| 摘要: |
| 根据2001年6月16日—10月27日大西洋中部金枪鱼延绳钓渔场现场所作的生物学测定数据，应用统计与回y-3的方法分别对黄鳍金枪鱼(Thunnus albacares)的性腺成熟度、摄食等级、摄食种类、性比、又长分布、叉长与纯重的关系、叉长与原条鱼重的关系、原条鱼重与纯重的关系等进行了研究。结果表明，(1)性腺成熟度Ⅵ级占的比例最高，为47.06%。(2)摄食等级以1级为主，其次为0级，分别占45.45%和18.18%。(3)胃含物中以鱿鱼出现的频率为最高，占44.44% ，其次是沙丁鱼和杂鱼，分别占27.78%和25.00%。(4)雄性与雌性的性比约为1.43比1。(5)优势又长为1.31—1.47m，占31.44% ，平均又长为1.39m。(6)不分性别、雄性和雌性黄鳍金枪鱼叉长(FL)与纯重(DW)的关系可表达为：DW = 5.6632×10-6FL3.1951。(7)不分性别、雄性和雌性黄鳍金枪鱼又长(FL)与原条鱼重(RW)的关系分别为：RW = 8.5072×10-6FL3.1390、RWM = 1.1229×10-5FLM3.0847、RWF = 7.1711×10-6FLF3.1721。(8)不分性别、雄性和雌性黄鳍金枪鱼原条鱼重(RW)与纯重(DW)的关系分别为：RW = 1.1339DW、RWM = 1.1320DWM、RWF=1.1399DWF。 |
| 关键词: 大西洋中部,金枪鱼延绳钓渔场,黄鳍金枪鱼,生物学特性 |
| DOI： |
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| 基金项目:国家“863”计划资助项目，818-11-03号；上海市教委捕捞学重点学科基金资助项目，科02-155号；上海市教委2003年度上海高校优秀青年教师后备人选资助项目，03YQHB125号。 |
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| PRELIMINARY ANALYSIS OF BIOLOGICAL CHARACTERISTICS OF YELLOWFIN TUNA THUNNUS ALBACARES IN THE TUNA LONGLINE FISHING GROUND OF THE CENTRAL ATLANTIC OCEAN |
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SONG Li-Ming, CHEN Xin-Jun, XU Liu-Xiong
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Ocean College，Shanghai Fisheries University
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| Abstract: |
| This is a part of the Chinese first tuna high sea fishery project of observation and investigation in Atlantic high sea fishing ground pursuited to the technical standard of international fishery organization. From 16th June to 27th Oct.2001, three large-scale tuna longliners were operated in the area of 12°50′N—04°11′S, 41°22′W—15°30′W, and Yellowfin tuna were randomly sampled and later were analyzed. The deep freezer longliners, 740 GRT and 56m LOA were used to target Bigeye tuna (Thunnus obesus), along with Yellowfin tuna (Thunnus albacares), Swordfish (Xiphias gladius), Albocore (Thunnus alalunga) and Billfish (Istiophoridae)as bycatch, The samples were analyzed for the items of the gonad maturity (classified Ⅰ—Ⅵ), feeding intensity (classified 0—4), species composition of the prey (squid, sardine, miscellaneous fish, shrimp and the other crustacean), fork length (FL) distribution and sex ratio. The relationship between FL, dressed Weight (DW) and round weight (RW) were also simulated using power regression method. In total, 36 individuals were sampled. Among them 34 individuals were measured and modeled statistically. In detail, gonad maturity (of 34 fish), ingestion (32), and feeding intensity (34), sex (35)samples were analyzed. Our results indicated: (1) Maturity at Ⅵ of the gonad was dominant up to 47.06%. (2) feeding intensity was mainly in the class 1, or class 0, occupied 45.45% or 18.18%, respectively. (3) The composition of prey was squid (44.44%), sardine (27.78%)and miscellaneous fish (25.00%). (4) The male-female ratio was 1.43:1. (5) The dominant fork length was 1.31—1.47m, 31.44% , with a mean value of 1.39m. (6)The relationship between FL and DW of male, female and mixed yellowfin tuna was identical and indicated by DW = 5.6632×10-6FL3.1951. (7)Relationship between FL and RW of yellowfin tuna (mixed, male and female) was indicated by RW = 8.5072×10-6FL3.1390, RWM = 1.1229×10-5FLM3.0847, RWF = 7.1711×10-6FLF3.1721, respectively. Establishing the FL-RW relationship separately for male and female is beneficial for stock assessment. FL-DW (or RW) function reported in this paper can be referenced for preliminary estimation of theFL-DW (or RW) relationship of yellowfin tuna. (8) The relationship between RW and DW (mixed, male and female)was indicated by RW = 1.1339DW, RWM = 1.1320DWM, RWF=1.1399DWF, respectively. The conversion factor (mixed sex)from DW converted to RW was 1.1339, slightly higher than 1.13, recommended by ICCAT as the conversion factor in the Atlantic Ocean. |
| Key words: The Central Atlantic Ocean, Tuna longline fishing ground, Yellowfin tuna Thunnus albacares, Bio1ogical characteristics |
