CALIFORNIA FISH-GAME "CONSERVATION OF WILDLIFE THROUGH EDUCATION" California Fish and Game is a journal devoted to the conser- vation of wildlife. If its contents are reproduced elsewhere, the authors and the California Department of Fish and Game would appreciate being acknowledged. The free mailing list is limited by budgetary considerations to persons who can make professional use of the material and to libraries, scientific institutions, and conservation agencies. Indi- viduals must state their affiliation and position when submitting their applications. Subscriptions must be renewed annually by returning the postcard enclosed with each October issue. Sub- scribers are asked to report changes in address without delay. Please direct correspondence, except regarding paid subscrip- tions, to: CAROL M. FERREL, Editor California Fish and Game 987 Jedsmith Drive Sacramento, California 9581 9 Individuals and organizations who do not qualify for the free mailing list may subscribe at a rate of $2 per year or obtain individual issues for $0.75 per copy by placing their orders with the Office of Procurement, Documents Section, P.O. Box 20191, Sacramento, California 95820. Money orders or checks should be made out to Office of Procurement, Documents Section. In- quiries regarding paid subscriptions should be directed to the Office of Procurement. u D VOLUME 59 JULY 1973 NUMBER 3 Published Quarterly by STATE OF CALIFORNIA THE RESOURCES AGENCY DEPARTMENT OF FISH AND GAME STATE OF CALIFORNIA RONALD REAGAN, Governor THE RESOURCES AGENCY NORMAN B. LIVERMORE, JR., Secretary for Resources FISH AND GAME COMMISSION SHERMAN CHICKERING, President, San Francisco PETER T. FLETCHER, Vice President Rancho Santa Fe TIMOTHY M. DOHENY, Member Los Angeles C. RANS PEARMAN, Member San Gabriel JOSEPH RUSS III, Member Ferndale DEPARTMENT OF FISH AND GAME G. RAY ARNETT, Director 1416 9th Street Sacramento 95814 CALIFORNIA FISH AND GAME Editorial Staff CAROL M. FERREL, Editor-in-Chief-- KENNETH A. HASHAGEN, Editor for Inland Fisheries. MERTON N. ROSEN, Editor for Wildlife ROBSON COLLINS, Editor for Marine Resources DONALD H. FRY, JR., Editor for Salmon and Steelhead HAROLD K. CHADWICK, Editor for Striped Bass, Sturgeon, and Shad. ..Sacramento —Sacramento -Sacramento .Long Beach ..Sacramento Stockton (158) CONTENTS Page Susceptibility and Resistance of Pheasants, Starlings and Quail to Three Respiratory Diseases of Chickens J. N. Allred, L. G. Raggi and G. G. Lee 161 The California Sablefish Fishery for the Period 1953-1969 Richard H. Parrish 168 Contributions to the Life History of the Silver Surfperch Eyper- prosopon cllipticum from the Oregon Coast Richard 8. Wydoski and Donald E. Bennett 178 Inconsistencies in Locating the First Annulus of Pacific Sardines Makoto Kimura 191 Fish Parasites Occurring in Thirteen Southern California Reser- voirs Richard L. Miller, Andrew C. Olson, Jr. and Lee W. Miller 196 Notes Wolverine Records in the Pacific Coastal States and New Records for Northern California Charles F. Yocom 207 First Record of a Golden Eagle Death Due to Avian Cholera Merton N. Rosen, Karen D'Amico and Edward J. O'Neill 209 An Albino Grey Smoothhound Mustelus californicus Gill Joel L. Cohen 210 Book Reviews 212 Retirement of Leo Shapovalov 215 Errata 216 (159) Calif. Fish and Game 59(3) : 161-167. 1973. SUSCEPTIBILITY AND RESISTANCE OF PHEASANTS, STARLINGS, AND QUAIL TO THREE RESPIRATORY DISEASES OF CHICKENS 1 J. N. ALLRED 2 , L. G. RAGGI and G. G. LEE Department of Epidemiology and Preventive Medicine, University of California, Davis, California Ring-neck pheasants (Phasianus co/ch/cus torquafus), starlings (Sturnus vulgaris) and valley quail (Lophortyx ca/ifornica) are among the common avian species that inhabit the Central Valley of California and fre- quently can be seen in proximity to poultry houses. Since a large seg- ment of the poultry industry is located in this area, an attempt was made to investigate the role played by these species in the epidemi- ology of three common diseases of chickens by determining their sus- ceptibility to infectious laryngotracheitis virus (ILTV), infectious bron- chitis virus (IBV) and Mycoplasma galliseptitum (MG). INTRODUCTION A review of the literature indicates that pheasants are susceptible to ILTV and MG (Beach 1931; Biester and Schwarte 1965; Hudson and Beaudette 1932; Jordan 1966; and Van Roekel 1955). Two species of quail are susceptible to IBV, i.e., European quail (Coturnix coturnix) (Biondi and Schirvo 1966) and Japanese quail (Coturnix coturnix japonica) (Edgar and Waggoner 1964) and a third species, bobwhite quail (Collinus virginianus), was found susceptible to MG (Madden, Henderson, and Moses 1967). Starlings and quail are reported (Biester and Schwarte 1965) resistant to ILTV. It has been over 30 years since the report on ILTV was published and we felt it advisable to repeat this work. MATERIALS AND METHODS Inocula The ILTV used was the 151st egg passage of a commercial vaccine strain. It is still highly pathogenic for chickens. The ILTV was stored as a suspension of ground chorioallantoic membrane (CAM) in al- lantoic fluid (AF) in sealed ampules at — 70 C and at time of inocula- tion had a 50% embryo plaque-forming units (EPFU50) of 10 5 per ml. The inoculum consisted of a 1 : 5 dilution of this suspension in tryptose broth (Difco). The IBV used was the Massachusetts strain with a 50% embryo inf ec- 1 Submitted for publication January 1973. 2 Partial requirement for Master of Preventive Veterinary Medicine degree. Present address : Veterinary Services, Animal and Plant Health Inspection Service, USDA, Hyattsville, Maryland. (161) 162 CALIFORNIA FISH AND GAME five dose (EID 50 ) of 10 6 2 per ml. The inoculum consisted of a 1:5 dilution of AF in tryptose broth. The virus used for the serum neutral- ization (SN) test was the egg-adapted DA strain with a 50% embryo lethal dose (ELD 50 ) varying between 10 G and 10 7 . The MG consisted of a broth (Difco PPLO) culture containing 10 9 viable organisms per ml. Hosts The pheasants were obtained from a hatching and brooding unit operated by the California State Fish and Game Department. Adult starlings were trapped by the Vertebrate Ecology Laboratory, Univer- sity of California at Davis (UCD) and had been in captivity for sev- eral months. The quail were purchased from a commercial quail breed- ing farm in the lower Central Valley of California. Eggs Embryonating chicken eggs used for virus isolation and SN testing were obtained from the Experimental Animal Resources (EAR), UCD. Housing of Experimental Birds The pheasants used for ILT in lot 3 (Table 2) and quail for IB studies were housed in the maximum isolation building of EAR. In all other studies the birds were kept in wire cages under open sheds with metal roofs. The sheds were in an open field 200 ft apart and were cleaned and disinfected between experiments. Birds were fed a com- mercial chicken growing ration containing 27% protein. Virus Isolation and Serology Virus isolation in embryonating eggs was conducted as outlined in Methods for the Examination of Poultry Biologies (National Academy of Science, 1963). The SN procedures used were those of Fabrieant (1951) and Cun- ningham (1957). The Spearman-Karber method for estimating equivalent doses (ED go ) was used (Finney 1964). The serum plate agglutination test using S 6 antigen, serial AJD-27 (H. E. Adler, UCD) was used for the MG tests. Challenge Procedure The surviving pheasants inoculated with ILTV in lot 3 were chal- lenged 21 days PI by an intratracheal injection of 0.2 ml of virus broth suspension containing 4 X 10 3 EPFU.