Population structure of pink salmon (Oncorhynchus gorbuscha) in Hokkaido [Japan]: Geographic variation in catch fluctuations and morphometric characteristics for odd-year class
2008
Hoshino, N., Hokkaido. Fish Hatchery, Eniwa (Japan) | Fujiwara, M. | Kasugai, K. | Miyakoshi, Y. | Takeuchi, K.
We examined the geographic variation in catch fluctuations and morphometric characteristics for the odd-year class of pink salmon (Oncorhynchus gorbuscha) returning to Hokkaido. Factor analysis for the data on catch in the coastal area of Hokkaido detected 4 regional factors of fluctuation, i.e. Wakkanai-Sarufutsu, Oumu-Rausu, Shibetsu-Ochiishi, and Hamanaka-Kushiro. Significant differences were observed among 9 river samples for many morphometric lengths. These variations in morphometric lengths were mainly characterized for proportional variation of caudal peduncle by principal component analysis. Several meristic counters such as fin ray had significant differences among the 10 river samples, especially for females. In our present study, the environmental factors that cause the geographic variation in pink salmon have not been clarified. We need to understand the ratio of natural population to the hatchery-released population, morphometric variation in fry of both populations and so forth.
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