SAMPLES, CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH (MM). 1967 SALINITY interval PPT INT. C 16.6 16*9 IT.O 19.9 20.0 22.9 23.0 29.9 26,0 26.9 29.0 3U9 32.0 36,9 35.0 3T,9 36.0 39.0 U.6 39.8 10. • SNPUS. CATCH NlN-MAX MEAN 0 0 0 0 0 0 0 0 0 0 13.0 IS. 9 SMPLS. CATCH NIN-MAX mean 0 0 0 0 0 1 0.000 6 0.633 iir- 196 151.0 1 0.000 0 a 0.625 117- 196 15U0 16.0 ia.9 shpls. CATCH MJN-MAK MEAN 0 0 0 0 1 28.Q00 07- 147 112. a 1 100.000 102- 162 110*7 6 2.750 75 169 1 13.6 LJ 6. 306 91- 262 169.6 0 19 11.666 75- '262 162, > 19. 0 2L.9 SMPLS. CATCH MIN-MAX MEAN 0 0 0 0 0 2 u.soo 1 76- 1 76 176.0 6 1. /50 12S- 166 160.1 21 >.333 56- 2)6 162.7 0 27 6.666 56- 236 159.7 22,0 SHPUS. C*KH M(4N 0 0 Q 0 0 1 0*000 1 0.000 12 9.333 103- 231 156.0 0 U 8.000 103- 231 156.0 29.0 27. « JHfLS. CATCH KtN'HAA NCAN 0 0 0 0 0 6 69.290 99- 177 136. 2 2 1.500 106- 192 157,} 16 12.666 109- 235 169.6 0 26 1 7.666 95- 235 163.3 2t.» 29.9 SMPLS. Catch MIN-MAX HiAN 0 0 0 0 0 Q 2 19.000 95- 178 1X6.3 0 0 2 19.000 95- ifa 14*., J 10. • 29.9 Smpls. CATCH nlN-HAX MEAN 0 0 0 0 1 28.000 87- 1X7 112.8 9 33. Ill 95- 177 132.0 19 3.366 75- 196 137.6 65 0.169 56- 262 157.2 0 96 9.797 56- 262 147.0 1968 salinity interval PPT TEMP INT. C 16.6 16.9 17.0 19.9 20.0 22.9 21.0 2S.9 26.0 28.9 29.0 31.9 32.0 36.9 35.0 37.9 38,0 39.6 16.6 39,8 10. a U.9 SMPLS. CATCH MIN-MAX MEAN 0 0 0 0 0 0 0 0 0 0 13.0 15.9 SMi-LS. CATCH HIN-MAX mean 0 0 0 0.000 6 1.2^0 96- 137 116.1 0 6 3.S33 150- 230 100.1 0 0 1 1 2.56!, 96- 230 1 76.0 L6.0 10.9 SMPLS. CATCH M in-max MEAN 0 0 0 2 9,S00 110- 192 163.0 2 9.000 lOx- 153 12X.9 3 17.666 in- 178 1X9.1 6 0.500 161- 177 171.3 8 5.125 127- 228 169,} u 21 6. 100 io6- 220 151-9 19.0 21.9 SMPLS. CATCH MIN-MAX mean 0 u 0 3 1.000 222 206. 7 a 2.000 i/a- 213 196.6 3 0.000 a l.SOO 1X3- 207 iai.9 5 6.60O 153- 229 180. 1 i 0.000 20 2.2^ 163- 22^ lai.o 22.0 2A.9 SMPLS. CATCH MIN-MAX mean 0 0 0 0 2 9.S00 93- 130 106.0 0 2 0.000 0.000 0 6 Z.J7} 83- 130 106.0 2S.0 27.9 SMPLS. CATCH MlH-MAX mean 0 0 0 t 0.000 1 U.DOO 3 0.000 1 0.000 6 6.000 126* 220 166,6 3 12.333 120- 220 171.5 15 6.066 126- Z2U uo.e 28.0 20. S SMPLS. CATCH MIN-MAX MEAN 0 1 o.ooo 0 0 2 0.000 3 1.333 121- 170 160.0 1 39.000 99- 170 127-0 1 o.ooo 0 a 5.375 99- 170 127-8 10.8 29.9 SMPLS. CATCH MtN-MAX MiAN 0 1 0.000 0 7 3.162 130- 222 166* 7 19 3.092 83- 213 119.0 12 6.790 ll/- 170 169.0 2X 3.208 99- 230 1X7.8 26 6. >83 126- 229 165.1 6 9.2>0 126- 220 171.5 91 3.967 83- 230 151.6 NEKTONIC AND BENTHIC FAUNAS 53 TABLE 14 (Continued) 1969 &ALINITT INienVAL FPf TCM IHT. C 16«« lb. 9 IT.O 20.0 22.9 23.0 25.9 Zb.O 2t.9 29.0 J1.9 IZ.O iA.9 55.0 37.9 30.0 39.0 16.6 39.8 supis. 10. < CATCH 12.9 MCAN 0 0 0 0 0 0 L o«ooo 1 0.000 0 2 0.000 SMACC. is.o catch 1».9 HIH-HAA HE AN 1 0.000 0 0 2 0.000 1 0.000 7 uooo 132- ITO 160.0 6 OaOOO 1 0.000 0 18 0.300 132- 170 160. a iHPlS. lA.O CATCH IS. 9 NIN-NAA HtAN 0 0 t 0.000 0 0 1 AS. 000 112- 19A ITS.} 7 1.205 157- 230 107.9 13 1.230 15a- ?22 100.5 2 0.000 is 2.916 112- 230 167.0 19.0 CATCM 21.9 »iIN-»AJl HtM 0 I 0.000 0 3 0.000 0 0 i 0.000 6 0.000 0 15 0.000 iH.Li. 22.0 CATCH 2A.« HIN-HAX MAN 0 0 0 L 0.000 0 0 0 0 0 1 0.000 AHPLl. 2S.0 CATCH 27. 9 MIN-HAA hEan 0 0 0 0 0 0 0 0 0 0 INPlA. 2».0 CAItM 29.% MIN^HAA HEAN 0 0 0 0 0 0 0 0 0 0 AMPLE. L 1 1 b L 0 Ui 21 2 60 10.. CATCH 29. S HIN-HAX MIAN 0.000 0.000 0.000 0,000 0.000 b.^00 112- I9<» I99.T O.ATJ 157- 2J0 187. 9 0.761 158- 222 IBS, 5 0,000 1.203 112- 230 166.5 principal areas of concentrations designated as the Campeche and South Florida grounds. Osbum, Maghan and Drummond (1969) mention that this shrimp^s preference for coral and shell sand bottom may be a factor in limiting its abundance in the northern Gulf, and further state that catches are principally made at night, which is in accordance with our data. Penaeus fluviatilis Say - White Shrimp A total of 450 white shrimp were taken during 1967-1968 only. No specimens were collected in 1969 (January through May). These individuals ranged from 66 to 195 mm in length. Penaeus fluviatilis was collected in all months with the greatest concentrations in May, June, December and January, This species was taken from 5 to 30 fathoms with 6 to 20 fathoms producing the greatest yields, Osburn, Maghan and Drummond (1969) found that 99% of the offshore white shrimp catch was taken in 20 fathoms or less. These authors also mention that white shrimp are occasionally taken at night, although the majority are taken during day trawling. Our samples produced the highest catch per unit of effort at night at all depths. Osbum, Maghan and Drummond 54 GULF RESEARCH REPORTS (1969) also stated that September - December produced 80% of the white shrimp catch. Our greatest catches fell in December and January. Young shrimp (under 100 mm) entered the catch in September, January and March through August. Shrimp under 70 mm were collected in January, May, July and September. The January and September recruitment of smil shrimp is probably due to the emigration from Mississippi Sound caused by cooler temperatures. The influx of shrimp under 70 mm in all seasons is no doubt due to the long spawning season (spring to late fall) reported by Christmas and Gunter (1967) and others. Subrahmanyam (1971) reported that species of this genus probably spawn throughout the year in Gulf waters. Penaeus fluviatilis was taken at temperatures and salinities ranging from 13.0° to 28.9° C and 24.6 to 39.8 ppt respectively. The greatest numbers were caught in salinities ranging from 26.0 to 31.9 ppt (Table 15). Penaeus fluviatilis is a very large component of the shrimp fishery of this area. In 1963, 1,018,000 pounds of white shrimp were harvested from the offshore areas of Mississippi and southeastern Louisiana (Christmas and Gunter 1967). Sicyonia brevirostris (Stimpson) - Rock shrimp Fifty-seven specimens were taken at temperatures between 17.1° and 27.3° C and at salinities between 27.8 and 34.6 ppt. They were caught at depths of 10 to 50 fathoms with the largest number being taken at a depth of 10 fathoms. Total lengths ranged from 44 to 106 mm. This species and Sicyonia dorsalis were taken at the same depths, and occasionally occurred together. Sicyonia dorsalis (Kingsley) There were 345 specimens taken at temperature and salinity ranges of 15.1° to 26 .5° C and 24.6 to 38.7 ppt respectively. Individuals were recorded at depths of 5 to 40 fathoms with the majority being found between 20 and 40 fathoms. Hildebrand (1954) found Sicyonia dorsalis to be most abundant in depths of 15 to 25 fathoms. Solenocera vioscai Burkenroad A catch of 20 specimens was recorded at temperatures between 18.5° and 19.3°C and salinities between 25.2 and 27.9 ppt. These were found only at 50 fathoms. Individuals ranged in size from 79 to 80 mm. Burkenroad (1939) found S. vioscai in Louisiana in depths from 20 to 100 fathoms. Hildebrand (1954) noted the species to be most common from 31 to 37 fathoms. NEKTONIC AND BENTHIC FAUNAS 55 TABLE 16 DISTRIBUTION OF PENAEUS FLUVIATILIS BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES, CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH (MM). 1967 SALlNIir INTESVAl PPF 1HT» C 16. « 16.9 17.0 19.9 20.0 22.9 2J.0 25.9 26,0 20.9 29. D 51.9 12.0 J4.9 )5.0 37.9 30.0 39.0 16.6 39.8 S«PIS, )0.a CATCH 12.9 I4IN-HAX HtAH 0 0 0 0 0 0 0 0 Q 0 SMPLS. 15.0 CATCH 15,9 HtN'HAiC mCan 0 0 0 0 0 1 1.000 125- 125 125.0 6 1,16b lOS- 190 151.6 1 1.000 |6l- 161 Ul.O 0 0 1.125 105- 190 150. 1 iPPLS. 16. D CATCH ie.9 HIN-MAX hEan 0 0 0 0 1 15.000 99- 109 152.7 i 3.000 I5S- 10A 17i».Q 6 13.500 56- 195 127. 6 13 1.538 87- 189 131,7 0 19 6.7 36 56- 195 150. L 5HPLS* 19.0 CATCH 21 .9 MIN-HAX MEAN 0 0 Q 0 0 2 0,000 0.000 21 0.000 0 27 0.000 iMPCS. 22.0 CATCH 2A.0 Hlh'HAA MEAN 0 Q 0 0 0 1 o.ooo 1 0,000 12 0.083 63“ 160 110. 7 0 16 O.OTl 6l- 180 110.7 ^MPLS. 25.0 catch 27.9 MIN-HAX HtAN 0 a 0 0 0 0.500 60" 75 71,5 2 O.OOO la 2. 611 as- US 102.1 0 26 2.0AI 60- 116 100.5 2H.0 CATCH 20. ^ MIN-MAX MEAN 0 0 0 0 0 0 2 0.500 «3- 63 83-0 0 0 2 0.500 S3- 03 03.0 iHPLS. 10«0 CATCH 29.5 MIN-HAX MEAN 0 0 0 0 1 15.000 99- 109 152.7 9 0,666 66- 106 162.0 12 1.261 56- 111 110. 1 65 1.061 63- 189 116.3 0 95 1.595 56- 195 130.5 TIHP IMT. C 16.6 16.9 iT.y 19.9 20.0 22.9 SALINITY 23.0 2S.9 1968 TNTEftVAL 26.0 20.9 PPT 29.0 31.9 17.0 I*..-! 35,0 3T,9 30.0 39. Q 16.6 39.0 SHPLS. 0 0 0 0 0 0 0 0 0 0 10. i CATCH 12.0 MIN-MAX MEAN SMPL&. 0 0 0 1 6 0 6 0 0 11 IJ.O CATCH 0.000 1.250 3.033 2.5*5 15.9 MlN-MAX 96- IIT 150- 230 96- 2 30 MEAN 116.1 188.1 17*. 0 SMPIE. 0 0 0 2 2 3 6 0 0 21 U.o Catch 4.SOO ' 9.000 IT. 666 0.800 6.17S 6.380 l»., MIN-MAX 130- 192 lOA- U3 Il7- 178 161- 177 177- 778 106- >7d MEAN 1.3.0 12**9 1*9,1 171.3 169,5 151*9 smplj. 0 0 0 1 a 3 a 5 1 20 14.0 CATCH uooo 2.000 0.000 1.600 6.600 0.000 2.285 21,9 MIH'MA* 168- 222 178- 2li INI- ZOI 153- 229 161- 279 ■EAN 206. 7 19* .6 181.9 lao. 1 103. Q SMPLi, 0 0 0 0 2 0 2 * 0 P 22^0 catch o.xoo 0.000 0.000 7.175 26.9 MIN-NAA 63" IJO 03- 130 MEAN 106.0 106.0 SHPCi, 0 0 0 1 1 3 1 6 i 15 2S.0 catch 0.000 0.000 0.000 0.000 6.000 12.333 * M 06 e\ 2T.4 H in-max 126- 220 128- 220 126- 770 NfAN 1*6.* 171.5 160, b SMPIS. 0 1 0 0 2 3 i 1 0 ZA.D CATCH 0.000 o.ooo 1.333 19.000 Q.OQO 5.3T5 29,8 NlN-MAX 121- IfO 99- 170 99- 170 mean lAa.o 177.0 177.8 SHPLS. 0 1 0 T 19 \z 7* 2* * 91 10. t catch 0.000 3. Lb2 3.052 *.750 *. J0 3 9,750 3.967 29.5 MIN-MAX 130- 222 03- 213 117- 178 99- 210 126- 729 128- 220 03- 230 MEAN 166. T 119.0 1A9.0 1A7.8 165.1 171.5 151,6 56 GULF RESEARCH REPORTS Solenocera sp. Ten unidentified specimens of Solenocera were taken at tem- peratures of 18.6'^ to 18.9® C and salinities of 35.0 to 37.2 ppt. All were found in 50 fathoms of water. Trachypeneus similis Smith A total of 272 individuals of this shrimp was collected. This species was encountered in 1967-68 only and in the months of January, March, May, June and December. These individuals varied 49 to 101 mm in len^h and were collected in 5 to 20 fathoms with the greatest abundance occurring at 10 fathoms. The month of greatest abundance was December. Night trawling produced the highest catch per unit of effort at all stations. Temperature and salinity ranged 17.0® to 25.0® C and 24.6 to 37.2 ppt. Subrahmanyam (1971) collected larval stages of this species in aU months off Mississippi and mentioned that peak spawning activity occurred in June, July and November. Hildebrand (1954) found this species to be quite common in his study area but uncommon at depths less than 12 fathoms. Trachypeneus similis is common in Mississippi Sound (GMEI data). Trachypeneus similis contributes a small percentage of the commercial shrimp catch in Mississippi but is not usually recognized in the large quantities of brown and white shrimp ( fide J.Y. Christmas). Eldred (1959) reported that T. similis and its congener T. constrictus contributed about 7% to the commercial catch in the Tortugas area of Florida. SCYLLARIDAE Scyllarides nodifer (Stimpson) - Spanish lobster A total of five specimens appeared in the catch during 1967 and 1968. A single specimen was taken in 1967 at 40 fathoms. The specimens collected in 1968 appeared at 30 and 40 fathoms. Tem- peratures and salinities ranged between 19.2® and 23.0® C and 23.2 to 34.6 ppt respectively. There is a ready market for Spanish lobster as they are occasionally available in local fish markets, but no com- mercially exploitable stock has been located. Scyllarus sp. Six unidentified individuals were taken at temperatures between 17.0® and 22.0°C and at salinities between 28.8 and 36.5 ppt. They NEKTONIC AND BENTHIC FAUNAS 67 were found at depths ranging from 30 to 50 fathoms. Specimens were deposited in the Gulf Coast Research Laboratory museum. PORCELLANIDAE Porcellana sayana Leach A total of five P. sayana appeared in February at 30 fathoms. The temperature and salinity were 16 .4° C and 35.6 ppt respectively. Porcellana sayana is fairly common in less than 10 fathoms around the Mississippi Sound barrier islands ( fide J.Y. Christmas). Paguridae Benthopagurus cokeri There were ten individuals caught at temperatures between 18.6° and 20.0° C and at salinities between 35.0 and 37.8 ppt. These were found at the 50 fathom station. Pagurus floridanus Benedict - Hermit crab Eighteen P. floridanus were caught at temperatures between 13.0° and 23.1°C and at salinities between 31.2 and 35.3 ppt. Specimens were caught in 5 to 10 fathoms of water, with the majority being from the 5 fathom depth. Most of the specimens were found in gastropod shells. This hermit crab is very common in Polinices and Thais shells in Mississippi Sound. Petrochirus bahamensis Hay and Shore Thirty-nine specimens were caught at temperatures between 14.1° and 29.0°C and siinities between 16.6 and 37.4 ppt, between 10 and 50 fathoms. Lengths ranged from 40 to 142 mm. Hildebrand (1954) found P. bahamensis to be the common hermit crab on sandy bottoms in his study area. He attributed their absence on the muddy bottoms to the scarcity of gastropod shells. Williams (1965) places this species in synonomy with P. diogenes (Linnaeus). Most of the large specimens occupied Busy con shells, and more often than not, small specimens of P. bahamensis were found in the same shell with the large individuals. RANINIDAE Raninoides louisianensis Rathbun Five R. louisianensis were collected during the three years of this study. Specimens were found only at 40 and 50 fathoms. Temperatures ranged between 18.3° and 20.3° C and salinities were between 24.9 and 58 GULF RESEARCH REPORTS 35.4 ppt. Hildebrand (1954) found specimens only from 31 to 37 fathoms. Raninoides sp. An unidentified specimen was obtained in April of 1969 at Station 3 in a night haul. The temperature and salinity were 17.4° C and 34.9 ppt respectively. This specimen is in the Gulf Coast Research Laboratory museum. Dromiidae Dromidia antillensis (Stimpson) A single specimen of D, antillensis was taken in 1967 at Station 1 in January. The temperature and salinity at the time of capture were 17.2° C and 26.6 ppt respectively. We have collected this species with a covering of compound ascidians in miscellaneous trawl hauls in Dog Keys Pass (between Horn and Ship Islands). Dromidia sp. An unidentified specimen of Dromidia was collected in January 1968 at a temperature of 14.8° C and a salinity of 28.5 ppt. The specimen was taken at 5 fathoms. Leucosiidae Persephona crinita Rathbun Two specimens of P. crinita were taken in 1967, one from 10 fathoms and another from 50 fathoms. The 10-fathom specimen was taken in January with the temperature at 16.0° C and the salinity at 34.7 ppt. The 50-fathom specimen was taken in May at a temperature of 18.6°C and a salinity of 35.0 ppt. Hildebrand (1954) found ovigerous females in June. CALAPPIDAE Calappa springeri Rathbun Fifth-three specimens of C. springeri were collected in tem- peratures between 14.1° and 28.0° C and in salinities between 16.6 and 38.7 ppt. They were taken in 10 to 50 fathoms. Carapace widths ranged from 67 to 134 mm. Hildebrand (1954) caught this species in almost every drag made between 12 and 25 fathoms; however, only a few were taken each drag. Hildebrand (1954) found C springeri at all fishing grounds examined except the Obregon grounds off Campeche. NEKTONIC AND BENTHIC FAUNAS 59 Hepatus epheliticus (Linnaeus) - Calico crab Nineteen specimens were collected, at depths between 5 and 50 fathoms. Temperatures ranged from 14.2° to 27.3° C and salinities ranged from 24.9 to 37.4 ppt. Carapace widths ranged from 35 to 80 mm. Only a few were captured by Hildebrand (1954) in 12 to 19 fathoms, and he remarked that this species appeared to be more abundant shoreward to 12 fathoms. Our data tend to agree with his observation. PORTUNIDAE Callinectes sapidus Rathbun Only 141 blue crabs were collected during this study. This crab was obtained in all months with the exception of November and December. The depths ranged from 5 to 50 fathoms with the greatest concentration at 20 fathoms. Sexes were always segregated in our hauls. The greatest con- centration of both males and females occurred at 20 fathoms Females were most abundant (60% of 115 recorded determinations). We have observed large concentrations of ‘‘berried” females around the barrier islands. In the summer “berried” females were often seen swimming at the surface in the study area. Only three specimens, all female, were taken at 50 fathoms. These measured 75 mm, 83 mm and 140 mm in carapace width. Gunter (1950) stated that he has observed females in “berry” swimming several miles from shore, and Daugherty (1952) stated that the female moves offshore to spawn. Hildebrand (1954) found relatively few blue crabs in his study and stated that he encountered no males. Gunter (1950) and Daugherty (1952) noted the lack of males in the offshore environment. Our specimens measured 50 to 181 mm. The temperatures and salinities of the collections ranged from 14.9° to 29.0°C and from 24.6 to 37.1 ppt respectively (Table 16). Callinectes similis Williams - Gulf crab Three hundred four specimens were collected. This species was obtained at Stations 1, 2, 3, 4 and 6 in all months. These individuals ranged from 39 to 171 mm in carapace width. They were most abundant at 20 fathoms. The temperatures and salinities of the collections ranged from 13.3° to 29.0°C and from 24.9 to 37.4 ppt 60 GULF RESEARCH REPORTS respectively (Table 17). There was a slight preference for salinities ranging from 29.0 to 31.9 ppt. Approximately at midnight on 29 May 1968 in 5 fathoms of water we observed hundreds of small (approximately 40 mm carapace width) C. similis swimming on the surface in an apparent inshore immigration. The spawning season of this crab must be rather long as catches of small crabs were made in January (39 mm), May (40 mm) and June (44 mm). Callinectes similis was abundant in GMEl samples, but the largest specimen was 142 mm in carapace width. Specimens larger than 100 mm were not taken in salinities less than 15.0 ppt. Callinectes similis is not usually harvested in estuarine waters because of its small size. Location of concentrations of large Gulf crabs offshore could provide a new source of crab meat. TABLE 16 DISTRIBUTION OF CALLINECTES SAPIDUS BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES, CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAl^ TOTAL LENGTH (MM). 1967 salinity inurval ppt IHT. C 16.4 16.9 17,0 19.9 20.0 22.9 21.0 21.9 26.0 28.9 29.0 31.9 3^.0 3^.9 33.0 37.9 36x0 39.3 16,6 39.8 L0«l L2«Q 5HPLS. CATCH M|f4-NAX MEAN 0 0 0 0 0 0 0 0 0 0 11.0 11.9 SMPIS. CATCH niH-HAi head 0 0 0 0 0 1 0.000 6 0,000 L 0.000 0 8 0.000 14. 0 ie .9 i.PLS. CATCH hih-haa HE AH 0 0 0 0 1 0.000 1 o»ooo it 0,000 LJ 0.000 U 19 u.ono 19.0 ?1.9 SHPLS. CATCH min-max MEAN 0 0 0 0 0 2 0.000 6 0.000 2L 0,809 30- B9 6 /. i 0 27 U.629 30- H9 67,1 22.0 24.V SHPLS. CATCH NIN-MAX hEan 0 0 0 0 0 1 0.000 1 0.000 12 0.L16 ff’ 93 66.2 0 13 0.337 / f- 93 B6.2 21.0 27.9 5HPLS. CATCH HIN-HAX NEAH 0 0 0 0 0 s 0,000 2 1 4^00 aT 18 0.666 66- lai 103.8 U 2*. 0.623 66- 181 102.1 28.0 29 . S IHPIS. CaICM MIM'MAX MEAN 0 0 0 0 0 0 2 1.300 - 163 136 . i 0 0 7 1.300 134 - I 6 i 138. 1 10 . a 29.1 INPLI. Catch MlN-MAX MEAN 0 0 0 0 1 0.000 9 0.000 A6 19 0*313 - 163 129*2 63 0.323 30- Iftl 04.0 0 94 0.423 30- IBl 88.2 NEKTONIC AND BENTHIC FAUNAS 61 TABLE 16 (Continued) 1968 ^AWiNltY IMt£RV*L PPf TEMP INT. c 16.6 16.9 IT.O 19.9 20.0 22.9 2>.0 2S.9 26.0 26.9 29.0 31.9 32.0 35,9 3S.0 37.9 36.0 39*fl 16.6 39,8 I0.fi CiTCH MIN-HAX MEAN 0 0 0 0 0 0 0 0 0 0 SMPLS. It.O C*TCH 11.9 MIN-HAK HE An 0 0 0 1 0.000 A 0.000 0 6 0.000 0 0 11 0,000 SHPLS. l&.O CAICN ie.9 HIN'NAK MEAN 0 0 0 2 4,000 6S- 87 7S,« 2 0.000 3 4.000 76- 100 «7.0 6 0.000 a 0.000 0 2L 0.952 6S- 100 82. d SNP4.S. I«.0 CAICH 21.9 HIN-HAA mean 0 0 0 i 0.000 a 0. I?S 92- 92 92.0 3 0.000 A o.soo T5- 140 94, H s 0.000 1 0,000 28 Q. 176 7S- 140 94.3 INPLS. 22.0 CATCM 29.9 NIN-.AX MEAN 0 0 0 0 2 0.000 0 2 0.000 4 0.000 0 8 0.000 IjMPLi. CATCH MIH-NAX MEAN 0 0 0 1 0.000 1 0.000 3 0,333 140- 140 140.0 1 0.000 b 0.000 3 0,000 IS 0.066 140- 140 140,0 INPLS. 2«.0 CATCH 29.5 TlIN-^a* MEAN 0 1 0.000 0 0 2 0.000 3 4.333 66- 120 92.0 1 0.000 1 0.000 n 8 1,62S 65- 120 92.0 SNPLS. 10. 1 CATCH 29. J HIN-HAX MIAN 0 1 0.000 0 7 1.1A2 6S- 87 7>.8 19 O.OS2 92- 92 92.0 12 2. 166 65- 150 91.5 24 0. L66 7S- 140 94*8 24 0.000 4 0,000 91 0.5^8 65- 15U 89.2 1969 salinity INTERVAL PPT TEMP IMT. C 16.6 16.9 IT.O 19.9 20.0 22.9 23.0 25.9 26.0 28.9 29,0 31,9 32.0 34,9 JS.O 37.9 38,0 39.8 16.6 39.8 SNPLS. lO.B CATCH 12.9 HIN'NA* mean 0 0 0 u 0 0 1 0.000 1 O.OQO 0 ? 0,000 SNPLS. 13.0 CATCH 11.9 MIN-NAA NEAN 1 0.000 0 0 2 O.SOQ 92- 92 92.0 1 0.000 7 0,ST1 71- 67 79.2 6 0.000 1 4.000 75- 102 06.3 0 18 o.soo 71- 102 84*2 SMPLi. U.O CATCH It. 9 HIN-MAX MEAN 0 0 1 0.000 0 0 1 3aOOO rs- los 69.4 T 0.000 L3 0.000 2 0,000 24 0,125 73- lOS 89.4 SMPLi* 19.0 CATCH ZU9 MIN-MAX MEAN 0 1 0.000 0 3 0.000 0 0 s 0.000 6 l.OOO 0 13 0.066 SMPLS. ZZ.O CATCH 2'A.9 MIN-MAX MEAN 0 0 0 1 2.000 151- 1Tb US. 5 0 0 0 0 0 L 2,000 IS5- 176 L6S,3 SNPLS, 25,0 CATCH 27.9 NIH-NAA NEAN 0 0 0 0 0 0 0 0 0 0 SNPLS. 21.0 CATCH 29.5 HIM-NAT NIAN 0 0 0 0 0 0 0 u 0 0 SNPLS. 10. t CATCH 29.1 NIN-HAX NEAN L 0.000 1 0.000 1 0«Q0Q 6 o.soo 92- 176 141.0 1 0.000 8 0.B7S 71- 106 85. 7 19 0.000 21 0,238 7S- 102 86.3 2 0.000 60 0.230 71- 176 94.2 62 GULF RESEARCH REPORTS TABLE 17 DISTRIBUTION OF CALLINECTES SIMILJS BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES, CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH (MM). 1967 salinity iNTEAVAt PPt IHT. C 16.6 16.9 17.0 19.9 20.0 22,9 21.0 2S.9 26.0 20.9 29,0 51.9 12.0 >A.9 11.0 17.9 38.0 39.8 16.6 39,8 SN.LS. 10. S CATCH 12. « MlH-HAX ncan 0 0 0 0 0 0 0 u 0 0 SMFLS. L3.0 CATCH 15.9 HIN-MAX MEAN 0 0 0 0 0 1 0.000 6 3.000 39- 92 73.3 1 0.000 0 8 2.230 J9- 92 73,3 SHPLS. 16.0 CATCH It. 9 min-max MEAN 0 0 0 0 62- 1 1.000 62 62.0 1 0.000 A 1.000 *7- 47 6T.0 11 1.749 19- 91 00.2 0 19 1-673 ir- 91 77, b JHPlJ. 19.0 CATCH 21.9 HIN~MAX MEAN 0 0 0 0 0 2 2.500 60- 159 67.6 6 0,750 62- 96 82,6 21 L.OOO 75- 100 66.9 0 27 1.076 60- 159 60.0 SHPCS. 22.0 CATCH 26.9 MIN-MAX MEAN 0 0 0 0 0 i 0.000 1 0,000 12 0.000 0 16 0.000 SMrc&« 25,0 CATCH 27,9 HIN-HAX MEAN 0 0 0 0 Q 6 2.2 50 69- 170 iOl.5 2 0.000 10 1.000 63- 113 79,6 0 26 1.125 63- 170 87-0 SMPL5* 2B.0 CATCH 29.5 NlN-NAX MEAN 0 0 0 0 0 0 2 0.500 87- 97 07,0 0 0 2 0.500 87- 87 07.0 SMtcS. 10. » CATCH 29.} HIN-MAX MEAN 0 0 0 0 62- 1 1.000 62 62.0 9 1,555 60- 170 90.9 19 1.368 39- 96 73.9 65 0,953 59- 113 61.2 0 96 i.U95 39- 170 80,7 SALINl TV 1968 interval PPI TEH, IHT. C 16,6 16.9 17.0 19.9 20.0 22-9 21.0 2S.9 26.0 28-9 29.0 31.9 32.0 16.9 Jl.O 17.9 36,0 19.6 16,6 39,8 EHtCS. 10. « CATCH 12.9 NIN-HAX MEAN 0 0 0 0 0 0 0 0 0 0 SN.LS. IJ.O CATCH IS. 9 MlN-MAX MEAN 0 0 0 1. 000 61- 6) 61.0 6 0.250 0 6 0.000 0 0 11 0,161 63- 63 63,0 SHPLS. 16.0 catch It. 9 nin-nax MEAN 0 0 0 2 2.000 7S- 90 01. 1 2 D.SOO 1 3.000 51- 96 76.6 6 0.833 66- 66 78.3 0 1.375 7J- 109 66.5 0 21 1.420 SI- 109 01.0 SHPLS. 19.0 CATCH 21.9 MIH-HAX HEAN 0 0 0 3 0.000 8 0,000 3 l.OOO 76- 86 63,2 8 3.000 58- 95 73,6 5 0.^00 109- 109 109.0 1 0.000 28 1.035 5b- 109 75.4 SHPLS. 22.0 CATCH 26.9 HiN-MAX MEAN 0 0 0 0 69' 2 0.500 69 69.0 0 2 0.000 0.210 01- 31 01.0 0 8 0.250 69- at 65.0 SMPtS. 25.0 CATCH 27.9 MIN-MAX MEAN 0 0 0 1 0.000 1 0,000 3 r.ooo 50- 126 82.3 1 l.OOO 75- 0 7 79.3 6 1 .000 72- III 89.6 3 0,000 15 1.066 50- 126 03.6 SHPLS. 2t.O CATCH 29. S MtN-HAX MEAN 0 1 0.000 0 0 61 2 1.000 90 76.6 3 2,666 92- 106 98,7 1 0.000 1 11.000 58- 120 91,5 0 0 2.629 50- 120 90.5 SNFLS* 0 10. • CATCH 2f.S HtN-HAX MEAN 0 19 U 0 . 26 ) >.416 A9- 90 50- 126 TO.l 86,6 26 26 1.250 1.291 58- 95 S8- 120 76, T 69,6 69 ' 91 1.2^0 126 62.3 0.000 0.716 63- 90 80.6 0.000 NEKTONIC AND BENTHIC FAUNAS 63 TABLE 17 (Continued) 1969 SALINITY INTERVAL OPT INT. 16.6 IT.O 20.0 2S.0 26.0 29.0 32.0 39.0 36.0 16*6 C 16.9 19.9 22.9 29.9 28.9 31.9 3*. 9 37.9 39.6 39. B SNPLS. 0 0 0 0 0 0 L L 0 2 ia.« 12.9 MIN-HAX o.uoo 0.000 0.000 JNPL5. 1 0 0 z 1 7 6 1 0 18 IJ.O CMCH 0.000 0.000 0.000 1.1*2 0.000 0.000 0. 664 14. « MIn.wAA 71- 96 71- 94 MEAN 62.3 B2.3 SNPLS. 0 0 L 0 0 1 T 13 2 24 i*.o catch 0.000 o.ooo O.OOO 0.000 0.129 IB.9 MIN-MAX T2- 89 72- 69 HEAN 76.7 76.7 JMPLS. 0 1 0 0 0 9 6 0 19 l«.0 CATCH 0.000 0.000 1*200 0*300 0.600 3T,. HIH-HAK T9- ITl 69- 72 69- 171 H(AN 10S.2 TO.S 97,6 SMELL. 0 0 0 1 0 0 0 0 0 1 tt.O CATCH 1.000 1*000 2A.9 MIM-MAK 101 - lOl lOl- 101 mean 101. 0 101.0 SMPLS. 0 0 0 0 0 0 0 0 0 0 T5.0 CATCH ;T.« MIN'MAA MEAN 0 SMPLS. 0 0 0 0 0 0 0 0 0 0 28.0 CATCH 29.5 MIN^MAX mean SNPLS. 1 1 1 6 1 a 19 21 2 60 lO.S CATCH 0.000 0.000 0.000 0. 166 0.000 1.000 0.AT3 0. 142 0.000 0.390 29.5 MTN-MAK 101 - lOl 71- 96 li- Ifl 69- 72 69- 171 mean 101.0 B2.3 9*. 