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拟锥齿鲨是金枪鱼延绳钓渔业中常见的兼捕鱼种,处于海洋食物链的顶端,对海洋生态系统的稳定和多样性起着极其重要的作用。根据我国金枪鱼渔业国家观察员在热带大西洋海域(4.24°～14.03°N,38.28°～27.13°W)调查时采集的383尾拟锥齿鲨样本,按不同性别对其生物学特征进行初步研究。结果表明:拟锥齿鲨雌雄性比约为1∶0.36,且存在显著性差异;雌、雄性拟锥齿鲨的优势叉长范围分别为75～95 cm、65～90 cm;雄性肝重指数与性腺的发育程度关系不明显,雌性性成熟个体的肝重指数小于未成熟个体;雄性成熟个体占雄性总数的96.8%,雌性性成熟度以Ⅱ期和Ⅳ期为主,性成熟个体占雌性总数的56.12%,雌性拟锥齿鲨50%性成熟叉长为84.6 cm;摄食等级以0级为主,其次为1级,分别占52.38%和33.86%;胃含物中以沙丁鱼出现频率最高,其次为鱿鱼,分别占72.56%和27.44%;雌、雄的叉长和重量关系式分别为:WR=2×10-5LF2.7614,WR=2×10-6LF3.3287。
Quasi-conical sharks are common bycatch in longline fisheries and are at the top of the marine food chain and play an extremely important role in the stability and diversity of marine ecosystems. According to the biological characteristics of 383 specimens collected from the tuna fishery observers in the tropical Atlantic Ocean (4.24 ° ~14.03 ° N, 38.28 ° -27.13 ° W), their biological characteristics were preliminarily studied. The results showed that the ratio of male and female was about 1: 0.36, and there was a significant difference between them. The dominant fork lengths of female and male beaked sharks were 75-95 cm and 65-90 cm, respectively. The male liver index And the degree of gonadal development is not obvious, the female of sexual maturity individuals liver index is less than immature individuals; male mature individuals accounted for 96.8% of the total number of males, female sexual maturity in Ⅱ and Ⅳ, sexual maturity accounted for female 56.12% of the total, and 50% of the female mature beaked sharks had a sexual maturity of 84.6 cm. The feeding grade was mainly 0 grade, followed by grade 1, accounting for 52.38% and 33.86% respectively. The highest frequency of sardines appeared in the stomach contents , Followed by squid, accounting for 72.56% and 27.44% respectively. The relationship between fork length and weight of female and male was WR = 2 × 10-5LF2.7614 and WR = 2 × 10-6LF3.3287, respectively.