Reproductive biology of needle fish, Tylosurus acus melanotusin the waters around Hisao-Liu-Chiao, Taiwan

• Main Authors: Yu-Hsin Chang, 張玉欣
• Other Authors: Yih-Yia Liao
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/25146468287451797929

碩士 === 國立高雄海洋科技大學 === 漁業生產與管理研究所 === 98 === This study is aimed to investigate the reproductive biology of needlefish, Tylosurus acus melanotus, in the Hisao-Liu-Chiao waters off southwestern Taiwan. A total of 658 specimens (329 females and 329 males) were collected monthly from the catches of driftnet between July 2008 and August 2009. The relationship between the length of eye fork length (EFL) and body weight (BW) relationships of females and males is no significantly different between sexes (BW=0.0105EFL2.7904 ； r2=0.87 ； p<0.05 ； n=658). By means of histological examination, the oocyte development can be clearly categorized into seven stages. The spawing season extends from April to August based on the macroscopic appearance, histological examination of ovaries, estimations of gonadosomatic index and frequency of oocyte diameter. The size at 50% maturity was estimated 56.79 and 53.31 cm for the female and male. Sex ratio was no significantly different 0.5 with Chi-squared test (p>0.05). Mean fecundity of this species were estimated as 14,836-56,320. The relationship between fecundity (F) and body weight (BW) was as the follow：F＝ 19.158BW+8618.4 (r2=0.86； p<0.05； n=21).