碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 94 / Abstract
Reproductive biology and stomach content of the sharpspine skate, Okamejei acutispina, in the northeastern Taiwan waters were examined in this study. Specimens were collected at Dasi fish market; in Yilan county from October 2004 through November 2005. All specimens were captured from the adjacent waters of Gueishan Island, Auti and Peng Chia Yu by trawlers at the depth of 100~200m. A total of 339 males and 373 females (including 109 pregnant individuals) were used for reproductive examination and 677 specimens were used for stomach content analysis. The sexes combined DW-TW relationship was described as: TW =0.0174DW 3.042 (n = 712, P＜0.0001). Sizes at maturity were estimated to be 26.2 cm and 23.7 cm DW for females and males, respectively. The sex ratio of total specimens was not significantly different from 1:1 based on Chi-square test (P＞0.05). Sharpspine skate is oviparous and possess paired functional ovaries. The length of egg case was 5.1±0.39 cm and the width was 2.7± 0.27 cm. According to monthly changes of GSI and the appearance of egg cases, the sharpspine skate produce egg case all the year around, but the peak is from October through March. Histological examination suggested section that the reproductive cycle of male and female are synchronized. Forty-three (6.5％) of 677 stomachs examined were empty, and crustacean was the most important food item (79.8%), followed by fish and cephalopod.
Key word: Okamejei acutispina, reproductive cycle, sizes at maturity, stomach content.
| Identifer | oai:union.ndltd.org:TW/094NTOU5451004 |
| Date | January 2006 |
| Creators | Shu-Ju Chang, 張淑如 |
| Contributors | Shoou-Jeng Joung, 莊守正 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 86 |
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