2 70.9 87*1 Ovalipes ocellatus (Herbst) Three specimens of O. ocellatus were taken in 1968. The temperature and salinity ranges were 19.2° to 21.0°C and 23.2 to 28.8 ppt respectively. Due to mutilation only one of the three specimens was measured (carapace width 45 mm). The depth ranged from 10 to 50 fathoms. Gunter (1950) recorded four specimens among twenty-one trawl hauls off Port Aransas, Texas at salinities of 33.6 to 36.5 ppt. Portunus gibbesH (Stimpson) Sixty-four of these specimens were caught at temperature and salinity ranges of 14.5° to 27.3° C and 30.4 to 37.1 ppt respectively, with a depth range of 5 to 50 fathoms. Specimens ranged in carapace width from 33 to 90 mm. This crab was taken in all months with the exception of June^ October and November and was distributed almost equally across the depth range. Gunter (1950) recorded this species in lower Aransas Bay, Texas at a salinity of 19.2 ppt. Portunus sayi (Gibbes) There were twenty-two specimens of P, sayi caught between 5 and 10 fathoms witliin temperature and salinity ranges of 20.5° to 26.5° C and 33.6 to 38.7 ppt respectively. Carapace widths ranged from 43 to 58 mm. 64 GULF RESEARCH REPORTS Portunus spinicarpus (Stimpson) Thirty-six specimens of this species were caught in a depth range of 30 to 50 fathoms. They were taken from temperatures between 16.6° and 27.3° C and from salinities between 23.2 and 36.5 ppt. Carapace widths ranged from 32 to 70 mm. Hildebrand (1954) found this crab most abundant between 31 and 37 fathoms. Goneplacidae Chasm ocarcinus mississippiensis - Rathbun A single specimen was collected in February of 1969 from 50 fathoms at a temperature of 16,0° C and a salinity of 34.8 ppt. This specimen was deposited in the Gulf Coast Research Laboratory museum. Majidae Anasimus latus Rathbun There were 101 specimens of this crab caught at temperatures between 14.5° and 26.5°C and at salinities between 26.6 and 37.4 ppt. The depth range was 40 to 50 fathoms. Hildebrand (1954) caught a single specimen (an ovigerous female) in 19 fathoms off the Obregon fishing grounds. Ovigerous females were not found in our samples. The type locality of A. latus is very close to our Station 6 (Williams 1965). Libinia emarginata (Leach) - Spider crab Ten specimens were taken at temperatures between 14.2° and 25.2°C and at salinities between 24.9 and 37.2 ppt. Specimens were caught at Stations 1, 2, 4 and 6. Hildebrand (1954) noted this to be the most common large spider crab in his investigation, and it was taken from depths of 6 to 24 fathoms. He encountered ovigerous females in July and February (25 to 26 fathoms for the February specimen). Gunter (1950) took specimens in lower Aransas Bay, Texas at a temperature of 9.9° C and a salinity of 17.6 ppt. Stenocionops spinimana (Rathbun) Forty of these crabs were caught at temperatures between 15.3° and 25.2° C and at salinities between 23.2 and 37.4 ppt. They were found at depths of 20 to 50 fathoms. NEKTONIC AND BENTHIC FAUNAS 65 Stenorynchus seticornis (Herbst) - Arrow crab Eleven arrow crabs were caught at temperatures between 17.8° and 25.1° C and .salinities between 31.5 and 37.8 ppt. They were collected in 50 fathoms of water. A May specimen measured 35 mm. ECHINODERMATA ASTEROIDEA Astropectinidae Astropecten duplicatus Gray Fourteen specimens were caught at depths of 20 to 50 fathoms They occurred at temperatures between 15.2° and 20 .3° C and at salinities between 23.8 and 36.5 ppt. Astropecten sp. Four unidentified specimens of Astropecten were caught in 1967 at temperatures and salinities ranging from 19.0° to 20. 5° C and 36.2 to 36.4 ppt respectively. They were taken at depths of 40 to 50 fathoms. LUIDIIDAE Luidia clathrata (Say) There were 330 individuals caught in temperatures between 13.0° and 29.5°C and in salinities between 26.2 and 39.8 ppt. The majority of specimens were caught in 5 to 10 fathoms, with only one being caught at 50 fathoms in 1968. Hildebrand (1954) noted that a few specimens were found in Texas at 12 to 18 fathoms, and two were from 19 fathoms at the Obregon fishing grounds off Campeche. Luidia clathrata is the only starfish commonly found in Mississippi Sound (GMEI data). ECHINASTERIDAE Echinaster modestus There were three specimens found in temperatures ranging from 18.3° to 21. 9° C and in salinities ranging from 33.2 to 35.5 ppt Depths of capture ranged from 40 to 50 fathoms. 66 GULF RESEARCH REPORTS ECHINOIDEA Clypeasteridae Clypeaster sp. Three unidentified specimens of Clypeaster were found in tem- peratures and salinities ranging from 16.4° to 18.6° C and 36.5 to 36.9 ppt respectively. All specimens were taken at 30 fathoms. They have been deposited in the Laboratory museum . HOLOTHUROIDEA Molpadiidae Molpadia cubana Deichmann A total of seven specimens appeared in 1967 and 1968 with none being taken in the 1969 hauls. The six 1967 specimens were collected at 20 fathoms during January, February and May. These specimens were taken from temperatures between 15,6° and 20.3° C and from salinities between 32.7 and 36.8 ppt. A single specimen taken in June of 1968 was found at a temperature of 25.0° C and a salinity of 37.0 ppt. Hildebrand (1954) noted the presence of M. cubana near shell bottoms in deeper offshore waters. Systematic Account - Fishes A total of 129 species (93,563 specin^ens) representing 103 genera and 57 families .was collected. Species density and contribution to the total trawl fish catch of each family encountered are presented in Table 18. Those families considered to be of commercial importance and their contribution to the catch are shown in Table 19. Families Sciaenidae, Sparidae and Stromateidae were represented by the greatest numbers and comprised 83% of the total catch. NEKTONIC AND BENTHIC FAUNAS 67 TABLE 18 CONTRIBUTION OF EACH FAMILY TO TOTAL CATCH OF FISHES Fnmily Xo. of Species TotaJ No. Specimens Family No. of Species Total No. Specimens Carchrirhinidae 2 8 Scianidae 9 42,152 Sphyrnidae 1 20 Mullidae 1 162 Squatinidae 1 17 Sparidae 4 28,608 Rhinobatldae 1 1 Ephippidae 1 69 Tnrpedinidae 1 9 Trichiuridae 1 172 Rajiidae 2 41 Scombridae 2 65 Dasyatidae 2 12 1 Gobi idae 1 16 Clupeldae k 326 ( Scorpaenidae 3 213 Engraiil tdae 2 3,736 Trlglidae 11 1,118 Synodontidae 3 1,425 Uranoscopidae 3 14 Ariidae 2 557 Brotulidae 1 14 Aiigutll idae 1 6 Ophidildae 2 307 Nuraenidac 1 78 Scromateldae 2 7 ,058 Congridae 2 15 Sphyraenldae 1 8 OphichthLdae 1 1 Nugilidae 1 1 Bregma cerot idae 1 2 Polynemidae 1 1 Gadidae 3 271 Bothidae 13 1,441 Macrouridae 1 63 Soleldae 2 118 Syngnathidae 2 10 Cynoglossidae 2 66 Zeidae 1 1 Echeneidae 1 3 Serranidae 6 1,779 Dal istidae 3 82 Lu tjanidac 2 169 Ostracildae 1 21 Priacanthidae 1 4 Tetr adontidae 2 70 Branch lost eg Idae 1 11 Diodontidae 1 8 Poma toraidae 1 3 Batrachoididae 1 104 Rachycontridac 1 1 Lophlldae 1 1 Carangidae 5 2,573 Antennarlidae 1 49 Gerr Idae i 25 Ogcoccphal idae 4 396 Pomadasyidae 1 62 TOTALS 129 93,563 TABLE 19 COMPOSITION BY COMMERCIALLY IMPORTANT FAMILIES OF FISHES FAMILY % of Total Catch Sciaenidae 45.05 Sparidae 30.58 Stromateidae 7.54 Engraulidae 3.99 Serranidae 1.90 Bothidae 1.54 Triglidae 1.19 Ariidae .60 Clupeidae .35 Lutjanidae .18 Trichiuridae .18 Scombridae .07 Total , . . 93.17 68 GULF RESEARCH REPORTS Annotated List of Species CHONDRICHTHYES Squaliformes CARCHARHINIDAE - Requiem Sharks Mustelus cams (Mitchill) - Smooth dogfish The smooth dogfish was taken in both 1967 (three specimens) and in 1968 (one specimen). In March of 1967 a 963-mm TL (3,178 kg) specimen was taken at Station 1 and in June of the same year, two other specimens, 690 mm TL (1.814 kg) and 825 mm TL (2.268 kg), were collected at 50 fathoms. The March specimen was taken at 20.6° C and 30.3 ppt while 20.9° C and 37.8 ppt were recorded for the June specimens. In March of 1968 at Station 6, a 974-mm TL specimen weighing 4.327 kg was captured at a temperature of 15.3° C and a salinity of 34.6 ppt. Scoliodon terraenouae Richardson - Atlantic sharpnose shark The sharpnose shark first appeared in the catch in August of 1967 at 50 fathoms. The specimen measured 633 mm TL and weighed .986 kg. A temperature and salinity of 25.1°C and 36.8 ppt were recorded on this occasion. In 1968 three additional specimens were captured, one (959 mm TL and 3.901 kilograms from 20 fathoms) in Januarj*^ and two (550 and 688 mm TL with no weights recorded) in October. The 1968 specimens were collected at temperatures between 18.4° and 24.8° C and salinities between 30.5 and 35.7 ppt. We have taken some small S. terraenouae in miscellaneous trawl hauls in Mississippi Sound, Sphyrnidae - Hammerhead sharks Sphyrna tiburo (Linnaeus) - Bonnethead Twenty bonnethead sharks were taken in three years. These sharks ranged in size from 390 to 930 mm TL and were taken at temperatures and salinities ranging between 14.6° and 26.1° C and 25.8 to 37.4 ppt. Gunter (1945) found the salinity limits to be 22,8 to 36.2 ppt. Clark and von Schmidt (1965) remarked that S, tiburo may have a continuous mating season during the spring and fall. Hoese and Moore (1958) noted that individuals they collected in late August ranging from 342 to 369 mm were recently born. Gunter (1945) took specimens 308 to 315 mm in September and October. The smallest bonnethead (390 mm TL) in our samples was caught in December. NEKTONIC AND BENTHIC FAUNAS 69 Specimens collected in March were from 400 to 433 mm TL. Specimens collected in June and July at GMEI stations in Mississippi Sound were 383 to 400 mm TL. Our GMEI September and November collections ranged from 416 to 695 mm TL with the smallest specimen in November. Squatinidae - Angel sharks Squatina dumerili Le Sueur - Atlantic angel shark Seventeen angel sharks ranging in size from 227 to 1,003 mm TL were taken during the 3 years. Temperatures ranged between 15.3° to 20.0° C and salinities ranged between 33.5 to 37.8 ppt. The greatest catch occurred in the month of March with fourteen specimens being captured. The area of greatest concentration was at 40 fathoms. The largest specimen, collected at Station 6 in February 1969, aborted 10 young on deck, and these were successfully returned to the laboratory alive. Since they were premature each had a large yolk sac. Sizes of young ranged from 215 to 238 mm TL. Additional Observations - Squaliformes A large number of sharks were observed and taken incidentally to the regular collection program. These species taken only by handline and identified were Aprionodon isodon (Muller and Ilenle); Carcharhinus limbatus (Muller and Henle); Carcharhinus falciformes (Muller and Henle); Negaprion brevirostris (Poey) and Sphyrna zygaena (Linnaeus). Among this group of sharks Carcharinus limbatus was the most abundant. At our offshore stations sharks were obser\'ed in greatest numbers from March through November, with the majority occurring at the deeper stations (30 to 50 fathoms). We have utilized small bonnethead and other sharks for food. There is an abundant, unexploited population of sharks in the northern Gulf. Rajiformes Rhinobatidae - Guitar fishes Rhinobatos lentiginosus (Garman) - Atlantic guitarfish A single specimen of R, lentiginosus was collected at Station 1 in September 1967. A temperature and salinity of 26.1° C and 30.4 ppt respectively, were recorded at this time. The specimen measured 419 mm in len^h and was 107.3 grams in weight. 70 GULF RESEARCH REPORTS TORPEDINIDAE - Electric rays Narcine brasiliensis (Olfers) - Lesser electric ray. Nine specimens ranging in size from 245 to 395 mm TL were taken. Seven occurred in 1967 at temperatures ranging between 17.0'’ to 17. 2° C, Salinities were recorded as being between 26.6 and 32.4 ppt. The remaining two electric rays were collected in 1968 at temperatures and salinities between 21,8° to 24.0° C and 31.8 to 33.6 ppt respectively. Gunter’s (1945) limits for the. same factors were 15.4° to 29.5° C and 30.6 to 36.5 ppt. This species appeared in greatest numbers (eight) at 5 fathoms. We have taken numerous N, brasiliensis in miscellaneous hauls around the barrier islands and in the shallow passes. Rajidae - Skates Raja eglanteria Bose - Cleamose skate Twelve R. eglanteria, 220 to 573 mm TL, were encountered. Temperatures ranged between 16.9° and 29.0°C, with salinities ranging between 26.6 and 37.2 ppt. Four were collected in 1967, six in 1968 and two in 1969. Specimens were found at all stations. Raja texana Chandler - Texas skate This species of Raja was taken in slightly greater abundance than R. eglanteria. Twenty-nine specimens ranging in length from 205 to 573 mm TL were taken at salinities from 27.0 to 39.8 ppt and temperatures from 13.5° to 27.3°C. Gunter’s (1945) temperature limits were 13.7° to 25.5°C. Hildebrand (1954) reported R, texana to be present in the shallow Gulf all year long. The present specimens were taken in greater numbers at deeper offshore stations. We have taken a few R. texana in miscellaneous Mississippi Sound hauls. Dasyatidae - Stingrays Dasyatis americana Hildebrand and Schroeder - Southern stingray Two D. americana were collected during the study. A 341 -mm TL specimen weighing 1,193 kilograms was taken in September 1967 at Station 1. The temperature was 26,1° C, and the salinity was 30.4 ppt. The second specimen appeared in the net at Station 5 in February 1969. The temperature and salinity were 16.9° C and 33.5 ppt. This ray measured 1,925 mm TL and weighed 37.65 kilograms. Although only six small southern stingrays were collected in GMEI samples, we have observed many larger specimens during the summer in shallow water on sandy bottom around the barrier islands. These data NEKTONIC AND BENTHIC FAUNAS 71 conform to the statement of Gunter (1945, p. 22) - *‘so far as available information goes it is present in water of hi^ salinity and inhabits the open Gulf or the parts of the bays near the passes.” Dasyatis say (Le Sueur) - Blunt nose stingray Ten D. say were collected at Station 2 during the study. In March 1967 one specimen was taken at a temperature of 14.6® C and a salinity of 35,4 ppt. A single ray taken in November 1968 occurred at a temperature of 25.2° C and a salinity of 36,5 ppt. This specimen measured 1,169 mm TL. The remaining eight rays were taken in 1969 at temperatures and salinities ranging from 13.5° to 14.9° C and 31.2 to 31.5 ppt, respectively. These eight individuals ranged in size from 260 to 1,162 mm TL. Additional Observations - RAJI FORMES In early September 1968 at the 5-fathom station a single Manta birostris (Walbaum) was observed near the boat. The manta measured approximately 8 feet across the disc. This species has been un- commonly reported in offshore surveys. Manta rays were a common sight in the study area before World War II ( fide J.Y. Christmas). Fishermen searched for rays resting at the surface because lemonfish (cobia - Rachycentron canadum) were nearly always found in their shade. A boat, approaching carefully, could get within casting distance. Occasionally several lemonfish could be hooked before the ray sounded. In the intervening years, indiscriminate spearing and shooting have so reduced the population that the manta ray is a rare sight off Mississippi. OSTEICHTHYES Clupeiformes Clupeidae - Herrings Brevoortia patronus - Gulf menhaden Few menhaden were taken in trawl samples. Gunter (1958) reported the failure of trawls to sample menhaden in Mississippi waters. Roithmayr’s (1965) work on the composition of the commercial bottomfish fishery shows that few menhaden are taken by the trawl fishery. The total catch in our samples comprised four specimens, all taken at Station 1 . 72 GULF RESEARCH REPORTS In December 1967 a 200-mm TL specimen weighing 99.2 grams was taken at a temperature of 17.2° C and a salinity of 26.6 ppt. A november 1968 specimen measuring 180 mm TL and weighing 141 3 grams appeared at a temperature and salinity of 16.4° C and 36.5 ppt. In January 1969 two menhaden (132 and 162 mm TL, 22.5 and 55.2 grams, respectively) were taken at a temperature of 14.1° C and a salinity of 32.1 ppt. GMEI data show that menhaden are in the estuarine area all year. Over 95% of the 62,802 specimens collected (April 1968 through March 1969) in one year were taken in seines. Christmas, Gunter and Whatley (1960) described the estuarine nature of the Mississippi menhaden fishery. Combs (1969) showed that B. patronus spawns in Gulf waters from October through March. Christmas (unpublished data) took menhaden in the offshore study area with gill nets at the 20-fathom curve. The Gulf menhaden is present in vast numbers and with the Atlantic species supports the largest fisher>’ in North America. New record catches have been taken in the menhaden fishery in recent years. They must have been abundant at offshore stations during this study but they avoided the trawls. Etrumeus sadina (Mitchill) - Atlantic round herring Temperatures and salinities ranged from 19.6° to 27.3°C and 27.0 to 35.7 ppt for the fifty-three specimens collected. Round herring were found only at 10 and 20 fathoms. They were found in May and July 1968 and in April and May 1969. A size range of 70 to 135 mm TL was recorded. Harengula pensacolae Goode and Bean - Gulf sardine A temperature range between 12.0° and 29.5° C and a salinity range between 19.9 and 37.5 ppt were recorded for 266 specimens acquired in all three years. Specimens ranged from 80 to 167 mm TL, and a total weight of 4,734 kilograms was noted Specimens were found no deeper than 10 fathoms. Gunter (1945) and Reid (1954) noted the disappearance of H. pensacolae from inshore waters from December through early spring. Our offshore catches increased from late winter through early spring. The Gulf sardines were taken in GMEI samples in all months but were relatively rare from November through April. About 90% of the 2,416 specimens collected in 1968-69 were young of the year caught at seine stations. NEKTONIC AND BENTHIC FAUNAS 73 Opisthonema oglinum (Le Sueur) - Atlantic thread herring Atlantic thread herring, like menhaden were rarely caught in our trawl samples. Three Atlantic thread herring were collected. A single 142-mm TL specimen weighing 35,0 grams was taken in January 1968 at Station 1. The temperature and salinity at this time was 14.8‘'Cand 28.5 ppt. In April 1969 two specimens, 113 and 135 mm TL, and weighing 13.5 and 22.4 grams, were collected at Stations 1 and 2, respectively. The temperature and salinity extremes were 19.6° C and 35.7 ppt. Miles and Simmons (1950) and Christmas, Gunter and Whatley (1960) mention that the thread herring makes up only a small percentage of the menhaden catch. Fuss, Kelley and Prest (1969) suggested a spawning season from March through August with noticable peaks in June for the Fort Myers, Florida, area. A spawning period during May and June has been established by Hildebrand (1963) for the Beaufort, North Carolina area. Bullis and Thompson (1967) estimated that the thread herring stocks in the Gulf of Mexico amount to 1 million tons. They showed that this species is in the northern Gulf throughout the year. This species was not taken in GMEI samples. A thread herring fishery started operations at Charlotte Harbor in 1967 (Fuss et al. 1969) but this resource is not exploited in the northern Gulf. Mississippi menhaden fishermen ( fide J. Y. Christmas) prefer not to catch thread herring when menhaden are available, because the oil yield is low. EngrAULIDAE ’Anchovies Anchoa hepsetus (Linnaeus) - Striped anchovy A total of 2,052 striped anchovies were collected. They were taken during all months and at all depths ranging 5 to 50 fathoms; however, the majority were taken only out to 20 fathoms. The 5- and 10-fathom stations yielded the greatest catch. At all stations in all three years, day sampling produced the largest catch by far. The sizes of specimens ranged from 72 to 156 mm TL. The temperatures and salinities of collections ranged from 13.0° to 29.0° C, and 26.7 to 37.4 ppt respectively. In all three years, the month of April yielded the highest catch per unit effort and also the largest specimens were taken in this month. Hildebrand and Cable (1930) reported the striped anchovy reaches maturity at approximately 75 mm. If this is correct we collected only mature specimens. They also indicated that spawning occurs between April and July both inshore and offshore in the Beaufort, North Carolina iirea. Gunter (1945) found ripe individuals in the Gulf in May, and Springer and Woodburn (1960) took ripe or 74 GULF RESEARCH REPORTS nearly ripe adults from March through May and young individuals in July and December in Tampa Bay area of Florida. Since a spring spawning period is indicated by these workers the large catches in April, May and June are probably indicative of the spawning component in the offshore Mississippi area. Gunter (1945) reported an almost total absence of this species from the bays of Texas during colder months. Our larger catches in October and November indicate a migration to warmer deeper waters in the study area. Gunter (1945) reported taking this species at a salinity of 2.5 ppt and Simmons (1957) took this fish at salinities up to 85 ppt. Gunter and Hall (1965) reported this species from as low as 1.8 ppt in south Florida. The majority of our specimens seemed to prefer salinities ranging from 29.0 to 37.9 ppt. (Table 20). The approximate total mass was 27.84 kg. Larger catches of this species would probably have been recorded had trawls with a smaller mesh size been employed. GMEI samples often included A. hepsetus from May through October A few were collected in April and November. One December sample included A, hepsetus. They apparently were not in estuarine waters from January through March. The total length range in the estuarine study area was 9 to 160 mm. Young striped anchovies appeared in seine hauls from April through July, indicating a spring spawning season with utilization of the estuarine nursery area. There are no good estimates of the total striped anchovy stocks in the Gulf; we believe however, that this species would support a fishery. Gunter (1938a and 1941) estimated this to be one of the most abundant species in the shallow Gulf. This resource is harvested only incidentally in the industrial bottomfish fishery. Both fishing and processing methods will require development before these anchovies can be profitably exploited in Gulf waters. Anchoa mitchilli (Valenciennes) - Bay anchovy The bay anchovy (1,684 specimens) appeared only in Janu^, February, April and August. Gunter (1945) stated that apparently A. mitchilli is most common in the Gulf during winter and spring while being somewhat scarce in the summer months. Our data tends to agree since, as stated previously, the fish was taken during colder months and virtually disappeared in the summer. Specimens ranged from 44 to 90 mm TL, and were taken at temperatures and salinities from 13.0° to 29.0°C and 28.5 to 33.8 ppt. NEKTONIC AND BENTHIC FAUNAS 75 TABLE 20 DISTRIBUTION OF ANCHOA HEPSETUS BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES, CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH (MM). 1967 salinity INTEAVAL PPT TfM INT. 16.6 IT.O 20.0 2)«0 26.0 29.0 32.0 J4.0 18. 0 16.6 C 16.9 19.9 2Z.9 29.9 2».9 J1.9 SA.9 37-9 39.6 39,0 SNPLS. 0 0 0 0 0 0 0 0 0 0 lo.t catch 12.9 NIN-HAlf HEAN SML$. 0 0 0 0 0 1 6 1 U 8 ij.a CATCH 3.000 1.666 0.000 1.625 19»« A(N*PAX 98- 1 10 106- 124 98- 130 MEAN 112.6 111.0 SHfLJ. 0 0 0 0 1 1 A 13 0 19 16,0 CAttH 2.000 9.000 0.240 21.769 16*096 10.9 MIH^MAX 97- 119 109- 120 116- 116 103- I9J 9 7- 151 MEAN Loa.o 116,6 116.0 116.6 116.5 SHOLi. 0 0 0 0 0 2 A 21 0 27 19.0 CATCH 6.900 18.400 0.0A7 3.Aor 21.9 .IN-HAX lOT- IJJ 102- 137 133- 133 102“ 137 H(*N iir.i 116.6 139.0 116.9 SNl-li. 0 0 0 0 0 1 1 12 0 lA 22.0 CATCH 62.000 1.000 0.093 A. 71A 2A.9 HIN-HAX 100- 111 lU- 118 129- 129 lUO- 133 HCAN 111.1 118.0 129.0 113.7 SHPLS. 0 0 0 0 0 * 2 10 0 2A 20.0 CATCH Q.rjo A. 900 0,959 0,916 22.9 MIM-MAX 126- 116 U2- 124 87- 125 87- 116 MEAN ni.i 111.6 9T-9 LiO.A IHPLS. 0 0 0 0 Q 0 2 V 0 2 20.0 CATCH 29.9 MIIA-MAA 0.000 0.000 HI AN SNPLS. 0 0 0 0 1 9 19 65 0 9A 10.. CATCH 2.000 10. AAA 5.104 A. 936 5.668 29.9 HIM>HAX 9T- 119 98- 116 102- UT #7- 1S» 67- 153 MEAN lOA.O 116.9 116*3 114.1 115.6 TEM. IHT. C 16.6 16.9 lT-0 19-9 20.0 22.9 salinity 21.0 25.9 1968 INTEAVAL 26.0 28.9 PPT 39.0 3i.9 32. 0 3A,9 35.0 37.9 18.0 >9.8 16.6 19.8 4H.C5. 0 0 0 0 0 0 0 0 0 0 10. • CATCH 12.* HIN-HAX MIAN SMPCS. 0 0 0 1 A 0 6 0 0 11 11.0 CATCH 20.000 12.T50 4,666 9.000 11.9 MIN-HAX 96- 126 72- 119 96- 119 T2- 119 MEAN 111.1 112.1 1 1A«0 112. 6 SMPCS, 0 0 0 2 2 1 6 8 0 21 16.0 CATCH 0.000 12.000 0.000 0.000 81.500 12.942 11.9 MlN-NAI 105- 115 90- lAO 90- 160 MEAN 115.1 ilA.A 116.6 SM.lS, 0 0 0 3 0 1 6 4 1 20 19.0 CATCH 0.000 0.000 0,000 16.750 0.000 0.000 10,500 21f9 AIM-MAX 105- 146 105- 156 MtAN 12 7.0 127.0 SM.C1, 0 0 0 0 1 0 2 A 0 9 22.0 CATCH 56.000 27.000 9.500 25.000 2..<> NIN-NAX no- 137 III- 160 101- 119 101- 160 MEAN 121.0 121.9 115,2 121.1 JH.CI. 0 0 0 L 1 1 1 6 \ 14 25.0 CATCH 0.000 19.000 2r, 333 0,000 0 . 166 0,000 6.900 2T.9 MIN-HAX 91- U9 no- 162 lAtt- 140 93- 140 KEAN 106.1 122*6 168.0 119.4 IHPll. 0 1 0 0 2 3 1 .1 0 0 28.0 CATCH 0,000 5.000 21.000 17.000 0.000 11.250 29.5 MIN-HAX 80- 106 tOT- 118 BO- 106 00- 1)0 MEAN 86. T 125,1 ttT.l U3,a SM.LS. 0 1 0 7 19 12 2A 24 4 91 10.8 catch 0.000 2.85T 11.157 12.083 16*3/5 29.658 0,000 16.210 29.5 MIH-MAX 9A- 126 72- 119 lOT- 162 00- 1S6 90- 168 /2- 156 MEAN iii.i 115.8 121.3 120.6 llA.0 110*4 76 GULF RESEARCH REPORTS TABLE 20 (Continued) 1969 SALtHirV INTERVAL RRT TEMP INT. C U.A 16.9 ir.o 19.9 20.0 22.9 2B.0 25.9 26. 0 28. 9 29.0 51.9 32.0 J-..9 35,0 If. 9 58,0 Ib.b 39,8 10.1 1Z.9 SKPLS. CATCH HIN-HAA MCAN 0 0 0 0 0 Q 1 0.000 1 0.000 0 2 0,000 IJ.O CATCM 19. « MlN-MAl MCAKI 1 0.000 0 0 2 0.000 1 5.000 100* 112 11-.. 2 T U 5 ri lU - 150 121.0 6 0.000 L 0.000 U 18 g .888 100- 132 118.9 16.0 IB. 9 &MPL & A CATCH MINt-HAX MEAN 0 0 1 0.000 0 0 1 0.000 T 0.000 0.000 2 0*000 2-9 o.OOO 19.0 21.9 SHPLS. CATCH HIN-HAA mean 0 1 0.000 0 1 1. Ill 105- l^l 119.2 0 0 5 5.200 lOv - L 28 lib . 