-, . Birds showing acute respiratory signs or death within 5 days were considered susceptible to challenge. Experimental Plan Infectious Laryngotracheitis Adult pheasants (lot 2, Table 1) which had resisted an inoculation of IBV 4 weeks earlier, were inoculated IT with 0.1 ml of ILTV con- taining 10 4 EPFU 50 as a trial run to determine if they were susceptible to this virus. Following this experiment lot 3, consisting of 26 six-week- old pheasants, was placed in three 10" X 2' X 3' metal cages. Cages 1 and 2 were about 6 inches apart and contained 10 birds each (eight inoculated and two uninoculated contact controls). Cage 3 was about 6 ft from cages 1 and 2 and contained six uninoculated controls. Each SUSCEPTIBILITY TO DISEASE 163 pheasant was inoculated intratraeheally (IT) with 0.1 ml of virus broth suspension containing 2 X 10 3 EPFU 50 . On days 1, 2, 3 and 4 post inoculation (PI) two birds were killed and portions of the trachea and larynx were fixed in 10% formalin, sectioned and stained with hema- toxylin and eosin for histopathology, and the remainder used for virus isolation. All birds found dead were necropsied and portions of trachea were treated as above. Embryonating eggs that developed plaques on the CAM during virus isolation attempts were harvested, and the AF used for hemagglutination test and the CAM for histopathology. Four to six serial passages were made from eggs not showing plaques on initial inoculation. At 21 days PI the immunity of all surviving birds was challenged as indicated above. TABLE 1. Responses of Pheasant, Quail and Starlings to Infectious Laryngotracheitis Virus Species and lot Age (months) Dosage EPFUbo Clinical symptoms Virus isolations Histo- pathology Mortality* Pheasant 2 Pheasant 3 Quail 1 Starlings 2 12 IK 2 12 10< 2 X 10' 2 X 10' 2 X 10' + + • + + + + 7/8 14/16 0/3 0/22 * Numerator = number of birds died; denominator = number of birds inoculated. Twenty-two starlings (Table 1) were inoculated IT with 0.2 ml ILTV containing 2 X 10 3 EPFU 50 . They were observed daily for clinical signs and on days 2 and 6 PI two birds were killed for histo- pathology and virus isolation. Infectious Bronchitis All birds (Table 2) inoculated with IBV were bled for SN test at the time of inoculation and again at 21 days PI. The pheasants were bled from the wing vein or from the heart. The starlings and quail were bled from the jugular vein (Kerlin, 1964). Each bird was examined daily for respiratory signs by exercising and ascultation for tracheal rales. On the second, third and fourth day PI two birds were killed for virus isolation and histopathology of the trachea. Four to six serial passages were continued in embryonating eggs from each trachea be- fore considering the sample negative for virus. Twenty-one young pheasants (lot 4, Table 2) were inoculated IT with 0.2 ml of IBV sus- pension containing 2 X 10 5 EID.-, . In an adjoining wire cage nine pheasants of the same hatch were kept as un inoculated controls. These were also bled for SN tests as above. Synergism Studies The second lot of starlings was first inoculated with ILTV, 4 weeks later they were inoculated with MG and 2 weeks later, inoculated with IBV. The quail were first inoculated with IBV, 6 weeks later they were inoculated with ILTV and 3 weeks after the ILTV exposure they were inoculated with MG. Four pheasants were inoculated with MG and 2 weeks later with IBV in an attempt to see if synergism would occur. Each bird inoculated with MG received approximately 0.25 X 10° MG organisms. The starlings were inoculated into the left abdominal 164 CALIFORNIA FISH AND GAME air sac, the pheasants and quail intranasally and IT. Preinoculation and postinoeulation agglutination tests (21 days PI) were made. The birds were killed and examined for air sacculitis at the second bleeding. RESULTS Tables 1, 2 and 3 summarize the results. A few additional remarks are made from our observations on ILT in pheasants. TABLE 2. Responses of Pheasant, Quail and Starlings to Infectious Bronchitis Virus. Age Number Dosage Clinical Virus SN antibody Species and lot (months) inoculated EIDso symptoms isolation response Pheasant 1 8 9 10 5 _ _ Pheasant 2 12 12 105 — — — Pheasant 4 IX 21 2 X 105 — — — Quail 1 1 11 0.5 X 105 ±* — ±t Starlings 1 10 13 2.5 X 105 — — — Starlings 2 12 1G 2.5 X 105 " * Bronchial rales for 2-3 days only, t Nonspecific response (log NI = 1.5). TABLE 3. Responses of Pheasants, Quail and Starlings to Mycoplasma gallisepticum.* Species Age (months) Number inoculated Clinical symptoms Antibody response Air sacculitis Pheasant .. Quail Starlings 12 4 2 16 l/4t 0/2 0/16 4/4 0/2 0/16 0/4 0/2 0/16 * Uniform dosage of 2.5 X 10 s viable organism per bird. t Numerator = number of birds showing response; denominator = number of birds inoculated. Signs Audible rales with a sneezing and flipping of the head to expel mucus appeared as early as the second day PI. Hofstad (1965) gave 2 to 4 days incubation for chickens. Dyspnea usually appeared on the third or fourth day, and death came less than 24 hr later. Typical "pump- handle" breathing was observed in two or three of the adult birds. Only four birds (16%) recovered after having developed dyspnea. A high mortality of 12% is recorded for a natural outbreak in chickens (Biester and Schwarte 1965). Pathology All birds autopsied after signs developed and hemorrhagic tracheitis, many with mucus casts that occluded the trachea, almost identical with that described in the chicken (Biester and Schwarte 1965). Histopathology A progressive desquamation of the tracheal mucosa commencing on the second day PI with almost complete sloughing by the fourth day was noted as compared with 6-7 days in the chicken (Mayor 1968; Van Der Heide, Chute, and O'Meara 1967). Typical type A (Cowdry) SUSCEPTIBILITY TO DISEASE 165 intranuclear inclusion bodies as described in chickens (Biester and Schwarte 1965; Mayor 1968; and Van Der Heide, Chute and O'Meara 1967) were observed on the fourth day PI. Virus Isolation Virus was isolated from the trachea on the second, third and fourth da}*s PI. Isolations were made from an eye swab and laryngeal swab 14 days PI from one control and one convalescent bird respectively. Contact Transmission and Immunity Two of 16 pheasants in lot 3 survived the ILTV inoculation. These two birds developed acute respiratory signs and recovered. When chal- lenged they again developed acute respiratory signs and recovered the second time. Of the four uninoculated contact birds only one developed detectable signs (eye lesions). When challenged three were resistant and one susceptible. Of the six controls, separated by 6 ft of space, four were challenged. All four were susceptible and three of them died. Only one of the four pheasants showed clinical evidence of a respira- tory infection with MG, i.e.. slight dyspnea with audible rales and slight nasal discharge. No puffing of the sinus was noted. The quail inoculated with IBV developed bronchial or tracheal rales which were audible by holding the bird to the ear on the third and fourth days PI. No other signs were detected. Virus isolation was not successful. The PI neutralizing index (NI) was insignificant on blood samples taken on the 28th and 35th day PI using four and five eggs per dilution and repeating the SN test 3 times. DISCUSSION The result reconfirms the earlier reports (Biester and Schwarte, 1965; Hudson and Beaudette, 1932; Jordan, 1966; and Kernohan, 1931) that pheasants are highly susceptible to ILTV. This work also indicates that ILT can be transmitted from pheasant to pheasant by direct contact and that the virus can persist for at least 14 days which was the longest period tested after inoculation in recovered birds. Ad- ditional work will be needed to determine if pheasants can become carriers or constitute a reservoir of ILT infection for chickens. Also it should be determined if ILTV can produce an outbreak of disease in wild and commercial flocks of pheasants. M. gallisepticum elicited only a mild response in the ring-neck pheasants, but under certain conditions natural outbreaks of this dis- ease do occur (Biester and Schwarte 1965; Keymer 1961). This experiment did not produce conclusive evidence that valley quail are susceptible to the three agents used. Clinical signs were ob- served on the second and third days after IBV inoculation ; however, the virus was not recovered and the post inoculation neutralizing in- dices were nonspecific. Under the conditions of this experiment adult starlings were not susceptible to ILTV, IBV or MG. It is interesting to note that pheasants, immunologically more closely related to chickens (Mainardi 1959), were the most susceptible to ILTV and MG. 166 CALIFORNIA FISH AND GAME ACKNOWLEDGMENTS The authors gratefully acknowledge the assistance of Mr. Merton N. Rosen and Mr. John Azevedo and the California Department of Fish and Game for providing the pheasants, and Dr. Robert G. Schwab, Animal Physiology, U.C.D., for providing the starlings. SUMMARY Both adult and young pheasants were found highly susceptible to intratracheal inoculation with ILTV. Transmission of ILTV from inoculated to uninoculated pheasants occurred on direct contact. Acute conjunctivitis appeared in one of four contact controls while the other three showed no signs. Three, including the bird with conjunctivitis, of the four controls were im- mune to challenge. Transmission did not occur in birds separated by 6 ft. Four 7-week-old pheasants gave a serological response to inoculation with MG, but only one showed clinical signs. Both adult and young pheasants were found refractory to IBV. Starlings were found refractory to ILTV, IBV and MG. Mild clinical signs were noted in 6-week-old valley quail inoculated with IBV. Virus isolation was not successful and the results of the SN tests were nonspecific. Valley quail were found resistant to ILTV and MG. REFERENCES Beach, J. R. 1931. A filterable virus the cause of infectious tracheitis of chickens, J. Exp. Med. 54 : 801-808. Biester. H. E. and L. H. Schwarte. 