碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 99 / Portunus sanguinolentus is one of the most important commercial species for crab pot fisheries in waters off Penghu. A total of 1180 specimens (672 female and 508 male) were collected from Magon fishing market between April 2009 and March 2010 to investigate reproductive biology of crab pot-caught P. sanguinolentus. Carapace width (CW) and body weight (BW) of P. sanguinolentus specimens were ranged from 102.1-177.4 mm and 57.56-375.04 g, respectively. The relationship between CW and BW in female and male were expressed by fitting into the following regression equations: BW=5.3195×10-5CW3.0238 (Female); BW= 3.4518×10-5CW3.1194 (male). The maximum likelihood ratio test further indicated that the above equations varied significantly with sex (P<0.05). Chi-squared test for CW of female and male indicated that a higher proportion of female occurred when the specimens were less than 150 mm in CW. Inversely, a higher proportion of female occurred when the specimen were larger than 150 mm in CW. The external features and weight of ovaries varied significantly during development, which can be utilized as simple indicators to determine the maturity of female P. sanguinolentus. Based on monthly variations in the relative proportion of female belonging to matured stages and gonadosomiatic index (G.S.I), the peak of spawning occurs in February, and June-July. Gravid female specimens were obtained in the whole year and features of their extruded egg mass also varied significantly during development. The relationships between the weight of extruded egg mass (Wegg) and CW, and BW were expressed as the following regression equations: Wegg=2.1289×10-6CW3.2505, Wegg=0.0712×BW1.0742. The relationships between the egg number of extruded egg mass (Negg) and CW, and BW were expressed as the following regression equations: Negg=1.3882×CW2.7462, Negg=1.3995×104BW0.8273. Batch fecundity of female P. sanguinolentus ranged from to 391,219 to 1,682,039 and mean batch fecundity was 986,252.
| Identifer | oai:union.ndltd.org:TW/099NTOU5451006 |
| Date | January 2011 |
| Creators | Sung-Hua Wang, 王崧華 |
| 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 | 59 |
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