Reproductive biology of the black porgy Acanthopagrus schlegelii in the coastal waters off southwestern Taiwan

• Main Authors: Liao, GuaiHao, 廖冠豪
• Other Authors: Chiou, WannDuen
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/63465102791775163033

碩士 === 國立高雄海洋科技大學 === 漁業生產與管理研究所 === 99 === This study aims to investigate the reproductive biology of black porgy, Acanthopagrus schlegelii , in the coastal waters off southwestern Taiwan. Between August 2007 to August 2008 and February to April 2009, a total of 531 specimens (328 males, 190 females and 13 hermaphrodite) of A. schlegeli was sampled by bottom trawlers and collected in Jia-Ding and Dang-Gang fish markets, Taiwan. The species is protandrous hermaphrodite. By means of histological examination, the oocyte development can be clearly categorized into eight stages while the gonad development can be determined in seven stages. The spawning season extends from January to April based on the macroscopic appearance, histological examination of ovary, estimation of gonadosomatic index and monthly variation of percentage proportion of gonad development. Mean fecundity( ±SD), mean batch fecundity ( ±SD)and relative batch fecundity( ±SD) of this species were estimated as 819,875±325,110 and 498,312±367,166 and 578±403 (eggs/g), respectively. The females outnumber males with increasing body length. The sex ratio (female/total×100%) is 35.78% (190/518×100%). The sizes at 50% maturity are estimated 353.5 mm FL and 318.6 mm FL for the female and male, respectively.