单 位：
上海海洋大学海洋科学学院;上海海洋大学大洋渔业资源可持续开发省部共建教育部重点实验室
关键词：
拟锥齿鲨;金枪鱼延绳钓;生物学特征;热带大西洋
摘 要：
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。
译 名：
Preliminary analysis of the biology of the crocodile shark,Pseudocarcharias kamoharaiin the tropical Eastern-central Atlantic Ocean
作 者：
GAO Chun-xia1,TIAN Si-quan1,2,3,DAI Xiao-jie1,2,3,WU Feng2,XU You-wei1(1.College of Marine Sciences,Shanghai Ocean University,Shanghai 201306,China;2.The Key Laboratory of Oceanic Fisheries Resources Exploitation of Shanghai Education Commission,Shanghai Ocean University,Shanghai 201306,China; 3.Scientific Observing and Experimental Station of Oceanic Fishery Resources,Ministry of Agriculture,Shanghai Ocean University,Shanghai 201306,China)
关键词：
Pseudocarcharias kamoharai;tuna longline fishery;biological characteristics;tropical Eastern-central Atlantic Ocean
摘 要：
Crocodile shark,Pseudocarcharias kamoharai,is a common by-catch species of tuna longliner.As an important part of the oceanic food chain,it plays a vital role in the marine ecosystem.According to the total of 383 crocodile shark samples collected by China's national tuna fisheries observers in the tropical Eastern-central Atlantic Ocean(4.24°-14.03°N,27.13°-38.28°W),the biological characteristics of both females and males of crocodile sharks were analyzed and described,respectively.The results can be summarized as follows:(1) The female-male ratio was 1:0.36,and with significant difference;(2) The dominant fork length of males and females was 75-95 cm,65-90 cm,respectively;(3) There was no significant difference between Hepatosomatic indices(HSI) and gonad development for male of P.kamohara,however,HSI of mature individuals was greater than that of immature individuals of female;(4)96.8% of males and 56.12% of females were mature.Maturity stages at Ⅱand Ⅳof females' gonads were dominant and the size at 50% maturity(L50) of female was 84.6 cm in fork length;(4) Feeding stage 0 was dominant with the percentage of 52.38%,and feeding stage 1 accounted for the percentage of 33.86%;(5) The prey composition in the stomachs of these shark samples was mainly sardine(72.56%) and squid(27.44%);(6) The relationships between fork length and round weight for females and males was described by WR=2×10-5LF2.7614,WR=2×10-6LF3.3287 respectively.Due to the difficulty for collecting the oceanic species samples,this study contributed to a better understanding of crocodile shark in biological characteristics,and the information from this study would be helpful for some regional fisheries management organizations to conduct stock assessment and decision making.
