库克群岛海域长鳍金枪鱼脂肪含量

根据2012年9月21日至11月15日库克群岛海域金枪鱼延绳钓调查数据,对所捕获的长鳍金枪鱼的叉长分布、脂肪含量分布、脂肪含量时空分布、脂肪含量与叉长的关系进行了分析,结果表明:(1)渔获中长鳍金枪鱼叉长范围为0.50~1.14 m,平均叉长为0.95 m,其中0.90~0.99 m为优势叉长,占80.36%;(2)长鳍金枪鱼的最低脂肪含量为0.3%,最高脂肪含量为4.6%,平均脂肪含量为2.0%,其群体组成丰富;(3)从9月底至10月中旬,脂肪含量较低,10月中旬以后,脂肪含量随时间推移逐渐升高;(4)西北部(11°S~13°S,162°W-168°W)长鳍金枪鱼的脂肪含量较高,为2.7%~3.0%,其他海域的较低,为1.0%~2.5%;(5)长鳍金枪鱼叉长(0.85~1.14 m)与脂肪含量无显著相关性(P0.05)。研究认为:(1)10月中旬以后,长鳍金枪鱼开始存储脂肪,从而为产卵准备;(2)调查期间,捕获的长鳍金枪鱼基本是成熟个体,开始生殖洄游,即从南部返回北部的热带水域;(3)库克群岛西北部海域11°S~13°S,162°W~168°W之间可能为长鳍金枪鱼的产卵场。

The fat content of albacore tuna in waters near Cook Islands

Based on the survey from September 21, 2012 through November 15, 2012 in the waters near Cook Islands by Chinese tuna longliner, we analyzed the biological characteristics of albacore tuna, such as fork length distribution, fat content distribution, the temporal and spatial distribution of fat content, and the relationship between fat content and fork length. The results showed: (1) The fork length of the albacore tuna was 0.50-1.14 m, the average fork length was 0.95 m, and dominant with 0.90-0.99 m, accounted for 80.36%; (2) The minimum fat content of albacore tuna was 0.3%, the maximum fat content was 4.6%, and the average fat content was 2.0%, and the size composition was very rich; (3) From September 21 to October 13, 2012, the fat content of albacore tuna was low, while after October 13, 2012, the fat content of albacore tuna increased over time; (4) In the northwest area (11°S-13°S,162°W-168°W), the fat content of albacore tuna (2.7%-3.0%) was higher than that of the other areas (1.0%-2.5%); (5) There was no significant relationship between fat content of albacore tuna and its fork length(0.85-1.14 m, P>0.05). This study suggested: (1) After mid-October, the albacore tuna started to store fat to prepare for spawning; (2) The albacore tuna captured in the survey were mature individuals, basically, and they began to spawn and were migrating from the southern waters to northern tropical waters; (3) The spawning might occur in the northwest area (11°S-13°S, 162°W-168°W) of the waters near Cook Islands.