8 & 1.500 112- 2<.J L 22.6 0 15 3.000 104.* 1-.1 \ Lti .5 22.0 2*.0 CATCH hin>ha)i mean 0 0 0 L Q.OOO 0 0 0 0 0 1 Q.OOO 29.0 2T.. SNRli. CATCH HIN'MAA mean 0 0 0 0 0 0 0 0 0 0 2».0 catch 29.4 HIN-HA* MtAN 0 0 0 0 0 0 0 0 0 0 10. » 29.4 SMPkS. CATCH HIN-MAX MIAN 1 0.000 L 0.000 L 0.000 b 1.666 lOS- 1*1 119.2 L 5.000 100- 112 ll ->.2 8 I.i)r5 U4- 150 121. 0 19 1.^68 128 U6.8 21 0.-*2B U2- lAJ 122 . b 2 o.uoo bO 1.01b lOQ- U3 U6.b By far the greatest number of specimens was taken at the 5-fathom depth with only a few being found in 10 fathoms. No bay anchovies occurred beyond 10 fathoms. The mesh size of the trawl could have allowed a number of smaller bay anchovies to escape capture. Bay anchovies were the most abundant fish in GMEI samples. Myctophiformes SynodontidAE - Lizardfishes Saurida brasiliensis Norman - Largescale lizardfish Two largescale lizardfish were taken, one in March 1967 from 50 fathoms and another in April 1969 from 20 fathoms- The March specimen measured 95 mm TL and weighed 4.3 gm, and the fish collected in April measured 133 mm TL and weighed 17.4 gm. The temperature and salinities were 20.0°C and 37.8 ppt (March) and 17.8'' C and 39.8 ppt (April). NEKTONIC AND BENTHIC FAUNAS 77 Synodus foetens (Linnaeus) - Inshore lizardfish A total of 1,413 inshore lizardfish were collected during all months and at all stations. Although they were taken at depths ranging 5 to 50 fathoms, Stations 3 and 4 at depths of 20 and 30 fathoms respectively produced the greatest yields. These specimens ranged 99 to 478 mm TL. The temperatures ranged 12.0° to 29.5® C and the salinities 16.6 to 39.8 ppt. Our smallest specimen (99 mm TL) was taken in November; however, specimens 115 mm TL and 117 mm TL were taken in July and August, respectively. Gunter (1945) said this species probably spawns in the spring. Reid (1954) concurred, but Springer and Woodburn (1960) found very small individuals in November and December. Miller (1965) took a 93-mm specimen in March and mentioned this could be a product of fall spawning. Hildebrand (1954) found no seasonal trends for this fish, and our catch records tend to coincide with his findings. Smaller S. foetens (38 to 279 mm TL) were taken in GMEl samples. Trachinocephalus my ops (Forster) - Snakefish Ten snakefish were taken, three in 1967 and six in 1968 (177 to 300 mm TL, size range for both years). These fish occurred at temperatures and salinities ranging 16.4° to 25.5° C £ind 23.2 to 37,8 ppt. A single specimen (218 mm TL) was caught in a day haul in April 1969 at a temperature of 18.4°C and a salinity of 37.4 ppt. Fish were obtained only at 30 and 40 fathoms. This species did not occur in GMEI samples. Cypriniformes Ariidae - Sea catfishes Bagre marinas (Mitchill) - Gafftopsail catfish Five gafftopsail catfish were collected during the study, three in September 1967, one in November 1967, and one in February 1969. The specimens taken in 1967 ranged from 163 to 340 mm TL and were taken at temperatures and salinities ranging from 14.0° to 26.1° C and 31.5 to 32.4 ppt respectively. All of these fish were collected at Station 1. The February 1969 specimen was from Station 1 and measured 191 mm TL and weighed 46.0 grams. The temperature and salinity at this time were 14.0°C and 31.5 ppt. Total weight for 5. marinas was 1.013 kilograms. Gudger (1918) and Gunter (1945) reported the spawning period 78 GULF RESEARCH REPORTS of the gafftopsail catfish to be in May and June for a very short duration. Our catches of young fish in February (191 mm) and November (164 mm) indicate the possibility of first year fish leaving the estuarj' during the colder season. GMEI bay samples with one exception in February included gafftopsail from April through October only, and a large male carrying eggs with well developed embryos was taken in June 1966. Gafftopsail catfish are marketed for the table in Mississippi. Most of the catch (20,000 pounds in 1965) has been taken incidentally in other fisheries, including the industrial bottomfish and menhaden fisheries. Christmas, Gunter and Whatley (I960) observed P. mariniis in 52% of the menhaden hauls they sampled. Gafftops were the fifth most abundant species (2.8%) caught in the menhaden fishery. Most of the gafftops were removed by the fishermen and either eaten or sold in the food-fish market ( fide J.Y. Christmas). Galeichthys felis (Linnaeus) - Sea catfish A total of 552 sea catfish was collected and they were taken in all months. Specimens were obtained at depths ranging from 5 to 50 fathoms but were taken in largest numbers at 5 fathoms. Gunter (1945) found few fish in winter in the Texas bays and none in January, Hildebrand (1954) noted this fish was not common offshore during the winter months and our data are in agreement. However, Miller (1965) found this species more abundant during the colder months with a sharp decline as temperatures warmed. Although an increase in numbers was expected during the colder months due to an offshore migration to escape colder temperatures, this was not in evidence. The catch increased during the warmer months with June showing the greatest catch. Our observations of the absence of this fish from the Mississippi Sound and adjacent bays during the winter months (GMEI data) coupled with the scarcity of sea catfish at depths to 50 fathoms indicate a wide winter scattering of G. felis from this area. The sizes of the sea catfish taken ranged 132 to 361 mm TL. The temperatures and salinities varied 12.0° to 29.5° C and 24.9 to 37.5 ppt. The highest catch per unit of effort during the study occurred in 1967 at temperature and salinity intervals of 19.0° to 21. 9° C and 29.0 to 31.9 ppt respectively (Table 21). ANGUILLIPORMES ANGUILLIDAE - Freshwater eels Anguilla rostrata (Le Sueur) - American eel The first specimen of A. rostrata appeared in November 1967 at a NEKTONIC AND BENTHIC FAUNAS 79 temperature and salinity of 19.5” C and 35.4 ppt. The specimen measured 409 mm TL and weighed 70.1 g. In 1968 four eels were collected (one each from Stations 2, 3, 4 and 6) in temperature and saJinity ranges of 15.2° to 22.0° C and 33.0 to 34.6 ppt respectively. These individuals ranged in length and weight from 376 to 495 mm TL and from 71.3 to 144,3 g, A single February 1969 specimen, 445 mm in TL and weighing 98.3 g, was taken from 20 fathoms at a temperature of 15.1° C and a salinity of 30.1 ppt. Bullis and Thompson (1967) suggested that eel stocks would support a small fishery. This resource remains unexploited in Miss- issippi. MuraENIDAE -Morays Gymnothorax nigromarginatus (Girard) - Blackedged moray This represents the only species of moray taken during the study. Seventy-eight specimens (1967 - 5, 1968 - 54, and 1969 - 19) were collected at temperatures and salinities ranging from 15.2° to 28.0° C and 19.9 to 39.8 ppt. The size range was 224 to 477 mm TL with a total mass of 9.139 kg. Gymnothorax nigromarginatus was collected in all months. None were taken at less than 20 fathoms. CONGRID AE - Conger eels Congrina flaua (Goode and Bean) - Yellow conger The yellow conger eels (four specimens) were taken only in 1968 (January, October and November) at temperatures and salinities ranging between 15.2° and 19.3° C and from 27.9 to 37.4 ppt. These eels ranged from 197 to 414 mm TL. Congrina flava has rarely been reported in the northern Gulf. Roithmayr (1965) found them in industrial bottomfish catches- Specimens were taken from 20 to 50 fathoms. Hoplunnis macrurus Ginsburg - Silver conger A single specimen taken at 50 fathoms during June 1967 in a night haul measured 447 mm TL and was taken at a temperature and salinity of 18.3° C and 35.4 ppt. Seven fish (210 and 549 mm TL) were taken in 1968. Temperatures and salinities for these specimens ranged between 15.3° to 26.5°C and 25.2 to 38.7 ppt. Three fish (296 and 426 mm TL) taken in 1969 were found at temperatures of 16.7° too 20.5°C and salinities of 19.9 to 35.7 ppt. The 1968 and 1969 specimens were collected between 20 and 50 fathoms. Hildebrand (1954) reported this species and noted females with eggs in January and May. 80 GULF RESEARCH REPORTS TABLE 21 DISTRIBUTION OF GALEICHTHYS FEUS BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES, CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH (MM). 1967 InTERI^AL PRT \HJ. C Ib.b Lb. 9 17.0 19.9 20.0 22.9 21.0 25-9 28.0 28.9 29.0 Jl.9 12.0 1*.9 J5.0 JT.9 18.0 19, B 16.6 19-8 SHPL&. L0«8 CAKtl 12. Q MIN-MAX MEAN 0 0 0 0 0 0 0 0 0 0 SMPLS. 11.0 CATCH HtN-MAX MEAN 0 0 0 0 0 1 0.000 6 O.&ll 165- 125 273.2 1 2.000 209- 161 2B5.U u 8 0.875 165- 161 2T6.5 S«PIS. U.O CATCH 18.? HIM-HAA MEAN 0 0 0 0 1 1 .ouo 175- 175 irs-o 1 0.000 MEAN 291.5 288.3 2/1.6 SHPLS. 0 0 0 2 2 1 6 a 0 21 18.0 CATCH 1.000 I. 000 o.ooo 0.800 1.625 0.952 10*9 MIN-MAX Z6fr- JOfl 283- 313 Zfcl- 285 W9- 2 78 199- 111 MEAN 28/. 0 298.0 276,6 223. 3 2*5.2 SHPci. 0 0 0 1 6 1 8 1 2B 19.0 CATCH 0.000 0*000 0.000 0.7 50 u.ooo 0.000 0,21* Z1.9 min-max 205- 335 20*- 3)5 mean 212. 8 272.8 SMPCi. 0 0 0 0 2 0 2 4 0 6 ZZ.O CATCH 0*000 5,mQO 1 . 750 2.125 Z..9 NIN-MAK 231 272 282- 313 231- 313 MEAN 253.3 2Bi. 1 265.6 SMPLi. 0 0 0 1 1 1 1 6 i 15 25*0 catch 0.000 8.000 0.666 3.U00 0.000 0.000 0*066 ZT.9 HIN-MAX 230- 313 192- ZO* 249- 79* 192- 313 MIAN 261. L 198.0 270.0 265. r SMP1.S. 0 1 0 0 2 1 1 1 0 6 za.o C8TCH 0.000 6.000 0.666 O.OOO 0.000 2.250 Z9.8 MIN-MAX 201- 219 263- 288 2U1- 273 MEAN 2*7.0 265.5 2*9.1 SH.LSt 0 1 0 7 19 12 2* 2* 4 91 10.1 CATCH 0.000 O.STl 2.000 0.331 0.916 0, Hii 0.000 0,967 29.5 HlN-HAX 288- 108 178- 313 I9Z- Z88 2U5- 338 199- 313 1/6- 115 MEAN ZS9.Z 283.8 231.7 264.0 255.8 259.1 NEKTONIC AND BENTHIC FAUNAS 81 TABLE 21 (Continued) 1969 IILINITV iNrEDviL PPT T(M» IHT. C lfr.& ir.o 19.9 10. 0 II. 9 13.0 23.9 lA.O IB. 9 29.0 31 .9 32.0 36.9 35.0 31.9 3B.0 39.8 16.6 39.9 inpii. 10. » C*TCM 11. * KIN-N** Real Q 0 0 0 0 0 1 0.000 1 6.000 265- 331 302.0 0 2 2.00Q 265- 331 302,0 SNPLS. l».Q CatCM RlR-RAl HtaN 1 0.000 0 0 2 0.000 1 3.000 L66- 315 247.0 f 1.57i 156- 336 233. S 1.000 TAB- 2 TO 219.0 i 0.000 0 18 Ulll 158- 336 23L. 3 smrls. t«.0 C*«Ch i».* rix-r** ream 0 0 L Q.OOO 0 0 0.000 J O.OOD u O.QOO 2 OaOOO 26 0.000 iR^LS. ig.O CAKH II.* MIN'HAA HEAR 0 1 0.000 0 1.333 1B7> Zli.l 0 Q 5 8.600 206- 320 251.4 6 1.333 200- 201 265,2 0 IS 3.600 187- 320 269.2 11.0 CATCH I*,* N1H-HAI MCAH 0 0 0 1 u.ooo 132- 232.9 0 0 0 0 0 L 11.000 III- lAl 232.5 SHPiS. 19.0 CATCH ITt* HIN-MAX REAM 0 0 0 0 0 0 0 0 Q 0 SnEiS. la.O CATCR I*.S HIN.RAf MEAN 0 0 0 0 0 0 0 0 0 0 WLS. 1 i 1 6 1 0 19 21 I AO 10. « CATCH 1«.5 HIM-NAX KAH 0.000 0.000 0.000 2.666 112- 265 232.B 1.000 UA- 113 lAT.O UlTi lAB- 13A 111. a 2.526 166- 320 247.3 0.571 200- 331 266. L 0.000 1.500 132- 336 26S.3 OPHICHTHIDAE Ophichthus ocellatus (Le Sueur) - Spotted eel A single large specimen measuring 184 cm and weighing 14.6 g was taken in March 1969 from 40 fathoms. The temperature was 16.4° C and the salinity was 35.7 ppt. This species occasionally occurs in commercial catches offshore. Gadiformes Bregmacerotidae Bregmaceros atlanticus Goode and Bean - Antenna codiet This species was represented by two specimens, both measuring 56 mm TL and weighing 0.8 g. The two fish were taken together in a March 1967 haul from 50 fathoms. The temperature and salinity were 20.0°C and 37.8 ppt. 82 GULF RESEARCH REPORTS Gadidae - Codfishes and Hakes Physiculus fulvus Bean One specimen of P. fulvus, 104 mm TL, was collected at 50 fathoms in February 1969. The temperature was 16.0° C and the salinity was 34.8 ppt. This species of gadid is seldom listed in literature concerning the Gulf of Mexico. Urophycis floridanus (Bean and Dresel) - Southern Hake One hundred and ten southern hake (75 to 375 mm TL) were collected during the three years of sampling. They were found at all stations. No southern hake were caught in December and January. The temperatures and salinities ranged 13.3“ to 26.5° C and 24.6 to 38.7 ppt. Juveniles are usually inshore from January through April (Gunter 1945, Reid 1954, Moe and Martin 1965). During the present study several individuals ranging from 75 to 100 mm TL were acquired in deep offshore waters. GMEI records show that U. floridanus is common in the estuarine study area from February through April. They apparently move to deeper water in the warm months. The minimum size in Mississippi Sound was 37 mm TL. Urophycis regius (Walbaum) - Spotted Hake The spotted hake comprised 160 specimens in our samples. This species has been rarely reported in other survey.?. Specimens ranged in size from 83 to 245 mm TL. Urophycis regius and U. floridanus were occasionally taken simultaneously. Temperatures and salinities for spotted hake ranged between 13.3° to 27.0°C and 16.6 to 38.2 ppt respectively. Seasonal occurrence of spotted hake in the estuarine study area (GMEI samples) was similar to observations of southern hake. M ACROU RID AE -Grenadiers Steindachneria argentea (Goode and Bean) A total of 63 S. argentea was taken in November 1968 in the same haul at Station 3. These specimens ranged in size from 77 to 147 mm TL with the total weight being 382.0 grams. The fish were taken at a temperature of 16.4° C and a salinity of 37.4 ppt. NEKTONIC AND BENTHIC FAUNAS 83 Gasterosteiformes Syngnathidae - Pipefishes and seahorses Hippocampus erectus Perry Hippocampus erectus was taken only in 1968 on two occasions (Station 2, July - 5 specimens; Station 6, August - 3 specimens). Temperature and salinities ranged from 21.9° to 26 .4° C and from 29.0 to 33.2 ppt. Hippocampus zosterae Jordan and Gilbert - Dwarf seahorse Two specimens of if. zosterae were recorded; both in 1967. A July specimen from Station 3 was taken at a temperature of 22. 4° C and a salinity of 36.5 ppt. The other specimen was collected at Station 4 in August. The temperature was 25.2° C and the salinity was 36.0 ppt, Zeiformes Zeidae Zenopsis ocellata (Storer) - John Dory A single specimen of Z. ocellata was collected in an October 1968 haul from the 50-fathom station. The fish measured 198 mm TL and weighed 150.7 g. The temperature and salinity were 21.8°C and 26.6 ppt. Zenopsis ocellata hi rarely been reported in the literature concerning the Gulf of Mexico. Perciformes Serranidae - Sea basses Anthiasicus leptus Ginsburg A single 116-mm TL specimen of A, leptus was taken from 50 fathoms in February 1969. A temperature and salinity of 16.0°C and 34.8 ppt were noted at this time. This species has been uncommonly reported in the literature. Hoese (1958) lists A. leptus as being taken in the Gulf from 150 fathoms. Centropristes ocyurus (Jordan and Evermann) - Bank sea bass A total of 951 bank sea bass was taken. They were encountered in all months and at depths of 5 to 50 fathoms with concentrations at 20 and 50 fathoms. These specimens measured 83 to 135 mm TL. All measurements were from snout to tip of the caudal filament. If caudal 84 GULF RESEARCH REPORTS filaments were damaged or missing, only standard lengths were taken, and these are not recorded here. The temperatures and salinities ranged from 14.0° to 29.0° C and 16.6 to 38.7 ppt respectively (Table 22). Springer and Woodbum (1960) took this species from 6 to 10 fathoms off Tampa Bay, Florida. Roithmayr (1965) lists this fish as being taken in the industrial bottomfish catches of the north-central Gulf. Centropristes philadelphicus (Linnaeus) Rock sea bass A small number of rock sea bass (147) was taken in 1967 and 1969 at temperatures and salinities from 12.0° to 22.9° C and 24.9 to 37.9 ppt. This species appeared only in the first five months of each year with no specimens being taken in the remaining months. Catches were greater at the deeper stations. Gunter (1945) reported specimens in offshore Texas waters in March, May, August and September. Miller (1965) states that spawning may extend from spring through the summer. A size range of 105 to 275 mm TL was recorded for the captured specimens. Small rock sea bass (21 to 130 mm TL) were taken at GMEI stations in Mississippi Sound. Diplectrum arcuarium Ginsburg - Sandfish A total of 371 specimens was collected in three years. Fish were taken at temperatures and salinities between 12.0° to 28.0°C and 24.6 to 37.9 ppt respectively- Hildebrand (1954) and Miller (1965) reported this species to be most abundant between 15 and 30 fathoms. In this study specimens were taken in greater numbers from 10 to 20 fathoms. Fish range in size from 75 to 150 mm TL, We have taken numerous small sandfish from Mississippi Sound in miscellaneous trawl hauls. Serranus atrobranchus Cuvier - Blackear bass A total of 305 individuals of this species was taken. They were encountered at depths from 5 to 50 fathoms. The greatest numbers were taken at 20 fathoms. The size range was from 50 to 131 mm TL. The temperatures and salinities ranged 15.2° to 29.0° C and 24.6 to 38.6 ppt respectively. Fish were taken in all months with the greatest abundance being found in the cooler months of October through March. Dawson (1966) encountered this species in 15 to 20 fathoms of water off Grand Isle, Louisiana. Serranus notospilus Longley - Saddle bass Four specimens of the saddle bass were taken. All were collected in a March 1967 haul from 50 fathoms and were from 72 to 93 mm TL. The temperature was 20.0° C and the salinity was 37.8 ppt. NEKTONIC AND BENTHIC FAUNAS 85 TABLE 22 DISTRIBUTION OF CENTROPRISTES OCYURUS BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES, CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH (MM). 1967 SALINITY IMTEAVAL PPT FfNl^ INT. 16.6 17.0 20.0 23.0 74.0 79.0 17. Q js.o 18.0 16.6 C 16*9 19.9 72.9 79.9 71.9 11.9 14.9 37.9 39.8 19.8 ShFLS. 0 0 0 0 0 0 0 0 a 0 la.* CATCH 17.9 HIH-IU* nCAN 0 0 0 0 0 X 6 I 0 a U*0 CATCH NIN-NAX O*O0O 0*000 0.000 0.000 MCAN MPLS. 0 0 0 0 1 1 A 13 0 19 U.O catch 0.000 2.000 0*000 L0«aA6 r.52b IB. 9 HIN-HAX 117- 791 117- 791 HEiin 17S.S 175.5 MPlS. 0 0 0 0 0 2 A 2L 0 27 19.0 CATCH 0.000 0.000 1.444 2.851 21*9 HIN->MAX 117- >15 117- 115 HEAM 707.0 707.0 SAPLJ. 0 0. 0 0 0 1 i 12 0 14 77.0 CATCH 0.000 0*000 7*666 4.571 74.9 NIN'HAX 170- 785 120- 285 HEAN 159*9 159.9 SHPLS. 0 0 0 0 0 A 7 18 0 2A 79.0 CATCH 0.2SO 1.000 3.666 3.061 2T.9 N1N-NAX 81- 87 81- 87 MEAN 85.0 85,0 5HPLS. 0 0 0 0 0 0 2 0 0 2 7*.0 CATCH tv. 9 nIH-MX 0.000 0.000 MEAN SMALL. 0 0 0 0 L 9 19 65 0 94 10.* CATCH 0.000 0.119 5.784 A, 095 19,9 MlH-MAl 81- 115 83- 315 MEAN 1968 leo.i 180.1 salinity INTEAVAL ppt TIM* IMT, lb. A lT-0 70.0 71.0 26.0 29.0 32.0 35*0 18.0 16.6 C 14.9 19.9 72.9 79.9 71.9 11.9 3A.9 37.9 3^*8 39.8 tHPLS. 0 0 0 0 0 0 0 0 0 0 10.1 CATCH 11.9 nlM'HAX MEAN iMPLi. 0 0 0 I A 0 6 0 0 11 19.0 CATCH 0.000 0.000 9.811 j.iii 19.9 MIN-MAX 97- ISO 97- 180 MEAN U0.3 140.1 *MPLi. 0 0 0 7 7 3 6 e 0 71 lA.O CATCH 71.900 0.900 fl.666 A *666 17.750 11.71B 1*.« nin-max 101- ITS 189- 199 101- 189 MEAN 171.1 189.0 179.4 SNMlS. 0 0 0 1 i 3 a 5 1 28 19.0 CATCH 11.9 MIN-MAX 2*666 9.47S A. 000 2.290 A, 600 0*000 1.785 MEAN SMPLS. 0 0 0 0 7 0 ?. 0 ' 8 72.0 CATCH 79.9 NIN-MAX 1.000 ll.SOO 1.750 5.000 NCAN IM*Ll. 0 0 0 1 1 1 1 6 3 15 a9«0 CATCH 1Tm9 HIH-NAX 0.000 0.000 6.000 0.000 1.111 0.333 2.200 MIAN SMPLS. 0 1 0 0 2 1 1 1 0 8 aa.o CATCH 29.9 Hlff-HAX 0.000 0*000 1.111 0.000 7.000 0*750 MIAN SM*V9. 0 1 0 T 19 12 74 74 * 91 10.9 CATCH O.OOO T.7#i 2.974 9*900 6*666 7.A16 0.750 5.010 M.f NIN-MAX lOJ- 179 9T- 180 169- 189 97- 189 MAH 171.1 140.1 189.0 177.1 86 GULF RESEARCH REPORTS TABLE 22 (Continued) 1969 ^UINITV INIEKVIL fPl ItMf INI. C 16.6 16.9 kT.O 19.9 20*0 22.9 29.0 24.9 26.0 26.9 29.0 31.9 32.0 36.9 34.0 37.9 Jb.u 3Q.fi Ib.b 19.fi INPLl. 10.1 CATCH 12.9 NIH-NAX MEAN 0 0 0 a 0 0 1 0.000 1 0.000 0 2 0.000 SMPCJ. 13.0 CATCH 13.9 HIN-NAX MEAN 1 1.000 0 0 z 2.000 1 0.000 T I. 162 b 2.000 1 3.000 0 i.bbb SMPCS. 19.0 catch ia.9 HIH-HAX MEAN 0 0 1 0.000 0 0 1 0.000 7 2.102 13 k.3fl6 2 0.000 26 1.3T4 SHFIS. 19.0 CAfCH 21.9 MEAN 0 1 27.000 0 4 0.000 0 0 5 1.000 6 2.400 0 14 3.133 ANPLS. 22.0 CATCH 2A.9 HIH'MAx HI AN 0 0 0 1 0.000 0 0 0 u u i o.ooo SHPLS. 23.0 CATCH 2T.9 NIN-HAX MEAN 0 0 0 0 0 0 0 0 0 0 SHPeS. 2t.O CATCH 29.3 HIH-NAX NtAN 0 0 0 0 0 0 0 0 0 u 3nPL3. 1 L L 6 1 a 19 2L 2 60 10. • CATCH 1.000 27.000 0.000 0.666 0.000 L .000 \ .666 I.TIA 0.000 1 .813 29. » HIN-HAX HfAN LUTJANIDAE - Snappers Lutjanus campechanus (Poey) - Caribbean red snapper A total of 122 Caribbean red snapper were taken. They occurred in all months. These fish were from 66 to 305 mm TL. The temperatures ranged from 15.4“ to 28.9“ C and salinities varied from 24.6 to 39.8 ppt. Specimens occured at depths from 5 to 50 fathoms. This is the only red snapper species taken in our samples and all were relatively small specimens. Adults concentrate around rough bottom not covered in our sampling. The red snapper fishery takes a variety of species. Carpenter (1965) listed L, campechanus as sixth in importance. He indicated that heavy fishing pressure may have reduced snapper stocks on the known grounds. Mississippi landings of red snapper exceeded 2.3 million pounds in 1965 (Lyles 1967). We have taken several species of young red snappers in Mississippi Sound. The wide distribution of young fish as indicated in these studies may be an important factor in the maintenance of stocks. Little is known of the details of their life history in the study area. NEKTONIC AND BENTHIC FAUNAS 87 Prist ipomoides andersoni Ginsburg - Wenchman Forty-seven wenchman were taken at temperatures and salinities ranging from 15.6° to 27.0° C and 26.6 to 37.9 ppt. The size range for these individuals was 155 to 271 mm TL. All fish with one exception (5 fathoms, one specimen) were taken at 30 fathoms or deeper. This species contributes to the red snapper fishery (Carpenter 1965), PRIACANTHIDAE - Bigeye Priacanthus arenatus Cuvier - Bigeye Four specimens of the bigeye were taken. One fish taken in July 1967 from 40 fathoms measured 146 mm TL and weighed 51.0 grams. The temperature was 20.6° C and the salinity was 37.2 ppt. In September 1968 a 185 mm TL specimen (50 fathoms) weighing 69.5 grams was collected at a temperature and salinity of 18.9° C and 37.4 ppt. The two 1969 (March and May) specimens were taken at a temperature range of 16.6° to 18.2° C and a salinity of 36.5 ppt. The March fish (50 fathoms) were 215 mm TL and weighed 124.0 grams. The specimen collected in May (50 fathoms) was 148 mm TL and 36.0 grams in weight. BRANCHIOSTEGIDAE -Tilefishes Caulolatilus cyanops Poey - Blacklined tilefish This was the only species of tilefish collected. Eleven specimens (140 to 307 mm TL) were taken at salinities and temperatures ranging between 19.9 and 37.8 ppt and from 15.3° to 20.5^C. All fish were collected in 50 fathoms of water. POMATOMIDAE - Bluefishes Pomatomus saltatrix (Linnaeus) - Bluefish Three bluefish were collected during the study, all in 1968. A January specimen measuring 123.0 mm TL and weighing 17.0 g was taken in 5 fathoms. Two specimens taken in September measured 320 and 346 mm TL and weighed 335.5 and 430.7 g respectively. The September specimens, in order as above, were taken at Stations 4 and 5 with temperatures and salinities recorded as 21.0°C and 36.5 ppt and 19.3°C and 24.9 ppt respectively. The January temperature and salinity were 14.8° C and 28.5 ppt. Although only three specimens of this fish were caught it is much more abundant in the area than this catch indicates. Charter boats and sport fishermen occasionally bring in large 88 GULF RESEARCH REPORTS catches of bluefish. We have observed numerous bluefish in passes between the barrier islands in the Mississippi Sound area. Bluefish landings in Mississippi have shown wide fluctuations with 72,000 pounds reported in 1965. Rachycentridae - Cobias Rachycentron canadum (Linnaeus) - Cobia One cobia was taken in January 1968 at 30 fathoms with a salinity of 16.2 ppt and a temperature of 33.0° C. This fish was 510 mm in length and weighed 730.2 g. Apparently this species is quite abundant along the shallow .offshore waters as well as being present in the deep Gulf during late spring, summer and early fall. Rachycentron canadum is sought by sports fishermen and is of potential interest in commercial fisheries. Small quantities have been reported in Mississippi landings. A few young cobia were taken in GMEI samples. We have collected early juveniles (Circa 30 mm) in both inshore and offshore waters. Little is known about the life history, migration and stocks of this species in the study area. We have observed young in the industrial bottomfish catch throughout the year, indicating that at least some cobia remain in offshore Mississippi waters all year. CaranGIDAE - Jacks, Scads and Pompanos Caranx crysos (Mitchill) - Blue runner A single blue runner was taken in June 1967 from 10 fathoms. The temperature was 25.6°C and the salinity was 32.0 ppt. We have often observed large schools of blue runners feeding at the surface in shallow Mississippi Sound and Gulf waters. Chloroscombrus chrysurus (Linnaeus) - Bumper A total of 229 bumpers was taken. Fish appeared in all months and were encountered from 5 to 30 fathoms. The greatest numbers were obtained at 5 to 10 fathoms. Miller ^1965) found 90% of his specimens in 3 to 6 fathoms. Gunter (1945) took this fish at temperatures of 25,4° to 30.0° C and salinities of 16.5 to 37.2 ppt. HUdebrand (1954) stated that C. chrysurus occurred at temperatures from 13,0° to 29.5° C, and the salinities were from 23.0 to 37.9 ppt. Roithmayr (1965) found this fish to be a component of the northern NEKTONIC AND BENTHIC FAUNAS 89 Gulf industrial bottomfish catch. Christmas, Gunter and Whatley (1960) found only one bumper in menhaden catch samples, but Miles and Simmons (1950) found that this species and the Atlantic thread herring comprised 50.4% of the fishes other than menhaden in the Texas menhaden fishery. Selar crumenophthalmus (Bloch) - Bigeye scad Eighty-three S. crumenopthalmus were collected at salinities and temperatures ranging from 27.0 to 37.4 ppt and 15.1° to 26.5° C. Specimens ranged in size from 100 to 235 mm TL, and a total mass of 3.605 kg was recorded. This species is uncommonly reported offshore; however, Roithmayr (1965) does list it in his study of the industrial bottomfish. Trachurus lathami Nicholas - Rough scad Rough scad were included in samples from all stations and in each month, but 68% of the 1,960 specimens were caught in the May samples in 1968. In these samples, total length range, with a mean of 84,6 mm, was 61 to 133 mm. Most of these were caught at Station 2 where the temperature and salinity were 20. 