open access

https://hdl.handle.net/2115/35565

Maturation and age in days of Pacific saury Cololabis saira (Brevoort) in the central North Pacific Ocean during the summer

日本語

中部北太平洋

1996-05-15

日本水産学会

Bulletin of the Japanese Society of Scientific Fisheries

62(3)

361-369

The maturation process and age in days of female Pacific saury Cololabis saira (Brevoort) in the central North Pacific Ocean were examined based on histological observations and otolith daily growth increments. The maturation process of Pacific saury used in this study (243-342mm in knob length) was divided into 6 stages: early yolk vesicle stage, late yolk vesicle stage, yolk formation stage, maturation stage, atretic stage I, and atretic stage II. Atretic stage fish were considered to be post-spawning as many degenerated oocytes were observed. The large size group (more than 296mm), in which fish were more than 1.5 years old as estimated from daily growth increments in otoliths, contained spawning and post-spawning individuals, although all individuals from the medium size group (241-295mm), from 10 months to 1 year and 3 months old, were immature. Since post-spawning fish were seen to have recovered their initial condition factors, it is suggested that they survive beyond the first spawning season. Based on observations of asynchronously developing oocytes, it is considered that Pacific saury spawn several times during a single spawning season.

学術雑誌論文

Version of Record

© 1996 The Japanese Society of Fisheries Science

0021-5392

1349-998X

AN00193422