1965. Diseases of poultry. Iowa State Col- lege Press, Ames, Iowa. 5th ed. 411-426. Hofstad, M.A. 1965, p. 605-632. Biondi. E. and A. Schirvo. 1966. Investigations into the susceptibility of various small passerine birds to the virus of infectious bronchitis. Acta Med. Vet. 12(6) : 537-547. Cunningham, C. H. 1957. Infectious bronchitis virus. Am. J. Vet. Res. 18(68) : 648-654. Cunningham. C. H. 1963. Laboratory guide in virology. Burgess Publ. Co., Minneapolis, Minn. 5th ed. p. 8-13, 16-35, 66-68. Edgar. S. A. and R. Waggoner. 1964. Pathogens of Coturnix cot u mix japonica. Quail Quart. 2(2) : 11-14. Fabricant. J. 1951. Studies on the diagnosis of Newcastle disease and infec- tious bronchitis. Cornell Vet. 41 : 68-80. Finney, D. J. 1964. Statistical methods in biological assay. Hafner Publ. Co., New York, N.Y. 2nd ed. p. 515-553. Hudson, C. P. and F. R. Beaudette. 1932. The susceptibility of pheasants and a pheasant bantam cross to the virus of infectious bronchitis. Cornell Vet. 22 : 70-74. Jordan, F. T. W. I960. A review of the literature on infectious laryngotracheitis. Avian Dis. 10 : 1-26. Kerlin, R. E. 1964. Venipuncture of small birds. J. Am. Vet. Med. Ass. 144 : 870-874. Kernohan. G. 1931. Infectious laryngotracheitis in pheasants. J. Am. Vet. Med. Ass. 78 : 553-555. Keymer, L. F. 1961. Infectious sinusitis of pheasants and partridges. Vet. Rev. 73 : 1,034-1,038. SUSCEPTIBILITY TO DISEASE 167 Madden, D. L., W. H. Henderson and H. E. Moses. 1967. Case Report : Isolation of Mycoplasma gallisepticum from bobwhite quail (Colinus virginianus) . Avian Dis. 11 : 378-380. Mainardi, D. 1959. Immunological distance among some gallinaceous birds. Nat- ture 184 : 913-914. Mayor, V. Y. 1968. Histopathological aids to the diagnosis of certain poultry diseases. Vet. Bull. 38(5) : 273-285. National Academy of Science. 1963. National Research Council Publication No. 1038. Methods for the examination of poultry biologies. Revised ed. p. 11-34, 60-79. Van Der Heide, L., H. L. Chute and D. C. O'Meara. 1967. A comparative investigation of the cause of an experimental infection with infectious laryngo- tracheitis in chickens. Avian Dis. 11 : 149-153. Van Roekel, H. 1955. Respiratory diseases of poultry. In: Advances in veterinary science. (C. A. Brandley and E. J. Jungherr, eds. ) Acad. Press Inc., New York. 4th ed. p. 64-105. Calif. Fish and Game 59(3) : 16S-177. 1973. THE CALIFORNIA SABLEFISH FISHERY FOR THE PERIOD 1953-1 969 1 RICHARD H. PARRISH Marine Resources Region California Department of Fish and Game This report on the California sablefish fishery from 1953 to 1969 updates Phillips and Imamura's (1954) report, which described the fishery from 1941 to 1952. The otter trawl sablefish catches remained quite stable (962,557 to 2,157,047 lb.) from 1953 to 1969. This was probably due to the small variation in fleet size and that sablefish is an inci- dental species in otter trawl landings. Sablefish catches by the longline fleet declined to a low of 147,275 lb. in 1963. In 1964 the longline catch showed a strong recovery apparently due to increased demand and the catch rose to a peak of 2,401,057 lb. in 1967 primarily because of an increase in the catch per delivery. INTRODUCTION Sablefish (Anoplopoma fimbria) are distributed from Baja Cali- fornia, Mexico to the Bering Sea in depths between shore and at least 700 fathoms. Sablefish were caught commercially as early as 1879 when Lockington (1881) noted them in San Francisco fish markets. From 1916, when statistics were first recorded for the California fish catch, to 1952 an- nual sablefish catches fluctuated between 83.623 lb. in 1916 and 6.3 million lb. in 1945. Landings declined after 1945 and landings in 1946 and 1952 ranged from 902,110 lb. to 2.6 million lb. (Phillips and Imamura 1954). An assessment of the condition of the California sablefish stocks for the years 1941 to 1952 was made by Phillips and Imamura (1954). They concluded from their analysis of fishing effort using the average annual pounds per delivery of longline vessels at the major landing ports of Eureka, Fort Bragg, and Monterey that no stock depletion existed and that the annual catch fluctuations were associated with demand. The fishery from 1953 to 1969 and an assessment of the condition of the stocks are described in this report. The data from the major ports of Eureka, Fort Bragg, and Monterey are treated together in contrast to Phillips and Imamura's (1954) analyses by individual ports. HISTORY OF THE FISHERY The California sablefish catch has shown a long upward trend since catch statistics began in 1916. The trend line shows a peak during the depression (1935) when landings rose to 2.8 million lb. and sablefish livers brought a higher price than the rest of the fish. Market demand caused a surge in the landings to 6.2 million lb. in 1945 and landings have shown a sharp upwards trend from 1.8 million lb. in 1963 to 4.1 million lb. in 1969. (Figure 1). Phillips and Imamura (1954) suggested 1 Accepted for publication February 1973. ( 168) SABLEFISH FISHERY 169 that the annual fluctuations in the catch were associated with demand as they found a negative correlation of —0.73 between the cold storage holdings of sablefish at the beginning of the year and the catch for fli llions of Pounds 1915 1925 1935 1945 1955 1965 FIGURE 1. The California sablefish catch from 1916 to 1969 that year from 1946 to 1952. This situation has persisted through 1969; the correlation coefficient for the years 1946 to 1969 is —0.71, (Fig- ure 2). The limiting factor in the California sablefish landings has tradi- tionally been market demand with the greatest demand for large fish, over 7 lb., which are marketed as "smoked cod." Sablefish are also known as blackcod or candlefish and the smaller fish are often filleted and marketed as butterfish. There is a large price difference with size. The large fish presently bring the fisherman from 12 to 14 cents per pound in the round. The price for medium fish, 5 to 7 lb., is 6.5 cents, while 4.5 to 5.5 cents per pound is paid for small fish under 5 lb. 170 CALIFORNIA FISH AND GAME Millions of Pounds 1945 1950 1955 1960 1965 FIGURE 2. Cold storage holdings of sablefish on December 31 vs California landings for the subsequent year Before 1943, sablefish were landed principally by a large fleet of small 2-3 man longline boats, the majority of which fished primarily for rockfish. (Phillips 1939). This "rockcod" fishery has nearly disap- peared and the present small longline fleet expends the majority of its effort in relatively deep water 200-400 fathoms, fishing specifically for sablefish. The otter trawlers have accounted for approximately half of the sablefish landings since the rapid development of this fleet during the mid-forties. Sablefish are caught by otter trawlers during fishing operations for Dover sole, rex sole, petrale sole and rockfish. The trawl caught sablefish are smoked or filleted. Sablefish is also an important species in animal food landings of which they comprise up to 44% of the total. The ports of Eureka, Fort Bragg, and Monterey have continued as major sablefish ports and San Francisco has had substantial sablefish SABLEFISH FISHERY 171 co •o ■n o *C V Q. 3 Q u c o °5> 4) ■o ■o X in « 0) o ■O e 3 o a c < "a *- o CO < MHMOlC'lNCD'fOOSOiNOOJrOifitD c3 (NMCCiOCOOl'OC'lWCO'tiOiOCOOlO'f o ^lOOCONOiCCOlONM^iOa^i'M -4-3 io N »o oo en n oo oj o »o oj" co co io od ai to V LOlOCOCDOJCOCOHHHOCDCOHO>HlO ■+-" COWOOOi-tNOl^cOOOO^OOcNNCNH c3 43 rH IN CN CN CN ** *H CN i-H CN i-T CN CN CO" CO* CO TjT w o ' l© I © 00 t-- iOO) ICO W3 ' ICO llO^OO IdH 1 CN O ll^lllllliHCOIOI CO 100 5 o! 03 CO oj COOOSOffl^CDNNOOCDiOCD c t- O lOlOcOiOOCOiO'J'CONCON'tH IHCO go ONioiOHiNinmflJOoooiN icocn bo a Tj< CN t- —1 -H rt < .t~00Ot-t>-0005Tt0>-iCOtom'}'CN^-ltDCD05CO a HHNNcOHCOCMNrtMlOcOrtH rt m cnicj-^o w oi h n m oo in os -^ § 03 cNCN-H'^iOcN>-it-.0)00t0r»i0-H^05O >> (OiONhioOOMONNhOMOOOI 0) HOOOCNCtOOOlO^tONNOiOONOliO o oOHK)woioi>cj)Ofi-ioonrtoiN CI OOCOHOlMDCOOliOONHNONNH m CDCOO CO hcOtJIN^iiOlOOCOIO o 3 o o O100CqcDCOO-l*Omi , OCl(MCOON .S3 OOOOOHOO*OCI^cD0)01icj00cOiO bX oS HCOHt>COO«COHNCNcOejr-NCD LOCONOlOOiOOHcOOOOJCOONCOf oomiooDcoooi'CJcoiioocDcionH 4S MCOmt'OIOOMONcOrHNtONCOODO M ■H fa cjocooocONNmcoconNiiHOiinH OOrHNOClOiOONCJCIr-OONTfOOrtrt d Ot'OIHTfrtCOOt-rHCOCOiOCJNI'O) cu COHOOlNHHNCDOr>SH[«t«SM (-. iflif)010rOOiOOOOcDi0 010)CCOiHH 3 lOCO'^CO'^'^'»J i 00cNCO'^O50000O5O5lCi W »-t b OS a> fH CO'*iOONOOoO'^cNCO , J ,l OcDNOOOJ lOlOiO'OiO'OiOcDCDOCDcDCDcDOCOCO O3O5O5O5O>O5O5O5C0^OiOSCrftOSO5OSC7)O5 172 CALIFORNIA FISH AND GAME D) D t O o -X 0) k 3 *■ .5 V ««- 0. ~JZ x a i- u k «•- 0) vn O e k 0) S X V jb 0) "D 4- e 4) e ■o e -E in 01 w U) '3 p Irt k Ik c C 3 a. _ 3 C C < < NHOHlflOOOS'frtNHOJHHHS £ inHtDHMMNnsh.oco'j'nom^ d lOOOOi'Oh'NONClHOQOCOOHO 40 HO»lO*M9OhSNO00O O o H cooooNos«oo*finso^Mn.