6° C and 30.7 ppt. Temperature and salinity ranges for all samples including this species were 14.4° to 29.0° C and 23.8 to 38.7 ppt. A total length range of 61 to 219 mm was observed. Minimum size showed a general increase from May through the rest of the year. Gunter (1945) and Hildebrand (1954) found rough scad in their samples. Vomer setapinnis (Mitchill) - Atlantic moonfish Vomer setapinnis was collected only in 1967 (298 specimens) and 1968 (2 specimens). A temperature and salinity range of 13.3° to 28.9° C and 30.3 to 37.9 ppt was recorded for these fish. Gunter (1945) took the moonfish at 14.2 • 30.0°C and salinities of 17.4 to 37.2 ppt. He found 96.8% of the fish at salinities above 30.0 and he took none in January and February'. Vomer setapinnis ranged in size from 74 to 318 mm TL. The majority of specimens (253) were collected at 5 fathoms. Fish did not appear in February and October, and April was the month of greatest abundance. Gerridae -Mojarras Eucinostomus argenteus Baird and Girard - Spotfin mojarra Twenty-five specimens were collected (1967, 6; 1968, 18; and 1969, 1), The 1967 and 1968 fish ranged in size from 87 to 119 mm 90 GULF RESEARCH REPORTS TL and were taken at temperatures and salinities ranging from 17.0° to 28.0° C and 26.6 to 37.4 ppt. The 1969 specimen (152 mm TL) occurred in February in 30 fathoms at a temperature and salinity of 14.1° C and 16.6 ppt. POMADASYIDAE - Grunts Orthopristis chrysopterus (Linnaeus) - Pigfish Sixty -two pigfish were obtained in all years of the study. All months were represented with the exception of February, July and October. Specimens measured 101 to 224 mm TL. The temperatures ranged from 14.5° to 28.9°C and the salinities from 26.2 to 37.4 ppt. The largest numbers taken were from November through January, agreeing with Gunter’s (1945) catch in the Gulf. Moe and Martin (1965) also show an increase in collections during the winter months. Moe and Martin (1965) mention that the pigfish is common in the more saline waters of the northern Gulf, and our records show the largest catches at salinities above 29.0 ppt. Pigfish were in GMEI samples from April through October, ranging from 42 to 240 mm TL. A few were taken in the 5.0 to 9.9 ppt salinity range. We have found this species to be abundant in the grass beds around the Mississippi barrier islands. SCIAENIDAE - Drums Baridiella chrysura (Lacep^e) - Silver perch Bairdiella chrysura was taken at a temperature range of 10.8° to 21.8°C and a salinity range of 21.8 to 33.2 ppt. Specimens appeared only in 1968 (6) and 1969 (6). These individuals ranged in size from 110 to 153 mm TL. An inshore spawning season from mid-spring to mid-summer appears to be accepted (Gunter 1945, Hildebrand and Cable 1930, Miller 1965). This species is rarely caught offshore (Gunter 1945, and Miller 1965), but it generally leaves the bay waters in winter. The present data tend to corroborate this contention since most specimens were taken in 5 fathoms of water. Cynoscion arenarius Ginsburg - White trout White trout comprised 2.83% of the total catch of fishes, ranking fifth in abundance. Trout, including both white and sand, comprised 5% of the industrial bottomfish catch in 1959-63 (Roithmayr 1965). This species was taken at all stations. The highest concentrations were found at 5, 20 and 50 fathoms. The 50-fathom station produced NEKTONIC AND BENTHIC FAUNAS 91 the highest catch per unit of effort. The maximum monthly catch per unit of effort was taken in January 1968. The 1967 and 1968 maximum catch per haul were both in March, Diurnal differences varied. In 1967 and again in 1969 (by a factor of four) day hauls were most productive. There was little difference between catch per unit of effort for day and night hauls in 1968. White trout were taken at temperatures ranging from 10.8° to 29.5°C, The salinity range was 16.6 to 39.8 ppt. The largest catch per unit of effort in this study was concentrated in the temperature range 16.0° to 18.9° C and salinity range 26.0 to 31.9 ppt. (Table 23). Total length range was 71 to 453 mm. The largest specimens appeared in March (453 mm TL) and September (434 mm TL). Mean total length was 233 mm. In March 1969 at the 50-fathom station we collected 45 (5 males and 40 females) fish with running milt and roe. Their total lengths were from 350 to 370 mm. Males were smaller (mean TL = 350.6 mm). Females averaged 357.1 mm. Gunter (1938 and 1945) reported ripe specimens from inshore waters in March^ April, May and June. Guest and Gunter (1958) noted an offshore migration in the cooler months. Gunter (1945), Miller (1965) and Simmons (1951) indicated a spring and summer spawning period in the Gulf. White trout were abundant in GMEI samples in Mississippi Sound. A winter migration to Gulf waters was indicated by reduced numbers from December through March. Young of the year started moving into the nursery area in April. Cy noscion nothus (Holbrook) - Sand Trout Cynoscion nothus was taken at all stations. Sizes ranged from 70 to 380 mm TL for the 104 specimens collected. Information presented by Gunter (1945) and Miller (1965) indicates that the spawning season may extend from spring through fall. This species was occasionally taken with C. arenarius but occurred in much smaller numbers. Temperatures and salinities ranged from 14.3° to 29.0°C and 21.6 and 38.6 ppt. A total weight of 7.994 kilograms was recorded. GMEI samples included 120 sand trout from 994 samples. They were more evident in warm months. Similar information was given by Gunter (1946). The minimum salinity interval for this species was 10.0 to 14.9 ppt. Total length range was 22 to 224 mm. In general the salinity distribution is higher than for C. arenarius. 92 GULF RESEARCH REPORTS TABLE 23 DISTRIBUTION OF CYNOSCION ARENARIUS BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES, CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH (MM). 1967 SALINITT iNTCflVAL PPT TtNp IHT. C IA.6 14.9 17.0 19.9 20.0 22.9 21.0 25.9 26*0 20.9 29*0 >1.9 32.0 >4.9 35*0 37,9 30*0 39. a 16.6 39, e 10. • lZ.00 172- 360 269.2 0 2/ fa.O/<> 172- 36l> ^69. 2 22.0 29.9 1N9L1. CATCH HIN-HAX HE AM 0 0 0 0 0 1 2A.0OO 100- 2A7 184.6 1 1.000 245- 245 245.0 12 3. 166 19S- 310 235.0 0 4. 500 100- 310 215,9 29.0 2T,9 SM9LS. Catch NIN-NAA NIAM 0 0 0 0 0 4 4.750 160- 27S 219. > 2 0.000 le 1.722 laS- 277 235.3 0 24 2»OUi 160" 277 22V. 2 21.0 29.9 SHrcS. catch M]N*MAX MAN 0 0 0 0 0 0 2 5,000 19U- 280 229* r 0 0 2 5. QUO 190- 2fln 229.7 10.9 29,1 SMPLSn CATCH MIN-NAX HCAH 0 0 0 0 1 71,000 76- 196 U^.9 9 6,222 108- 276 199.2 19 6.47i /J- 2flU 159.7 66 «. 2/0 152- 190 24 J. 9 0 9*1 B.2tj7 />- 390 21 s.a 1968 SALINITY INTERVAL PPl TEMP tNT. C 16.6 16.9 17.0 19.9 20.0 22.9 23.0 25.9 26.0 28-9 29.0 31.9 32.0 14,9 35.0 37,9 3B.D 39.8 16.6 39*0 10. ■ u.. SHPLS* CATCH MIN-MAX MEAN 0 0 0 0 0 0 0 0 0 0 11.0 IS. 9 SMPLS. CATCH MIN-MAX MEAN 0 0 0 1 0.000 4 42.750 85- 242 127. 7 0 6 6.500 147- 422 271.1 0 □ 11 19.090 as- 422 163.2 lA.O IS. 4 5MPL5. CATCH MIN-MAX MCAN 0 0 0 2 12*500 201- 129 26|*6 2 10*500 117- 226 183.0 3 U3.333 157- 275 204.6 6 7.500 l6i- 320 243.3 a 4* 375 157- >8/ 214.0 0 21 22.190 IIT- )«7 214.1 19*0 21*9 &HPLS. CATCH HIN'HAX MEAN 0 0 0 3 0*311 250* 258 258.0 0 2.175 221- 314 262*4 1 2.000 113- 187 144.1 0 5-125 222- >12 282.0 5 6.600 205- 357 206 260.3 1 1 .000 206 206.0 28 1.607 Ui- 357 267*0 22.0 24.9 SNPU. CATCH HIN'HAX mean 0 0 0 0 2 0.000 0 2 17,500 20U- ilA 2 M.a 4 2.250 199- 276 232.2 0 8 5.500 199- 314 263.7 25*0 27,9 SHPLS. CATCH hih-mAx HEAN 0 0 0 1 0.000 1 0.000 i o.ooo 1 1.000 434- 434 434.0 6 2.000 102- 293 212.5 3 0.000 IS 0.866 182- 434 229. S 28*0 29*5 5MPL5. CATCm MIN-MAX MEAN 0 1 0.000 0 0 2 i.soo 14J- 1T» 172.4 3 0.000 L 0.000 1 0.000 0 8 0.17S 163- 179 172.6 10*0 29*5 SHPI.4. CATCH HIN-HAX HEAN 0 1 0.000 0 7 J.71A 20}- }29 241.4 19 11.24} as- 3SA ISl. J 12 28.8}] 111- 2TS 202.8 24 6.708 147- 434 270.2 24 3.708 167- 387 206 24i*0 4 0.250 - 206 206.0 91 9. 197 05- 434 216.9 NEKTONIC AND BENTHIC FAUNAS 93 TABLE 23 (CJontinued) 1969 StLlNtTV INTEKVIL PPt TtHP INT. I».» IT.O 20.0 21.0 26.0 29.0 12.0 JS.O JS.O 16.6 C 16.9 19.9 22.9 26.9 26.9 11.9 16.9 IT. 9 19.8 19.8 SUPLi. 0 0 10.8 C6TCH 12.9 ■C6f4 0 0 0 0 1 1 1.000 0.000 98- 98 98.0 0 2 0.600 98- 98 98.0 SMPLl. 1 11,0 t*tCH 5.000 15,9 MIN-nlX 216- 110 MEAN 268.0 11.000 2.000 2.000 1,666 0.000 110- 290 Tl- 168 76- 218 96- 286 226.6 116.6 166.9 190.8 0 18 1.611 71- 110 196.8 IPPIS. 16.0 ClICN 18.9 alN-MlK m £6N 0 0 0 0 1 7 II 2 26 1.000 12.857 68.000 7.000 16.208 192- 192 196- 112 192- 661 226- 116 192- 651 192.0 212. A 256,1 251.6 266.1 5KPIS. i9.o catch 21.9 MIN'PAH hEan 0 1 1.000 266- 265 265.0 0 10 0.666 167- 206 186.0 0 6 6 8,700 l.llJ 156- 280 219- 155 216.6 261. I 0 15 1,666 166- 156 221,5 5N81.5. 22.0 catch 26.9 HIH-BA* heah 0 0 O 1 0 12.000 181- 211 197.6 0 0 0 0 1 12.000 181- 211 197.6 iHPis. oooooooooo 25.0 C»TCH 27.9 NlN-MAA MIAN SlffCJ. OOOOOOOOOO 28.0 CATCH 29.5 HlH-HA* DEAN 5IM*I.S. 1 I 10.8 CATCH 5.000 1.000 29.5 HIN-HAl 216- 110 265- 265 HEAH 268.0 265.0 16 18 0.000 6.000 2.000 1.875 110- 290 71- 158 75- 218 216.0 116.6 168.5 19 21 2 60 15.671 10.095 7.000 16.650 96- 132 192- 651 226- 115 71- 651 221.5 256.6 251.5 211.0 Equetus acuminatus (Bloch and Schneider) - Cubbyu Thirty -eight specimens (108 to 289 mm TL) were taken at temperatures and salinities ranging from 16.4° to 27.2° C and 23.2 to 37.9 ppt. Equetus acuminatus appeared from 20 to 50 fathoms. Roithmayr (1965) does not list this species. Larimus fasciatus Holbrook - Banded drum Specimens were taken in 1967 (47), 1968 (13), and 1969 (9). They were collected at temperatures and salinities from 14.5° to 28.9° C and 26.6 to 38.7 ppt respectively, Gunter (1945) took four specimens in Texas offshore waters at a salinity range of 26.7 to 35.2. A total length range from 94 to 202 mm TL was noted for these individuals. The majority of specimens were taken at 20 and 30 fathoms, and sizes taken offshore were rather consistent throughout the year. Hildebrand and Cable (1934) reported spawning from May to October. GMEI samples included banded drum with a total length range of 21 to 189 mm and all were taken at salinities above 20.0 ppt. 94 GULF RESEARCH REPORTS Leiostomus xanthurus Lacepede - Spot. The spot was represented by 6,457 specimens which accounted for 6.90% of the total fish catch. Fish were taken in all months and at all stations; however, Leiostomus was found in greater abundance at the deeper stations. During 1967 and 1968 night hauls were more productive than those taken in the day. Numbers in day hauls far out-ranked night hauls in 1969. The largest catch per unit of effort for the 3-year period occurred in May (40 fathoms) at a mean temperature and salinity of 19. 5*^0 and 35.1 ppt and in December (50 fathoms) at a mean temperature of 21.5°C and a mean salinity of 33.2 ppt. Temperatures and salinities for ail specimens ranged from 14.1° to 29.5° C and 24.9 to 38.7 ppt. A definite preference for temperatures from 19.0° to 21.9°C was evident. The greatest catch per unit of effort in all three years wa.^ at salinities from 32.0 to 37.9 ppt (Table 24). There appears to be an offshore movement as the spot increases in size, and a late fall and winter offshore spawning period is believed to occur. Gunter (1945) found fish with well developed roe and milt in early November and January and noted spent individuals in late January. Dawson (1968) observed ripe fish during October, December and February off North Carolina. Spots spawn in their second year (Pearson 1929, Hildebrand and Cable 1930, Dawson 1958). A size approximately 200 mm is attained by two years. Nelson (1969) found that fish of this size group are primarily concentrated in 15 fathoms of water and deeper during January and February. He remarked that, in the northeastern Gulf, spawning apparently occurs in the deeper offshore waters. Roithmayr (1965) found L. xanthurus to be the second most abundant species in the northern Gulf of Mexico industrial bottomfish industry. Micropogon iindulatus ranked first. These results correspond to previous findings of Gunter (1936, 1938a, 1941 and 1945) concerning the relative abundance of shallow Gulf fishes. Menticirrhus americanus (Linnaeus) - Shoemaker A total of 139 southern kingfish ranging from 95 to 330 mm TL were collected. These were taken in all months with the exception of July and October. The greatest numbers were collected in January, March and May with the peak in January. Gunter (1938c and 1945) noticed an offshore migration of these fish from Louisiana and Texas during colder months. Our specimens were obtained at temperatures ranging from 14.1° to 28.9°C and salinities from 24.6 to 37.4 ppt. Moe and Martin (1965) state that this .species is uncommon in low-salinity waters. Our data show that this fish prefers waters ranging from 23.0 to NEKTONIC AND BENTHIC FAUNAS 95 TABLE 24 DISTRIBUTION OF LEJOSTOMUS XANTHURUS BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES^^ CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH (MM). 1,967 SALINI rv iNitKVAC PPf TEMP INT. 16.6 I T.O 20.0 23.0 26.0 29.0 32.0 35.0 3S.0 16.6 c 16.9 19.9 22,9 2S.9 28.9 31 .9 JA.9 37.9 39.8 39.6 SNPLS. 0 0 Q 0 0 0 0 0 Q 0 10. e c*rCH 11.9 MEAN SMPLS. 0 0 0 0 0 1 6 1 0 s li.O 0.000 l.^OO 0.000 1.125 KIN-MAV 170- 192 170- 192 «EAN U4,4 ISA. A 0 0 0 0 1 L 4 13 0 19 Iti.O CATCH 0.000 2.000 IB. T6Q 13.230 13.105 tQ4V HIN-HAV 1 bB- - 198 Hi- 236 180- 261 155- 251 mean iTStO 203.6 206.7 205.5 SMPLS,. 0 0 0 0 0 2 A 21 0 27 19.0 CATCH 0.000 U6«2S0 2A.0AT 16...S 21.9 M|n-mA« 186- 230 126- 290 126- 290 MtAN 203.2 195.6 19J.7 SnPi$. 0 0 0 0 0 1 1 12 0 lA iJ.O CATCH o.noo 0.000 3.B13 3.2.5 193- 264 193- 26A MEAf4 212.5 212.5 SAPlS. 0 0 0 0 0 A 2 18 0 24 29.0 CATCH 3.900 0.000 25.166 I9.A5S 27,9 lAO- - 210 IT5- 230 140- 2J0 heam 173. 5 203.7 200. A SKPLi. 0 0 0 D 0 0 2 0 0 2 2a. 0 CATCH i.ioo 1.500 29.9 hih-haa 1*/- 192 1A7- 192 MEA^ 163.8 163.8 iHPC J. 0 J 0 U 1 9 19 66 0 9A 10. a CATCH 0.000 1. fTT 33.4Ti 16.092 19.646 29. i MiN-MAA 1^0' ■ 210 lAT- 236 126- 290 126- 290 MEAN i7A.a 201.0 201.7 201.0 TEMP INI. r. 16.6 16.9 17,0 19.9 ZOrO 22.9 SALlNUr 23.0 25.9 1968 INTERVAL 26.0 28.9 ppt 29.0 JI-9 32.0 3A,9 35.0 37,9 38.0 39,8 16.6 39,0 5HPL5. 10.6 CATCH 12.9 HIN-HAA .£AH 0 0 0 0 0 0 0 0 0 0 6MPLS. 13.0 CATCH 15.9 MlN-MAX mean 0 0 0 1 0.000 4 7.00Q 148- 234 174.8 0 6 2a 166 143- 232 196.4 0 0 11 3.727 143-' 234 181.6 SKPL5. 16.0 CATCH 18.9 MIN-MA* MEAN 0 0 0 2 0,000 2 11.500 153- 230 185.3 3 0,666 220- 224 222.0 6 3.500 196- 222 20a«2 6 10.375 157- 257 199,9 0 21 6.1A2 153- 257 199.0 (MACS. 19,0 catch 21^9 MIN-MAA MEAN 0 Q 0 3 1.666 183- 208 191.8 e 0.500 181- 203 192.2 3 12.333 102- 255 202.1 A 94*000 190- 298 215.2 5 105. AOO 1*9- 278 217.8 1 3.000 190- 207 197. J 28 AA.5T1 102- 298 21A.5 SMPLi. 22.0 CATCH 24.9 NIN^MAX MEAN 0 0 0 0 2 0.000 0 2 0,000 A 1.750 183- 25A 71*. 0 0 8 0..75 Ui- 25A 218.0 SMPLS. 25.0 CATCH 27. 9 niN-HAX n(ah 0 0 0 1 0.000 1 0.000 3 1.000 1 0.000 6 1.500 li2- 195 177.2 3 1.000 205- 2U 209.0 15 0.t66 152- 211 185.1 SMPCS. 28.0 CATCH 29.5 HIN-NAA HIAN 0 1 0.000 0 0 2 2.000 153- 135 175.2 3 1.666 179- 210 201.2 1 o.ooo 1 0*000 0 1.125 153- 210 189.6 iHPiS. 1D.« catch 29.5 HIN-HAX hian 0 1 0.000 0 7 0.714 193- 208 L9I.8 19 3.105 148- 236 180.1 12 3.750 102- 255 203.9 24 29,416 U3- 298 213*5 24 26.083 152- 278 208.8 4 1.500 190- 213 203.1 91 15.901 102- 298 207.2 96 GULF RESEARCH REPORTS TABLE 24 (Continued) 1969 SiLlNUr INTERVAL PPT TCHP iNT. C 16.6 16.9 17.0 19.9 20.0 22.9 ii.') 26.0 28. 9 29.0 31.9 32.0 36.9 15.0 37.9 50.0 39.0 16.6 59,3 10. u 12.9 SHPLS. CATCH KlN-NAK MEAN 0 0 0 0 0 0 1 0.000 1 0.000 0 2 0.000 1 UO L^.9 catch MlN'MAii mean 1 0.000 0 0 162- i i.OOO ■ 210 182. J 1 0.000 ; 3.162 162- 195 160.1 6 1.500 126“ 225 169.2 1 0.000 0 18 2.055 128- 225 165.9 L&.O 18.9 SHPLS. CATCH MEAN 0 0 1 0.000 0 0 1 u.ooo T 6.628 110- 261 205.0 13 10.230 188- 257 212.6 z 6.000 l»0- 770 706.0 76 7.U6 no- 741 710.9 19.0 21.9 JHPlS. C.ICH HiN-n.X MEAN 0 L 0.000 0 196- 2.355 ■ 215 205. A 0 0 5 0.000 t 801.666 lT^- 261 0 14 701.11) 177- 761 711.0 22.0 241.9 5HPLS. CaTCm mtn-max MEAN 0 0 0 1 0.000 0 u 0 0 0 1 0.000 29.0 2 7.9 SMPuS, CATCH H(N-MAX mean 0 0 0 0 0 0 0 0 0 0 28.0 29.9 S"PL4. C*ICh hin-h.K MEAN 0 0 0 0 0 0 0 0 0 0 ! 0.8 29.5 SMPL5. CATCH MIN-HAX MEAN 1 0.000 1 0.000 1 0.000 162 6 2.166 - 215 196. 7 1 0,000 a 2.750 162“ 195 160.1 19 2.105 llO- 196.9 ;l 1^9.666 UZ- ?61 71?. 0 2 6.000 190- 220 206.0 60 53.766 liO- 261 205.8 28.9 ppt. Bearden (1963) suggested that this fish is possibly eury haline but Gunter (1945) did not take M. americanus at a salinity lower than 14.5 ppt. It was not taken in Mississippi GMEI samples at less than 5 ppt. Hildebrand and Cable (1934) found that the shoemaker may spawn in both inshore and offshore waters from April through September in the Beaufort, North Carolina, area and found young fish in both areas. Gunter (1938c) found fish with well -developed roe from April to June in offshore waters in Louisiana. Gunter (1945) also found ripening fish in April and November while working in Aransas Bay, Texas, indicating a very long spawning period in the Gulf. Reid (1954) took ripe females in April and August at Cedar Key, Florida. Our smallest individual was taken in January. Moe and Martin (1965) found their smallest fish in the same month; however, they collected small fish ranging 44 to 52 mm during all months except May and suggested fall -spring spawning period in the Gulf. GMEI samples included specimens from 17 to 255 mm TL with a mean of 86.2 mm. Kingfish are utilized in Mississippi waters by both commercial and sports fishermen. Fishery statistics (Lyles 1967) show a maximum Mississippi catch of 1.3 million pounds in 1953. NEKTONIC AND BENTHIC FAUNAS 97 Micropogon undulatus (Linnaeus) - Croaker Croaker was the most abundant species in our samples, comprising 34.91% of the catch. The greatest annual concentrations appeared in September (1967) and in May (1968 and 1969.) Bathymetric distribution of catch per unit of effort shows the highest average at 40 and 50 fathoms. Seasonal catch per unit of effort was highest in the spring (March, April and May) and fdl. At the 5 -fathom station the highest catch occurred in fall and summer. Catches were higher at 10 and 20 fathoms in fall and winter and in spring and summer at 30 fathoms, At 40 and 50 fathoms, winter and summer catches were higher. In general, night catches were higher but there were exceptions. Croakers were collected at temperatures of 13.0° to 29. 5° C and at salinities 16.6 to 39.8 ppt. Maximum catches per unit of effort occurred at temperatures between 19.0° and 21.9° C. The best average catch occurred at the salinity interval 35.0 to 39.8 ppt. (Table 25). The TL limits of croakers in our samples were 100 and 327 mm with a mean at 192 mm. Specimens under 110 mm TL were collected in January, February, March, May and September. The largest specimens (315 and 327 mm) were taken in March. Monthly mean TL ranged from 161 mm (September) to 209 mm (January) in 1967 and 170 mm (February) to 211 mm (March) in 1968, The croaker was the third most abundant species in GMEI samples. Croakers were collected in all seasons and at all salinities with a total length range of 7 to 402 mm. The mean length was 111.9 mm. In general, our data support the fall migration (at about 100-mm minimum according to our data) offshore and a major spawning period in the fall as reported by such authors as Gunter (1945), Hildebrand (1954), Springer and Bullis (1956), Miller (1965) and Nelson (1969). Roithmayr (1965) sugge.sted that croakers nearing the size of 180 mm are approaching 2 years of age and arc capable of spawning for the first time. Fish of 210 mm or so in size were in their third year, and large croakers (averaging 300 mm) were estimated to be between 5 and 7 years of age (Roithmayr 1965). These estimates of age are about double those of Gunter (1945) and Herke (1971) and are probably in error. There is already heavy fishing pressure on this species to supply over 50% of the commercial bottom fish taken from the Gulf (Roithmayr 1965), The rapidly developing market for croaker as a food fish will probably increase the pressure on the larger fish. 98 GULF RESEARCH REPORTS TABLE 25 DISTRIBUTION OF MICROPOGON UNDULATUS BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES, CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH (MM). 1967 Tf WP INI. L L&a6 L6.9 17, a L9.9 20.0 22.9 bALlNlfP InKRVAL 21.0 26.0 25.9 2ft,9 PPT 29.0 11*9 12.0 1**.9 15,0 IT. 9 16.0 19. U 16.6 19. a SMPiV. 0 0 0 0 0 0 0 0 0 0 10. s C*IC.' 12,9 mN-M4X Sm’1.9. 0 0 0 0 0 i 6 1 0 e k>.0 C*»Ch i .000 1. 166 0.000 1.000 li.v IJA- ITA 110- 18B no- 188 NEAN 1 76.0 I5t!,5 L60.S SuPLi. U 0 0 0 1 1 6 11 0 19 Ib.O catch 0.000 190,000 11,000 06,07b 71.631 ka.9 I2fl“ IttT 165- 216 IU6- 250 106- 250 nCan 159.2 129. 1 193. » 107.6 SMPLb. 0 0 0 0 0 2 6 21 0 27 ly.O CATCH 2.900 220.000 10(..S21 115.629 21.9 15*.- 189 iso- 257 120- 115 120- 115 HEAH 165.2 198-2 ^06, 9 203. a SHPlS. 0 □ 0 0 0 1 1 12 0 16 22.0 catch 0.000 0.000 119.333 102.285 2*.. 9 108- 2T8 108- 278 191.0 191.0 SHPli. 0 0 0 0 0 6 2 16 0 2a 2!>*0 CATCH 88.290 0.500 0b, 646 79,501 27,9 Hlh-HAH 115- 250 201- 203 121- 252 123- 250 mean liA.A 20J,0 T99.7 188.1 SHPtS. 0 0 0 0 0 0 2 0 0 2 28.0 CAICM 200.500 200.500 29. S nlH-MAX lOQ- 260 100- 2D0 HE AN 166*2 168.2 0 0 0 0 1 9 19 65 0 96 10.0 catch 0.000 61.000 /0.5/6 9r.60CI 67.595 29.9 HTN-HAX 126- 250 100- 200 106- 115 lOQ- 115 MEAN 156.6 100.9 196.6 192.3 TEMP iNf. C 16.6 16.9 17.0 19.9 20.0 22.9 salinity 23.0 25.9 1968 [HTE.VAl 26. Q 2B.9 PPT 29,0 31,9 32.0 36.9 is.o If. 9 3B.0 39, a 16.6 39.6 SHPL5. 0 0 Q 0 0 0 0 0 0 0- 10.8 CATCH 12.9 H1N-HA» hEan 5MPtS4 0 0 0 1 6 0 6 0 0 11 13.0 CATCH 0.000 0*750 ri.si) 39.656 15.9 HlH-MAX 150- 170 108- 29* 108- 29* mean 160.0 205.6 20*. 7 5MPL5. 0 0 0 2 2 3 6 8 0 21 L6.0 CATCH 6.000 6.000 215.000 20?*666 80.250 120*333 L0.9 MIN'HAX 120- 261 163- 266 m- 2Tr 121- 250 122- Z99 120- 299 MEAN 199.1 195.* 191. ) 181.1 186.* 186.8 iMPli. 0 0 0 3 « 1 a 5 1 28 19.0 CATCH 1150533 917.000 7.666 16.875 177*000 0,000 ll9.*8* 21.9 MIN-MAX ITT- 252 105- 2*6 117- 232 le2- 2*8 12V- 258 105- 250 HE AN 195.6 19T,T 189.* 193,8 106.9 191.2 5MPL5. 0 0 0 0 2 0 Z 6 0 a 22.0 CATCH 0.000 0.000 120.750 60.175 26.9 MIN-MAX 153- 232 151- 212 KEAN 191 .* 191.4 SHPLS. 0 0 0 1 1 3 1 6 1 11 25.0 CA1CH 0.000 16,000 0.000 1.000 *1.331 852. Ill 188.111 27.9 KIN-HAA 115- 157 155- 155 127- 21* 166- 297 127- 297 HtAN 1*5.1 155.0 168.7 199,1 182.* SMPL5. 0 L 0 0 2 5 1 i 0 6 20.0 CATCH 0.000 116.000 231.311 8.000 *.000 121.000 29.5 MIN-MAX 115- 216 106- 2*7 1*6- 218 16*- 200 106- 2*7 MEAN 1*9.5 200.1 168.6 195.0 167. 7 SMPL 5 . 0 1 0 7 19 12 26 2* 6 91 10.8 CATCH D.DDO 59.71* *10. *71 11*. 000 7A.625 9*. 250 639.250 177.967 29.5 min-hA* 120- 261 105- 2*6 106- 277 100- 296 121- 299 166- 297 105- 299 mean 195*7 178.* 193.6 191.6 106.6 199.1 187*6 NEKTONIC AND BENTHIC FAUNAS 99 TABLE 25 (Continued) 1969 SALINJTV iSiCfIVAL PPF TEhP c 16. 16.9 IT.O 19.9 20.0 22.9 29.0 2S.9 26.0 26.9 29.0 JU9 32.0 34.9 14.0 37.9 38.0 39.8 16.6 39.8 SKPLS, k0*9 CATCH a 0 0 0 0 0 1 0,000 1 o.ooa 0 2 0.000 SMPtS, U.O C»TCH 1 A. 000 190- 230 206.7 0 0 2 3.000 lAO- ITU 150.0 0.000 r U714 137- 275 IBI.T 6 65*666 155- 299 207. 1 i 20.000 170- 710 190.0 0 le 24.666 137- 299 200.4 SttPLS. U.O C4TCn kS.<) MEtkk 0 0 1 19.000 lao- 219 200,1 0 0 i 143. COO 146- 258 190.0 7 235,857 1C3- 757 190.0 13 99.076 104- 327 202.2 7 150.000 146- 217 190.5 24 150. TOO 10>- 321 199.4 SHPIS. CATCH 21.9 MEAN 0 1 0.000 0 J 8.000 187- 226 203.6 0 0 4 0.600 146- 190 175.3 6 607.000 107- 760 203.6 0 15 2764600 107- 260 201.1 suns. 22.0 C«TCM MEAN 0 0 0 1 0.000 0 0 0 0 0 1 0.000 3iPlPI.S. 2S.0 CATCH 27. « HIN-HAI MEAN 0 0 0 0 0 0 a 0 0 0 ^MPLSn 26.0 CATCH MEAN 0 0 0 0 0 0 0 0 0 0 SNPLS. 