Relationships between reproductive characters and growth history in female masu salmon Oncorhynchus masou
2001
Shimoda, K. (Hokkaido. Fish Hatchery, Eniwa (Japan))
The relationships between the reproductive characters and growth history of pond-reared female masu salmon were studied by the method of individual tagging from smolt stage (age of 0**+, in April) to maturation (age of 1**+, in August and September). Number and size of mature eggs were associated with growth history. The maximal correlation coefficient between mature egg number and body weight appeared at April in the maturation year. Mature eggs number was strongly associated with growth in body weight during the period (11 months) of smolt stage to April in the maturation year. Mature eggs' size was strongly associated with specific growth rate from April to maturation in the maturation year. These results suggested that the mature eggs number seemed to be determined by body size in April in the maturation year, and the mature eggs' size was influenced by the growth rate after April in the maturation year. Mature body size was strongly associated with body size of the past. But mature body size was not associated with the specific growth rate of the past. Therefore, larger females produced a larger number of eggs, but the mature eggs' size was not correlated with the mature body size.
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