北海道根釧地域におけるトミヨ属魚類の分布と形態

概要

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The author collected 440 specimens of Pungitius tymensis, 26 of P. pungitius and 17 of P. sinensis in Kushiro and Nemuro Districts, eastern Hokkaido. P. tymensis so far reported had been only from the rivers flowing into the Japan Sea, except for a single male from the Tokachi River flowing into the Pacific Ocean. This is the first report for an abundant occurrence of P. tymensis in the above-mentioned districts. In the Bekanbeushi River and the Kushiro River, both flowing into the Pacific Ocean, P. pungitius is common, cohabiting with P. tymensis in the catchment-area of the former river. In the rivers flowing into the Sea of Okhotsk, however, P. sinensis is not rare, while no P. pungitius has been found so far. In these rivers, habitat segregation appeared to exist between P. sinensis and P. tymensis, the latter living upstream. Concerning variations in the number of dorsal spines and of scutes, the following sequences were observed. In P. tymensis: Kushiro and Nemuro Districts > Sapporo area. In P. pungitius:Southern Kuriles > Kushiro and Nemuro Districts > Sapporo area. No geographical variation was apparent in P.sinensis.
社団法人日本動物学会の論文
1967-08-15