학술논문

Spawning frequency and batch fecundity of skipjack tuna Katsuwonus pelamis in the tropical west-central Pacific Ocean / 中西部熱帯太平洋におけるカツオの産卵頻度とバッチ産卵数の推定
Document Type
Journal Article
Source
日本水産学会誌 / NIPPON SUISAN GAKKAISHI. 2008, 74(5):802
Subject
カツオ
バッチ産卵数
中西部太平洋
産卵頻度
Language
Japanese
ISSN
0021-5392
1349-998X
Abstract
The spawning frequency and batch fecundity of skipjack tuna Katsuwonus pelamis collected from the tropical west-central region of the Pacific Ocean between July 2003 and April 2006 were examined. The estimated mean spawning frequency of individuals collected between 06:00 and 15:00 was 0.50, indicating the spawning intervals of 1.99 days. Batch fecundity was estimated by counting the number of advanced oocytes with diameter≥0.5 mm at the final mature phase (i.e. those containing a migratory nucleus stage or hydrated oocyte in the ovary). Of 23 females analyzed, the mean batch fecundity and relative batch fecundity were 615,000 oocytes and 147.8 oocytes per gram of somatic weight, respectively.