コイチNibea albifloraの成熟と産卵について〔英文〕

概要

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This report presents the results of a study of oogenesis, gonadial development and spawning in N. albiflora. The study is based on particular examinations of the ovaries and the eggs within the ovaries of the fish collected in the Seto Inland Sea. By histological study, the oogenesis of this species is fundamentally similar to that of other marine teleosts reported until now. Frequency distribution of the ova diameter of mature ovary has three modes: one is the evident mode of the ripe eggs group segregated, and the other two are the mode of maturing eggs group. Spawning occurs from late May to early August, and the height of the spawning season is in June and early July. It may be considered in all aspects that each fish spawns more than once during the spawning period. Since on females less than 198mm in standard length are found to be fully mature, the biological minimum size is about 20cm. The relationship between the fish size (Lcm) in standard length and the number of ovarian eggs (N) more than 0.2mm in diameter is indicated by the exponential equation: N=18.02 L3.216. Futhermore, the number of eggs (N') which is shed at a single spawning by each fish may be estimated by the equation: N'=0.9090 L3.581.
日本水産學會の論文