1 1 1 6 1 8 19 21 2 60 10.9 catch 29.9 NIN-NAA MEAN 4.000 190- 790 706.7 0.000 19.000 iao> 21 S 200.1 9.000 uo- 226 192.9 0.000 99.TT4 137- 248 197.0 107.709 103- 299 200.2 250.952 105- 327 202.4 14..000 166- 217 190.4 136.833 101- 327 200.2 Roithmayr (1965) found that the croaker maintained adequate stocks under increasing pressure from 1959 to 1963. Stocks still seem to be adequate. Pogonias cromis (Linnaeus) - Black drum In November 1967 one black drum, 662 ram TL, 4.3 kg in weight was collected flrom 5 fathoms. The temperature and salinity were 17.0° C and 32.4 ppt. In 1969 four specimens were collected at Station 1, one at Station 2, and one at Station 5. Five of these were taken in March (67 at 55 mm TL and 0.44 to 2.0 kg) and one in January (593 mm TL and 3.4 kg). For the 1969 specimens temperatures ranged between 14.2° to 16.9° C and salinities between 29.9 and 37.4 ppt. MULLIDAE - Goatfishes MuUus auratus Jordan and Gilbert - Rpd goatfish One hundred sixty- two specimens were collected during the study. Moe and Martin (1965) reported three fish from a depth of 13.3 fathoms (24.4 meters) at a temperature of 30.0°C and a salinity of 35.6 ppt. In the present survey temperatures and salinities ranged between 14.0° to 27.0° C and 16.6 to 38.2 ppt respectively. A size range of 115 100 GULF RESEARCH REPORTS to 228 mm TL was recorded. The majority of M. auratus were collected at the deeper offshore stations (30 and 40 fathoms). Spar ID AE - Porgies Archosargus probatocephalus (Walbaum) - Sheepshead The sheepshead was encountered on three occasions, twice in 1967 and once in 1969. Single specimens were taken from Stations 1 and 2 in 1967 in April and January, respectively. The January temperature and salinity were 23.1'’ C and 31.9 ppt. In April, temperature and salinity were 16.0 and 34.7 ppt. The January and April specimens measured 546 and 320 mm TL and weighed 4.6 and 1.4 kg respectively. In January 1969 the third fish measuring 490 mm TL and weighing 1.1 kg was taken from 20 fathoms at a temperature and salinity of 16.7°C and 31.5 ppt. Lagodon rhomboides (Linnaeus) - Pinfish This species was taken in every month except April. A total number of 1,990 fish was recorded. They comprised 2.12% of the entire catch of fishes. Pinfish were taken in greatest abundance at 30, 40 and 50 fathoms. The greatest number during the three years was taken in March. This is due to a very heavy catch in March 1969 (1,015). In 1967 the largest catch per unit of effort was in August. The greatest catch per unit of effort in 1968 was in November. A comparison of total day and night hauls shows a higher catch per unit of effort for night hauls in 1967 and 1968 and for day hauls in 1969. Night hauls at 50 fathoms excelled in catch per unit of effort. These data highlight for the first time the extensive offshore distribution of this species. Temperatures ranged from 13.5° to 28.7° C with salinities between 24.9 and 37.8 ppt. There appeared to be a preference for temperatures from 16,0° to 27.9°C and salinities from both 23.0 to 38.9 ppt and 35.0 to 37.9 ppt (Table 26). Springer and Woodburn (1960) noted a diminishing number of fish inshore after December. Caldwell (1957) suggested an offshore migration in cold weather. Moe and Martin (1965) corroborated the offshore movement and stated that their specimens were probably of the first year class (79 to 109 mm TL). Our data are in agreement since we observed specimens of similar size (97 to 103 mm TL) beginning to occur in catches during November, December and January. All fish ranged from 97 to 217 mm TL. An approximate total weight of 145.239 kilograms was recorded. Darnell (1958) noted a change in food habits as the pinfish NEKTONIC AND BENTHIC FAUNAS 101 TABLE 26 DISTRIBUTION OF LAGODON RHOMBOJDES BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES^ CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH (MM). 1967 SALlr*| rt INTERVAL ppr INT. C 16.6 16.9 17.0 19.9 70.0 77.9 71.0 75,9 76.0 28.9 29.0 11.9 37.0 16.9 35.0 J 7,9 16.0 39.6 16.6 39,8 iUKS. 10. a CATCH 12. « Mlh-HAX hcan 0 0 0 0 0 0 0 0 0 0 SMPLAa i\,Q CATCH lSa9 HIN'MAX HEAN 0 0 0 0 0 1 O.OOO 113- 6 0. 166 111 11 J.U 1 0.000 0 e 0. 125 111- 111 lll.O lA.O CATCH U.9 niN-NAX HEAN 0 0 0 0 1 0.000 1 0.000 6 OfOOO 13 ^.697 115- 196 170.6 0 19 J.210 115- 198 ITO.6 tHRLS. 1*.B CATCH 21. « HiN-nax hCan 0 0 0 0 0 2 7.500 105- UV 1L6.6 6 0,000 71 3.571 iMb- 715 176. 1 u 2/ 7.967 105- 715 L72.4 SHPtS. 22.0 CATCH 24. T MIH-MX mcah 0 0 0 0 0 L 0.000 1 O.OOO 12 4.666 147- 703 171.6 0 14 4.000 147- 703 171.4 2).0 CATCH 21. T NIN-NAA HfAH 0 0 0 0 0 4 0.260 166- 166 166.0 2 O.OOO le 6.222 146- 202 iia.T 0 74 4. 708 146- 702 1 78.6 SHRCi. 2A.0 Catch 2«.s HIH-MAX HIAN 0 0 0 0 0 0 110- 7 3.000 • 176 15U6 0 0 2 3.000 130- 176 151.6 aMRLC. 10. a CATCH 29.} niH-NAA MIAir 0 0 0 0 1 0.000 9 0.666 105- 166 124,6 111- 19 0.368 - 176 166.1 65 4*676 115- 215 175.1 0 94 1.172 105- 216 I7J.5 1968 SALINITY INTERVAL PPT TfHP INI. C L6.6 16.9 IT.O 19.9 20.0 77.9 21.0 2S.9 26.0 78.9 29.0 11.9 37.0 16.9 15.0 IT. 9 Jb.O 39. B 16.6 19.8 SHPLi. 10. A CATCH 12.9 NIN-HAX MAH 0 0 0 0 0 0 0 0 0 0 }HRLS. !».0 catch 1}.9 HIN-MAX MEAN 0 0 0 1 0.000 6 0.000 0 97- 0 2.666 - 703 170,7 0 0 11 1.454 97- 201 170.7 IHRlC. 16.0 CATCH 11.9 hih-max MEAN 0 0 0 2 0.000 7 0.000 y 0.000 112- 6 0.500 - 190 167,6 8 6.500 101- 190 U9.6 0 21 1.057 101- 190 150.0 19.0 CATCH 21.* MIN-MAX mean 0 0 0 i.yn ITT- 191 1S7.7 e 1.62} 1}*- 1*2 ITl.l > 10, My 116- isa 160,7 I6T 8 1.500 - |90 171-6 5 1.600 165- 21T 194.2 1 0.000 28 2.678 136- 217 164,4 iNMli. 22.0 CATCH 24. 9 HIM-HAX MEAN 0 0 0 0 2 16.600 140- 209 160.2 0 2 0.000 4 0.760 150- 169 162.0 0 8 19.600 140- 709 1 79,6 iMRli. 2).D CATCH 21.* MlN'HAX mean 0 0 0 1 0.000 1 0.000 i 0.333 188- 188 188.0 117- 1 1.000 * 137 137. 0 6 2.111 114- 192 171.9 3 0.000 15 1.066 IJ4- 192 170.7 IMRIS. 29.0 CATCH 29.1 MIN-MAl MEAN 0 1 0.000 0 0 1 0.000 3 0.000 1 0.000 1 0.000 0 8 0.000 iMPCS. 10. » CATCH 29.1 HIN-MAX NEAN 0 1 0.000 0 7 0.57 L 177- 191 187. 7 19 8, ri6 160- 209 179.1 12 2.666 114- 166 161.1 97 24 I.IXJ - 201 166.6 24 2.641 101- 217 159.7 6 0.000 91 3.741 97- 717 1 70. *1 102 GULF RESEARCH REPORTS TABLE 26 (Continued) 1969 S*L|N1TV INT£HV*L PCI INI . C 16.6 16.9 17,0 19,9 ZO.Q 22.9 23.0 2S.9 26*0 20.9 29.0 3L.9 32.0 3^,9 35,0 37,9 38.0 39.0 16.6 39.8 SHPLS. 10. * C*TCH U.4 PiN-PA* MEAN 0 0 0 0 0 0 1 o.noo 1 0.000 0 2 0.000 SHPLS- 11. 0 CATCH |S*9 MIN-NAX MEAN L 0,000 0 0 2 0,000 1 0.000 T 0.209 LOS- UL lor.o 6 0.333 157- 173 165,0 1 0.000 0 lu 0.222 10}- 17} U6.0 SMPtS. 16.0 CATCH IB. 9 HIH-HAA h€aK 0 0 1 0,000 0 0 1 0,000 7 0. I 2T.9 HtN-MAA 77- 91 74- 20 7 7A. 207 HEAN 94.7 139.6 139. i SHPLS, 0 0 0 0 0 0 2 0 0 2 28.0 CATCH s.ooo 3.000 29.1 HIN-HAX 72- 101 72- lUl HEAN 89.1 ft9*3 3HPIS. 0 0 0 0 1 9 19 65 0 9A 10.8 CATCH 0.000 0 6 AAA 61.117 150.261 Ub.iOb 29.5 MIN-NAX 7 7- 91 72- 183 65- 219 65- MEAN 1968 84.7 124.1 144.4 1A1.6 SALINI lY INTERVAL PPT TEMP INI . 16.9 17.0 20.0 23*0 26.0 29.0 32.0 31.0 3S.0 16.6 c 16.9 19.9 22.9 21.9 28.9 St .9 SA.g 37.9 39.8 39.1 IHPLI. 0 0 0 0 0 0 0 0 0 0 10. a CATCH 12.9 MIN-MAK hEan SMPLS. 0 0 0 1 A 0 6 0 0 ll 11.0 CATCH 0.00& 0.000 68.83) 37.141 15. 9 RIN-MAX 107- 186 107- 186 HEAN 136*6 IJ8.6 SHPlS. 0 0 0 2 2 3 6 a 0 21 16.0 CATCH A. 500 2.100 A*3SS 170.833 12.121 14.714 IB. 9 NIH-HAA Hi- 130 101- 216 Bl- 111 102- 182 66- 176 66- 216 MEAN 116.8 161.2 102.0 133.7 1 14.9 V7.1 SHPLS. 0 0 0 3 0 ) 6 1 1 28 19.0 CATCH 201.000 124.000 105.666 104.000 L5A.800 209,000 267.392 21 .9 MIN-MAX 98- 181 87- 190 los- 186 13- 183 81- 194 98- 143 53- 196 MEAN 139. A l>4,8 U8.1 120.4 127.6 121.3 129.9 SHPLS. 0 0 0 0 2 0 2 A 0 8 22.0 CATCH 160.500 0.000 128.210 111.210 24i*9 M)N-HAX 90- 178 44- 171 64- ire MEAN U6. 1 91.1 in. 7 SMPLSp 0 0 0 1 1 s L 6 J ii 21.0 CATCH 0.000 6,000 138.666 JS.OOO 136.333 11.666 *7.333 27,9 MIN-MAX 79- 93 IS- 170 69- 102 61- 187 64- 101 11- 187 MEAN *3.1 Hl.l ■ 9.1 123.1 90*0 111.4 SHPlS. 0 1 0 0 2 3 1 1 0 « 2B.0 CATCH 0.000 2.000 23.000 0.000 100.000 71*621 29.1 HlN-HAX 66- 76 58- 107 56- 112 36- U2 MEAN 70.0 65.6 86*6 86.1 SHPLS. 0 I 0 7 19 ■ 2 24 24 6 91 10. g Catch 0.000 87.428 241.263 67. 9U 96.0AI 112. 56J 61.000 123.718 29.5 MIN-MAX 98- 181 66- 214 11- 186 13- 186 56- 196 6A- 165 13- 216 MEAN 137,6 134.3 117.8 127.0 114.8 111.2 123.2 NEKTONIC AND BENTHIC FAUNAS 105 TABLE 27 (Continued) 1969 SAli^lTv interval PPT rewp C 16. b 16.9 ir.O 19.9 ?0.0 Z2.9 21.0 25.9 26,0 2fl.9 29.0 li.9 32.0 35.9 35.0 37.9 )S.O )9.8 16.6 39.8 lu.d SHPLS. CATCk Mn-xaX 0 0 a 0 0 0 1 0.000 1 0.000 0 Z 0.000 43.0 5XPL5* CATCH HjN-NAK HkAN 1 200.000 iw- lao 141.1. 0 0 2 125.500 96' L82 150.9 1 0.000 7 7.000 90- 167 lis.2 4 140.))) 9?- 18) 1)1.) 1 9.000 80- 111 10). 2 0 18 72.888 80- 187 135.6 10. 0 18.9 irPL^. CAftH f1lN-NA* MEAN 0 0 1 8.000 lU- 162 130. T 0 0 1 0.000 1 71.289 'JO- 194 ID. 9 u 128.230 98- 256 107- 133.6 2 8.000 127 115.2 25 91.250 90- 256 1)0.7 i9.0 /I .9 CATCH n|N-PAX Hf AN 0 1 12.000 llA- 161 U1 .5 Q ) 18). Ill 100- 198 1)1.2 0 0 5 i.ooo 53- llT 76*5 0 9B.00U 98- 190 1)5,0 0 15 61.000 53- 195 132. L !>,.0 sneLS, catch N IN-MAX mean 0 n 0 1 0.000 0 0 0 0 0 1 0.000 ?>,0 SMI-L!.. c»rc" Min-niK 0 0 0 0 0 0 0 0 0 0 ShPLS. CATCH MIN-MAI mean 0 0 0 0 0 0 0 0 0 0 40. a 29.5 SNPLi* CATCH H IN^niX mean 1 200.000 112' ISO IAI.4 1 12.000 IIA- 161 lii .5 i 8.000 llA- 162 130. 1 6 1)3.900 96- 199 1)4.9 i 0.000 8 1.750 90- 167 n5«2 19 7C.A52 53' 195 126.0 Zl 96.190 so- 246 107- l)».7 2 8*000 • 127 115.2 60 73.616 53- 256 132. i Specimens were taken at salinities ranging from 16.6 to 39.8 ppt. A salinity preference in this range was not apparent in our data (Table 27). Sizes ranged from 53 to 256 mm TL, with small and large fish occurring together during all months. The largest individuals appeared from March through June. A spawning period in the spring has been suggested by Hildebrand (1954) and Miller (1965). Roithmayr (1965) listed S. caprinus as the sixth most important species in the northern Gulf industrial bottom fishery. Our records show an approximate total mass of 1,337 kg, second in order of total weight. Longspine porgies were not taken in GMEI samples but we have 106 GULF RESEARCH REPORTS scarcity of this species in the Gulf during warmer months with the exception of single collections in August and September. Their September collection was in 254 fathoms (465 meters) while all others were taken in depths varying from 6 to 37 fathoms (11 to 68 meters). The specimens we collected measured from 62 to 255 mm TL, The temperatures of collections varied from 13.5'’ to 28.0° C and salinities from 23.8 to 38.6 ppt. Gunter (1945) noted that this fish prefers salinities over 30.0 ppt. Our findings concur with his. The majority of our collections were taken in salinities above 32.0 ppt. Smaller fishes ranging 62 to 96 mm TL were taken during all months in which the species occurred. Hildebrand and Cable (1938) reported that spadefish spawn offshore in the summer in the Beaufort, North Carolina, area. Reid (1954) mentioned that this species probably spawns in the spring around Cedar Key, Florida. Spadefish (17 to 229 mm TL) were taken in GMEI samples in all salinity ranges above 10 ppt with a maximum catch per unit of effort in the 20 to 24.9 ppt interval. The spadefish is an excellent panfish. They often concentrate around anchored boats and buoys. TRICHIURIDAE - Cutlass fishes Trichiurus lep turns Linnaeus - Atlantic cutlass fish A total of 172 individuals was taken in all months with peak numbers in the winter and spring months. Total length range was 175 to 820 mm. Temperatures ranged 13.0° to 27,3° C and salinities 24.9 to 37.7 ppt. The smallest individuals were obtained in November and January. These are probably the product of spring spawning as inferred by Miller (1965). Dawson (1967) and Miller (1965) collected very young fish in May and Jime (under 127 mm), and Dawson (1967) found larvae averaging 9.5 mm mean length in late April in plankton samples. Roithmayr (1965) lists this fish as contributing 5% by weight of the total catch of industrial bottomfishes in the north-central Gulf in 1969 to 1963. Our catch per unit of effort for this species was much higher in day sampling during 1967 and 1968; however, a reversal was found for Stations 4, 5 and 6 in 1969. Dawson (1967) took only 0.6% of his specimens during night trawling and explained that T. lepturus is known to feed at the surface at night. He took 11,388 cutlass fish in 188 hauls off Grand Isle, Louisiana. NEKTONIC AND BENTHIC FAUNAS 107 We have observed dense schools of young cutlass fish in Mississippi Sound and adjacent waters. This was one of the 20 most abundant fishes in GMEI samples. Observed total length in the estuarine study area was 32 to 707 mm. SCOMBRIDAE - Mackerels and tunas Scomber colias Gmelin - Chub mackerel This species appeared only in 1968 and 1969. Fifty-six were taken in 1968 at temperatures and salinities ranging between 21.0° and 24,0° C and from 27.0 to 27.8 ppt. A length range of 81 to 229 mm TL was noted for these specimens. One chub mackerel (229 mm TL) was taken at 40 fathoms in March 1969. The temperature and salinity at the time were 16.9° C and 35.7 ppt. Hildebrand (1954) examined an individual (23 mm TL) taken in April from 33 to 49 fathoms (60 to 90 meters) and remarked that the ovaries appeared to be almost ripe. The species is uncommonly reported in the literature concerning the northern Gulf. We have taken early juvenile Scomber colias with seine hauls from grass beds around Horn Island in the spring, but they did not appear in GMEI samples. Scomberomorus maculatus (Mitchill) - Spanish mackerel Eight Spanish mackerel were taken, 5 in 1967 (5 and 10 fathoms) and 3 in 1968 (10 fathoms). Specimens measured 177 to 297 mm TL with a total mass of 1.034 kg. Mackerel were collected at temperatures between 19,4° and 28.9° C and salinities between 31.6 to 37,4 ppt. Numerous schools of S. maculatus were observed on several occasions offshore. Large schools of Spanish mackerel have been found near the Mississippi offshore barrier island passes during the summer. We have also observed numerous schools of small Spanish mackerel in the Sound. A few specimens were caught in GMEI samples. This species usually appears in Mississippi waters in April and remains until late fall. Sports fishermen take large numbers of this species. Commercial fishermen only incidentally take Spanish mackerel. Although the extent of this resource is not known the supply seems to be adequate to support a commercial fishery. 108 GULF RESEARCH REPORTS GOBIIDAE - Gobies Bollmannia communis Ginsburg Sixteen specimens of B. communis were collected. Four fish taken in 1967 and eleven in 1968 (all from 5 and 20 fathoms) were collected at temperatures and salinities of 16.5° to 29.5° C and 24.6 to 36.5 ppt respectively. Only one of the 1967 specimens was measured (75 mm TL in March), and only one in 1968 (90 mm TL in June). The remaining specimens were damaged enough to prevent a proper TL measurement from being recorded. Hildebrand (1954) took 770 specimens from the deep-water brown shrimp grounds. Miller (1965) found 22 fish; 21 were from 15 fathoms and one from 12 fathoms. SCORPAENIDAE - Scorpionfishes and rockfishes Neomerinthe pollux (Poey) - Spiny cheek scorpionfish One individual, 388 mm TL and 453 grams in weight, was taken in May 1967 at Station 6. The temperature was 18.6° C, and the salinity was 35.0 ppt. This species is rarely reported from the northern Gulf. Pontinus longispinis Goode and Bean - Scalyhead scorpionfish Seven specimens (72 to 90 mm TL) were collected in March 1967 at Station 6. Temperature and salinity were recorded at 20.0° C and 37.8 ppt. This species did not recur in subsequent samples. Scorpaena calcarata Goode and Bean - Smoothhead scorpionfish A total of 205 specimens (57 to 273 mm TL) were collected in 48 samples. A temperature and salinity minima and maxima were recorded at 14.1° and 27.0°C and 16.6 and 39.8 ppt. Catch per haul was highest at 30 fathoms where 50% of all hauls included this species. These hauls took 57% of the total number. Gunter (1948) reported this to be the most abundant scorpaenid in the shallow Gulf. Smoothhead scorpionfish were collected in all months except January at Station 4. At Station 3 they were not collected from June through October and the one specimen from Station 2 was taken in February. They were not found in Station 5 samples from October through February. Total lengths less than 90 mm were recorded throughout the year and 94% of these measurements were between 57 and 109 mm. All of the 12 specimens over 180 mm TL were collected in the period February through May. NEKTONIC AND BENTHIC FAUNAS 109 Triglidae -Searobins Bellator militaris (Goode and Bean) - Horned searobin This species was represented by sixty-seven specimens (ranging from 67 to 113 mm TL). Moe and Martin (1965) collected one specimen, and other surveys have not reported B. militaris as being common in the northern Gulf. Specimens were taken no shallower than 30 fathoms with temperatures and salinities between 14.1° and 25.2° C and 16.6 to 37.4 ppt respectively. Peristedion gracile Goode and Bean A total of six specimens was collected in March 1967 at Stations 4, 5 and 6. The temperature range for these fish was 19.0° to 20.0° C, and salinities were recorded between 36.2 and 37.8 ppt. The Station 4 individual was 168 mm TL and weighed 30.3 grams. Two fish from Station 5 measured 159 and 165 mm TL, and weighed 20.4 and 26.5 grams, respectively. Three specimens were collected at 50 fathoms and ranged in length from 166 to 190 mm TL and from 30.0 to 44.3 grams in weigh t- Prionotus alatus Goode and Bean - Spiny searobin Three specimens were taken in one haul from 50 fathoms in May 1967. Specimens were 110, 111 and 113 mm TL and were taken at a temperature of 20.0° C and a salinity of 37.8 ppt. Prionotus ophryas Jordan and Swain - Band tail searobin A single specimen of P. ophryas was collected from 50 fathoms in March 1967. The fish measured 160 mm TL and weighed 57.8 g. The temperature was 20.0° C and the salinity was 37.8 ppt. Prionotus paralatus Ginsburg - Mexican searobin This species of searobin was taken only in 1967 and only during January (1 specimen, 156 mm TL) and March (33 specimens, 117 to 184 mm TL). The first specimen occurred at a temperature of 18.6° C and a salinity of 36.9 ppt at Station 4. March specimens were taken at temperatures and salinities ranging between 18.6° to 20.0°C and 36.2 to 37.8 ppt respectively. Prionotus pectoralis Nichols and Breder - Blackwing searobin A total of 22 blackwing searobins was taken in 1967 at Station 4. Specimens taken in March (10) ranged from 156 to 201 mm TL, and those in June (12) ranged from 155 to 204 mm TL. All fish were 110 GULF RESEARCH REPORTS collected within a temperature and salinity range of 20.0° to 20.4° C and 36.7 to 37.8 ppt. Prionotus roseus Jordan and Evermann - Bluespotted searobin This species was represented by nine specimens. In November 1967 one specimen (176 mm TL and 54.0 g) appeared in a night haul at 30 fathoms. The remaining eight specimens were taken in 1968 and ranged from 107 to 186 mm TL. These fish were collected in waters with temperatures and salinities ranging from 15.2° to 22.0° C and 23.2 to 37.0 ppt respectively. Prionotus roseus was not listed by Roithmayr (1965). Prionotus rubio Jordan - Blackfin searobin The majority of the specimens (877) of this species were found deeper than 10 fathoms. Hildebrand (1954) found numerous specimens and noted that this species prefers deep waters. Our fish ranged from 68 to 328 mm TL. Miller (1965) found indications of a fall and virinter spawning period. Temperatures and salinities ranged from 14.0° to 29.0° C and from 16.6 to 39.8 ppt. Prionotus scitulus Jordan and Gilbert - Leopard searobin Forty-seven leopard searobins were taken. They were obtained in all months with August being the peak month of capture. The temperatures ranged from 14.2° to 28.0° C, and the salinities varied from 24.9 to 37.2 ppt. The majority of specimens were taken at salinities above 32.0 ppt. The length range was 72 to 230 mm TL. Moe and Martin (1965) reported that the majority of their specimens came from depths of 25 to 45 feet. Our specimens were fairly evenly distributed from 5 to 30 fathoms. Moe and Martin (1965) collected their smallest specimens in February and March; ours were obtained in March and December. GMEI samples at higher salinities included P. scitulus. Prionotus stearnsi Jordan and Swain - Shortwing searobin Seventeen P. stearnsi appeared in the three years of sampling at temperatures and salinities of 16.1° to 20.5°C and 33.5 to 37.4 ppt respectively. A size of 79 to 134 mm TL was noted for these individuals. Roithmayr (1965) does not list P. stearnsi as occurring in the industrial botlomfish hauls; however, Oregon hauls in the Gulf have taken this species. NEKTONIC AND BENTHIC FAUNAS 111 Prionotus tribulus Cuvier - Bighead searobin Thirty-five individuals of this species were obtained in all months except April, October and December. These specimens were 49 to 285 mm TL. The temperatures ranged from 14.3° to 28.9° C and salinities from 29.3 to 36.8 ppt. The smallest specimen was taken in February. Gunter (1956) collected small individuals in March and April in Texas; however, Springer and Wood burn (1960) found that young appeared in late fall and winter in the Tampa Bay area of Florida. Hildebrand (1954) found a nearly ripe female in August on the Obregon shrimp grounds. Miller (1965) took small specimens in February and June. Moe and Martin (1965) also took small specimens in February and March. Moe and Martin (1965), Hildebrand (1954) and Miller (1965) noted that this species prefers shallower waters. Our data show indications of this also, with the majority of specimens being taken from 5 to 20 fathoms. This was far and away the most common searobin taken by Gunter (1945) in Texas waters. He did not fish in waters deeper than 10 fathoms. This was the most abundant searobin in GMEI samples. Uranoscopidae Astroscopus y-graecum (Cuvier) - Southern stargazer A single specimen of the southern stargazer was collected in January 1968 at 50 fathoms. The fish measured 210 mm TL and weighed 152.9 grams. Temperature and salinity at this time were 15.1° C and 26.2 ppt. The southern stargazer was collected in numerous GMEI samples, and early juveniles were evident in fall and winter hauls. Uranoscopus sp. An unidentified specimen of Uranoscopus was taken in March 1967 in 30 fathoms at a temperature of 20.0° C and a salinity of 36.7 ppt. The fish measured 119 mm TL and weighed 33.5 grams. This specimen was deposited in the Gulf Coast Research Laboratory museum. Kathetostoma albigutta (Bean) - Lancer stargazer Twelve Kathetostoma albigutta were taken during the three years at temperatures between 14.1° and 25.5°C and salinities between 16.6 and 37.2 ppt. Specimens measured 106 to 165 mm TL. 112 GULF RESEARCH REPORTS Brotulidae - Brotulas Brotula barbata (Block and Schneider) - Bearded brotula Three B, barbata were collected in 1967, ten in 1968 and one in 1969. Specimens ranged from 197 to 414 mm TL in 1967 and 1968. They were collected at temperatures and salinities ranging between 15.3° to 22.4°C, and 33.2 to 37.4 ppt respectively and at 20, 40 and 50 fathoms. The 1969 specimen was 565 mm TL and weighed 1,814.4 grams. Capture of this fish came at 50 fathoms in January at a temperature of 16.8° C and a salinity of 36.5 ppt. Miller (1965) took two in Texas. We have taken numerous specimens of small B. barbata in less than ten fathoms around Horn Island, Mississippi. OPHIDIIDAE -Cusk-eels Lepophidium graellsi (Poey) - Cusk-eel Our samples included 211 L. graellsi. This species was collected from all stations. Sizes ranged from 69 to 290 mm TL, and specimens were collected at temperatures from 14.3° to 28.9° C and salinities from 19.9 to 39.8 ppt. Ophidion welshi (Nichols and Breder) - Crested cusk-eel Thirty specimens wore taken at a temperature range of 14.0° to 28.0°C, and a salinity range of 25.7 to 37.4 ppt. A size range of 107 to 215 mm TL was noted for these individuals. The majority of specimens taken in this study were from 5 fathoms with a few from 10 and 20 fathoms. Miller (1965) indicated that O. welshi was more likely to be found at less than a 6-fathom depth. Great abundance has not been reported, GMEI samples took 24 crested cusk-eels in 484 trawl samples. Total length range in the estuarine study area was 25 to 183 mm. All specimens less than 100 mm TL were found in salinity less than 30 ppt. Strom ATE iDAE - Butterfishes Peprilus alepidotus (Linnaeus) - Northern harvestfish A total of forty -two northern harvestfish was taken with 98% being taken in winter and spring months. Miller (1965) collected the NEKTCNIC AND BENTHIC FAUNAS 113 majority of his specimens in June. Gunter (1945) collected P. paru in August, January and March in the Gulf at temperatures ranging from 13.7° to 30.0°C and salinities ranging from 33.0 to 36.7 ppt. Our data shows a temperature range of 14.2° to 21.5°C and a salinity range of 26.2 to 37.4 ppt. Specimens measured from 90 to 227 mm TL. Peprilus burti Fowler - Butterfish Caldwell (1961) places P. burti Fowler in the synomony of P. triacanlhus (Peck). Specimens were taken in all months and at all stations with the greatest numbers being found at 10 and 50 fathoms. A total of 7,016 fish were collected, and this number represents 7.49% of the total fish catch. The greatest numbers were taken in April and May with other sizeable catches appearing in June, August, October and January. The greatest catch per unit of effort in 1967 occurred at the 10-fathom depth, and the 30-fathom station showed only slightly less. In 1968 the greatest CPUE, which far surpassed that from other depths, occurred at 50 fathoms. The 5-fathom station showed the greatest catch per unit of effort in 1969. The largest CPUE from 50 fathoms was associated with a mean temperature and salinity of 19.9° C and 34.4 ppt respectively. A comparison of day and night hauls shows a much higher CPUE during the day for all stations. Hildebrand (1954) noted this for his hauls by remarking that greater catches occurred during “the early morning and day-time drags.” Springer and Bullis (1952) noted captures of this species with midwater trawls, and Caldwell (1961) noted that butterfish may school at the surface, near midwater, or at the bottom. This species occurred at salinities ranging from 16.6 to 39.8 ppt. Gunter (1945) found a salinity range of 15.6 to 35.2 ppt for Peprilus with the majority of specimens appearing at salinities greater than 30.0 ppt. Both a preference for salinities in the range 23.0 to 37.9 ppt with the largest catch per unit of effort at 26.0 to 38.9 ppt are shown in Table 28, Temperatures ranged from 10.8° to 29 .5° C. Gunter (1945) found this fish at a temperature range of 12.6° to 28.0° C and Miller (1965) noted temperatures of 12.8° to 25.7° C when catches were made. Specimens taken ranged from 24 to 240 mm TL, and small fish were taken with large ones in all months. In GMEI samples butterfish were fifth in numbers of fishes caught by seines and trawls. Their total lengths were from 17 to 171 mm. Phillips, Burke and Keener (1969) discussed the association of young butterfish with coelenterates. We have observed this 114 GULF RESEARCH REPORTS TABLE 28 DISTRIBUTION OF PEPRILUS BURTI BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES, CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH (MM). 