Materials and Methods 



From 10 October to 12 November 1972, 

 hybridization experiments were carried out 

 between 1-yr-old male cherry salmon parr from 

 anadromous stock and female rainbow trout, Sal- 

 mo gairdneri; pink salmon, 0. gorbuscha; chum 

 salmon, 0. keta; coho salmon, 0. kisutch; sockeye 

 salmon, 0. nerka; and chinook salmon, 0. 

 tshawytscha. Our cherry salmon were reared at the 

 Washington State Department of Fisheries' 

 Minter Creek Hatchery from eyed eggs sent in 

 1971 by the Hokkaido Salmon Hatchery, Sapporo, 

 Japan. Incubation facilities were located at the 

 Northwest Fisheries Center, National Marine 

 Fisheries Service, Seattle, Wash. The standard dry 

 fertilization technique was used in conjunction 

 with delayed fertilization techniques described by 

 Poon and Johnson (1970). All fertilization took 

 place within 3 h of collection, with the exception of 

 pink salmon eggs (14 h). There were no apparent 

 effects from delayed fertilization. Numbers of 

 eggs incubated ranged from 1,700 to 8,400; sur- 

 vival was based on the total eggs in each lot. 



Discussion 



Oshima (1957) reported that cherry salmon have 

 successfully hybridized with redspot salmon, 0. 

 rhodurus, for many years. Other than hybrids of 

 cherry salmon with redspot or Asian pink salmon, 

 hybrids of cherry salmon with other salmon and 

 trout are rare or unreported (Schwartz 1972; 

 Dangel et al. 1973). Results of our own 

 experiments, as shown in Table 1, show that 

 crosses of cherry salmon with chum, chinook, and 



pink salmon and with rainbow trout were highly 

 successful, each yielding higher hatching percen- 

 tages than their respective controls. The reason 

 for this phenomenon is not presently understood 

 but it does indicate an area for further research. 

 Only crosses of coho and sockeye salmon with 

 cherry salmon showed poorer survival than their 

 controls (Table 1). It is interesting to note that 

 though there was no hatch of the cherry x sockeye 

 cross, virtually all of the eggs were fertilized and 

 developed to notochord formation. Each of the 

 successful hybrid crosses yielded surviving fry to a 

 1 g or larger size accounting for over 85% of the 

 hatch, except for the rainbow and coho crosses 

 where survival to this size was less than 10%. 



Literature Cited 



Dangel, J. R., P. T. Macy, and F. C. Withler. 



1973. Annotated bibliography of interspecific hybridization 

 of fishes of the subfamily Salmoninae. U.S. Dep. 

 Commer., NOAA Tech. Memo. NMFS NWFC-1, 48 p. 

 Oshima, M. 



1957. Studies on the dimorphic salmons, Oncorhynchus 

 masou (Brevoort) and Oncorhynchus rhodurus Jordan & 

 McGregor, found in Japan and adjacent territories. Nire 

 Shobo (Nire Book Company), Sapporo, Japan, 81 p. 

 (Translated from Jap., 1972, Fish. Res. Board Can., 

 Transl. Ser. 2104.) 

 Poon, D. C, and A. K. Johnson. 



1970. The effect of delayed fertilization on transported 

 salmon eggs. Prog. Fish-Cult. 32:81-84. 

 Sano, S., and H. Eguchi. 



1936. Interspecific hybridization among salmonid 

 fishes. Hokkaido Sakemasu Fukajo (Hokkaido Salmon- 

 Trout Hatchery), 13 p. (Translated from Jap., 1968, Fish. 

 Res. Board Can., Transl. Ser. 1164.) 

 Schwartz, F. J. 



1972. World literature to fish hybrids with an analysis by 

 family, species, and hybrid. Publ. Gulf Coast Res. Lab. 

 Mus. 3, 328 p. 



Table l.-Hatching success of eggs of hybrid crosses and controls. 



Species' 



Number of 



degree-days 



incubated 



Salmo gairdneri X O. masou 

 Salmo gairdneri (control) 

 Oncorhynchus gorbuscha X O. masou 

 Oncorhynchus gorbuscha (control) 

 Oncorhynchus keta X O. masou 



Oncorhynchus keta (control) 

 Oncorhynchus kisutch X O. masou 

 Oncorhynchus kisutch (control) 

 Oncorhynchus nerka X O. masou 



Oncorhynchus nerka (control) 

 Oncorhynchus tshawytscha X O. masou 

 Oncorhynchus tshawytscha (control) 



'Female listed first and male last. 



396 

 321 

 512 

 593 

 436 



504 

 300 

 333 

 660 



642 

 426 

 486 



Percentage 

 hatched 



Previously 



reported 



results 



Reference 



39.5 

 34.7 

 71.6 

 62.5 

 94.1 



90.9 



26.5 



90.9 



0.0 



96.0 

 97.4 

 72.9 



85% hatch Suzuki and Fukuda 1971a, b 

 37-46% hatch Smirnov 1969 



77% hatch 

 0-96% hatch 

 0-69% hatch 



None 



0% hatch 

 0-3.3% hatch 



None 



Sano and Eguchi 1936 



Smirnov 1969 



Terao and Hayashinaka 1961 



Suzuki and Fukuda 1971a, b 

 Terao and Hayashinaka 1961 



448 



