碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 94 / Reproductive biology of holocephalan species, Hydrolagus mitsukurii in the northeastern waters off Taiwan were examined. Based on 432 Hydrolagus mitsukurii (218 females and 214 males) caught by bottom trawlers at the depths between 200 m and 600 m around Gueishan Island waters and collected at Dasi fish market during Nov. 2004 to Mar. 2006. In addition to a pair of characteristic claspers as other elasmobranches, males have a pair of anterior claspers and a front clasper. For females, both ovaries are functional and each gonopores separate without the cloaca. Sizes at maturity were estimated to be at 41.5 and 37.4 cm body length (BL) for males and females based on histological analysis. Hydrolagus mitsukurii is oviparous, and maximum ovum diameter was up to 3 cm. The testes is a diametric type, and mature sperm is found in the seminal vesicle all the year round. Monthly changes of gonad indices indicated that no seasonal reproductive cycle were found for this species. Ovarian fecundity was estimated as 2.70 ± 1.36 oocytes.
| Identifer | oai:union.ndltd.org:TW/094NTOU5451003 |
| Date | January 2006 |
| Creators | Hui-Ling Hung, 洪慧玲 |
| 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 | 80 |
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