Salvelinus miyabei Oshima is a small salmonid fish attaining about 25 cm in total length and is restricted only in Lake Shikaribetsu in central Hokkaido. Some 30 individuals of this fish were caught in Yanbetsu River which flows into this lake and artificial insemination was carried out on October 30, 1959. These specimens quite resemble the fluvial dwarf form of Dolly Varden, S. malma (Walbaum), in general characters, however, S. miyabei have somewhat more gill rakers and more developed ‘kype’ than those of non-migratory S. malma. The eggs of S. miyabei were measured 5.1～5.6 mm in diameter. Hatching took place about 80 days or more at the water temperature of 6.5～3.6℃. The newly hatched alevins preserving 70% alcohol were 15.0～16.3 mm in total length. About 50 days after hatching the alevins attained to the length of 19.4～20.8 mm. Two-thirds of yolk substances were consumed and parr marks were clearly visible on the body sides. Just emerged fry attained 21.8 mm. It took 3 months for the alevins to absorb yolk sac completely at the water temperature of 3.6～7.1℃. It was difficult to distinguish the present alevins and frys from those of migratory S. malma reported by Blackett (1968).
Mendeley出力