1967 SALINITV INTERVAL PPT INT. C 16.6 L6.9 1 7.0 19,9 20.0 22.9 23.0 25.9 26.0 2B.9 29.0 31.9 12.0 34.9 15.0 37.9 38. 0 39.0 16.6 39.3 SPtPLS, iO.tt CAfCh 12.9 HIN-MAX HEAN 0 0 0 0 0 0 0 0 0 0 SWPLS, 13.0 CaTCH IJ.1 MIN-KAK HEAft 0 0 0 0 0 1 18.000 54- 73 59-7 6 U5. 166 49- 104 81 . 1 1 0.000 0 8 B8.625 49- 104 79.7 SNPI.S. 16.0 C*TCH le.fl HIN-PAX NEAH 0 0 0 0 1 2.000 144- 157 150.5 1 0.000 4 7.500 38- 68 61.6 13 92.846 66- 205 39.2 0 19 65.210 3S- 205 04.9 SHPti. IQ.O CAlCn 21.9 HIm-MAX HEAN 0 0 0 0 0 2 2.000 95- 140 121.7 4 2.500 127- 165 15U,6 21 2.619 lUJ- 209 162,0 0 27- 2.888 08- /09 188.0 iHPLi- 22.0 catch 2A«9 HIN-MAX MEAN 0 0 0 0 0 1 46-000 75- 137 114.6 1 Q-OQQ 12 17.831 no- 210 152-2 0 14 18.571 75- 210 140.9 SMPLS. 25.0 CATCH 27.9 MIN-HAS MEAN 0 0 0 0 0 4 12.500 112- IBS 153,3 2 13.500 112- 160 140.7 18 34,611 105- 207 151.3 0 24 29. 166 105- 20T 150.7 shplS. 28.0 CATCH 29. J HIN-HAx HEAn' 0 0 0 0 0 0 2 10.000 127- 229 L60.2 0 0 2 10.000 127- 229 160.7 SMPtS. 10. B CATCH 29,5 AIN-HAX MEAN 0 0 0 0 1 2.000 1**- 157 150.5 9 iJ. 1 11 54- laa 127.4 19 40.947 30- 229 96.5 65 32,292 66- 210 139.0 0 94 31.882 38* 229 126.2 1968 SALINl ir INI ERVAL PPT [EHP INT. c 16.6 16.9 17.0 19.9 20.0 22.9 23.0 28.9 26.0 28,9 29. D 11.9 32.0 14.9 35.0 37.9 35.0 39.0 16.6 39.0 SMPLS. 10. « CATCH 12.9 MlN'HAX MEAN 0 0 D 0 0 0 0 0 0 0 smpls. li.O catch 15.9 MIN-MAX MEAN 0 0 0 L Q.OOO 120' 157 146.2 4 0.500 143- L53 148.0 0 6 3.000 lOB- 231 129.9 0 0 u 2.636 108- 231 135.6 SMPL5, 16.0 catch IS. 9 MIN'HAX mean 0 0 0 2 l.OOO 174- 205 269,5 2 2.500 142- 160 150-4 3 0.000 6 0.666 169- 205 166.0 0 3.000 117- 203 155.3 0 71 1*666 IIT- 205 160.1 SMPLS. 19.0 CATCH 2L.9 MIN-HAX MEAN 0 0 0 3 0.333 209- 209 209.0 8 300.128 81- 193 102.0 3 0.000 6 98. 750 24- 198 149.2 5 1.200 103- 137 121.1 1 0.000 2B 114.214 24- 209 L22.2 SMPLS. 22.0 CATCH 2A.9 MIN-MAX MEAN 0 0 0 0 2 10.500 tl- 2*0 1*«.5 Q 2 0.000 4 3*000 102* 166 135.0 0 8 0.128 61- 2A0 1A8.3 SMPLS. 25,0 CATCH 27.9 MIN-MAI MEAN 0 0 0 1 0.000 1 8.000 07- 127 113.8 3 21,000 71- 195 127.9 1 0.000 6 7.666 111- 193 140.1 J A. 000 m U7.7 15 6*600 71- 195 130.3 S.PLS. 28.0 CATCH 29.8 .IN-.AX MEAN 0 1 0.000 0 0 2 10.800 81- 158 112. A 3 3.333 78- 12B 9r - Y 1 5.000 61- 106 9i.6 1 0.000 0 0 4.500 76- 155 106.2 i.PtS. 10. e CATCH 29.8 HIN-MAX MEAN 0 1 0.000 0 7 1.71* 120- 209 187.1 19 130.210 81- 2*0 100. A 12 6.003 71- 195 123.2 24 14.041 24- 231 14 7.4 24 ).666 102- 203 142.3 A 3.000 9i- 132 112.2 91 36*197 24- 240 125.9 NEKTONIC AND BENTHIC FAUNAS 115 TABLE 28 (Continued) 1969 iALlNirr JNItHVAL fi'I TEMP INT4 c L4.6 U.9 17.0 19.9 20.0 22.9 23.0 2S,9 26.0 26.9 29,0 31.9 32.0 34.9 15,0 37.9 36.0 39,8 Ib.b 39.5 SBPLi. 10. s c«rcH 12 . s HIN-MHK •<(*)« 0 0 0 0 0 0 9.000 100- III 107.0 1 2.00U 125- 153 139.0 0 Z 5.500 100- 153 1 U.8 shpls. 13.0 t»tt« 13.0 HIN'MIX 1 5,000 156- 206 L69«0 0 0 i 2.500 19«. 216 203.4 1 lA.OOO 9A- lAO 127.3 7 4.714 65- 155 154.6 6 1.500 70- 2L0 174.7 1 0.000 0 19 3.66b b5- 216 156,6 SKOii. ie..o ctTCH 14,0 Mlh-MAX MEAN 0 0 L 0.000 0 0 1 0.000 f 2.142 155- 219 153.5 13 2.615 179- 221 196.4 170- 2 9.000 ■ 215 194.3 2^^ 2.791 136- 221 193.0 SHPIS. 19.0 CATCH 21.9 MiN-HAt H€AN 0 1 0.000 0 3 109.000 91- 196 116.6 0 0 5 9.000 85- 1S8 120.0 6 3.333 85- 205 124, b 0 16 26.133 83- 203 Lia.6 shpls. 22.0 CATCH 2A.9 KIH-HAX HCAH 0 0 0 1 0.000 0 0 0 0 0 1 0.000 smple. 23,0 CATCH 2t.9 Mlr*-HAtl MEAN 0 0 0 0 0 0 0 U 0 0 SHPLi. 26.0 CAICn 30.5 hjh-hax HE AN 0 0 0 0 0 0 0 0 0 0 SliPLi. 10, « CATCH 29.3 MIN-Ma* MEAN 1 5.000 156- 20fi 169.0 1 0.000 1 0.000 6 55.3)1 91- 2L6 121.0 1 Kr.OOO 94- 140 iZU> e 4.125 65- 155 154.6 19 4. 105 70- 219 117.1 2\ 2.666 85- 221 L6&.7 170- 2 9,000 • 215 194,3 60 8.933 65- 221 142.6 phenomenon many times. Apparently this species utilizes jellyfish for food. The occurrence of young fish in winter and spring hauls prompted Miller (1965) to suggest an early winter and possibly a fall spawning period. This species was listed by Roithmayr (1965) as a component of the industrial bottomfish catches. Our catch showed an approximate total weight of 1,891.6 kg, sixth in order of total weight. Although butterfish comprise an important part of Chesapeake food fish, they have not been harvested in the Gulf because of their smaller size in Gulf waters. Larger specimens taken in our samples proved to be an excellent pan fish. Sphyraenidae - Barracudas Sphyraena gauchancho Cuvier - Guaguanche Eight guaguanche were captured, five in 1967 (5 and 30 fathoms) and three in 1968 (5, 10 and 40 fathoms). The smallest specimen, 148 mm TL, appeared in November and the largest individual, 345 mm TL, 116 GULF RESEARCH REPORTS was taken in December. Fish were collected at temperatures and salinities ranging from 14.4® to 24.2°C and 26.6 to 37.0 ppt respectively. Mugilidae - Mullets Mugil cephalus Linnaeus - Striped mullet One specimen of the striped mullet was collected in November 1968 at 30 fathoms. This fish measured 355 mm TL and weighed 375.0 grams. Temperature and salinity readings of 16.4° C and 37.4 ppt were recorded. The striped mullet is generally an inshore species; however, spawning is accomplished in the deeper offshore waters. Gunter (1945) stated that spawning occurred in the Gulf near passes through outside beaches. Broadhead (1953) inferred that spawning takes place at 5 to 20 fathoms. Arnold and Thompson (1958) observed spawning striped mullet at the surface of 775 fathoms of water off the Mississippi River delta. POLYNEMIDAE - Threadfins Polydactylus octonemus (Girard) - Threadfin A threadfin measuring 183 mm TL and weighing 54.4 grams was collected at Station 1 in September 1967. The temperature and salinity at this time were 26.1°C and 31.6 ppt, respectively. GMEI samples included 2 threadfins. Periodically, young threadfin appear in the study area in large numbers ( fide Christmas). Pleuronectiformes Both ID A E - Lefteye flounders Ancylopsetta dilecta (Goode and Bean) - Three-eye flounder Three A. dilecta were encountered, one in each of the three years. In March 1967 at a temperature of 19.0° C and a salinity of 36.2 ppt, a 247 mm TL specimen weighing 129.2 grams was taken at 40 fathoms. At a temperature of 19.3° C and a salinity of 27.9 ppt, a 108 mm TL specimen weighing 13.9 grams was collected at 50 fathoms in October 1968. A 163 mm TL specimen weighing 43.5 grams was captured at 50 fathoms in May 1969 at a temperature and salinity of 20.5° C and 19.9 ppt. This species has been reported rarely from the Gulf. NEKTONIC AND BENTHIC FAUNAS 117 Ancylopsetta quadrocellata Gill - Ocellated flounder Three ocellated flounders were taken, two in August of 1 967 and one in January of 1968. The two August specimens measured 221 and 224 mm TL and weighed 150.6 and 163.0 grams, respectively. The 221 mm-specimen was taken at Station 1 at a temperature and salinity of 25.1^ C and 35.8 ppt. Readings of 22.4° C and 36.5 ppt were recorded for the 224-mm specimen. In January 1968 a 320-mm-TL fish weighing 399,8 grams was collected at Station 1 at a temperature and salinity of 14.8° C and 28.5 ppt. Springer and Woodbum (1960) collected two individuals at salinities of 30.1 and 31.3 ppt and temperatures of 22.0° and 27.7° C. Gunter (1945) found the salinity range in Texas waters to be 22.8 -36.7. Ancylopsetta quadrocellata is known to occur in shallow water in bays and offshore to depths of 80 fathoms (Springer and Bullis 1956). A spawning period in winter has been suggested (Joseph and Yerger 1956, Hildebrand 1955). GMEI samples included ocellated flounders from a wide range of salinity. Citharichthys macrops Dresel - Spotted whiff Four C. macrops were taken in one haul at 10 fathoms in June 1967. This is the total catch of this species. Sizes ranged from 133 to 148 mm TL with a total weight of 121 grams. The temperature and salinity at the time of capture were 25.0° C and 35.1 ppt. Gunter (1945) only took two off the Texas Coast. Springer and Bullis (1956) found C. macrops to be somewhat common at depths to 37 fathoms. This species apparently is not a regular component of trawl hauls, and its distribution is not clearly established. Citharichthys spilopterus Gunther - Bay whiff Fifty-five specimens (69 to 198 mm TL) were taken with the majority of specimens being collected at 10 and 20 fathoms. These fish were taken at temperatures and salinities between 14.9° to 29.0° C and 25.7 to 37.4 ppt from June through February. Gunter (1945) said there was apparently a winter movement offshore and Hildebrand (1954) noted a similar occurrence in his catches. The bay whiff was the second most abundant flatfish in GMEI samples. Fish were found in the estuarine study area from April through November and included total lengths from 18 to 125 mm. The late fall migration from the estuarine study area is clear but is not reflected in our samples. No specimens were taken in either area during March. 118 GULF RESEARCH REPORTS The 198 mm TL specimen collected at 50 fathoms in October weighed 58.8 grams. This is a very large northern Gulf bay whiff. Meek and Hildebrand (1928) considered their 170-mm specimen to be large for the species. Cyclopsetta chittendeni Bean - Mexican flounder A total of 375 Mexican flounders were taken. This species was represented in all months and was found at depths of 10 to 50 fathoms with the greatest number taken at 20 fathoms. The temperatures and salinities at which this species was encountered varied from 14.9° to 28.9° C and from 19.8 to 39.8 ppt respectively (Table 29). The sizes ranged from 68 to 335 mm TL. We took our smallest individual (68 mm) in August. Dawson (1968) also encountered fish of this approximate size in August. This species is considered quite common in offshore waters (Gunter and Rnapp 1951). Hildebrand (1954), noted that larger fish of this species prefer depths over 20 fathoms, whereas, younger individuals are found at depths of 12 to 20 fathoms. Dawson (1968) took this flounder at depths of 11 to 20 fathoms off Grand Isle, Louisiana with the majority being taken at 20 fathoms. Our data shows this depth preference. TABLE 29 DISTRIBUTION OF CYCLOPSETTA CHITTENDENI BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES, CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH 1967 lALlNIlT IHUHVJit ppr INT. LA. A 1 7.0 20.0 29.0 2A.0 29. U 32,0 15.0 33.0 16. A C LA. 9 Z2.9 25.9 28aV 31.9 3*6.9 37.9 39.3 39,3 &np|.s. 0 0 0 0 0 0 0 0 0 0 10.6 CATCH U.6 fliN-HAX HI AN S.PH. 0 0 0 0 0 1 A 1 0 8 13.0 C*TCli 0.000 0.000 1.250 1»*9 HIN-MAX 121- 111 173- 339 MEAN 209.6 209.6 SNPI.S. 0 0 0 0 1 1 A 13 0 19 U.O CATCH 0.000 0.000 O.UOO 2,iaA 1.831 It.* N|N-n*)i 117- 2A5 117- 245 183.1 164.3 0 0 0 0 0 2 4 21 0 27 1».0 C*TCH 0.000 0.250 3.095 2.555 21.4 HIN-MAX 153- 151 ao- 26i •0- 263 MEAN 153.0 169.3 169.2 SMffLl. 0 0 0 0 0 k L 12 0 !*• 22.0 CATCH 0.000 o.ooo k.AAA 1.528 2A.9 MIN-MAX 68- 261 A3* 26t mean 191,0 191.0 shrli. 0 0 0 0 0 2 la 0 25 29.0 CATCH 0-000 1.000 1.168 1.129 2T.9 HIN-HAX 185- 203 65- 247 85- 257 MEAN 197.0 185.8 IA9.7 SMPLS. 0 0 0 0 0 0 2 0 0 2 20.0 CATCH b.OOO 6.000 29.9 MlN-MAX 92- 122 92- 122 MEAN 108.8 103.6 SMRLS. Q 0 0 0 1 9 19 63 0 94 10.6 CATCH 0.000 0.000 1.315 7. 169 1.765 29.9 HIN-HAX 92- 335 A3- ZA3 63- 339 MEAN 15T.9 174.1 171. T NEKTONIC AND BENTHIC FAUNAS 119 TABLE 29 (Continued) 1968 TtMP INI. 16.6 17.0 20.0 2).0 26.0 29.0 32.0 35.0 18.0 16.6 c 16.9 19.9 22.9 26.9 28.9 31.9 36,9 37.9 39.8 19.8 shpls. 0 0 0 0 0 0 0 0 0 0 10.8 C6ICM 12.9 MEAN 5BP6S. 0 0 0 1 6 0 6 0 0 11 li-0 CitCH 0.000 0.000 0.633 0.656f 1^.9 niN-MAX 116- 267 116- 267 8E6N 177. B 177. B 5MPI.S. 0 0 0 2 2 3 6 8 0 21 16.0 CATCH 16.S00 0.000 26.666 0.333 0. 750 5.676 18.9 MlN-HlX 126- 232 111- 199 170- 202 220- 261 U3- 263 mean 169.1 156.6 1A6.0 237.8 161.6 iHPLS. 0 0 0 3 e 3 B 5 1 2f 19.0 CAK« 0.000 0.2^0 0.000 1.625 2.000 1.000 0.928 21.9 M]N-HAX 263- 266 205- 250 205- 273 222- 222 205- 271 HE*N 266.5 226.5 26/. 0 222.0 237.1 S8PL5. 0 0 0 0 2 0 2 6 0 8 22.0 C*rcH 0.000 6.000 2.000 2.000 26.9 KIH-H** 171- 222 705- 290 171- 780 niAH 193. 1 236,5 211.9 SHPLS. 0 0 0 1 L 3 1 6 3 15 25.0 CATCH 0.000 0.000 0.133 0.000 0.500 0.000 0.266 27.9 266- 266 169- 201 169- 266 HtAN 26*. 0 186.3 199.7 iHPL5. 0 1 0 0 2 5 1 1 0 8 2«.0 CAfCH 0.000 o.ouo 0,000 0.000 1.000 0.125 29.5 HIH-H** 192- 192 192- 192 H{*N 192.0 192.0 0 1 0 7 19 12 26 26 6 91 10. 8 catch O.OOtJ 6.716 0.105 6.250 1.166 1.166 0.2SQ 1.815 29.5 HIN-HA* 126- 232 263- 266 113- 266 116- 250 169- 280 222- 222 113- 280 mean 169.1 266.5 155.8 205.6 232. r 222.0 181.1 1969 SALINI TV INTECIVAL PPT TfAP INT. 16.6 17,0 20.0 21.0 26.0 29.0 32.0 35.0 3U.0 16.6 C 16.9 19*9 22*9 25.9 28.9 31.9 36.9 37.9 39.8 19.8 IHPtS. 0 0 0 0 0 0 , 1 0 2 10. tf CaTCh 12.9 min-hak 0.000 0.000 Q.OOO nEAx SHPLS. 1 0 0 2 L 1 6 L 0 la 11. 0 CATCH 0.000 0.000 0.000 0.62B 0.000 6.000 0.188 15,9 nlN-.Al 119. - 170 136- - 259 116- - 259 HEAN 151.1 172.5 163*6 SHPLS. 0 0 1 0 0 1 7 11 2 26 16.0 CATCH 0.000 2,000 1.162 1*615 0,500 1.133 18.9 HIH-HAK 126- - 262 172- 280 705- • 780 158- 158 126- . 280 MEAN 106.0 216.0 260.5 156.0 233.1 5HPL5, 0 1 0 3 0 0 5 6 0 15 19,0 CATCH 1,000 0.000 0.000 0.333 0.200 21.9 HlN-HlX 790- 290 219' - 260 219- - 290 HEAH 290.0 219.5 256.1 SHPLS. 0 0 0 1 0 0 0 0 Q 1 22.0 CATCH 26.9 MlN-AAX 0.000 0*000 HE AH SHPLS. 0 0 0 0 0 0 0 0 0 0 25.0 CATCH 27.9 HlH-HAX man SHPLS. 0 0 0 0 0 0 0 0 0 0 28.0 CATCH 29.5 HIN-HAA HEAN i«PL4. 10.1 CATCn 29.5 MEAN 1 1.000 290- 290 290.0 6 1 8 19 21 2 frO 0.000 0-625 0.621 1.2S5 0.500 0.700 126- 262 172- 2*0 IJ6- 280 158- 158 126- 290 166.6 236.0 210.6 158.0 221.1 0.000 0.000 Q.OOO 120 GULF RESEARCH REPORTS Engyophrys sentus Ginsburg - Spiny flounder Two spring flounders were taken in 1968 (20 and 40 fathoms). A March specimen measured 73 mm TL and weighed 3.0 grams. A November specimen measured 87 mm TL and its weight was recorded as 7.0 grams. The March temperature and salinity were 17.0° C and 24.6 ppt. The temperature in November was 21. 6° C and the salinity was 38.2 ppt. This species has been considered to be rare in Texas (Gunter and Knapp 1951). Hildebrand (1954) found E. sentus to be common at 15 fathoms and deeper. This species has been reported from 65 fathoms (Longley and Hildebrand 1941). Anderson and Lindner (1941) re- corded 28 specimens from 25 to 40 fathoms. The distribution is relatively unknown. Etropus crossotus Jordan and Gilbert - Fringed flounder Three hundred forty -five E, crossotus were taken with all specimens ranging from 54 to 205 mm TL. They were collected at temperatures and salinities between 13.3° to 29.0° C and 23.2 to 39.8 ppt. Etropus crossotus was found at all stations and during all months. The majority of fish were taken from 5 to 30 fathoms. Spawning occurs offshore from approximately March through June (Reid 1954; Moe and Martin 1965'). Our largest individuals (205 and 204 mm TL) were collected in May and July, respectively. Gunter’s (1945) data show offshore movement with the seasons, but they tell nothing of the far offshore distribution as presented here. GMEl samples included E. crossotus (15 to 130 mm TL) in all months. Paralichthys albigutta Jordan and Gilbert - Gulf flounder One Gulf flounder taken in June 1967 from Station 1 measured 169 mm in length and weighed 62.8 grams. The temperature was 26.1° C and the salinity was 29.3 ppt. Miller (1965) took one specimen at 6 fathoms and two at 9 fathoms. Gunter (1945), Hildebrand (1954) and Miller (1965) attest to the scarcity of this flounder in the northwestern and western Gulf, and our data are in agreement with their findings. Springer and Woodbum (1960) and Joseph and Yerger (1956) found this species quite common on the Florida coast. The absence of the preferred bottom (sandy) for this species could be one cause for its small numbers. We have taken P. albigutta (including early juveniles, 30 mm, and adults), though never in abundance in miscellaneous trawl hauls around the offshore barrier islands. NEKTONIC AND BENTHIC FAUNAS 121 Paralichthys lethostigma Jordan and Gilbert - Southern flounder A total of 37 southern flounders was taken during the three years of sampling. The lengths ranged from 127 to 452 mm TL. Tem- peratures ranged from 13.3^* to 28.0° C, and the salinities were from 19.9 to 37.9 ppt. Gunter (1945) found this species in temperatures varying from 9.9° to 30.5° C and salinities from 2.0 to 26.2 ppt. Gunter (1945) further stated that this fish seems to prefer salinities below 25 ppt, at least in the sizes he examined (up to 490 mm). Gunter (1945) found southern flounder with developing roe in October, and Ginsburg (1952) agreed by stating that the fish spawns in late fall to early winter. GMEI samples included 121 specimens (20 to 367 mm total length). They were taken in all seasons and throughout the salinity range. The southern flounder is a favorite food fish. It is sought by both sports and commercial fishermen. Mississippi landings (69,000 pounds in 1965) probably reflect only a fraction of the flounders caught for food. Paralichthys squamilentus Jordan and Gilbert - Broad flounder Twelve specimens of the broad flounder were collected in our samples. They varied 200 to 456 mm TL and were encountered at temperatures ranging from 14.0° to 25. 5° C and salinities ranging from 24.9 to 37.8 ppt; however, this species seemed to prefer salinities over 32.0 ppt. They were taken at Stations 4, 5 and 6. Syacium gunteri Ginsburg - Shoal flounder The shoal flounder was the most abundant flatfish in our samples. Gunter and Knapp (1951) also reported S. gunteri to be the most abundant flatfish on the brown shrimp grounds. This species was obtained during all months and at depths from 5 to 50 fathoms with the greatest numbers taken at 20 fathoms. Hildebrand (1954) and Miller (1965) took this fish in abundance, and Hildebrand (1954) mentioned it as being the most common fish on the brown shrimp grounds of the western Gulf. These authors also noted that this fish is more abundant at depths greater than 10 fathoms. Gunter (1945) took 192 individuals but found them only in the Gulf. Springer and Woodbum (1960) and Reid (1954) did not record this species, indicating this fish does not enter inshore waters near Florida. The sizes encountered ranged from 72 to 270 mm TL. Hildebrand (1954) mentioned that this is a small species and the largest fish he 122 GULF RESEARCH REPORTS measured was 178 mm. Miller^s (1965) largest fish was 155 mm. We took a number of individuals over 200 mm TL and the lai^est was 270 mm TL. Since size ranges were fairly standard over the entire year, length-frequency data proved to be of little value in determining growth rate. This species was obtained at temperatures and salinities varying from 14. 5^* to 29.0® C and from 23.2 to 38.7 ppt (Table 30). Syacium papillosum (Linnaeus) - Dusky flounder Twenty -eight S. papillosum were caught in 1968 (2) and 1969 (26). Specimens measured 114 to 270 mm TL and were taken at salinities and temperatures ranging between 16.6 to 37,4 ppt and 14.1® to 20.9® C. The majority of specimens were taken at 10 and 20 fathoms. Springer and Bullis (1956) caught S. papillosum in northern Gulf hauls. Hildebrand (1954) and Moe and Martin (1965) reported the species with Moe and Martin (1965) predicting an early summer spawning. Our fish were taken in January, February, March and November. The S. papillosum reported by Gunter (1933) were actually S. gunteri. It seems to be a more offshore fish than the latter species. Trichopsetta ventralis (Goode and Bean) - Sash flounder One hundred sixty-three specimens were taken at temperatures and salinities from 15.3® to 25.3® C and 19.9 to 37.8 ppt. A size range of 65 to 225 mm TL was recorded. These fish were taken from 20- to 50-fathom depths in all months except November, December, and January. About 85% of the catch came from 50 fathoms with catch per unit of effort in day hauls being greater than in night hauls. SOLEIDAE - Soles Gymnachirus melas Nichols - Naked sole A single specimen of G. melas was taken in March 1968 from 40 fathoms. The fish measured 153 mm TL and weighed 44.0 g. The temperature was 18.0® C and the salinity was 34.0 ppt. Gymnachirus texae (Gunter) - Naked sole A total of 117 specimens ranging from 64 to 125 mm TL with a total weight of 1.776 kg were collected. Salinities ranged from 16.6 to 37.8 ppt and temperatures were between 14.1® and 29.0° C. This species of Gymnachirus has been uncommonly reported from the northern Gulf. Supposedly the greatest depth recorded for this species is 58 fathoms (Springer and Bullis 1956). NEKTONIC AND BENTHIC FAUNAS 123 TABLE 30 DISTRIBUTION OF SYACIUM GUNTERI BY BOTTOM SALINITY AND TEMPERATURE INTERVALS SHOWING NUMBER OF SAMPLES, CATCH PER UNIT OF EFFORT, MINIMUM, MAXIMUM AND MEAN TOTAL LENGTH (MM). 1967 S*L[FflTY [NfEflVlt PPT lEMP IM». U.6 1 uo ^0.0 25.0 2(1.0 29.0 3^ .0 35. U 36.0 16. 6 c 16.9 19.9 22.9 2i.9 28.9 31.9 3b. 9 37.9 39.8 39.8 SMi>LS. 0 0 0 0 C 0 0 0 0 0 10. a CATCH ie.9 Hln-AAl MEAN SWPLS. 0 0 0 0 0 1 6 1 0 e 13.0 CATCH 15,9 HtN-HAX 0.000 D.UOD 0.000 0.000 hCah iUKlS, 0 0 0 0 1 1 b 13 0 19 1*.0 CATCH 0.000 lb. 000 1.250 1.307 2.000 ia.9 HIH-HAff 99- 156 T2" lib 86- 211 72- 211 nfAW i 1b.^ 9 3.6 127. r n T . 6. u u 0 0 u 2 b 21 0 27 19»0 CATCH 0.000 ] 1.000 0.90A 2.111 21.9 nIN-HAK eo 111 ■;a 2bS ao- 26 > HEA** 103.5 116.2 111. A SHPLS- 0 0 0 0 0 1 1 12 0 lA 22.0 CAfCH 0.000 0.000 2. 166 1,867 24.9 HtN-MAX 93- 203 9)- ?03 HEAN 126.2 126.2 SHPLS. 0 0 0 0 0 4 2 IH 0 2A 2S.0 CAICH 0.000 2.000 1. 166 l.ObL 2T,9 HIH'NAX lOT- I2b «5- 220 85- 220 MEAN 11b, 5 lb9«0 Ibl.b inns. 0 0 0 0 0 0 2 U 0 2 2«.0 CAICM 3.000 liOOO 29.* MIN-MAA 79- 16) 79- 163 "«AN 109,6 109.6 SMPL*. 0 0 0 0 1 9 19 65 0 9b 10. B CAtCn 0.000 l.TfJ 1. IQJ 1.276 l,6B0 29.9 HIN-HAA 99- IS6 T2- 16] 9i- 266 72- 265 HEAH llA.* 10b, 0 llb.T 121.1 TEHP IHI. C 16.6 16.9 17.0 19.9 20.0 22.9 SALINITY 23,0 25.9 1968 iNTCnvAL 1 26.0 28.9 29.0 il .9 32-0 3b, 9 35. Q 37.9 38.0 39.6 L6.6 39,9 SHPLS. 0 0 0 U 0 0 0 0 0 0 10. « catch 12.9 MIN-MAX HE An 0 0 0 1 b 0 6 0 0 11 13,0 CATCH o.ouo 0.250 0.666 0,b5b 1*.9 TilN-nAl 88- da 127- 165 aa- 165 MEAN Ha.o L6b,5 1*9.2 smpls. 0 u Q ? z 3 6 a 0 21 23.500 5.000 13.666 b.OOO 0.625 6.0*7 ia«9 mjn-hax 88- IT* 91- 120 99- 166 71- 270 97- U9 73- 270 hEan 117.9 109.9 1*2.1 158.3 109.6 139. a 5HPL&. 0 0 0 3 6 i 8 5 L 26 19.0 CATCH 2.111 l. 750 0.000 0.125 1.000 0.000 1.121 118- 211 90- lb2 113- 113 95- 190 90- 211 HE AH 155. 1 U6.2 111.0 1)9.0 L)2,7 5MPI&, 0 0 0 0 2 0 2 b 0 a 72.0 catch 0.500 0.50D 0.000 0.250 24.9 MIN-MAX 127- 127 lAQ- 1*0 121- IbO mean 127.0 1*0.0 133.5 ^hPl5. 0 0 0 1 t 3 1 6 3 15 25«0 CATCH 0.000 I.OUO 1 .000 0.000 5.666 0.666 2««66 27.9 MlN-hAX I2b- 126 127- iba 7$- 152 125- 220 78- 220 MEAN 12A.3 1 19.3 lib, 9 172,5 120.0 shpls. 0 L 0 0 2 ) 1 1 0 B 28.0 CATCH 0.000 0.500 b.333 o,uuo 7.000 2.625 29.S MIN-MAX 132- 132 102- 158 107- IJA 102- 15$ MEAN 132.0 126.6 122.1 125.5 SMPC5. 0 1 0 7 19 12 ?b 2b b 91 0.000 7. 7lA l.A7> 6.750 1.2 5U 2,5bl 0.500 2.5b9 88- 211 86- Lb2 96- 166 71- 770 78- 190 125- 220 71- 270 mean IbO. 1 LLb.l 138. b 15^,0 121.3 172.5 11*. 1 124 GULF RESEARCH REPORTS TABLE 30 (Continued) 1969 I«T. C Ib.b lb. 9 17.0 19.9 20.0 22.9 2J.0 25.9 2&.0 28.9 29,0 il.9 32.0 35.0 17,9 id* 0 ib«b 19. a 10.4 IJ.9 SWLS, CATCH mih-max mcan 0 0 0 0 U 0 1 Oa 000 1 0.000 0 2 o.ooo 11.0 SUPLS. urcH MEAN 1 0.000 0 0 2 0.000 1 o.ooc 119- i 0,926 * 159 1^9. J b u.ooo 1 1,000 ua- us ua . 