^O'0t-» Im 49 NHnnnoi»HNnf.ioHnoiNoo NfMON^ft-NOOOOOOOONNO >> 43 O a o HiiOOOHMH01*OOMHI)N» o H-fHifliOn!OONHrtON^(DHtO a oonoNt-ooooMoomnosofH — OOlNSI'OlflOhNOMmOOHON bo OmftlOHHNNNJlOOOI'OH a P)COM«N i-i CN IN IN .-H CN t~ ©_ CO o J f-H f— I 1 oioONMfcoiiOMoionoNnioKm ODO^iOOOHClinOlOMiOOJNHMO) CJ HHOHKItONOOIlOOlNPIMminMO o •p MjioonnoosoooonHHOis NOlI'MNiaOlfNOlflNOOnSPtO .2 CO ««MQ6**0»01(l»*Oq'*HN 'o 4-> 1-4 a O k I I I rOON P5 MO 100 I I lOlO I a o i i i icotNOi^o l co i i icon i os a i i i ihcooho 'i-h i ' toqo i CO u a IN i-T C-f ■* o ►J inooo^Oi-tHHiniortMinOHrtio OinoCOOO^OOlDiOiOOCOOCN^O S c3 in^ooioa>oooinooMNMno)H -*^ ^Ofl'IOOJ^HMMGHOOOiOOHif: be k CD l-NMCOOONNfinNOnf-MNN rtTfnCOnOiOITlClHNCONNNIi 03 k pq 4S 49 o -k3 1- o lOoifioomoinHooniNoirfNN'* o lOOOM^noitNoooonoiHino a iOO«NOOHifOOi0010«)'JMO a ooNOteonooONOi omoooo bo — NrtinW^CCrHiON N^OOON a HHWfiOHHH ro^qio^ o .-J p-l MiOfNOPlfNntlHOOOinNIN j£ HOOOtOOlCJUlMHNHNifJiOiOO Oj (OOHKMINnHNOlNMOOlOOIlO 43 oOH^^cfrtooioMnOhiONNin MHCflifNOOOMOOllNOOOCtN MnNNNNCOMNn-fNiOMfON c5 r o 3 W MOfiosfnn iMooxjipitOiDOi S) NifNmnoiaN lOowooonto a ocoooNONOin icNO^*oosr»cNi-* UA to d r ii , 'oooio co *? t>T -*r ^h o~ ncooooo>-* .■••. > • ^•> 1945 1950 1955 1960 1965 L100 Thousands of Pounds __ per 80 Boat 20 FIGURE 3. Annual California sablefish longline fleet size, average annual catch per boat, and average pounds per delivery 174 CALIFORNIA FISH AND GAME 10,000 and 25,000 lb. The average annual catch per boat during the period of 1964 to 1969 was greatly increased over the earlier period and peaked at 110,452 lb. in 1969 "(Figure 3). A large increase in the average pounds per delivery occurred in the revitalized longline fishery. Before 1964 the average sablefish delivery by longliners stayed quite constant at around 1,000 to 1.200 lb. The largest average landing was in 1960. 1,458 lb. and the smallest average occurred in 1950, only 769 lb. per delivery. Beginning with the 1964 season, the average delivery by longliners nearly doubled and has remained near 2,000 lb. from 1964 to 1968. In 1969 the catch per delivery rose to an all time high of 3,519 lb. (Figure 55. Number of Otter Trawlers 45. 35j Catch/ /Boat (thousands of lbs.) 25-1 15 MeanCatch per Delivery (hundreds of lbs.) 1955 1960 FIGURE 4. Annual California sablefish otter trawler fleet size, average annual catch per boat and average pounds per delivery SABLEPISH FISHERY 175 3). Two other factors may partially account for the large increase in the average delivery. In Eureka and Fort Bragg, the longliners have traditionally made 2 to 3-day trips to more distant and productive sablefish grounds when the market demand was high. The increased demand since 1964 may have resulted in an increase in the proportion of deliveries from these longer trips. In Monterey, where the longline fishery is essentially a day-boat operation, the increased demand has resulted in an increase in the number of "baskets" used per boat. Phillips and Imamura (1954) reported that the number of baskets 4. Millions of Pounds 1954 '56 58 60 '62 64 66 68 FIGURE 5. California sablefish landings from otter trawlers and longline vessels, 1953 to 1969 fished by a two-man crew was 10 to 15 a day. By 1969, the number of baskets used rose to 20 to 25 per day and three-man crews now normally set around 40 baskets per day. This increase in the number of baskets fished has forced many of the fishermen to coil and bait their gear on one day and fish the next day. The lack of quantitative data on changes in fishing tactics, in gear units, or in efficiency of longline vessels prevents determining if the great increase in average pounds of sablefish per delivery is due par- tially to an increased availability of sablefish off California. It seems reasonable that tactics, the increase in gear units, and the decrease in the longline rockfish fishery have caused the bulk of the increase in catch per delivery. The otter trawl sablefish fishery remained quite stable from 1953- 1969, with the annual catch for the four major ports varying between 962,557 and 2,157,047 lb. with no obvious trends. 176 CALIFORNIA FISH AND GAME Annual catch by port showed considerably more relative variation than did the combined catch. Eureka landings varied from 244,293 to 1,275,802 lb. and otter trawl landings in the Monterey area varied between 40,886 and 563,964 lb. (Table 2). Relative stability in the otter trawl landings was because sablefish are largely an incidental species in the otter trawl catch, and the nominal variation in the number of otter trawlers landing sablefish from 1954 to 1969 (43 to 54 boats). Mean sablefish catch per boat also showed little change (26,480 to 43,061 lb.). The 1953 season had a somewhat larger fleet landing sablefish (61) and a small (15,780) annual catch per boat (Figure 4). Mean catch per delivery showed little variation from 1953 to 1969 (849 to 1617 lb.). This suggests that the longline fleet catch has caused the recent increase in landings and the otter trawl fishery has been little affected by the increased demand for sable- fish since 1964 (Figure 5). Sablefish are apparently not a significant enough factor in the total otter trawl fishery for the increased demand to cause a change in fishing tactics. Sablefish is the dominant species in the California animal food trawl fishery. This fishery has been sampled for species composition since 1956 and sablefish have comprised up to 44.8% of the annual landings. Sablefish landings from the animal food fishery are not included in this analysis. The peak sablefish landings in the fishery occurred in 1960 when 1,194,459 lb. were landed (Table 3). TABLE 3. California Landings of Sablefish for Animal Food Year Sablefish 0b.) Percent of total Year Sablefish 0b.) Percent of total 1953 Not sampled Not sampled Not sampled 341,965 582,982 726,724 658,040 1,194,459 1,057,579 23.0 38.0 23.7 18.8 29.8 28.0 1962 308,289 341,207 778,822 1,149.460 1,014,927 793,374 789,838 872,998 16.4 1954 1963 33.0 1955 1964 44.8 1956 1965 40.0 1957. 1966 42.7 1958 1967 30.5 1959.. 1968 30.5 I960.. 1969 36.2 1961 The only recent work which has analyzed the economics of the Cali- fornia fresh fish trade is O'Rourke and DeLoachs (1971). They hypoth- esized a model to describe the relationship between demand, prices, and the California catch of 12 of the most important species in the fresh fish landings. Sablefish was the only species for which they were unable to find a satisfactory fit to their model. A possible factor causing a poor fit for sablefish was that the longline fishery showed a response to increased demand for sablefish but the otter trawl fishery was not affected. Another factor was that they assumed that economic control of the fresh fish trade was primarily within California. This is not the case for sablefish, where imports from the Pacific northwest and Japan have been of considerable magnitude (490,990 lb. in 1960, Table 4). SABLEFISH FISHERY TABLE 4. Shipments of Sablefish Into California by Origin 177 Year Pacific NW (lb.) Japan (lb.) Year Pacific NW (lb.) Japan (lb.) 1953 1954 1955 1956.. 459,109 447,387 452,470 493,132 255,613 224,674 301,041 490,990 246,054 168,000 1962 1963 1964 1965 1966 74,449 96,309 20,169 38,417 40,337 60,000 92,250 160,000 1957 1958 1967 1968 1969 297,125 1959.. 126,000 1960 1961 166,120 RECOMMENDATION The increased demand for California sablefish since 1964 has resulted in a significant increase in the longline fishery for sablefish. Recently considerable interest has also been shown in a "pot" or trap fishery for sablefish. Present domestic exploitation of sablefish remains at a low rate ; however, the effort on sablefish is restricted to a small propor- tion of the area inhabited by sablefish off California. This fact, plus the possible effects from the large foreign fishery on sablefish in the Pacific northwest, suggests that we should closely monitor this develop- ing fishery. REFERENCES Lockington, W. N. 1881. Report upon the food fishes of San Francisco. Report of the Commissioner of Fisheries of the State of California for the years 1878 and 1879. p. 17-58. O'Rourke, A. D. and D. B. DeLoach. 