碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 98 / Reproductive biology of the threadfin porgy (Evynnis cardinalis) was described based on 916 specimens caught by pot fishing boat in the northeastern waters off Taiwan and landed at Changtangli fishing port, Keelung, Taiwan from October 2008 to October 2009. The relationships between body weight (BW, g) and fork length (FL, mm) were estimated as BW 2.2 10-5 FL3.03 for females, and BW 3.1 10-5 FL2.97 for males. The sex ratio vs. FL was significantly different from 50%, except for the FL in 190-200 mm. The sex ratio of threadfin porgy decreased when the FL increased. The monthly change of GSI, oocyte diameter frequency distribution and histological examination suggested that the spawning season was occurred in October to March. The mean hepatosomatic indexes (HSI) and mean condition factors (CF) within both sexes were decreased in the spawning season. All developmental stages of oocyte appeared in some ovaries indicated ovarian development of this species was asynchronous. The fork length at 50% sexual maturity was 166.16 and 174.92 mm for female and male, respectively. Mean batch fecundity was 16,352 oocytes and range between 5,172 and 44,748.
| Identifer | oai:union.ndltd.org:TW/098NTOU5451027 |
| Date | January 2010 |
| Creators | Chih-Yeh Tu, 涂致曄 |
| Contributors | Cheng-Hsin Liao, 廖正信 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 73 |
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