0 0 18 0.222 1J9- 159 U9.Q lA.O SMPLS. CATCH nEan 0 0 1 O.QQO 0 0 IsJ- 1 ^.OOU ■ r o.bsi' 99- 15? Ill.l li 0.692 13i- 2U1 2 0 . uoo 2*. □ * 791 99- 201 l<.7, 1 1«.0 21.9 SMPtS. catch MIN-HAA MEAN 0 1 0.000 □ ) 0.000 0 0 5 Q.QOO h (j.OOO 0 15 0.000 22.0 29.9 S«PCS. CATCH MIN-MAX MEAN 0 0 0 1 0.000 0 D 0 0 0 k u.ooo 29.0 27. 9 iMPLS. CAICM MtH-MAK MEAN 0 0 0 0 0 0 0 a 0 0 21.0 29.9 iHMLi. CATCH MIN-MAX HCAm 0 0 0 0 0 0 0 0 0 0 10.1 29.9 SMPLS. CATCH MIN-MAX MEAN 1. 0«QO0 i 0.000 1 0.000 6 o.ooo 1 o.ouo 1 .i9 a o.a/5 “ 159 1^6. 1 19 0-115 99- 15 1 Ill.l 2i 0.97b IJl- 201 158. L 2 o.ood 60 0.381 99- 201 147.^ CYNOGLOSSIDAE - Tonguefishes Symphurus diomedianus (Goode and Bean) - Tonguefish Two specimens of S. diomedianus were taken. A March 1967 fish from 50 fathoms measured 150 mm TL and weighed 25.1 g. The second specimen was collected from 20 fathoms in January 1967. This fish measured 153 mm TL and weighed 44.0 g. The March temperature and salinity were 20.0° C and 37.8 ppt, respectively. The temperature and salinity for the January collection were 18.4° C and 36.7 ppt. Symphurus plagiusa (Linnaeus) - Tonguefish Symphurus plagiusa appeared in 1967 (33); 1968 (14) and 1969 (17). They were found at all stations. Specimens ranged in size from 102 to 156 mm TL and were taken at temperatures and salinities from 14.0° to 26.1° C and 26.2 to 37.2 ppt. These fish were taken in all months with the exception of June and November. Gunter (1945) found that 90.6% of his specimens were taken at salinities above 30.0 ppt. Miller (1965) found no apparent seasonal trends in either lengths or numbers caught. Our data show a preference for salinities above 29.0 ppt. Ginsburg (1951) recorded a maximum depth of 14 fathoms for NEKTONTC AND BENTHIC FAUNAS 125 this species and indicated that greater numbers were taken in inshore waters. Hildebrand (1954) increased the known depth range to 23 fathoms. Although most of our specimens came from 10 fathoms or less, we collected seven specimens at 30 fathoms, one at 40 fathoms and one at 50 fathoms. In inshore GMEI samples, S. plagiusa was eighteenth in numerical abundance. Total lengths ranged from 25 to 180 mm in all salinity intervals above 2.0 ppt. The highest CPUE (sizes 45 to 180 mm TL) was made at salinities above 30.0 ppt, and was followed closely by the CPUE (sizes, 38 to 121 mm TL) at 15.0 to 19.9 ppt. Maximum size inshore increased with salinity. ECHENEIFORMES ECHENEIDAE - Remoras Echeneis naucrates Linnaeus - Sharksucker The sharksucker, E. naucrates, was taken on three occasions. In March 1967 a 383 mm TL specimen weighing 230.5 grams was collected at a temperature and salinity of 20.0° C, and 36.7 ppt from Station 4. Two years later in 1969, again in March and at the same station, another specimen of the same size (383 mm) was taken at a temperature and salinity of 16.9° C and 35.7 ppt. In June 1967 a specimen measuring 602 mm was encountered at 30 fathoms at a temperature and salinity of 25,1° C and 36.8 ppt. This species was on numerous occasions seen associated with sharks and the cobia, Rachycentron canadum. TETRAODON TIFORMES Balistidae - Triggerfishes and filefishes Alutera scripta (Osbeck) - Scrawled filefish Alutera scripta (56 to 339 mm TL) was collected in 1967 (29 specimens) and 1968 (19 specimens). Temperatures and salinities were 15.2 to 26.5° C and 26.5 to 37.4 ppt. This species has been uncommonly reported from offshore waters in the northern Gulf. Batistes capriscus Gmelin - Gray triggerfish This species of triggerfish occurred in all years, and 26 specimens ranged in size from 107 to 335 mm TL. Temperatures and salinities were 14.0° to 24.0°C and 16.6 to 37.4 ppt. Specimens were taken no deeper than 30 fathoms, Gunter (1945) and Miller (1965) took only one specimen each. 126 GULF RESEARCH REPORTS Monacanthus hispidus (Linnaeus) - Planehead filefish Two specimens taken in 1967 appeared at Stations 1 and 4 in a temperature and salinity range of 14.3“ to 16.4“ C and 32.1 to 35.6 ppt. The 1968 catch (2) was collected in one sample in December at Station 4. A temperature and salinity of 21. 8“ C and 31.8 ppt were noted at this time. Four specimens were taken from Station 4 in 1969. Ranges in temperature and salinity were 15.5“ to 19.8“C and 34,0 to 37.4 ppt. Specimens ranged from 46 to 134 mm TL with a total mass of 249.3 g. GMEI samples included 44 M. hispidus (15 to 58 mm TL) from salinities above 20 ppt. OSTRACIIDAE - Trunkfishes Lactophrys quadricornis (Linnaeus) - Cowfish Twenty-one cowfish were taken during the three years. Tem- peratures and salinities from 13.5“ to 17.0“C and 26,2 to 33.2 ppt were noted for these specimens. Sizes ranged from 163 to 230 mm TL. This species is commonly taken from inshore grass beds during the warm months. Early juveniles were included in GMEI samples. The cowfish population is not large enough to support a commercial fishery but a large cowfish contains two small portions of white meat with excellent flavor and texture. Fishermen often select this species for their use (fide J.Y. Christmas). Tetraodontidae - Puffers Lagocephalus laevigatus (Linnaeus) - Smooth puffer Twenty-two specimens were taken during the three years. Smooth puffers ranged from 65 to 227 mm TL and were collected in waters ranging from 15.2“ to 27.0°C and 24,9 to 37,9 ppt. Hildebrand (1954) noted the preference of this species for deep water. Gunter (1945) did not collect L. laevigatus. Miller (1965) suggested an offshore spawning period during the fall in south Texas. We have taken a few specimens in miscellaneous trawl hauls in Mississippi Sound. Sphaeroides nephelus (Goode and Bean) - Southern puffer A total of forty-eight specimens appeared at temperatures and salinities ranging from 13.3“ to 25.2“C and 26.6 to 37,4 ppt. Fish ranged in size from 51 to 105 mm TL. Hildebrand (1954) reported a number of specimens from deep waters (15 fathoms; 27 meters, and deeper). Gunter (1945) and Miller (1965) stated that a fall and winter NEKTONIC AND BENTHIC FAUNAS 127 offshore movement seemed apparent. The present data agree with this observation. In colder months the catches of S', nephelus in our samples increased. This species was twentieth in order of numerical abundance taken by GMEI trawls and seines. In the estuarine study area they ranged from 12 to 105 mm TL and were taken at all salinities encountered above 5.0 ppt. Catch per haul decreased in the colder months. DIODONTIDAE ' Porcupinefishes Chilomycterus schoepfi (Walbaum) - Striped burrfish Eight specimens were collected; two in 1967, four in 1968 and two in 1969. The 1967 fish were taken from Station 1 at temperatures and .salinities ranging from 14.2^" to 14.3^C and from 32.1 to 32.5 ppt. In 1968 they were found at temperatures from 15.1° to 26.4°C and at salinities from 26.2 to 26.6 ppt. A temperature range from 10.8° to 20.2° C and a salinity of 33.2 ppt were noted for the 1968 specimens. Total length ranges were from 120 to 162 mm TL with a total mass of 892.6 g. Springer and Bullis (1956) listed C. schoepfi throughout the Gulf to depths of 50 fathoms. Our data show specimens from depths no greater than 10 fathoms. Gunter (1945) took 26 specimens, all in lower bay waters. In GMEI samples C. schoepfi (22 to 186 mm TL) were taken in salinities above 15 ppt. We have found them most often associated with grass beds around the barrier islands. BATR ACHOIDIFORMES BATRACHOIDIDAE -Toadfishes Porichthys porosissimus (Cuvier) - Atlantic midshipman The midshipman produced 104 specimens during this study at temperatures and salinities ranging from 14.1° to 28.0°C and 16,6 to 38.6 ppt. A total size range of 75 to 189 mm TL was recorded. Springer (1957) noted their disappearance from the bays from October through April, and our data show a greater offshore catch during January and October. It has been generally assumed spawning takes place in the spring and summer. The midshipman was in the GMEI study area. All specimens ranged from 30 to 196 mm TL in water temperatures above 15.0°C (with one exception, a small number of fish from 10.0° to 14.9°C) and salinities above 5.0 ppt. 128 GULF RESEARCH REPORTS LOPHIIFORMES LOPHIIDAE - Goosefishes Lophiomus sp. An unidentified species of Lophiomus was taken during this study. The specimen measured 108 mm and was taken at a temperature and salinity of 15.3°C and 34.6 ppt respectively. Capture occurred at 50 fathoms in March 1968. This fish was deposited in the Gulf Coast Research Laboratory museum. ANTENNARIIDAE - Frogfishes Antennarius radiosus Garman - Singlespot frogfish Forty -nine specimens were found in waters deeper than 10 fathoms at temperatures and salinities between le.e"* and 25.0“C and 19.9 and 37.4 ppt. Hildebrand (1954) found this species to be common in deep waters. Our specimens ranged from 42 to 170 mm TL in size. We have periodically collected A. radiosus in Mississippi Sound. Ogcocephalidae - Ratfishes Dibranchus atlanticus Peters A total of 235 specimens (39 to 93 mm TL) appeared in 1967 and 1968 at temperatures of 14.8° to 28.9° C and salinities of 23.2 to 37.8 ppt. This species was collected at all stations except the 5-fathom station. Catch per unit of effort was greatest at 30 fathoms. Halieutichthys aculeatus (Mitchill) - Spring batfish Specimens were taken in 1968 (77) and 1969 (40) with a size range of 61 to 98 mm TL being recorded. A temperature range of 15.2° to 29.0° C, and a salinity range of 19.9 to 38.2 ppt were noted. This species has been rarely reported. Hildebrand (1954) took 163 speci- mens, and Miller (1965) found only one at 9 fathoms, while noting a possible preference for deeper offshore waters. During this study the majority of fish were from the 40- and 50-fathom stations. They occurred in increasing numbers from 20 to 50 fathoms and were found at Stations 2 and 3 in August and November only. No specimens were taken in July. NEKTONTC AND BENTHIC FAUNAS 129 Ogcocephalus parvus Longley and Hildebrand - Roughback batfish One individual, 68 mm TL and 8.0 grams, was taken in 40 fathoms during March 1967* The salinity and temperature were 36.2 ppt and 19.0° C respectively. Ogcocephalus sp. Forty 'three unidentified specimens of Ogcocephalus were col- lected during the study. These individuals ranged from 56 to 294 mm TL. Temperatures and salinities ranged from 14.8° to 29.0° C and 23.2 to 37.4 ppt respectively. These specimens have been deposited in the Gulf Coast Research Laboratory museum. Relative Abundance Twenty- three species of fishes contributed 96.08% of the total number of fishes (Table 31). Twelve species of invertebrates included 95.21% of the total number of invertebrates (Table 32). These 35 species comprised 95.84% of the total catch. The contribution of the numerically more abundant fishes to the total mass of the catch is shown in Figure 9. The order of abundance by weight changes from a similar arrangement by numbers although the species are the same. Croaker, longspine porgy, spot, seatrout, lizard fish, butterfish, pinfish, bank sea bass, sea catfish and blackfin searobin, in that order, include most of the 93.88% (Table 31) of total mass of fishes contributed by the 23 numerically most abundant species. Roithmayr (1965) found that croaker, spot, seatrout, cutlass fish, sea catfisli and longspine porgy comprised about 85% of the offshore industrial bottomfish catch from 1959 through 1963. The cutlass fish comprised 1% of the commercial catch but was not an abundant fish in our samples. The other five species listed by Roithmayr (1965) comprised 82.44% of our samples, but not in the same order. The longspine porgy was the second most abundant fish by weight in our samples. This position was occupied by the spot in the industrial catch study. This difference is accounted for by the abundance of porgies at depths greater than 20 fathoms. Most of the commercial fishing was done in depths less than 20 fathoms; however, our samples extended out to the 50-fathom curve. Croakers comprised 43.5% of our samples but accounted for 51% of the offshore industrial catch. This difference can be accounted for by the commercial fisherman’s search for croaker concentrations. 130 GULF RESEARCH REPORTS TABLE 31 RELATIVE NUMBERS OF THE MOST ABUNDANT FISHES TAKEN IN TRAWL HAULS. Number Taken Percentage of Total Catch Percentage Total Catch of the of Fishes Number Weight Anchoa. hepsetus 2,052 1.73 2.19 0.43 Anchoa rnitohilli 1,684 1.42 1.79 0.04 Centropr'istea ocynrua 951 0.80 1.01 1.17 Chloi'csoorr^brna okrysurus 229 0.19 0.24 0.08 Cyalopeotta ahittendeni 357 0.31 0.40 0.38 Cynoacion arenariua 2,657 2.24 2.83 5.54 Dilt^cp'.chua atlantioua 235 0.19 0.25 0.03 Diplecvfim m'cuiteiGi 413 0. 34 0.44 0.17 Sy nodus foe tens 1,413 1.19 1.51 2.71 Tvaohu-rua lathomi 1,960 1.65 2.09 0.25 Vomer setup innis 300 0.25 0.32 0.06 TOTAL 90,006 76.01 96.08 93.88 TABLE 32 RELATIVE NUMBER OF THE 12 MOST ABUNDANT INVERTEBRATE SPEC- IES CAUGHT. Species Nvunber Caught % of Total catch Z of Total Invertebrates Renilla mullevi 16,808 14.21 68.14 Penaeua astecus 2,694 2.27 10.92 Lolligxmaula brevis 962 0.80 3.75 Squilta empuea 628 0.54 2.54 PenaeuR fluviatilie 450 0.39 1.82 Sioyonia dorsalis 345 0.30 1.39 Luidia alathrata 330 0.28 1.33 Catlin&cieB simitis 304 0.26 1.23 Loligo peaXei 294 0.17 1.19 TrachypeneuB similis 272 0.23 1.10 Aurellia anritjz 250 0.21 1.01 Penaeue duorarum 195 0.17 0.79 Totals 23,496 19.83 95.21 OF TOTAL CATCH 132 GULF RESEARCH REPORTS There is no evidence in our data that would indicate any great change in the species composition of the offshore fish population since Roithmayr’s (1965) study. Seasonal Bathymetric Distribution The five numerically most abundant species in our samples comprised 85.15% of the weight of fishes caught by trawl. The most abundant commercially exploited invertebrate species was the brown shrimp (Table 32). In our catch the ratio of shrimp-to-fish was far below the estimate (1:8, Roithmayr 1965) made for the shrimp fishery in 0-20 fathoms. Shrimp fishermen work only in concentrations of shrimp, and most of the catch is taken in less than 25 fathoms; consequently, we expected the shrimp catch to be relatively small. In Figures 10 and 11 the seasonal bathymetric distribution of the five most abundant fishes and the brown shrimp have been illustrated. Relative species abundance is also evident when total areas of figures Micropogon undulatus <5 10 S 20 30 g 40 50 JMi SPRING (MAR. -MAY) SUMMER FALL WINTER (JUN.-AUG.) (SEPT. -NOV.) (DEC. -FEB.) StenoComus capriiius SPRING SUMMER FALL WINTER (MAR.-MAY) (JUN.-AUG.) (SEPT. -NOV.) (DEG. -FEB.) Fig. 10 Offshore seasonal bathymetric distribution of Micropogon undulatus and Stenotomus caprinus. DEPTH IN FATHOMS DEPTH IN FATHOMS DEPTH IN FATHOMS DEPTH IN FATHOMS NEKTONIC AND BENTHIC FAUNAS 133 Cynoscion arenarius Lelostomus xanthurus SPRING SUMMER FALL WINTER (MAR. -MAY) (JUN.-AUG.) (SEPT. -NOV.) (DEC. -FEB.) Fig. 11 Offshore seasonal bathymetric distribution of three abundant fishes (Cynosion arenarius, Peprilus burti Fowler, and Leiostomus xanthurus) and the brown shrimp (Penaeus aztecus). 134 GULF RESEARCH REPORTS are compared. These figures and tables show seasonal movement in the study area. All of these species except the longspine porgy are abundant in the adjacent estuarine study area (GMEI data) as juveniles. Length-Frequency Distribution Monthly length-frequency distributions for the most abundant species were plotted. These figures represented the catch for each species from May 1967 through April 1969. Aliquots were used to estimate the total number per interval for each sample. The percentage of the monthly sample for each interval was based on the total catch for the month at all stations. Two or three modal groups were evident in most distributions. Recruitment of growing young was evident. Growth rate could be followed to some extent but is often confused by the long period of recruitment and overlapping of age groups. Estuarine Relationships The importance of estuarine nursery areas to commercial fishery production has been well documented in the last forty years. Relatively little attention has been given to the relationship of estuaries as generally defined to the offshore environment where all but a very few of the species comprising our estuarine dependent resources spend a part of their lives and spawn. These include, with the exception of oysters and possibly a part of the blue crab population, nearly all of the species contributing significant production to Mississippi Landings. This project was designed for close coordination with the concurrent cooperative GMEI program. In the accounts of species encountered in offshore samples we have (lo c. cit.) included some of the comparable data from GMEI samples: McHugh (1966) wrote as follows: “The estuarine environment, to satisfy the fisheries scientists, must include the offshore zone affected by land drainage. Otherwise no fishery resources other than oysters and clams can be considered entirely estuarine. Nevertheless, almost two-thirds of the United States* Commercial catch and much of the marine sport catch is composed of species that spend at least a part of their lives within the land-bound estuaries.” In the same paper McHugh suggested that: NEKTONIC AND BENTHIC FAUNAS 135 “It is perhaps best to define two estuarine zones, ‘inshore estuary’ and the ‘offshore estuary’ which is that region of the open sea in which the surface waters are measurably diluted by land drainage. The offshore limit of this zone has been defined arbitrarily as the 33.5®/oo isohaline.” Although detailed relationships of the inshore and offshore data must await further study, a few observations are in order now. The results of this study have shown that all of our stations should be included in the “offshore estuary” as defined by McHugh (1966). The highest annual mean surface salinity (Table 4) was 32.9 ppt at the 50-fathom stations. Fisheries production and management in these areas are inextricably linked. About 64% of the 179 species collected in this project have been observed in the Mississippi Sound. Among the species making significant contribution to commercial fisheries production in Mississippi, only the longspine porgy was not also abundant in GMEI samples. The seasonal bathymetric distribution (Figure 10) of porgies in our samples shows its preference for deeper water. This does not necessarily mean that the porgy, or any other species found in offshore waters for that matter, is independent of the “inshore estuary”. Practically nothing is known of the food re- quirement nor the source of food production for the porgy or other species that live in offshore waters without physically occupying the inshore estuary. The well known role of the inshore estuary as a nursery area is unquestionably most important. Relatively little attention has been given to the relationship of forage species and nutrients in estuarine and offshore waters. Acosta (1970) listed fourteen species of copepods collected at our offshore stations. All but four of these (71%) were found in concurrent copepod studies at GMEI stations (Fig. 2). Some of these species are generally accepted as being oceanic. Although the presence of oceanic species in the inshore estuary may be transitory they are, nevertheless, a part of the estuarine biota. Data from our GMEI and offshore studies are compatible. Detailed study of the combined data should add considerably to knowledge of those species. In general the mean length of specimens from the same fish species was less in GMEI samples than in offshore samples but maximum size in GMEI samples exceeded minimum size in offshore population. At least part of the adult population continues to utilize inshore waters some of the time in addition to depending on the inshore nursery area for their early development. 136 GULF RESEARCH REPORTS Few specimens of coastal pelagic species known to be abundant in the study area for at least a part of the year were collected in our samples. In this group menhaden is an outstanding example of an estuarine-dependent species that is already heavily exploited. Estimates of large unexploited pelagic resources and technological advances in fishing methods will undoubtedly lead to exploitation of other near shore pelagic resources. We still know little about this very large resource and its environmental relationships and requirements- Summary 1. From January 1967 through May 1969 a seasonal study of the nektonic and benthic faunas of the shallow Gulf off Mississippi was conducted. Sampling was carried out aboard the R/V Gulf Researcher. The need for acquisition of information in these waters has been emphasized by the expanding offshore fisheries. 2. Fixed stations were located in a southeasterly transect across the continental shelf at depths of 5, 10, 20, 30, 40 and 50 fathoms. Stations were occupied a total of 245 times during the 29-month sampling period. 3. An effort was made to obtain monthly day and night trawl, nekton and plankton samples. Quarterly dredge samples were obtained from November 1967 through May 1969. Sampling procedures and physical data were recorded on field sheets on board the vessel and later transferred to GMEI formats for the purposes of electronic data processing. 4- Water samples were obtained from three depths (surface, midwater and bottom) each time a station was occupied. Surface temperatures were read with a mercury, Celsius thermometer. Midwater and bottom temperatures were taken by ‘Tisheries-type** reversing thermometers which were attached to Nansen bottles. Water samples were frozen on board the vessel for the purpose of shore laboratory analyses. Samples were tested for the presence of nitrates, nitrites, ortho-phosphates and total phosphates. Secchi disc readings were made in order to determine approximate water transparency. Average temperatures decreased from surface to bottom at all stations. Differences increased with depth from 10 to 50 fathoms. Average bottom temperature showed a maximum difference of 2.4*' C between Stations 3 and 6, Only 0.1 °C difference in the average bottom temperature occurred at Stations 1 and 6. Minimum temperature averages occurred in January at Stations 1 and 4 and in February at other stations. The maximum average temperature (32®C) was found in NEKTONIC AND BENTHIC FAUNAS 137 June at Station 4. Seasonal temperature variations were less at the bottom than at the surface. Monthly average salinities ranged from 13.1 to 38.8 ppt with the maximum observation occurring at Station 3 in June 1968 (midwater). Maximum salinities had a range of 11.8 ppt at the surface and decreased to 6.8 ppt at the bottom. There was no clear pattern of areal or vertical distribution of salinity. Apparently salinity in the study area was more stable in the colder months. Two seasonal peaks of nitrate concentrations were evident throughout the water column, with the highest concentration usually appearing in January. Nitrites were not detected. Seasonal peaks in total phosphate concentration generally occurred when nitrates were low. Seasonal trends were similar at all stations throughout the water column. The total phosphate con- centration was highest (3.25) at Station 1 at midwater in May 1969. The minimum transparency observation (4 feet) was noted at Station 4 in June. Maximum observations increased from 28 to 130 feet as distances offshore increased. 5. Bottom samples were taken by a Forest grab at quarterly intervals. Stations 1, 2 and 3 show the finest sediments. Station 4 showed a high percentage of sand. Station 5 was variable in sand content (12 to 90%) throughout the study. Station 6 showed particles similar in size to those found at Stations 1, 2 and 3. Shell debris and foraminiferal tests were present at all stations. The majority of stations showed silty mud or sandy silt. Foraminiferal populations followed expectations with shal- low water forms found at Stations 1, 2 and 3, and deeper-water and pelagic forms found at 4, 5 and 6. 6. Plankton samples were collected from three levels (surface, midwater and bottom). Nets were towed for a period of 20 minutes. Nets measured 50 cm across the mouth and 200 cm in length (from mouth to bucket). Number 3 mesh nylon netting was used. The majority of samples and accumulated data were destroyed in hurricane Camille with only 71 samples (March through December 1968) being salvaged for re-examination. Samples were examined for abundant, commonly occurring forms, and their relative abundance was noted. Copepods were the most abundant zooplankters. Brachyuran zoea and megalops, Stomatopod l 2 Lrvae, Lucifer faxoni, Acetes a. caroUnae^ Penilia avirostris^ Doliolum 138 GULF RESEARCH REPORTS sp., and fish eggs and larvae were abundant. 7. Dredging operations were begun in November 1967, and quarterly samples were taken. A total of 43 hauls were made. Twelve invertebrate and three vertebrate species were collected. Ren mulleri was the most abundant species encountered, followed by Squilla empusa and CalUnectes similis. Other invertebrate species were not nearly as abundant. Centropristes ocyurus, Citharichthys spilopterus and Etropus crossotus were the only fishes taken in dredge hauls. The microscopic infauna was apparently very sparse. 