1971. The California fresh and frozen fishery trade. Calif. Agric. Exp. Sta. Bull. 850 : 1-79. Phillips, J. B. 1939. The rockfish of the Monterey wholesale markets. Calif. Fish Game 25 (3) : 214-225. Phillips, J. B. and Seigi Imamura. 1954. The sablefish fishery of California. Pac. Mar. Fish. Comm. Bull. 3 : 5-38. Calif. Fish and Game 59(3) : 178-190. 1973. CONTRIBUTIONS TO THE LIFE HISTORY OF THE SILVER SURFPERCH {HYPERPROSOPON ELUPTICUM) FROM THE OREGON COAST 1 RICHARD S. WYDOSKI 2 and DONALD E. BENNETT 3 Oregon Cooperative Fishery Unit OSU Marine Science Center Newport, Oregon The silver and redtail surfperches are the most common fish Inhabiting the surf zone of northern California and Oregon. Data on the life history of the silver surfperch from the Oregon coast were collected between June 1967 and January 1969. This paper provides the first published information on the biology of this species and includes summaries of age and growth by sex, length-weight relationships, relation between age and size to sexual maturity, fecundity, and a parasite that is unique to surf-dwelling embiotocids. Females grow faster than males and this characteristic was related to reproductive maturity. Silver surfperch first become sexually mature in Age Group I. Males are ripe in late September when copulation occurs. Females give birth to their young between late June and early August. Fecundity of the females was re- lated to their size with the smallest (174 mm TL) containing 4 embryos and the largest (221 mm TL) containing 17. The incidence of a mono- genetic trematode (D/c/idophora sp.) that is found only on the gills of surf-dwelling embiotocids is summarized by age and size of the fish. INTRODUCTION The silver surfperch, Hyperprosopon ellipticum (Gibbons), is dis- tributed along the Pacific coast from southern California to Vancouver Island, British Columbia (Tarp 1952: Peden 1966). This surfperch primarily inhabits the sandy surf zone but is also found around rocky outcroppings and jetties and sometimes in the mouths of estuaries. In northern California, the redtail (Amphistichus rhodoterus) and the silver surfperches are the most common surf species (Miller and Got- shall 1965). These two species are also the most common surf inhabi- tants in Oregon and probably in Washington. Miller and Gotshall (1965) ranked the silver surfperch ninth by number in the entire sportfishery and third in the ocean sport catch of shore fishermen from the Oregon border to Point Arguello, California. While studying the redtail surfperch from June 1967 through Janu- ary 1969, we were able to obtain data on some aspects of the life history of the silver surfperch. The study area included Alsea and Yaquina bays and approximately 14 miles of the surf zone between these bays along the central coast of Oregon. The published literature on this species has been limited to taxonomy, distribution, description, and 1 Accepted for publication January 1973. This research was conducted through the Ore- gon Cooperative Fishery Unit. Cooperating Agencies include the Bureau of Sport Fisheries and W T ildlife, Oregon Game Commission, Fish Commission of Oregon, and Oregon State University. 2 Present address : Washington Coop. Fishery Unit, Univ. Washington, Seattle. 8 Present address : Fish Commission of Oregon, Clackamas, Oregon. (178) SURFPERCH LIFE HISTORY 179 formation of keys. This paucity of information on the life history of surf -dwelling fish has been attributed to the difficulty in sampling this habitat (Schaefer 1967). This paper will describe aspects of the silver surfperch biology including the age and growth by sex, length-weight relationship, relation of age and size to sexual maturity, fecundity, and a parasite unique to surfdwelling embiotocids. The Bureau of Sport Fisheries and Wildlife (1959) and Stroud (1971) have empha- sized the need for this kind of information in their reviews of the national research program of our marine sport fisheries. METHODS AND MATERIALS Sampling of the surf zone and estuaries was made at least once monthly using gill nets, dip nets, and hook-and-line. Most of the silver surfperch were captured from June through September. All fish were weighed, measured, and dissected within a few hours after capture. The fish were either brought back to the laboratory while alive or the females were placed in individual plastic bags to avoid the loss of embryos. RESULTS AND DISCUSSION Conversion Factors Total length (tl) measurements are used for the various analyses in this paper. However, since many investigators have reported their 200 r 175 150 125 x i — ^ 100 Q Z < 50 25 Y = 0.782 X - 1.155 r = 0.9 98 n = 1 75 I 25 50 75 100 125 150 175 200 225 250 TOTAL LENGTH IN MM FIGURE 1. Regression of SL compared with TL for silver surfperch from the Oregon coast. (The numbers refer to overlapping points; the letters refer to 10 or more over- lapping points with A = 10, B = 1 1, C = 12, etc.) 180 CALIFORNIA FISH AND GAME results on embiotocids using other measurements, we calculated equa- tions to convert tl into standard (sl) and fork length (fl). Carlisle, Schott, and Abramson (1960) and Anderson and Bryan (1970) have reported that the tail length decreased with increased body lengths for four species of embiotocids. Our analysis of silver surfperch did not indicate a difference in this characteristic for fish between 40 and 242 mm tl (Figure 1). A similar relationship was found between fl and tl. The regression equation was Y = 2.429 + 0.9004X with r = 0.987 for 211 fish, where X = tl in mm and Y = fl in mm. Age and Growth Age determination was made by the scale method. Other investi- gators (Carlisle et al. 1960; AYares"l968; Bennett and AVydoski (1971, Ms.) have found that the scale method was reliable for age deter- mination in the Embiotocidae. To check the consistence of age assign- ments, we determined the ages separately and found that we agreed 91% of the time. The final age determinations were made by the senior author. Because of the high proportion of regenerated scales, the scale sample was taken from a key area of the body. This area was about four to eight scale rows below the lateral line and on an oblique from the origin of the dorsal fin. The scales from silver surfperch were very thin and delicate. This characteristic was also observed in the walleye surfperch, Hypcrpro- sopon argent aim, from California by Anderson and Bryan (1970) and from Oregon during the present study. All scales were, therefore, mounted in a glycerin-gelatin mounting medium (Lagler 1956) to avoid damage. Three checks were recognized from the structure of the scales: birth, spawning, and annulus checks. However, not all fish exhibited clear birth or spawning marks and some lacked these marks entirelv. Birth checks varied from very evident to slight in silver surfperch and this check was not found in a few fish. Apparently some young surfperch can adapt more readily when they pass from ovarian fluid of the female to seawater at birth. Spawning checks contained circuli that were relatively continuous and, therefore, could be dis- tinguished from true annuli. These checks were most easily recognized in the earlier years of life for females and were lacking from the scales as the female became older. This phenomenon was also noted in the redtail surfperch by the authors (Bennett and AVydoski Ms.) and perhaps can be explained because younger fish grow faster than older fish. Young females would begin to grow early in the spring when the embryos were small. As the embryos began to grow rapidly, the female's growth would be interrupted until birth occurred and then the female would resume her growth. The annulus and spawning checks would be superimposed in older females because little, if any, growth would occur in the female while the embryos were rapidly developing. True annuli could be recognized by the closer spacing of the circuli and by crossing over of circuli that could be traced entirely around the scale. Because annuli were most evident along the anterio-lateral radius of the scale, scale measurements were made along this axis by using a Bausch and Lomb microprojector at a magnification of 47.74 X. The SURFPERCH LIFE HISTORY 181 body-scale relationship for silver surperch was calculated by the method of least squares (Figure 2). The spread of points for scales from a key area was similar to that found for key scales in other embiotocids (Gordon, 1965; Wares, 