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根据2003-2004年1-6月印度洋中西部海域金枪鱼延绳钓所捕获的黄鳍金枪鱼数据,对其基本的生物学特征进行了研究。结果表明,2003年和2004年渔获物中黄鳍金枪鱼加工后体重分别为7~81 kg和20~78kg,优势组分别为20~50 kg和30~60 kg。叉长范围分别为70~180 cm和110~170 cm。2003年渔获物雌雄性比的平均值为0.71,月间性比组成差异较小;2004年渔获雌雄性比的平均值为1.00,月间性比组成差异较大。2003年各月的摄食等级以1-2级为主,月间差异较小;2004年摄食等级以一级为主,并且月间各等级组成差异大。当渔获个体的叉长小于100 cm时,其性比组成波动较大;当渔获个体的叉长范围在100~150 cm之间时,性比组成的变化相对较小,基本上维持在0.5左右,也就是说雌雄个体数量大体保持平衡;当渔获个体的叉长大于160 cm时,所有样本个体均为雄性。体长与体重关系为W=2×10-5L2.9269。
Based on the data of yellowfin tuna caught from tuna longline in the western and mid Indian Ocean from January to June 2003-2004, the basic biological characteristics were studied. The results showed that the body weights of yellowfin tuna were 7 ~ 81 kg and 20 ~ 78 kg respectively in 2003 and 2004, and the dominant groups were 20 ~ 50 kg and 30 ~ 60 kg respectively. The length of the fork is 70-180 cm and 110-170 cm, respectively. In 2003, the average ratio of male and female catches was 0.71, with a slight difference in monthly specific composition. The average ratio of female and male in catches in 2004 was 1.00, and there was a big difference in monthly specific composition. The feeding grading in each month in 2003 was mainly in 1-2 levels with little difference in the month. In 2004, the feeding level was mainly in first grade, and the composition of each grade in the month was quite different. When the length of the individual caught is less than 100 cm, the variation of the sex ratio is relatively large. When the length of fork is between 100 cm and 150 cm, the changes of the sex ratio are relatively small, 0.5 or so, that is, the number of male and female individuals generally maintain a balance; when the length of the individual caught fork 160 cm, all samples are male. Body length and body weight as W = 2 × 10-5L2.9269.