びわ湖におけるハスの成長に関する研究 : II. 成長過程にみられる成長の個体変異と補償作用について

概要

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Analyses was made of the variation of the individual growth and growth compensation observed in the "hasu" in Lake Biwa, on the materials principally collected from the spawners during the six years from 1963 to 1968. The age and body length at each age were estimated by the annual rings on the scale. The variation in individual growth of the first year of life was relatively small. The differences of hatching period, increase of variation of body length immediately after hatching, the variation with beginning of feeding, and the differences in feeding condition, were considered as the factors of this variation. The variances of body length at 1+ tended to decrease in the warm season and to increase in the cold season. This increased value was much the same as the variance at age II. The growth compensation was observed in the growth of the third year of life (between ages II and III). In previous studies made by many workers, this phenomenon was considered to be produced either by 1) the characteristic of the growth curve itself or 2) the difference in the time when fish reach the first maturity which depresses the growth. These two mechanisms are discussed in relation to the growth compensation observed in the "hasu."
日本生態学会の論文
1970-04-01