热带太平洋中东部大眼金枪鱼摄食强度的时空变化

摘要

根据中国金枪鱼渔业观察员项目于2006年2-11月在东太平洋水域作业的中国金枪鱼延绳钓渔船上收集的数据,对大眼金枪鱼Thunnus obseus摄食强度的时空变化进行了分析.结果表明:小个体大眼金枪鱼的摄食强度较大个体大眼金枪鱼的高,叉长小于140 cm的大眼金枪鱼的摄食强度相对较大;3--4月大眼金枪鱼的摄食强度较小,5-11月大眼金枪鱼的摄食强度相对较大;3月大眼金枪鱼的空胃率相对较高,5-11月大眼金枪鱼空胃率均低于15%;200～350 m水层中大眼金枪鱼的摄食活动非常活跃.各月份(x2=227.95,P＜0.0001)和不同叉长组(x2=364.61,P＜0.0001)大眼金枪鱼的摄食强度均存在显著性差异,且不同水层(x2=178.50,P＜0.0001)大眼金枪鱼的摄食强度也存在显著性差异.%The present study analyzes the spatial - temporal variation in feeding intensity of bigeye tuna ( Thunnus obesus) in the tropical eastern and central Pacific Ocean based on the data collected by tuna scientific observer on aboard Chinese tuna longliner operating in eastern Pacific Ocean from February to November in 2006 with supporting of China Tuna Fishery Observer Program. The results showed that the smaller bigeye tuna with fork length smaller than 140 cm had greater feeding intensity than the larger individuals did. The lower feeding intensity was observed from March to April and the higher feeding intensity occurred from May to November. Higher proportions of empty stomach were found in March, but the proportions of empty stomach are found below 15％ from May to November. The bigeye tuna showed an active feeding at a depth of below 200 m to 350 m. There were significant differences in feeding intensity in various months (x2 =227.95, P＜0.0001 ), fork length classes (x2 =364.61, P ＜0.0001 ) and water layers (x2 = 178.50, P＜0.0001 ).