2024-03-29T08:33:40Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/355412022-11-17T02:08:08Zhdl_2115_20049hdl_2115_141中部北太平洋におけるサンマ Cololabis saira の耳石日周輪に基づく年齢と成長の推定Esimation of the age and growth of Pacific saury Cololabis saira in the central North Pacific Ocean determined by otolith daily growth increments巣山, 哲桜井, 泰憲目黒, 敏美島崎, 健二660The age, growth, and hatch dates of the Pacific saury Cololabis saira in the central North Pacific Ocean were estimated by analysing the microstructure of otoliths. Saury samples were collected by drift nets of several mesh sizes from July to August 1989. Growth increments of otoliths were counted under a scanning electron microscope. The sauries were divided into an almost tri-modal size distribution: a small-sized group (x¯: 210mm in knob length, range 200-240mm), a medium-sized group (x¯: 260mm, 240-295mm), and a large-sized group (x¯: 315mm, more than 295mm). Ages in days of sauries of the large-and medium-sized groups were estimated at 560-690 days and 310-450 days, respectively. Birthdate analyses of the sauries showed that the large- and medium-sized groups were estimated to have hatched from November 1987 to January 1988 and from May to August 1988, respectively. It is estimated that the life span of the saury in the central North Pacific area is about 2 years.日本水産学会Journal Articleapplication/pdfhttp://hdl.handle.net/2115/35541https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/35541/3/58_1607.pdf0021-53921349-998XAN00193422日本水産学会誌589160716141992jpninfo:doi/10.2331/suisan.58.1607© 1992 公益社団法人日本水産学会publisher