Journal of Tropical Oceanography ›› 2014, Vol. 33 ›› Issue (2): 45-51.doi: 10.11978/j.issn.1009-5470.2014.02.006cstr: 32234.14.j.issn.1009-5470.2014.02.006

• Marine Biology • Previous Articles     Next Articles

Study on reproductive biology of yellowfin tuna Thunnus albacares in the waters of the Solomon Islands of the South Pacific Ocean

CHEN Feng1, 2, 3, GUO Ai1, 2, 3, ZHU Wen-bin1, 2, 3, ZHOU Yong-dong1, 2, 3, XU Han-xiang1, 2, 3, ZHANG Long1, 2, 3   

  1. 1. Marine Fisheries Research Institute of Zhejiang Province, Zhoushan 316100, China;; 2. Scientific Observing and Experimental Station of Fishery Resources for Key Fishing Grounds, Ministry of Agriculture, Zhoushan 316100, China; 3. Key Laboratory of Sustainable Utilization of Technology Research for Fishery Resource of Zhejiang Province, Zhoushan 316100, China
  • Received:2013-04-19 Revised:2013-06-18 Online:2014-04-02 Published:2014-04-02
  • Contact: 海洋渔业信息服务技术实验室建设项目(续)(2011F10004); 浙江省海洋渔业局远洋渔业探捕专项(浙海渔计[2013]110号)

Abstract: Reproductive biological parameters including size composition, sex ratio, percent of maturity, gonadosomatic index (GSI), and so on, were analyzed based on the 353 yellowfin tuna Thunnus albacores samples caught in the waters of the Solomon Islands from September to December, 2012. The results showed that the yellowfin tuna individuals caught consisted of two groups. The body size of female was significantly smaller than for male (p<0.001). The total sex ratio of female to male was 0.67︰1, significantly different from expected 1︰1 from spring to summer. But it was closely related to the months when the samples were taken and to the body size, increasing gradually from September to December, and was close to 1︰1 in December (p>0.05). However, it gradually decreased with fork length (FL) increasing, and males became predominant at 110 cm and larger (p<0.05). Furthermore, the proportion of female showed a linear negative correlation with FL; the correlation coefficient was -0.90 (p<0.01). Both the percentage of maturity and monthly mean of GSI of female and male increased from spring to summer, and in November and December they reached the relatively higher values, and percentage of spawning individuals of V-VI increased, suggesting that spawning population of yellowfin tuna occurred in the waters of the Solomon Islands from spring to summer and that the spawning individuals began to appear in October with a relatively higher proportion of spawning individuals in December investigated. The GSI was positively correlated with FL. The FLs at first maturity of female and male were estimated to be 97.4 cm and 103.7 cm, respectively, based on further analysis results. So, study on reproductive biology of yellowfin tuna helps to understand the status of its fisheries resources and has significance in assessing this stock in this area.

Key words: Thunnus albacores, Solomon Islands, sex ratio, gonadosomatic index, spawning

CLC Number: 

  • P735