races of men (Boyd 1950, Mouremt 1954), 

 breeds of cattle (Owen et al. 1947) and 

 inbred lines of chickens (Schultz and 

 Briles 1953). 



The studies of Fujino (1958) demon- 

 strating the occurrence of blood types in 

 whales are of particular interest to marine 

 biologists. 



Until recently there have been rela- 

 tively few published studies concerning the 

 possible existence of blood types in fishes. 

 Some of these demonstrated marked interspe- 

 cific differences in cellular antigens but 

 provided little or no evidence for intra- 

 specific heterogeneity of such antigens. 

 Noguchi (1903a, b) found that the serum of 

 several species of fishes would agglutinate 

 the red blood cells of other species but 

 no intraspecif ic differences were noted. 

 He did produce isoagglutinins and isohemoly- 

 sins in two species of turtle, Chrysemys 

 picta and Chelopus guttatus , demonstrating 

 that cold blooded vertebrates may possess 

 intraspecif ic antigenic differences, Toth 

 (1932) found no evidence for the existence 

 of blood types in carp from 280 cross- 

 matches. Jensen (1937) tested for natural 

 isoagglutinins in the cod ( Gadus morrhua ) 

 and also attempted to demonstrate individual 

 differences with the serum of a single 

 rabbit immunized with the red cells of an 

 individual cod. He did not find any conclu- 

 sive evidence for the existence of blood 

 groups in cod. 



Suyehiro (1949) reviewed the previous 

 Japanese literature in which there were 

 no instances of the demonstration of blood 

 types in fishes. He was evidently the 

 first to demonstrate individual antigenic 

 differences in fish blood cells since he 

 found a few instances of natural isoagglu- 

 tinins in the eel ( Anguilla japonic a ) and 

 the gilthead ( Sparus swinhonus Gimther). 

 In 249 crossmatches of blood cells and 

 serum from cod ( Gadus macrocephalus ) he 

 found no evidence for natural isoaggluti- 

 nins. Suyehiro also tested blood samples 

 from 336 fishes of 30 different species 

 with human ABO blood typing sera and found 

 that only 91 were agglutinated. In 21 of 

 the 30 species, individuals varied in their 

 reactivity to the human sera tested. 



Gushing and Sprsigue (1953) studied 

 the agglutinative activity of human anti-A 

 and anti-B sera and rabbit antisheep cell 



serum for the erythrocytes of a number of 

 species of fish. Considerable £intigenic 

 diversity was noted between species but no 

 individual differences were found within 

 the members of the species tested. 



Recent reports have indicated a major 

 breakthrough in the efforts to discover 

 blood types in fishes. Hildemann (1956) 

 applied the method of isoimmunization, 

 which has been so successful in detecting 

 blood types in other animals, to goldfish 

 ( Carassius auratus ) , One of the isoimmune 

 sera detected six different antigenic types 

 of goldfish. Immune rabbit sera were also 

 prepared by Hildemann, one of which de- 

 tected a single antigenic difference after 

 careful absorption. Gushing (1956) re- 

 ported the existence of individual anti- 

 genic differences in the oceanic skipjack 

 ( Katsuwonus pel amis Linnaeus) detectable 

 with natural isoagglutinins, normal bovine 

 serum, and the sera of rabbits immunized 

 with the whole blood of oceanic skipjack, 

 albacore (Germo alalunga Gemlin), or 

 Pacific mackerel ( Pneumatophorus japonicus 

 diego Ayres), Gushing and Durall (1957) 

 discovered and analyzed a natural isoagglu- 

 tinin system in the brown bullhead (Icta- 

 lurus n, nebulosus Le Sueur). This system 

 was found to be analogous to the human ABO 

 system in that four antigenic types were 

 found (i.e., some fish possessed antigen 1, 

 some antigen 2, some both antigens, and 

 some had neither), and when an antigen was 

 lacking, its corresponding isoagglut inin 

 was always present. Ridgway, Gushing, and 

 Durall (1958) found quantitative differ- 

 ences in the reactivity of the cells of 

 individual sockeye salmon ( Oncorhynchus 

 nerka Walbaum) with natural antibodies from 

 pig sera and demonstrated that there were 

 significant differences between geographi- 

 cally separated populations in the frequency 

 of the different types detected. 



Suzuki et al. (1958) have demonstrated 

 the existence of blood groups in species of 

 tunas amd have presented evidence which 

 suggests that differences exist between the 

 blood type frequencies of albacore from the 

 Pacific and Indian Oceeins. 



The present report provides further 

 evidence for the existence of blood types 

 in Pacific salmons and additional evidence 

 that some of these characters differ in 

 their frequency of occurrrence in different 

 races of the same species. 



