354 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



teleosts as well as other vertebrate groups. Recent 

 iiiulings of Suzuki, Shiniizu, and Morio (1958). 

 Sindermami and Mairs (1959), and Eidgway and 

 Klontz (1960) suggest that geographic variation 

 in antigen frequencies can also be expected. If 

 this is generally true, sucli variations may prove 

 important tx) population or racial studies of 

 marine fishes. 



The A blood-group antigens of redfish de- 

 scribed in this paper represent a first phase in 

 serological characterization of this important 

 marine fish species. Future work should include 

 quantitative studies of the distribution of A-group 

 antigens in redfish from widely separated areas, 

 to see whether there is variability in their fre- 

 quencies. Furthermore, search should be contin- 

 ued for other blood-group antigens in the species, 

 since adequate serological characterization may 

 depend on several such criteria. Just as in hu- 

 mans it is possible to make major racial separa- 

 tions based on the ABO blood-group system alone, 

 so an initial redfish population analysis may be 

 based only on the A antigens. However, more 

 precise population subdivisions and indications 

 of past migrations of humans have emerged 

 from studies of several blood-group systems, and 

 more complete understanding of redfish popu- 

 lations could depend on identification, description, 

 and use of more than one system. The initial 

 serological step has been taken, with encouraging 

 results, but more information on a mucli liroader 

 scale is necessary. 



Use of the varied approaches available to serol- 

 ogy, including study of sermii and egg proteins 

 as well as eiythrocyte antigens comparable to 

 those described here, should provide further data 

 for fish systematic studies, both above and below 

 the species level. It should be emphasized how- 

 ever that no single approach to problems of sub- 

 species, races, or subpopulations can be a panacea. 

 Serology may constitute one of several criteria in 

 such analyses, along with traditional morphomet- 

 ric and meristic studies, but a final synthesis 

 should include data from diverse methods of in- 

 N-estigation. It does seem, though, that once tech- 

 niques have been sufficiently standardized, serol- 

 ogy will provide a powerful tool for biological 



studies of such commercially valuable species as 

 the redfish. 



CONCLUSIONS AND SUMMARY 



Individual differences in ei-ythrocyte antigens 

 have been found to exist in redfish. Det«ction 

 of such differences was possible with absorbed 

 rabbit anti-redfish and anti-cod serum. 



Based on results of antiserum absorptions, two 

 closely related antigens, Ai and Ao have been 

 identified. Reagents were prepared which spe- 

 cifically agglutinated cells possessing each antigen. 



Using the reagents prepared by absorptions of 

 antisera, it has been found in limited sampling 

 that redfish possessing the erythrocyte antigen Ai 

 make up more than 75 percent of the Eastport 

 (Maine) population. 



Quantitative studies of antigen frequencies in 

 samples from each major fishing area should pro- 

 vide information about the intraspecies structure 

 of redfish. 



LITERATURE CITED 



Gushing, John E. 



1952. Serological differentiation of fisli bloods. 

 Science, vol. 115, No. 2989, p. 40-I-i05. 



1956. Observations on the serology of tuna. U.S. 

 Fish and Wildlife Service, Special Scientific Re- 

 port — Fisheries No. 18.3, 14 p. 



RiDGWAY George J. 



1957. The use of immunological techniques in racial 

 studie.s. U.S. Fish and Wildlife Service, Special 

 Scientific Report— Fisheries No. 208, p. 39-43. 



RniGWAY, Geokge J., J. E. Gushing, and G. L. Dueali,. 



1958. The serological differentiation of populations 

 of sockeye salmon {Oncorhynclniii ticrka Wal- 

 baum). U.S. Fish and Wildlife Service, Special 

 Scientific Report— Fisheries No. 257, 9 p. 



RiDGWAY, George J., and George W. Klontz. 



1960. Blood types in Pacific salmon. U.S. Fish and 

 Wildlife Service, Special Scientific Report— Fish- 

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 SiNDERMANN, Garl J., and Donald F. Mairs. 



19.59. A major lilood group system in Atlantic sea 

 herring. Copeia, 1959, No. 3, p. 228-232. 

 Suzuki, Akimi, Yasuyuki Shimizu, and Tado Mobio. 

 19.58. Serological studies of the races of tuna. I. 

 The fundamental investigations and the blood 

 groups of albacore. Nankai Regional Fisheries Re- 

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