三浦半島油壺におけるクサフグ, Fugu niphobles (Jordan et Snyder) の産卵についてII

概要

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The spawning season (SS) of the puffer at Arai Beach began in late May and continued until late July. Spawning occurred five times, following each full or new moon, with each spawning period (SP) lasting about 5 days. The interspawning period (ISP), the time between two successive SP, lasted for 8-11 days. We found that during the SP, puffers were strongly attracted to a lamp at night. As a whole, the testicular weight gradually decreased during the SS; however a peak testicular weight was always observed in each SP. Milt was artificially squeezed from more than 79% of all males caught during either the SP or ISP. Eggs were stripped from less than 30% of all females caught during the SP, and none were obtained during the ISP. The mean ovarian weights observed in each SP were not much different from each other. It appears that the same males release milt in every SP but that the females spawn only once in each SS. In spawning beds, the ratio of males to females is fourteen to one, but in burrowing places the ratio is one to three in favor of the females during the SS. This disparity in sex distribution appears to be related to the difference in the period of gonadal maturation between the sexes.
社団法人日本動物学会の論文
1978-03-25