东海近海带鱼群体相对资源密度、空间分布及其产卵群体的结构特征

摘要

根据2007年5月、2008年5月和6月东海近海渔业资源底拖网调查数据,对该水域带鱼群体的相对资源密度、空间分布及产卵群体的生长特征和繁殖特性进行了初步分析.结果表明,2007年5月、2008年5月和6月带鱼群体的相对资源密度分别为13.07±5.17、14.34±6.64、16.10±6.28 kg/h,出现频率均在85％以上,对总渔获量的贡献率分别为63.55％、60.20％、53.77％.东海近海带鱼产卵群体平均肛长为182.62mm,优势肛长为150～200mm;平均体重为102.77g,优势体重为50～110 g.雌、雄产卵个体间肛长-体重关系无显著差异(P＞0.05),呈等速生长,肛长-体重关系为W=4.520×10-5 L2.795(R2=0.929,n=349).经x2检验,带鱼产卵群体♀ ♂:♂均大于1,肛长210mm以下,雌性个体占优势,其所占比例随肛长增加而不断变大,雌雄个体的50％性成熟体长分别为164.65、171.65 mm.%Based on the fishery data collected by bottom trawls during the spawning season (May,2007 and May to June,2008) in coastal waters of the East China Sea,the relative stock density and distribution of hairtail Trichiurus lepturus and the biological characteristics and reproductive characteristics of its spawning stock were studied.The results showed that the relative stock density of hairtail spawning stock were 13.07±5.17 kg/h,14.34±6.64 kg/h,and 16.10t6.28 kg/h in May,2007,May and June,2008,respectively,and accounted for 63.55％,60.20％ and 53.77％ of the total catch,respectively.The occurrence frequencies of the fish were more than 85％ in three surveys.The average anal length of hairtail spawning stock was 182.62 mm,and the dominant anal length was 150～200 mm; Average body weight was 102.77 g,and the dominant body weight ranged from 50 g to 110 g.There was no significant difference in body weight and anal length relationship between spawning males and females (P＞0.05),and the body weight and anal length relationship was W=4.520× 10-5 L2.795(R2=0.929,n=349).According to Chi-square test,there were significantly more females than males in the spawning stock,and the group with the anal length less than 210 mm was dominant.Anal length at 50％ sexual maturity (L50) of female and male were 164.65 mm and 171.65 mm,respectively.