Abstract
The early life history of the land-locked miyabe char, Salvelinus malma mlyabei OSHIMA, was investigated in an inlet stream of Lake Shikaribetsu in central Hokkaido from 1971 to 1974. The ontogenetic process of this species was divided into seven developmental stages according to the ETAP theory of Vasnetzov. A relatively high proportion of drifting terrestrial insects was found in the food of all developmental stages except the alevin in every season of the year. Two developmental stages were found among juvenile fish which migrated into the lake. One stage consisted of smolt and/or presmolt-like fish which were 2 years or more old and varied from 105 to 155 mm in fork length. Migration occurred in June and July. Another stage consisted of relatively younger fish of different age and size classes. They migrated into the lake from July to Novemeber with a peak in October. It was suggested that these fishes were using the lake as a wintering area, since, of all the available water sources, it maintains the highest water temperature during the winter season.
