Our isoimmunization experiments 

 with sockeye salmon indicate con- 

 siderable antigenic diversity exists 

 in this species. Similar Eind more 

 extensive studies have been con- 

 ducted with rainbow trout and will 

 be presented in another paper. As 

 with other animals, isoimmunization 

 appears to be the most promising ap- 

 proach to the problem of blood group 

 differences in fishes. The species 

 of Pacific salmon are particularly 

 difficult animals on which to conduct 

 isoimmunizations as they invariably 

 die after becoming sexually mature 

 at two to six or seven years of age. 

 It is only shortly before their death 

 (two weeks to three or four months) 

 while they are on their spawning 

 migration that they become readily 

 available. They also grow quite 

 slowly in captivity and only one species, 

 the sockeye, can be readily held in fresh 

 water throughout its lifetime. At least 

 some of these difficulties can be overcome 

 and we hope to continue our attempts to do 

 so. 



ACKNOWLEDGMENTS 



The authors wish to express their 

 appreciation to Drs, R. S. Weiser, J. E. 

 Gushing and R. D. Owen for their valuable 

 advice and encouragement and to Mary La 

 Rocque and E. D. Ullman for excellent 

 technical assistance. 



Table 7. — Comparison of the specificities of isoimmune 

 sera produced in sockeye salmon. 



Serum 



Cells 



14-4 



14-6 



14-10 



15-1 



22-10 24-2 



+ Agglutination, No agglutination. 



Not tested. 



13-2 



problems involved in its practical 

 utilization are discussed. 



LITERATURE CITED 



BOYD, W. C. 



1950. Genetics and the races of man. 

 Little, Brown and Company, Boston. 



BRILES, W. E. , W. H. McGIBBON, AND 

 M. R. IRWIN 

 1950. On multiple alleles affecting 

 cellular antigens in chickens. 

 Genetics, vol. 35, No. 6, pp. 633- 

 652. 



SUMMARY 



1. Through the use of absorbed rabbit and 

 chicken antisalmon-erythrocyte sera, 

 blood types were demonstrated to occur 

 in sockeye, chinook, chum, and pink 

 salmon. 



2. Some of these types appear to differ in 

 their frequency of occurrence between 

 different geographic races. 



3. Isoimmunizations between individuals of 

 race of sockeye salmon indicated the 

 existence of at least eight different 

 antigenic types or combination of types 

 within this race. 



4. The usefulness of this kind of research 

 to fishery management and some of the 



BUKANTZ, S. C. , C. R. REIN, AND 

 J. F. KENT 

 1946. Studies in complement fixation. 

 II. Preservation of sheep's blood 

 in citrate dextrose mixtures (modi- 

 fied Alsever's solution) for use 

 in the complement fixation reaction. 

 Journal Laboratory Clinical Medi- 

 cine, vol. 31, No. 4, pp. 394-399. 



CUSHING, J. E. 



1956. Observations on the serology of 

 tuna. U. S. Fish and Wildlife 

 Service, Special Scientific Report — 

 Fisheries No. 183, 14 pp. 



CUSHING, J. E, AND G. L. DURALL 



1957. Isoagglutination in fish. Ameri- 

 can Naturalist, vol. 91, No. 857, 

 pp. 121-126. 