1968). Back calculation of growth was made 250r 2 25 |- Y= 18.6 6 + 1.2 7 X r = 0992 n : 210 200 175 5 2 150 Z o z < o 100 75 50 - 25 25 50 75 100 125 150 175 200 ANTEROLATERAL SCALE RADIUS IN MM (X47.74) FIGURE 2. Body-scale relationship for silver surfperch from the Oregon coast. (The numbers refer to overlapping points; the letters refer to 10 or more overlapping points with A= 10, B= 11, C = 12, etc.) by direct application of the body-scale regression equation (Table 1). Females were larger than males after the first annulus (Figure 3). This difference was related to sexual maturation in the silver surfperch. Faster growth in females has been found in other species of embioto- cids : redtail surfperch (Bennett and Wydoski Ms.) ; barred surfperch, Amphistichus argenteus, (Carlisle et al. 1960) ; white seaperch, Phanerodon furcatus, shiner perch, Cymatogaster aggregata, and wall- eye surfperch (Anderson and Bryan 1970) ; pile perch, Rhacochilus vacca, (Wares 1968) ; and striped seaperch, Embiotoca lateralis (Si- valingam 1953). In one exception to this trend, Gnose (1968) reported that male striped seaperch in Oregon grew faster than females. Because weight can be influenced by the amount of food in the stomach of a fish, different sampling periods, sample size, and other factors, a length-weight relationship was determined by combining all 182 CALIFORNIA FISH AND GAME e o u e o i a t 3 wo k. o _> w ■o c LU 1 a LU —I CD < 00 x r>. s to CO ©' *3 CS CS CS o *H L.1 © S3 to © X CO o o O H CS CS CS r- ■*< © CO © CS cs © X ■a CS ■«• « t- CS © r~ i^ ■* — < 3 © OB © CSH» CO « cs "3 CS « »H ^* CS cs c c 3 u a) S 43 CS JS <• in — CS *:"* i-H r-t © © 43 M a t X X «■« - i ^ CO CS © X *^ -~ -^ X X X X 00 i-l t> © — riC4 >-« 1— ^- I-H 1—1 cs cs CS ej 4B 43 o 43 d 3 O « "* IQ GO CD — <" CS ■H X © -. 1 "3 © CS © t>- ** KMN — ! — x © © © O N C N C 00 © CS X x © © © cs « CS t>. X — •* © CS © o « n n io *f CS ^ s t: K f ao ©OX n — « © "T x' © 10 T TT TT *r CO ** T © IQ l-~. t- t- CON t-* L* ^ C X ifl f © © X W t- c S £ fc a 2 2 CO CO ^< CO CS CS — © CO © cs © © © © © © ~* ~* © © re ' u O - — ~ = - ©©©©©— ia cc © © cs ^* — « cs re — ™ t; 2 ° a 3 *■—* i i i i i i i 'x 1 1 1 < i s 9 l t i £ i i i I I I I O 1 1 1 1 1 ~5 u "3 i i i . i i i a §.:::::! 1 •*> <£>!■■■■ 1 ** 1 &c Z - cob; < , . « ' 1 M „' a k ~ > > > Incrom (1 I II III... IV V > S 3 SURFPERCH LIFE HISTORY 183 250 l r- i i i i 1 J 200 - 2 2 - Z 1 50 . - X o z - LU _, 100 < 1 — o / d FEMALES MALES - 50 n ' I ' ' i i l i - 10 I u z o z 4 ^ < o - 2 r n. 0.988 105 0.983 32 0.968 74 I II III IV V VI VII AGE GROUP FIGURE 3. Calculated lengths at the end of each season of growth for silver surfperch from the Oregon coast. data (Figure 4). Separate length-weight relationships were also cal- culated for males, females, and immature fish, as follows : Sex Length-weight relationship Males log Y = 3.131 log X —5.106 Females log Y = 2.936 log X — 4.669 Immatures log Y = 3.148 log X —5.186 Where X = total length in mm, Y = weight in grams, r = correlation coefficient, and n = number of fish. Relationship Between Age and Size to Sexual Maturity Sexual maturity was determined by macroscopic examination of the gonads. Vascularization and enlargement of the testes from late June to early October were used as criteria for classifying the maturity of males. Immature males did not show any change in the morphology of their testes during this time. Females were judged sexually mature on the basis of their ovarian morphology. From late June to August spent females could be recognized by the enlarged and flaccid ovary. In immature females the ovary was small and firm. Silver surfperch become sexually mature in Age Group I (Table 2). All fish of both sexes in Age Group III or older are mature. In general, a greater proportion of the larger individuals from Age Group I and II for males and from Age Group II for females were mature (Table 184 CALIFORNIA FISH AND GAME O x O TOTAL LENGTH IN INCHES 1 2 3 4 5 6 7 8 9 225 200 1 log Y = a227 log X - 5.328 1 1 1 7 175 - r = 0.972 n = 211 • •/? 6 150 125 100 T 2 ' 3'/3 If " • • / 2» 3/ 5 4 75 57/ /: 3 50 y . 25 - i i *■• ' I | | i l 1 1 1 25 50 75 100 125 150 TOTAL LENGTH IN MM 175 200 225 250 FIGURE 4. Length-weight relationship for silver surfperch from the Oregon coast. (The num- bers refer to overlapping points; the letters refer to 10 or more overlapping points with A = 10, B = 1 1, C = 12, etc.) 2). Therefore, both size and age have an influence on maturity. This characteristic was more clearly demonstrated for the redtail surfperch where we had larger sample sizes (Bennett and Wydoski Ms.). A maturity index (gonad weight X 100 divided by body weight) was calculated for males to show the annual development of the testes. All males that were longer than 160 mm tl were included in these calculations, because males longer than this length would probably be mature during the next mating season (Table 2). The gonads become vascularized and heavier until the end of July (Figure 5). After this time, spermatogenesis is well underway and on September 25, 1968 three males were captured that readily emitted milt. When the males were ripe the maturity index was only about one-fourth of the value SURFPERCH LIFE HISTORY 185 m S o u o 4> u k. V a «*■ 3 IA u 0) _> 'J! o 2 "a 3 X • lO U5 5? § 888 8 £ ^-i .-I -h t— 1 > IZJ lH 1- N o I— 1 § 8888 8 8 8 SB ■-< rt ^H i-C rt > niooon t- i— f a !z ^H o 3 o Si Si •< a 888 8 8 :§ 8 se rt -H rt t— 1 *"■ 1-< > NOW cc I— 1 1 ^H 03 & M 1 a 88 8 p © © o o © © © © © 8 £ i-l i-H ►■* w oo co NNifliON to fc a © f~ )lNCN o f- H Mco^i JTJJ t 8 d) o w.E o> $'§ • » 0) 0) "£ c C 4) u *■ 01 o -c M 0) 01 O) o < UJ c/) .- j, — c C 0) c c o — .2.S O O) . J? *■ •— •— o U «= TJ o 194 CALIFORNIA FISH AND GAME environmental factors which affected the Pacific sardine ; but, this study indicates the change in Li was the result of scale reader bias. The consensus of opinions among scale workers is that consistency among a group of readers, or the presence of experienced readers guarantee results comparable to past results. However, there were two experienced readers present at the time the historical Li estimation began its abrupt increase in the mid-1940 's. The present study indicates that while the 1963 readers were consistent among themselves, their criteria were inconsistent with those of the original readers. Kimura and Sakagawa (1972) concluded on the basis of a comparison of Li of known age sardine with the average Li of fish aged by the early and recent scale readers that the early readers' L x estimations were closer to that obtained from the known age fish. The results obtained here indicate a need for some kind of standard or length-by-age values to serve as a reference to the readers in obtain- ing back-calculated length measurements. A suggested standard is a series of random, stratified-by-age scales, i.e., 0-, I-, II-, III-, . . . n-year-old fish scales, preferably selected from the time period when the validators of the scale (otolith and any other bony structures used in aging) method were in tenure, or were used by the validators as the basis of their study. For the sake of simplifying comparative read- ings and as assurance that the same scale will be read at all times, the initial readers of the standard series of slides should circle the selected scale with a marking pen. Similarly, the slides read routinely during a season should also be circled by the initial reader so that both a reader and the checker can be certain to have examined the same scales. The presence of such a set of standard slides probably would (i) assure continuity in the manner of the scale interpretation by the original validators of the scale or any other method used in estimating fish age, (ii) counteract and monitor the effect of dominance of any individual scale reader, and (iii) deter the occurrence of similarly costly mistakes as illustrated in this study. CONCLUSIONS The circa 1963 scale readers have not been reading like the original readers and, apparently, have not been following the same criteria in estimating the Li. The Li value change in time resulted from scale- reader subjectivity and was not caused by biological or environmental ACKNOWLEDGMENTS My thanks to the original scale readers, Dr. L. A. Walford, Mr. K. H. Mosher, and Mr. J. B. Phillips, and to the 1963 scale readers, Miss A. E. Daugherty, Mr. H. Hyatt, and Mr. Ft. S. Wolf, for participating in the scale-reading workshop. The editorial assistance of staff mem- bers of the National Marine Fisheries Services, and to a number of other staff members of the same organization who gave their time as "sounding boards" are acknowledged. REFERENCES Felin, Frances E. 1954. Population heterogeneity in the Pacific pilchard. U.S. Fish Wildl. Serv., Fish. Bull. 86(54) : 201-225. LOCATING FIRST ANNULUS 195 Felin, Frances E. and Julius B. Phillips. 