| Summary: | 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).
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