Table 6. — Demonstration of blood groups in pink salmon 



(Antiserum chicken E213 absorbed with red blood 

 cells from Cordova pink salmon #6) 



Sashin Creek 



Kodiak Cordova 



Sample number 

 Reaction 



12 3 4 5 6 7 



13 4 5 9 



+ + + + + 



have been conducted on sockeye salmon 

 (0. nerka ). The fish used in all of these 

 experiments were from the Columbia River 

 (where this species is known as the blue- 

 back salmon). In 1955 and 1956, 20 to 30 

 adult salmon migrating up the Columbia 

 River were captured and isoimmunized over 

 periods of one to two months without any 

 detectable development of isoimmune anti- 

 bodies. Since many of these fish died 

 before an adequate period for the produc- 

 tion of isoimmune antibodies had elapsed, 

 no conclusions about the antigenic het- 

 terogeneity of salmon could be drawn from 

 these experiments. 



In order to have fish available for 

 isoimmunization over a longer period, a 

 group of sockeye yearlings were obtained 

 from the Winthrop Hatchery of the U. S. 

 Fish and Wildlife Service in 1956 and 

 reared in salt water at the Deception Pass 

 Marine Research Station of the State of 

 Washington Department of Fisheries. Iso- 

 immunizations involving 100 fish, 50 pairs 

 being cross-immunized, were started in 

 August of 1957. During the period of this 

 experiment the water temperature ranged 

 from 14° C, to 9° C. with a mean of appro- 

 ximately 12* C. 



Of these 100 fish, 15 produced iso- 

 immune antibodies after periods of 7 to 14 

 weeks and 5 to 11 inoculations. Because 

 of the small size of these salmon, due to 

 their being reared in captivity, only small 

 amounts of the isoimmune sera could be 

 collected. In addition, the sera were of 

 low titer, most reacting only to 1 in 4 

 dilution. Sufficient amounts of serum were 

 obtained from seven of these fish to com- 

 pare the specificity of the reactions 

 against a number of individuals. 



The results of these tests are pre- 

 sented in table 7. Inspection of these 

 data reveals that all seven of the sera 

 possessed different patterns of specific- 



ity, and at least eight different 

 patterns of antigenic composition 

 were shown by the cells tested. Thus, 

 it would appear that the extent of 

 antigenic variability in salmon is of 

 the same order of magnitude as that 

 found in other animals which have 



^ been extensively studied. Further 



study and application of this hetero- 

 geneity will depend on the availabil- 

 ity of larger salmon, and experimental 



facilities for holding them. 



DISCUSSION 



The demonstration of blood group dif- 

 ferences in four species of Pacific salmon, 

 as outlined in this paper, along with the 

 demonstration that, in some cases, these 

 characters cEin serve as markers of racial 

 identity, indicates the existence of valu- 

 able tools for the solution of many of the 

 population problems encountered in the 

 mjuiagement and conservation of these impor- 

 tant fishes. However, more research and 

 developmental work must be done. One of 

 the biggest problems is in the production 

 of sufficient type-specific sera to test 

 large numbers of individuals from popula- 

 tions of interest. In all of the immune 

 sera we have produced in rabbits and 

 chickens, most of the antibodies reacted 

 with antigens possessed by all members of 

 the species or genus. The production of 

 type-specific sera in even small amounts 

 required large quantities of cells for 

 absorption. 



It is interesting to note that sev- 

 eral of the immune sera were capaible of 

 demonstrating blood group differences in a 

 species other than the one used for immuni- 

 zation, but could not be used to demonstrate 

 differences in the immunizing species. 

 This would appear to indicate that related 

 antigens are fixed in one species and 

 segregating in another. These observations 

 are somewhat analogous to antigenic rela- 

 tionships which have been demonstrated 

 between man and Rhesus monkeys (Landsteiner 

 and Weiner 1941), and recently between 

 cattle asid bison (Owen, Stormont and Irwin 

 1958), and between tahrs ( Hemitragus jam - 

 lahicus ) and a variety of other Artiodactyl 

 species (Stormont and Suzuki 1958). Fur- 

 ther extension of these observations in 

 fishes may result in the production of 

 type-specific sera in practical quantities. 