1948. Age and length composition of the sardine catch off the Pacific coast of the United States and Canada 1941-42 through 1946-47. Calif. Div. Fish and Game, Fish Bull. (69) : 122 p. Kimura, Makoto and Gary T. Sakagawa. 1972. Observations on scale patterns and growth of the Pacific sardine reared in the laboratory. Fish. Bull., U.S. 70(3) : 1,043-1,052. Marr, John C. 1960. The causes of major variations in the catch of the Pacific sardine, Sardinops caerulea (Girard). Proceedings FAO World Sci. Meet. Biology of Sardines and Related Species, Rome, 14-21 September 1959; 667-791. Phillips, Julius B. 1948a. Comparison of calculated fish lengths based on scales from different body areas of the sardine, Sardinops caerulea. Copeia, 1948, 2 : 99-106. . 1948b. Growth of the sardine, Sardinops caerulea, 1941-42 through 1946-47. Calif. Div. Fish and Game, Fish Bull. (71) : 33 p. Walford, Lionel A. and Kenneth M. Mosher. 1943a. Studies on the Pacific pil- chard or sardine (Sardinops caerulea). 2. Determination of the age of juveniles by scales and otoliths. U.S. Fish Wildl. Serv. Spec. Sci. Rep. 21, 29 p. (Reissued in Spec. Sci. Rep. Fish. 15 : 31-95, 1950.) . 1943b. Studies on the Pacific pilchard or sardine (Sardinops caerulea). 3. Determination of age of adults by scales and effect of environment on first year's growth as it bears on age determination. U.S. Fish Wildl. Serv. Spec. Sci. Rep. 21, 29 p. (Reissued in Spec. Sci. Rep. Fish. 15:96-131, 1950.) Wolf, Robert S. 1961. Age composition of the Pacific sardine 1932-1960. U.S. Fish Wildl. Serv. Res. Rep. 53, 36 p. Calif. Fish and Game 59(3) : 196-206. 1973. FISH PARASITES OCCURRING IN THIRTEEN SOUTHERN CALIFORNIA RESERVOIRS 1 RICHARD L. MILLER 2 and ANDREW C. OLSON, JR. California State University, San Diego and LEE W. MILLER Bay-Delta Fisheries Project California Department of Fish and Game Four hundred eighty fishes representing 13 freshwater species from 7 genera and 4 families were collected from 13 reservoirs and exam- ined for metazoan parasites. Dorosoma petenense, Cyprinus carpio, No- temigonus crysoleucas, Ictalvrus eatus, I. melas, I. natalis, I. nebulosus, I. punctatus, Lepomis cyanellus, L. macrochirus, Micropterus salmoides, Pomox/s annularis, and P. n/gromacu/atus were infected with one or more helminths. Parasites found were Digenea: Hysteromorpha triloba, Posthodiplostomum minimum, Uvulifer ambloplitis, and Cfinosfomum marginatum; Monogenea: Dactylogyrus extensus, Cleidodiseus price/, Uroeleidus dispar, U. ferox, U. furcatus, U. principalis, and Actinoeleidus fusiformis; Cestoda: Corallobothrium fimbriatum, C. giganteum, Proteo- cepha/us ambloplitis, Proteocephalus sp., and Bothriocephafus c/av/ceps; Nematoda: Contracaecum sp. and Custrongylides sp.; Acanthocephala: Southwellina hispida; and Hirudinea: Myzobdella moorei. Of these twenty parasites, four are new records for California. This survey will provide some baseline data for fisheries management in San Diego County and southern California. INTRODUCTION Only two extensive freshwater fish parasite surveys have been con- ducted in California. Haderlie (1953) sampled 2,010 fishes representing 36 species in northern California. Edwards and Nahhas (1968) exam- ined 236 fishes representing 26 species in the Sacramento-San Joaquin Delta. Studies of monogenetic trematodes from freshwater fishes, pri- marily in central California, have been made by Mizelle 1962 ; Mizelle and Crane 1964; Mizelle and Price 1964; Price and Mizelle 1964; Mi- zelle and Kritsky 1967a, 1967b; Crane and Mizelle 1968; Kritsky and Mizelle 1968; and Mizelle and McDougal 1970. In southern California, studies have dealt primarily with the incidence of Posthodiplostomum minimum metacercariae (Colley and Olson 1963; R. L. Miller 1967). Our study was initiated to determine the incidence and intensity of parasitic metazoans in fishes from reservoirs in San Diego County, Cali- fornia, and relate this to fisheries management policies concerning stock- ing and movement of fish. These reservoirs are primarily used for water storage, although fishing is an important use. The reservoirs were selected for study based on their geographical distribution (Figure 1), 1 Accepted for publication January. 1973. This study was partly financed by Fish and Game fine money provided by the San Diego County Fish and Game Commission. 2 Present address: Dep. of Zoology, Oregon State University, Corvallis, Oregon 97331. (196) FISH PARASITES 197 water source, and convenience of sampling. Barrett, Lake Henshaw, Loveland, Sutherland and Upper Otay reservoirs are completely de- pendent upon winter runoff, whereas El Capitan, Hodges, Lower Otay, Miramar, San Vicente, Sweetwater, Wohlford, and Mathews all have aqueduct connections for receiving imported Colorado River water. '•JH.ower Otay Reservoir MEXICO FIGURE 1. Map of the study area showing the reservoirs sampled for fish parasites. Lake Mathews in Riverside County is the distribution point for Colo- rado River water coming to San Diego County, hence our survey of 198 CALIFORNIA FISH AND GAME that water to determine its parasite fauna in relation to the San Diego reservoirs. SAMPLING AND EXAMINATION OF FISH Collections of 480 fishes were made from April to September 1966 in 13 southern California reservoirs (Figure 1). Two collections involving parasites not found during the survey are included in the list of para- sites and hosts. The fish represented 13 species from 7 genera and 4 families. Fish were collected by seines, gill nets, electrofishing, angling, and 5% emulsified rotenone. Our goal was to sample 10 fish of each spe- cies present in each reservoir. However, sampling difficulties precluded attaining that goal. All fish were examined within 3 days of collection. They were kept alive or placed on ice until necropsy; standard procedures were used to examine for external and internal parasites. The heart, pericardium, liver, spleen, kidneys, and gonads were removed and each was squeezed between gridded glass plates in order to make counts of the parasites present. The gills were removed and in some cases examined imme- diately for monogenetic trematodes, while in other cases they were frozen before examination. Counts of the monogenes are not quantita- tive because of the difficulty of thoroughly examining all the gill mate- rial, and because their microscopic size made them difficult to recover. As a result, incomplete collections were made and all monogenes from a fish species were preserved together rather than from individual fish. Trematodes, cestodes, and acanthocephalans were relaxed in tapwater, then fixed in AFA (alcohol-formalin-acetic acid) or 5% formalin. Leeches were relaxed in tap water with menthol crystals added, then fixed in AFA or 5% formalin. Nematodes were killed in hot alcohol and stored in an alcohol-glycerine mixture. Trematodes and cestodes were stained in Mayer's carmalum or Harris' haematoxylin and mounted in Permount, or mounted directly in Turtox CMC-10 or CMCS. CHECK LISTS OF PARASITES AND FISHES The results are arranged in two check lists. The first is a list of each parasite found in the survey, followed by a list of hosts. The fraction after the host species indicates the number of fish infected and the number of fish examined (incidence). The reservoirs from which the hosts were collected are listed, followed by the incidence of infection, the mean number of parasites per infected host (X), and the range in intensity of infection (R), if applicable, plus the locations from which the parasites were recovered. Two tables presenting the data on bluegill and largemouth bass are included within this list. The second check list presents the parasites under the host species. The fish are arranged in phylogenetic order following Bailey (1970) and the parasites are listed in their taxonomic categories following each fish species. The numbers in parentheses following the host species indi- cate the incidence of infection, while the number after each parasite indicates the number of fish in which the parasite was found. Except for Cleidodiscns pricei, no quantitative data are presented for Monogenea; i.e. incidence, mean number of parasites, or range of in- tensity of infection. In both lists larval forms are indicated by an asterisk (*) and new California records are indicated by the sym- bol (f). FISH PARASITES 199 List 