2009年秋冬季东南太平洋智利竹筴鱼的渔业生物学特征

根据2009年秋冬季(3~6月)东南太平洋智利竹筴鱼的渔业调查资料,对其群体组成、叉长与体重关系、性腺成熟度、摄食等级和渔获量作了初步研究。结果表明:叉长范围为100~650 mm,优势叉长组350~400 mm;体重范围为100~2 600 g,优势体重组400~800 g;3~5月性腺成熟度大部分为Ⅱ期,6月则有52%个体为Ⅲ期。3~5月总产量和CPUE(t/h)呈逐渐增加趋势,6月份均显著下降,仅为5月的38.7%和51.4%。冬季(6月)总产量的大幅下降,暗示该渔场的空间分布出现了一些新的变化。

Biological characters of Chilean jack mackerel (Trachurus murphyi) in the Southeast Pacific Ocean

Based on the survey data of Trachurus murphyi fishery in Southeast Pacific ocean in autumn and early winter of 2009,the paper analyzed population composition,relationship between fork length and body weight,gonad maturity,feeding stages and change of catch.Results showed that: the fork length ranged from 100 to 650 mm,and 350-400 mm for the dominant fork length.The body weight ranged from 100 to 2 600 g,and 400-800 g was the dominant body weight group.Gonad maturity mostly were at stage Ⅱ from March to May,but about 52% individuals were at stage Ⅲ in June.The total catch and CPUE(t/h) gradually increased from March to May,but decreased rapidly in June,only accounting for 38.7% in total catch and 51.4% in CPUE of that of May.The large decline of catch in June suggested that a new spatial-temporal change of the resource distribution of Chilean jack mackerel stock had occurred.