南太平洋所罗门群岛海域黄鳍金枪鱼的渔业生物学特性

Preliminary study on fishery biology of yellowfin tuna Thunnus albacares in the South Pacific Ocean near Solomon Islands

中文关键词: 黄鳍金枪鱼  渔业生物学  南太平洋所罗门群岛海域  延绳钓

英文关键词: Thunnus albacares  Fishery biology  South Pacific near the Solomon Islands  Long-line

中文摘要:

      根据2010年8~10月,在南太平洋所罗门群岛海域延绳钓作业渔场所采集的黄鳍金枪鱼数据，对其渔业生物学特性进行了初步分析。结果表明，1）叉长为47.5~166.5 cm，平均叉长为112.7 cm，优势叉长为80.0~90.0 cm和100.0~140.0 cm（75.0%）；体重为2.0~72.0 kg，平均体重为26.5 kg，优势体重为5~10 kg和15~40 kg（68.6%），雌、雄个体大小差异明显（ANOVA，P<0.01）；2）体重（RW）与叉长（FL）、纯重（DW）的关系分别为RW=1.159×10-5FL3.070和RW=1.118DW+0.684（不分性别）；3）雌、雄性比为1∶1.2。各叉长组性比变化显著（χ2=1 093.386，P<0.001），叉长大于140 cm时，雄性个体占优势；4）性腺发育以Ⅱ期为主（50%），初次性成熟叉长为113.4 cm。达到性成熟的个体中，34.0%的个体发育至Ⅴ期以上，说明调查期间为黄鳍金枪鱼繁殖期；5）空胃率高达51.6%，摄食种类主要为鱼类（67.5%）、头足类（18.0%）和甲壳类（14.5%）。不同叉长组的摄食等级存在显著变化（χ2=400.782，P<0.001）。

英文摘要:

      Research on basic biology of yellow-fin tuna Thunnus albacares is essential for its stock assessment. In this paper, some biological characteristics of T. albacares were preliminarily studied based on the long-line catches in the South Pacific Ocean near Solomon Islands from August to October 2010. The results are shown as follows: (1) The fork length (FL) ranged from 47.5 to 166.5cm with an average of 112.7 cm, and two dominant groups were found at 80.0 ~ 90.0 cm and 100.0 ~ 140.0 cm (75%); The raw weight (RW) varied between 2.0 and 72.0 kg with dominant groups at 5~10kg and 15~40 kg (68.6%), and the average weight was 26.5 kg. However, body size differed greatly between female and male T. albacares . (2) The relationships between RW and FL and dressed weight (DW) were RW=1.159×10-5FL3.070 and RW=1.118DW+0.684 respectively. (3) The sex ratio of female to male was 1∶1.2, but there were significant differences between size-different groups (χ2=1 093.386，P<0.001). The male was dominant in number when FL was over 140 cm. (4) Gonad samples were mainly at stage Ⅱ (about 50%). The length at 50% maturity (FL50%) was estimated to be 113.4 cm and 34.0% of individuals at greater FL had achieved stageⅤ~Ⅵ gonad maturity, indicating that the stock near Solomon Islands was in spawning period during the survey. (5) Based on the stomach content analysis, we found that T. albacares mainly preyed on fish (67.5%), cephalopods (18.0%) and crustaceans (14.5%), and the empty-stomach ratio was about 51.6%. Significant differences in feeding levels were found between FL groups (χ2=400.782，P<0.001).