1. PARASITES WITH HOSTS DIGENEA *Hysteromorpha triloba (Rud. 1819) Lutz 1931 Host: Ictalurus nebulosus (LeSueur) (3/3) : Lower Otay (3/3). Site : Muscles. These metacercariae were not recovered in the 1966 collections but Olson col- lected them on December 3, 1957, from Lower Otay. The infections were very conspicuous, making the muscles appear granular and caused fishermen to stop fishing for bullheads at that time. *Posthodiplostomum minimum (McCallum 1921) Dubois 1936 Hosts: Lepomis cyanellus Rafinesque (8/12) : Barrett (2/2) 35 (1-70) ; San Vicente (5/5) 20 (3-41) ; Sutherland (0/1) ; Sweetwater (0/1) ; Wohlford (0/1) ; Mathews (1/2). Lepomis macrochirus Rafinesque (111/125) : — see Table 1. Micropterus salmoides (Lacepede) (180/185) : — see Table 2. Pomoxis annularis Rafinesque (16/42) : Barrett (0/11) ; Hodges (3/15) 2 (1-3) ; Lower Otay (10/10) 122 (48-233) ; Sweetwater (3/6) 9 (1-24). Site : Liver, heart, spleen, kidneys, mesentery. The metacercarie of P. minimum were the most abundant of the parasites en- countered in the survey, infecting 97.3% of the bass, 88.8% of the bluegill, and 38.1% of the white crappie. All reservoirs in the survey had fish infected with P. minimum. Intensity of infections was highly variable between different species within the same water and between different waters with the same host. For example, in Lake Henshaw the mean number of metacercariae per largemouth bass was 814, with a range of 78 to 2,245, whereas 11 black crappie examined were completely free of P. minimum. In Barrett Reservoir 10 bass averaged 1,931 metacercariae each, with a range of 61 to 5,730, whereas 12 bass examined from San Vicente averaged only 23 per host, with a range of 5 to 154. Similar varia- tions were observed with bluegill (Table 1). t*Uvulifer ambloplitis (Hughes 1927) Dubois 1938 Host: Lepomis cyanellus Rafinesque (5/6) : Los Penasquitos Creek (5/6) : 40 (7-102). Site : Skin and muscles. These metacercariae were recovered from Los Penasquitos Creek, San Diego County, on March 16, 1969. The belted kingfisher, Megaceryle alcyon (Linnaeus), is the definitive host of this parasite (Olsen 1962). This sample, while not taken from a reservoir, is included here as a new record for California. *Clinostomum marginatum (Rud. 1819) Leidy 1856 Hosts: Dorosoma petenense (Gunther) (15/26) : El Capitan (9/10) 15 (8-26) ; Hodges (0/10) ; Lower Otay (6/6) 2 (1-3). Ictalurus catus (Linnaeus) (1/8): Lower Otay (1/5) 1; Sweetwater (0/3). Ictalurus melas (Rafinesque) (5/10): Lower Otay (5/10) 3 (1-7). Lepomis cyanellus Rafinesque (1/12): Barrett (1/2) 2; Mathews (0/2) ; San Vicente (0/5) ; Sutherland (0/1) ; Sweetwater (0/1) ; Wohlford (0/1). Lepomis macrochirus Rafinesque (30/125) : — see Table 1. Micropterus salmoides (Lacepede) (56/185) : — see Table 2. Site : Skin, muscles, coelom, mesentery, orbit of eye. This species was found in all of the reservoirs except Miramar and Sweetwater. The first occurrence in Dorosoma petenense was previously reported by L. W. Miller (1967). 200 CALIFORNIA FISH AND GAME MONOGENEA The following monogenes were all found on the gills : Dactylogyrus ejctensus Mueller and Van Cleave 1932 Host: Cyprinus carpio Linnaeus (5/9) : Hodges (0/1); Mathews (5/5); Sweetwater (0/3). Cleidodiscus pricei Mueller 1936 Hosts: Ictalurus catus Linnaeus (5/8) : Lower Otay (5/5) ; Sweetwater (0/3). Ictalurus mclas (Rafinesque) (5/10) : Lower Otay (5/10). Ictalurus natalis (LeSueur) (4/4) : El Capitan (3/3) ; Wohlford (1/1). Ictalurus ncbulosus (LeSueur) (2/5) : Barrett (0/2) ; El Capitan (1/2) ; Henshaw (1/1). Ictalurus punctatus (Rafinesque) (11/31) : El Capitan (11/11) ; Hodges (0/10); Mathews (0/5); Sweetwater (0/5). Vrocleidus dispar (Mueller 1936) Mizelle and Hughes 1938 Hosts: Lepomis macrochirus Rafinesque: Sutherland. Micropterus salmoides Lacepede : San Vicente. Vrocleidus ferox Mueller 1934 Host: Lepomis macrochirus Rafinesque: Sutherland. Vrocleidus furcatus (Mueller 1937) Mizelle and Hughes 1938 Hosts: Lepomis cyanellus Rafinesque: San Vicente. Lepomis macrochirus Rafinesque: Sutherland. Micropterus salmoides Lacepede : El Capitan. Vrocleidus principalis (Mizelle 1946) Mizelle and Hughes 1938 Host : Micropterus salmoides Lacepede : El Capitan ; Henshaw ; San Vicente. Actinocleidus fusiformis (Mueller 1934) Mueller 1937 Host: Micropterus salmoides Lacepede: El Capitan. CESTODA Corallobothrium giganteum Essex 1927 Host: Ictalurus punctatus (Rafinesque) (26/31): El Capitan (11/11); Hodges (10/10) ; Mathews (5/5) ; Sweetwater (0/5). Site : Intestine. Specimens measured from 4 mm to at least 39 mm in length and represented developmental stages from immature to gravid. During the examination these small worms were assumed to be growing forms of C. giganteum, with which they were associated. As a result, counts of each species were not made and many of the worms were not saved. It was noted that C. fimbriatum dominated the counts. The combined count of C. fimbriatum and C. giganteum in the El Capitan collection showed a range of 4 to 21 and a mean of 11 worms per fish while the Mathews range was 4 to 38 with a mean of 18. Corallobothrium giganteum Essex 1927 Host: Ictalurus punctatus (Rafinesque) (16/31): El Capitan (11/11); Hodges (0/10); Mathews (5/5); Sweetwater (0/5). Site : Intestine. The longest worm was 205 mm ; all worms had gravid proglottids. Proteocephalus ambloplitis (Leidy 18S7) Hosts: Micropterus salmoides (Lacepede) (14/185) : see Table 2. Site : Intestine. *Proteocephalus sp. Hosts: Lepomis cyanellus Rafinesque (6/12): Barrett (0/2); San Vicente (3/5) 20; Wohlford (1/1) 7; Mathews (2/2) 32 (14-50); Sweet- water (0/1); Sutherland (0/1). Lepomis macrochirus Rafinesque (11/125) : see Table 1. FISH PARASITES 201 Micropterus salmoides (Lacepede) (68/185) : see Table 2. Pomoxis annularis Rafinesque (1/42) : Barrett (0/11) ; Hodges (1/15) 10; Lower Otay (0/10); Sweetwater (0/6). Site : Liver, spleen, kindeys, gonads, mesentery, coelom. fBothriocephalus claviceps (Goeze 1782) Rud. 1810 Hosts: Lepomis cyanellus Rafinesque (2/12): Barrett (1/2) 2; San Vicente (1/5) 1; Sweetwater (O/l); Sutherland (0/1); Wohlford (0/1); Mathews (0/2). Lepomis macrochirus Rafinesque (16/125) : see Table 1. Site : Pyloric caeca and intestine. Our specimens most closely resemble the description given by Cooper (1918) and comparison specimens of B. claviceps loaned by J. T. Self. The other record of this genus in California is by Edwards and Nahhas (1968), who reported four imma- ture Bothriocephahis sp. in Lepomis cyanellus. NEMATODA *Contracaecum sp. Hosts: Lepomis macrochirus Rafinesque (6/125) : see Table 1. Micropterus salmoides (Lacepede) (32/185) : see Table 2. Pomoxis annularis Rafinesque (1/42) : Barrett (0/11) ; Hodges (0/15) ; Lower Otay (1/10) 1; Sweetwater (0/6). Pomoxis nigromaculatus (LeSueur) (8/14) : El Capitan (0/1) ; Hen- shaw (8/11) 4; Sweetwater (0/2). Site : Encysted in the mesenteries and pericardial cavity. Our specimens match the illustrations of Haderlie (1953), who identified them as Contracaecum spiculigerum (Rud. 1809). We have not placed these larval forms to species even though cormorants, the definitive hosts of C. spiculigerum, are often observed at the reservoirs. Eustrongylides sp. Host: Lepomis macrochirus Rafinesque (1/125) : see Table 1. Site : Muscles. ACANTHOCEPHALA fSouthwellina hispida (Van Cleave 1925) Witenburg 1932 Host: Micropterus salmoides (Lacepede) (5/185) : see Table 2 Site : Mesentery near intestine. According to Gerald D. Schmidt (pers. comm.) Arhythmorhynchus duocintus is a junior synonym of S. hispida. This is the first California record of this worm and apparently the first record of this juvenile in a freshwater fish in North America. Adults were collected from a black-crowned night heron, Nycticorax nycticorax, in the New York Zoological Park (Lincicome 1943). HIRUDINEA ^Myzobdella moorei (Meyer 1940) Meyer 1946 (Illinobdella m.) Hosts: Ictalurus punctatus (Rafinesque) (12/31): El Capitan (0/11); Hodges (10/10) 3; Mathews (2/5) 2; Sweetwater (0/5). Lepomis cyanellus Rafinesque (2/12) : Barrett (0/2) ; San Vicente (2/5) 3; Sutherland (0/1); Sweetwater (0/1); Wohlford (0/1); Mathews (0/2). Lepomis macrochirus Rafinesque (21/125) : see Table 1. Micropterus salmoides Lacepede (25/185) : see Table 2. Notemigonis crysoleucas (Mitchill) (4/9) : Lower Otay (4/5) 2; Suther- land (0/4). Pomoxis annularis Rafinesque (4/42) : Barrett (0/11) ; Hodges (0/15) ; Lower Otay (0/10) ; Sweetwater (4/6). Pomoxis nigromaculatus (LeSueur) (6/14) : Barrett (0/1) ; Henshaw (5/11) 3; Sweetwater (1/2) 8. Site : Skin and mouth. 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