8. Surface and benthic nekton samples were obtained each time a station was occupied, A total of 245 surface and 152 benthic hauls were made. The nekton net was towed for 30 minutes. All nekton data were lost in Hurricane Camille (August 1969). Up to this time the majority of collected specimens had been identified, and due to familiarity of records a list has been prepared of the species which were encountered most often. 9. Trawl sampling was done with a 40-foot balloon trawl. Each trawling operation lasted for a period of 30 minutes. Specimens were sorted, counted, preserved and labeled in the field. Laboratory work consisted of further identification of specimens and recording their measurements arid weights. Trawling produced a total of 118,242 specimens. The catch consisted of 50 species (24,679 specimens) of invertebrates and 129 species of fishes (93,563 specimens). Station 1 produced over 21% of the trawl catch and Stations 2 and 3 produced over 12 and 10% respectively. Over 13% of the trawl catch was taken at Station 4, and Station 5 produced the greatest percentage (22.7). The catch from Station 6 was 19.5% of the total. Renilla mulleri was the most abundant invertebrate encountered, comprising 68.14% of the number of invertebrates. The commercially exploited brown shrimp, Penaeus aztecus, was second in abundance (10.92% of the invertebrate catch). Twelve species of invertebrates contributed 95.21% of the total invertebrate catch. Twenty-three species of fishes comprised 96.2% of the total fish catch. The five most abundant species comprising 80.60% numerically, were croaker, longspine porgy, butterfish, spot and seatrout. In decreasing order of contribution by weight were the croaker, longspine porgy, spot, seatrout, lizardfish, butterfish, pinfish, bank sea bass, sea catfish and blackfin searobin. These species comprised 91.89% of the total weight of fishes. NEKTONIC AND BENTHIC FAUNAS 139 The families Sciaenidae, Sparidae and Stroma teidae were represented by the greatest numbers and comprised 83.2% of the total catch. Families considered to be of commercial importance contributed 93,2% to the total catch, 10. The seasonal bathymetric distributions of Penaeus aztecus, Micropogon undulatus, Stenotomus caprinusy Peprilus burtiy Leiostomus xanthurus and Cynoscion arenarius were illustrated. Sea- sonal movements and relative abundance of these species were evident. 11. Monthly length-frequency distribution for the brown shrimp croaker, longspine porgy, butterfish, spot and seatrout showed two or three modal groups in the majority of distributions. Both overlapping age groups and recruitment make growth rate determinations uncertain. 12. Relative species abundance indicated that fish stocks in the study area continue to maintain themselves under the current rate of exploitation by the industrial bottomfish fishery. 13. Few specimens of coastal pelagic species known to be abundant in the study area were collected and the void in our understanding of these resources remains. Literature Cited Abbott, R.T.A. 1954. “American Seashells” XIV 513 pp., 40 pis., D, Van Nostrand Co, Inc., New York. Acosta Danny J. 1970. The copepods south of Dog Keys Pass; Their abundance, distribution, seasonal variation, temperature and salinity tolerances. Unpubl. Ph. O. Dissertation, Univ. South Miss. J-VII, 1-78. Anderson, W. W. and M. J. Lindner. 1941. Notes on the flatfish Engyophrys senlus Ginsburg. Copeia 1941 (l)t 23-27. Arnold, Edgar L., Jr, and John R. Thonmson. 1958. Offshore spawning of the striped mullet, Mugil cephalus in the Gulf of Mexico. Copeia, (2): 130-132. Bailey, R.M., E.A. Lachner, C.C. Lindsay, C.R. Robins, P.M. Roedel, W.B. Scott, and L.P, Woods. 1960. A list of common and scientific names of fishes from the United State.s and Canada. Amer. Fish. Soc. Comm, on Names of Fishes, Spec. Publ. No. 2 (Sec. Ed., 1966): 1-J02. Bearden, C.M. 1963. A contribution to the biology' of the king whitings, Genus Meniicirrhus, of South Carolina. Cont. Bears Bluff Lab., 38:1-27, Berry, Richard and J. Bruce Kimsey. 1964. Summary Information. Processed Rept. (Mimeo ). Bur. Comm. Fish. Biol. Lab., Galveston, Texas. Bigelow,^ H.B, and Mary Sears. 1939, Studies on the waters of the continental shelf, Cape Cod to Chesapeake Bay. III. A Volmetric Study of the Zooplankton. Mem. Mu.s. Comp. Zool. Harv., 54: 179 378. Broadhead, Gordon C. 1953. Investigations on the black mnWeiy Mugil cephalus L., in northwest Florida. Fla. St. Brd. Cons., Tech. Ser. No. 7: 1-33. Bullis, Harvey R., Jr. and John R. Thompson. 1967. Progress in exploratory fishing and gear research in Region 2. Fiscal year, 1966. U.S. Fish and Wildl. Ser., Cir. 265: i-tii + 1-14. 140 GULF RESEARCH REPORTS Burkenroad, M.D. 1939. Further observations on Penaeidae of the northern Gulf of Mexico. Bull. Bingham Ocean. Coll., 6(6): 1-62. Caldwell, David K. 1955. Distribution of the longspined porgy, Stenotomus caprinus. Bull. Mar. Sci. Gulf and Carib., 5(3): 230-239. 1957. The biology and systematics of the pinfish, Lagodon rhomboides (Linnaeus). Bull. Fla. St. Mus., 2(6): 77-173. . 1961. Populations of the butterfish, Poronofus triacanthus (Peck), with systematic comments. Bull. South Cal. Acad. Sci., 60(1): 19-31. Cameron, James N. 1969, Growth, respiratory metabolism and seasonal distribution of juvenile pinfish (Lagodon rhomboides Linnaeus) in Redfish Bay, Texas. Cont. Mar. ^i. Univ. Tex,, Vol. 14: 19-36. Carpenter, James S. 1965. A review of the Gulf of Mexico Red Snapper Fishery, U.S. Fish and Wildl. Ser., Cir. 208: i-iii + 1-35. Christmas, J.Y., Gordon Gunter and Edward C. Whatley. 1960. Fishes taken in the menhaden fishery of Alabama, Mississippi and eastern Louisiana. U.S. Fish and Wildl. Ser., Spec. Sci. Rept. 339: 1-10. , Gordon Gunter and Patricia Musgrave. 1966. Studies of annual abundance of postlarval penaeid shrimp in the estuarine waters of Mississippi, as related to subsequent commercial catches. Gulf Research Rept., 2(2): 177-212. and Gordon Gunter. 1967. A summary of knowledge of shrimps of genus Penaeus and the shrimp fishery in Mississippi waters, ftoc. of Symp. on Crust., Part IV. Marine Biol. Assoc. India. Clark, Eugenie and Katherine Von Schmidt. 1965. Sharks of the Central Gulf Coast of Rorida. Bull. Mar, Sci., 15(1): 13-83. Collier, Albert. 1958. Gulf of Mexico physical and chemical data from ALASKA Cruises. Fish, Wildl. Ser. Spec. Sci. Rept. Fish., No. 249: 1-417. Combs, Ralph M. 1969. Embryogenesis, histology and organology of the ovary of Brevoortia patronus. Gulf Res. Rept., 2(4): 333-434. Darnell, Rezneat N. 1958. Food habits of fishes and larger invertebrates of Lake Pontchartrain, Louisiana, and estuarine community. Publ. Inst. Mar. Sci. Univ. Tex., Vol. 5: 353-416, Daugherty, F.M, 1952* The blue crab investigation, 1949-50. Tex. Jour. Sci., 4(1): 77-84. Dawson, C.E, 1958. A , study of the biology and life history of the spot Leiostomus xanthurus Lacepede, with special reference to South Carolina. Bears Bluff Lab., No, 28. 1966. Additions to the known marine fauna of Grande Isle, Louisiana. Proc. La. Acad. Sci. (1966): 175-180. 1967. Contributions to the biology of the cutlass fish (Trichiurus lepturus) in the northern Gulf of Mexico. Trans. Amer. Fish. Soc., 96(2): 117-121. 1968. Contributions to the biology of the Mexican Flounder, » setts chittendeni, in the northern Gulf of Mexico, Trans. Amer. Fish. 7(4): 504-507. Drennan, Kirby L. 1963. Surface circulations in the northeastern Gulf of Mexico. Gulf Coast Research Laboratory Ocean. Sect., Tech. Rept., No. 1: 1-116, 6 Figs., 26 pits., 19 Tabs. 1966. Airborne measurements of infrared sea ter^eratures in the northern Gulf of Mexico. Gulf Coast Research Lab. Ocean. Sect. Tech. Rept., No. 2: 1-10, 21 Figs., 1 Tab. Eldred, Bonnie. 1959. A report on the shrimp (^Penaeida^ collected from the Tortugas controlled area. Fla. St. Brd. Cons., Spec. Sci. Kept., No. 2: 1-6. Fuss, Charles M., Jr., John A. Kelly, Jr., and Kenneth W. Prest, Jr. 1969. Gulf thread herring: Aspects of the developing fishery and biological research. Inst. Mar. Sci. Gulf Carib., Fish Inst. Proc. 21st Ann. Sess. (1968): 111-125. NEKTONIC AND BENTHIC FAUNAS 141 Galtsoff, Paul S. 1954. Historical sketch of the explorations in the Gulf of Mexico. In Gulf of Mexico, Its origin, Waters and Marine Life. Fish. Bull. Fish. Wildl. Ser., 55(89): 39-65. Ginsburg, Isaac. 1951. Western Atlantic tonguefishes with descriptions of six new species. Zollogica, 36(3): 84-101. 1952. Flounders of the genus Paralichthys and related genera in American waters. U.S. Fish Wildl. Ser. Fish. Bull., 71: 266-351. Gudger, E.W. 1918. Oral gestation in the gafftopsail catfish Felichthys felis. Carnegie Inst. Wash. Publ., No. 252: 25-32. Guest, William C. and Gordon Gunter, 1958. The sea trout or weakfishes (Genus Cynoscion) of the Gulf of Mexico, Gulf States Mar. Fish. Comm., Tech. Summ. 1: 1-40. Gunter, Gordon, 1933, The flatfish, Syacium papillosum (Linnaeus) in Louisiana Copeia. 1933 (1): 35. . 1936, Studies on the destruction of marine fish by shrimp trawlers in Louisiana, La. Cons. Res. 5(4): 18-24 and 45-46. 1938a. The relative numbers of species of marine fish on the Louisiana coast. Amer. Nat., Vol. 72: 77-83. 1938b. Notes on invasion of freshwater by fishes of the Gulf of Mexico, with special references to the Mississippi-Atchafalaya River system. Copeia, (2): 69-72. 1938c. Seasonal variations in abundance of certain estuarine and marine fishes in Louisiana, with particular reference to life histories. Ecol. Monog., 8: 313-346. 1941. Relative numbers of shallow water fishes of the northern Gulf of Mexico, with some records of rare fishes from the Texas Coast. Amer. Midi. Nat., 20: 194-200. 1945. Studies on Marine fishes of Texas. Publ. Inst, Mar. Sci. Univ. Tex., 1(1): 1-190. 1948. Notes on fishes of the genus Scorpaena from the South Atlantic and Gulf Coasts of the United States, with descriptions of two new species. Copeia. 1948. (3); 157-166. 1950. Seasonal population changes and distribution, as related to salinity, of certain invertenrates of the Texas coast including the commercial shrimp. Publ. Inst. Mar. Sci. Univ. Tex,, 1(2): 7-51, 8 figs. 1956a. Some relations of faunal distributions to salinity in estuarine waters. Ecology, 37(3): 616-619. 1956b. A revised list of euryhaline fishes of North and Middle America. The Am. Mid. Nat., 56(2): 345-354. 1958. Menhaden populations. In Annual Report, Gulf Fishes Investigations. Mimeo. Rept.: 1-106. . and Gordon E. Hall, 1963. Additions to the list of euryhaline fishes of North America. Copeia, 3: 596-597. and G.E. Hall. 1965. A biological investigation of the Caloosha tehee Estuary of Florida. Gulf Research Reports 2(1): 1-71. _and F.T. Kn^p. 1951. Fishes, new, rare, or seldom recorded from the Texas coast. Tex, Jour. Sci., 3(1): 134-138. Hardy, A.C. 1956. The open sea. Its Natural History: The World of Plankton. Houghton Mifflin Co., Boston: 335 pps. Herke, William M. 1971. Use of natural, and semi-impounded, Louisiana tidal marshes as nurseries for fishes and crustaceans. Ph.D. Dissertation, Louisiana State University, Baton Rogue, La. 242 pp. Hildebrand, Henry H. 1954. A study of fauna of the brown shrimp {Penaeus aztecus Ives) grounds in the western Gulf of Mexico. Publ. Inst. Mar. Sci. Univ. Tex., 3(2): 233-366. 142 GULF RESEARCH REPORTS - 1 9SB- A study of the fauna of the pink shrimp, Penaeus duorarum (Burkenroad), grounds in the Gulf of Campeche. Publ. Inst. Mar. Sci. Univ. Tex. 4(1); 169-232. Hildebrand, Samuel F. 1963. Family Clupeidae. In Bigelow, Henry B., ctal. Fishes of the Western North Atlantic, Memoir, Sears Found. Mar. Res., 1 (Part 3): 61-88. and Louella E. Cable. 1930. Development and life history of fourteen teleostean fishes at Beaufort, North Carolina. Bull. U.S. Bur. Fish., 46(1931): 383-499. and .1934. Reproduction and development of whitings or kingfishes, drums, spot, cro^er, and weakfish or sea trouts, family Sciacnidae, of the Atlantic Coast of the United States. Bull. Bur. Fish., 48: 41-117. and .1938. Further notes on the development and life history of some teleosts at Beaufort, N.C. Bull. Bur. Fish., 48: 506-642. Hoese, Hinton D. 1958. A partially annotated check-list of the marine fishes of Texas. Pub. Inst. Mar. Sci. Univ. Tex. 5: 312-353. and R.B. Moore, 1958, Notes on the Life History of the Bonnetnose shark, Sphyrna tiburo. Texas Jour. Sci., 10(1): 69-72. Hopkins, T.L. 1966. The plankton of the St. Andrew Bay system of Florida. Pubis. Inst. Mar, Sci. Univ. Tex,, 11:12-64. Joseph, E.B. and R.W. Yerger. 1956. The fishes of Alligator Harbor, Florida, with notes on their life history. Fla. St. Univ, Stud., No. 22: 111-156. Kelly, John A,, Jr. and Alexander Dragovich. 1968. Occurrence of macrozooplankton in Tampa Bay, Florida, and the adjacent Gulf of Mexico. Fish. Bull. Fish Wild. Ser., 66: 209-221. Kramer, A. 1895. On the most frequent pelagic copepods and cladocers of the Hauraki Gulf. Trans. Proc, N.Z. Inst., 27: 214-223. Leipper, Dale F. 1954. Physical oceanography of the Gulf of Mexico. In Gulf of Mexico, Its Origin, Waters and Marine Life. Fish. Bull. Fish, Wildl. Ser., 55(89): 119-137. Lockhead, John H. 1954. On the distribution of a marine cladoceran, Penilia avirosiris Dana (Crustacea, Branchipoda), with a note on its reported bioluminescence. Boil. Bull., 107(1): 92-105. Longley, William H. and Samuel F, Hildebrand. 1941. Systematic catalogue of the fishes of Tortugus, Florida^ with observations on color, habits, and local distributions. Carnegie Institution of Washinrton, Pub. 535 (Papers of the Tortugus Laboratory, Vol. 34) 331 p., 34 ^s. [Edited and completed by Samuel F. Hildebrand. ] Lyles, Charles H. 1967. Fishe^ statistics of the United States 1965. U.S. Fish and \Yildl. Ser,, Bur, Comm. Fish. Marukawa. H. 1921. Plankton list and some new species of copepods from the northern waters of Japan. Bull. Inst. Oceanogr. Monaco., 18(383): 1-15, McHugh, J.L. 1966. Management of Estuarine Fishes. In A Symposion on estuarine Fishes. Am. Fish. Soc., Sp. Publ,, No. 3: 133-154. Meek, S.E. and S.F. Hildebrand, 1928. The marine fishes of Panama. Field Mus. Nat. Hist., Zoo. Ser. 14(3): xxv-xxix + 709-1,045. Miles, D.W. and E.C. Simmons. 1950. The menhaden fishery. Bull. Texas Game Fish and Oyster Comm., 30:1-28. Miller, John M. 1965. A trawl survey of the shallow gulf fishes near Port Aransas, Texas. Publ. Inst. Mar. Sci. Univ. Tex., 10:80-107. Moe, Martin A. and George T. Martin, 1965. Fishes taken in monthly trawl samples offshore of Pinellas County, Florida with new additions to the fish fauna of the Tampa Bay Area. Tul. Stud, in Zoo., 12(14); 129-151. Moore, Donald R. 1961. The marine and brackish water mollusca of the state of Mississippi. Gulf Res. Rept., 1(1): 1-58. NEKTONIC AND BENTHIC FAUNAS 143 Nelson, Walter R. 1969. Studies on the croaker,^ A^icropogon undulatus Linnaeus and the spot, Leiostomus xanthurus Lacepede, in Mobile Bay, Alabama. Journal of Marine Science 1(1): 1-92. Osburn, Kenneth W,, Bruce W. Maghan and Shelby B, Drummond. 1969. Gulf of Mexico shrimp atlas. Bur. Comm. Fish., U.S. Dept. Int. Cir. 312: 1*20. Pearson, J.C. 1929. Natural history and conservation of the redfish and other commercial sciaenids on the Texas Coast. Bull. U.S, Bur. Fish., 44(1928): 129-214. Phillips, P.J., W.D. Burke and E.J. Keener. 1969. Observations on the trophic significance of jellyfish in Mississippi Sound with quantitative data on the associative behavior of small fish with medusae. Trans. Amer. Fish. Soc., 98(4): 702-712. Reid, George K. 1964. An ecological study of Gulf of Mexico fishes in the vicinity of Cedar Key, Florida. Bull. Mar. Sci. Gulf & Carib., 4(1): 1-94. Rivas, Luis R, 1968. Fisherman’s atlas of monthly sea surface temperatures for the Gulf of Mexico. Ich. Lab. Mus. Univ. Miami, Cont. 58, Cir. 300; 1-33, Roithmayr, Charles M. 1965. Industrial bottomfish fishery of the northern Gulf of Mexico, 1959-63. Fish and Wildl. Ser. Spec. Sci. Rept. Fisheries, No. 518: 23 pp. Siebanaler, J.B, 1952. Fishes taken by the M/V Oregon in shrimp trawls off the coast of Mississippi, 1950-1952. Mimeo. Import: 1-7. Simmons, Ernest G. 1951. Fish Trap Investigation. Texas Game and Fish Comm. Marine Laboratory annual Report, 1950-51, 1-15 (Mimeographed). 1957. An ecolorical survey of the Upper Laguna Madre of Texas. Publ. Inst, Mar. Sci. Univ. T^x., 4(2): 156-200. and H.D. Hoese, 1959. Studies on the hydrography and fish migration of Cedar Bayou, a natural tidal inlet on the central Texas coast. Publ. Inst. Mar. Sci. Univ. Tex., 6:56-80. Springer, Stuart and H.R. Bullis. 1952. Exploratory shrimp fishing in the Gulf of Mexico. Fishery leaflet. U.S. Fish and Wildl. Ser., 406: 1-34. .and 1956. Collections by the Oregon in the Gulf of Mexico, U.S. Fish and Wildl. Ser. Spec. Sci. Rept., 196: 1-134. and J.R. Thompson. 1965, Collections by the exploratory fishing vessels Oregon I, Silver Bay, Combat and Pelican made during 1956-1960 in the southwest North Atlantic. U.S. Fish, and Wildl. Ser. Spec, Sci. Rept., 50: 1-130. Springer, Victor G. 1957. Mysterious midshipman. Tex. Game and Fish., 15(11); 6-7. and Kenneth D. Woodburn. 1960. An ecological study of the fishes of the Tampa Bay area. Fla. St. Brd. Cons. Prof. Papers. 1; 1-104. Subrahmanyam, C.B. 1971. The relative abundance and distribution of penaeid shrimp larvae off the Mississippi Coast. Gulf Research Reports, 3(2); 291-345. Williams, Austin B. 1965. Marine decapod crustaceans of the Carolinas. U.S. Fish and Wildl. Ser. Fish. Bull,, 65(1): 1-298. Woodmansee, Robert A. 1966. Daily vertical migration of Lucifer. Planktonic numbers in relation to solar and tidal cycles, Ecol., 47(5): 847-850. 144 GULF RESEARCH REPORTS Index FAMILY AND GENERIC NAMES Underlined page numbers indicate location of species accounts Species Page Number Ace tee a. carolinae Actinidae Alutera scrip to Anasimus latue Anehoa hepsetue Anchoa mitchilli Anehoa sp Ancylopaetta dilecta .... Ancylopsetta quadroeellata Anguilla rostrata Anguillidae Antennarlldae Antennarius radiosus . . . Antherinidae Anthiaaieus leptus Aprionodon iaodon .... Archaaargua probatocephalua Ariidae Astropecten duplicatua . . Astropeeten ap Astiopectinidae Aatroacopua y-graecum . . Atherinidae Aurellia aurita . . . 28,29,30,31,32,43 45 43, 125 64 30, 35, 43, T3^ 75, 130 JM, 130 29, 35 ^ T6 67. 78 67,128 1^ 43 M . . 69 100 67, 77 65 65 65 Ill 43 44, 130 Bagre marinua 77 Bairdiella chrysura • • ^ Balia tea capriacue 125 Balistidae 39, 43, 67, 125 Batrachovdidae 67, 127 Bellator militarie . . 109 Benthopagurus eokeri 57 BoUmannia communis 108 Bothidae 28, 30. 37. 39. 67, 116 Branchiostegidae 67, 87 Branchloaaychie americanus 38, 39 Bregmaceroa atlanticus 81 Bregmacerotidae 67, 81 Brevoortia patronua 71 Brotula barbata 112 Brotulvdae 67 Bunodactia sp ^ Buaycon perversum 46 Calappa apringerl 58 Calappidae 58 Callia^tia polypus ^5 Callinectea aapidua 43, 60 Callineetea aimilis 39, 43, 62, 130, 138 Caiangidae 36, 67, 88 Caranx cryaoa 31, 36. 88 Carcharhinidae 67, 68 Carcharhinua falciformea 69 Carcharhinua limbatua 69 Caulolatilua cyanopa 87 Centropristea ocyurua 39, 83, 85, 130, 138 Centropriatea p/iilodc(p/iicu5 84 Chaetodipterua faber 105 NEKTONIC AND BENTHIC FAUNAS 145 Chtutnocarcinus miseissippiensis Chilomy ct^ru6 schoepfi . . . . Chloroscombrue chrysurus . . . Citharichthye macrope . ... . Citharichthys spilopterus . . . Clupeidae Clymenella torquata Clypeaster sp Clypeasteridae Congridae . . , . Congrina flava CycXopsetta chittendeni . . . . Cynoglossidae Cynogcion arenarius Cynofcion nothue Cynogcion sp ^ 127 88,130 ... 117 . . . 39. 40. 117. 138 . . . . 28,^,67,71 38,39 §6 66 67 79 118, 130 67,124 90 . 92. 130, 133, 139 n 30,36 Dasyatidae ...... Dagyatis americana Daayatia gay . . . , . Dibranchug atlanticus Diodontidae Diopatra cuprea . . , Diplectrum arcuarium Doliolum sp Doryteuthig plei . , . Dromidia antillensig Dromidia sp Droroiidae 67, 70 70 ri 128 , 130 67,127 ^,39 ^,130 28. 29. 30, 31,^ ^ ^ ^ 58 Echeneidae 67,125 Echeneig naucrateg 125 Echlnoster modestug . 65 Ecblnasteridae 65 EngrauUdae 43, 67, 73 Engyophrys gentug 120 Epbippidae 67, 106 Equetug acuminatue . 93 Etropug croggotug 39, 120, 130, 138 Etrumeua aadina 72 Eucinogtomug argenteus ^ Exocoetidae 43 Gadidae 43, 67, 82 Galeichthyg felig 78, 80, 130 Gertidae 67, 89 Gobiidae 67, 108 Goneplacidae . 64 Gymmjchiru* melag 122 Gymnachirug texae 122 Gymnothorax nigromarginatus ^ Halieutichthyg aculeatus 128 Harengula pensacolae 72, 130 Hepatug epheliticus 59 Hippocampus erectus 83 Hippocampus zosterae ' . 83 Hoplunnis macrurus . 79 Hormathiidae 45 Kathetostoma albigutta 111 Lactophrys quadricornis Logocephalus laevigatus Lagodon rhomboides Larimus fasciatus . . . 126 30, 36, 100. 101, 130 93 146 GULF RESEARCH REPORTS Leioatomua xanthurua Lepophidium graellai liBUcosiidae Libinia emarginata . . Liriope te trophy la . . LoliginidRe LoUgo pealei ..... LoHiguncula brevia . . Lophildae Lophiomue BP Lucifer faxoni .... Luidia clathrata . . . Luidiidae Lutjanidae Lutjanua campechanua ^,95, 130. 133, 139 112 , 130 58 64 ^.28 46 £7^, 130 46. 48.130 67,128 IM 28, 29, 30, 31, 32. 43 130 . . 66 67, 86 . . 86 Macrouxidae Majildae Manta biroatria . . . . . Melongenidae Menidia beryllina . . . Menticirrhua americanua Micropogon undulatua . Molpadia cubana . . . . Molpadiidae Monacanthua hispidua . Mugil cephalua Mugilidae ....... MiUidae Mullue auratua Muxaenidae Muetelua cania 67 64 71 46 43 94 36. 97, 98. 130, 132, 139 ^ 66 IM 43, 43. 61, 116 43,67 43, M 67,79 68 JVorci'nc braailienaia 70 Negaprion bj-evirostria 69 Neomerinthe pollux 108 Octopodidae 47 Octopua vulgarua 47 Ogcocephalidae 67, 128 Ogcocephalua parvua 129 Ogcocephalua sp 129 Oikopleura ^ Oikopleura sp 28, 29 Ophichthidae 67, 81 Ophichthua ocellatua 81 Ophidiidae 67,112 Ophidian welahi 112 Opbiuxoldae .29,34 Opiathonema oglinum ^3. Orthopriatis chryaopterus 90 Ostraciidae 67,126 Ovalipea ocellatua 63. 43 Fagxiridae Pagrua eedecium Pagrua sp Pagurua floridanua . . . , Paralichthys albigutta . , Paralichthys lethoatigma , Paralichthya aquamilentua Pecten papyraceua . . . , Pectinidae Penaeidae . . 28, 57 . . . IM . . 39,40 . . . . . . . . . . . , . in 38, 39, 46 . ... 46 .... 50 NEKTONIC AND BENTHIC FAUNAS 147 Permeus aztecua .... Penaua duorarum . . . Penaeua fluviattlia . , . Penilla avirostris .... Peprilua aleptdotus . . . Peprilus burti Peprilua paru Periatedton gracile . , .* Peraephona crtnitia . . Petrochirua bahamertaia Phyaalia phyaalia .... Physicutua fulvua . . . Pogoniaa cromia .... Polydactylus octonemua Polynemidae Pomadasyidae Pomatomidae ..... Pomatomue aaltatrix . . Pontinua longiapinia . . Porcellana aayana ... Porcellanidae Porichthya poroaiasimua Portunidae Portunus gibbeaii . . . Portunueaayi ..... Portunue apinicarpua . . Portunua sp Priacanthidae Priacanthus arenatua . . Prionotua alatua .... Prionotue ophryae . . . Prionotua paralatus . . Prionotua pectoralis . . Prionotua roseua .... Prionotua rubio .... Prionotua acitulua . . . Prionotua atearnai . , . Prionotua tribulua . . . Priatipomoidea anderaoni 52, 130, 133, 138, 139 W, 130 51, W, 56, 130 28. 29, 31, 33 11^ 43, 113 , 114, 130, 133, 139 113 ^ ^ 45 ^ ^ 116 67,116 67.90 67, 87 87 108 ^ . ... 57, 28 127 . ... 43, 69 39, 43, ^ ....«, 63 64 . ... 39, 40 . . . . 67, 87 87 . . . . . 109 IM 1^ . . . . . . . . 130 uo ^ 87 Rachycentridae . . . . Rachycentron canadum Raja eglanteria Raja texana Rajiidae Raninidae ....... Raninoidea louiaianenaia Raninoidea sp. Renilla mulleri . , RenilUdae Rhinobatldae Rftinobatoa lentiginoaua Roasia tenera 67, 88 71 ,^ 70 70 67, 70 57 57 39, 130, 138 45 67, 69 69 47 Sagitta sp 28, 29, 30, 31, ^ Saurida braailienais 76 Sciaenldaa 36, 67, 90 Scoliodon terraenovae ^ Scomber colias 107 Scomberomorua maculatus 107 Scombridae 67, 107 Scorpaena calcarata 108 Scorpaenidae 67, 108 Scyllaea pelagica 46 Scyllaeldae 46 Scyllafidae 56 148 GULF RESEARCH REPORTS Scyllarides nodifer . . . Scyllarus sp Selar crumenophthalmus Sepiolidae Sergestidae Serranidae Serranus atrobranchua . Serranua notoapilua . . Sicyonia breviroatria . . Sicyonia doraalia .... Soleidae Solenocera vioacai . . . Solenocera sp Sparidae Sphaeroidea nephelua Sphaeroidea parvua . . Sphyraena quachancho Sphyraenidae Sphyrna tiburo .... Sphyrtta zygaena .... Sphyrnidae Squatina dumerili . . . Squatinidae Squilla chydaea .... 5qu/I{a empuaa Squillidae Steindachneria argentea Stenocionopa apinimana Stenorynchua aeticornia Stenotomua caprinua Stromataidaa Syacium gunteri . . . , Syacium papillosum . . Symphurus diomedianus Symphurua plagiuaa . . Syngnathidae Sygnathua floridae . . . Sygnathua acovelli . . . Syaodontldae Synodus foetena . . . . M 66 89 47 32, 43 67, 83 84. 130 84 .... 39, 40, M, 130 M, 130 67. 122 :64 ^ 36, 67, 100 1^ 43 115 67,115 M 69 67, 68 69 67, 69 39, 49 . . 38, 39, 130, 138 49 82 64 ^ 103, 104, 130, 132, 139 43,67,112 121, 123, 130 IM 124 43. 67. 83 43 43 35, 67, 76 77.130 Tetraodontidae .... Torpedinidae Trachinocephalus myopa Trachurua lathami . . . Trachypeneua similia . , Trichiuridae Trichlurua lepturua . . Trichopsetta ventralia Triglidae ... 43, 67, 126 67, 70 77 M, 130 M, 130 67,106 1 ^ 30, 31. ^,67, 109 Ulmaridae 44 Uranoscopidae 67, 111 Uranoscopua sp Ill Urophycia floridanua ^ Urophycia regiua 43, 82 Vomer aetapinnls 130 Zeidae Zenopaia ocellata 67. 83 . . 83