SEROLOGICAL STUDIES OF ATLANTIC REDFISH 



By Carl J. Sindermann, Fishery Research Biolojiist 

 Bureau of Commercial Fisheries 



Knowledge of tlie population struetnre of com- 

 mercial mai'ine fish species is important as a 

 basis for management. Trad itionally, information 

 about intraspecies groups has been derived from 

 morphometric and meristic studies, tagging, or 

 age and grow-th studies. Valuable data have been 

 obtained through the use of sucli methods, and it 

 seems reasonable that the greater the number of 

 criteria used, the more accurate will be the con- 

 clusions. For tliis reason, and because of the 

 ultimate need for genetic information about intra- 

 species groups, attention has been directed re- 

 centl}' toward serological methods of population 

 analysis, and particularly toward blood-group re- 

 search. Serological studies of marme fishes 

 (Gushing, 1952, 1956; Ridgway, 1957; Eidgway, 

 Cu.shing. and Durall, 1958; Suzuki, Shimizu, and 

 Morio, 1958: Sindermann and Mairs, 1959; Ridg- 

 way and Klontz, 1960) have demonstrated indi- 

 vidual ditferences in red-blood-cell antigens, and, 

 in some studies quantitative differences m the 

 frequency of occurence of antigens in different 

 populations. Knowledge of such differences 

 should pro\e as useful in fishery investigations 

 concerned with population or racial problems as 

 that of the racial distribution of human blood 

 groups has to anthropological studies. 



Before quantitative studies are possible, how- 

 ever, the often slow but always essential develop- 

 ment of blood-group systems and standardization 

 of reagents for their demonstration must be car- 

 ried out. This paper is concerned with the recog- 



XoTE. — This paper was prosPiited as part of the United States 

 contribution to an international redfish symposium at Copen- 

 haeen. Denmark, in October 19.59, sponsored jointl.v by the Inter- 

 national Council for the Exploration of the Sea and the Inter- 

 national Commission for the Northwest Atlantic Fisheries. An 

 abstract appears in vol. 150. Rapports et ProcSs-Verbeaux. Cons 

 Int. Expl. Mer, 1961. 



The author acknowledfres the assistance of Donald Malrs and 

 Alva I''arrln, Boothbay Harbor, Maine, and Georpe Kelly, Woods 

 Hole. Massachusetts. 



.\pproved for publication. December 13, 19(>0. Fishery 

 bulletin 191. 



nifion and description of blood-group antigens in 

 redfish, Sebastes mai'inu.s (L.), which in recent 

 years has become a commercially \aluable species 

 in the western Xorth Atlantic. Attention has 

 lieeu directetl to this fish because of confusion 

 about certain iiH>i|)hologically recognizable groups 

 which arc possibly of subspecies stature, and be- 

 cause of a lack of knowledge concerning the popu- 

 lation structure within these groups. Such 

 problems should be amenable to serological in- 

 vestigation; the blood group antigens described 

 here represent a first, tentative, but necessary step 

 in this process. 



METHODS 



Samples of redfish blood were obtained from 

 Eastport, Maine, and Georges Bank in the south- 

 em Gulf of Maine. Blood was taken directly 

 from the heart; cells for testing were washed 

 from clots with a 1.4 percent saline solution and 

 were used in ajDproximately 4 percent suspensions. 

 Antisera were prepared in rabbits and chickens 

 by injections of individual and pooled samples 

 of washed redfish blood cells diluted 1 : 1 witli 

 saline. Usually, a single, short injection series 

 was used to develop as specific antisera as possible. 

 Six injections of 1 milliliter each were given on 

 alternate day.s. Rabbits were trial bled 10 days 

 after the last injection, and, if the antiserum (iter 

 l)roved satisfactory, food was withheld and tlic 

 animals were bled terminally on the following 

 day. Rabbit antisera wei'e also prepai'ed by in- 

 jecting red cells of cod, herring, alewife. lainpii'v. 

 and sheep. 



Cell agglutination tests were made at room tem- 

 perature within 72 hours from the time the fish 

 blood was taken, although reactions of refriger- 

 ated cells did not change noticeably up to 7 days. 

 Tube agglutination tests used 0.'2 ml. antiserum 

 dilution and 0.05 ml. cell suspension. Readings 

 were taken after 15 luinutos incubation at room 



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