BLOOD TYPES IN PACIFIC SALMON 



by 



George J. Ridgway and George W. Klontz 



U. S. Fish and Wildlife Service 



Seattle, Washington 



ABSTRACT 



Intraspecific differences in erythrocyte antigens (blood types) were shown to occur in four species 

 of Pacific salmon, the sockeye or red salmon ( Oncorhynchus nerka ). the chinook or king salmon (O. 

 tshawvtscha) . the chum salmon (O. keta) , and the pink salmon (O. qorbuscha ) ■ Antisalmon-erythiocyte 

 sera prepared in rabbits and chickens were used after absorption of species-specific antibodies. Some 

 of these blood types were shown to differ in their frequency of occurrence between different geographic 

 races. In addition, isoimmunizations were conducted on one race of sockeye salmon. Antisera of 

 seven different specificities were prepared and at least eight different patterns of antigenic composition 

 were displayed by the cells tested. 



These results indicate that considerable antigenic diversity exists in salmon. Reagents to detect 

 valuable markers for the investigation of geographic races of salmon should be obtained through further 

 research. 



INTRODUCTION 



One of the most importcint problems in 

 fishery biology is recognition of "races", 

 or reproductively isolated subpopulations , 

 of fishes. Since there may be little or no 

 interbreeding or recruitment between such 

 populations, successful regulation or 

 management of fishery resources must be con- 

 ducted in such a way as to recognize their 

 independence. 



Present methods for distinguishing 

 between the races of a particular species 

 of fish are based on tagging by various 

 means, or by seeirching for morphometric or 

 meristic differences between the races 

 (Rounsefell and Everhart 1953). 



It has been shown with many animals 

 (Mayr 1942, Dobzhansky 1951), including 

 fishes (Gordon 1947), that reproductively 

 isolated subpopulations of species differ 

 in the frequencies of one or more varieible 

 genes. Therefore, a very useful adjunct to 

 the methods of racial identification, now 

 used in fishery management and research, 



would be the recognition and definition of 

 genetically controlled polymorphic charac- 

 ters. One class of such characters which 

 has been found in every animal adequately 

 investigated is intraspecific antigenic 

 variations in the red blood cells. These 

 characters are more simply known as blood 

 types. 



Lcumdsteiner (1900) was the first to 

 demonstrate the occurrence of blood types. 

 He found them in man with natural isoagglu- 

 tinins. In the same year Erlich and Mor- 

 ganroth (1900) demonstrated blood types in 

 goats using immune isohemolysins induced 

 by transfusions. Subsequently, many addi- 

 tional instances of intraspecific antigenic 

 differences have been demonstrated. The 

 results are most notable in the case of man 

 (Race and Sanger 1954), cattle (Stormont 

 et al. 1951) and chickens (Briles et al. 

 1950). 



In each of these species, blood types 

 have been used to study reproductively 

 isolated populations. Thus, blood type 

 frequencies have been used to characterize 



