碩士 / 國立海洋大學 / 漁業科學學系 / 90 / This study was examined the reproductive biology of Sphyna zygaena occurred in northeastern Taiwan waters. The individuals were mainly captured by harpoon and longline from surface to 200 m in depth from Nov. 2000 to Feb. 2002. A total of 722 individuals (including 387 female and 335 male) of smooth hammerhead shark, Sphyrna zygaena was determined in this study, and also included the additional 5 gravid female specimens. Females and males reached sexual maturity at about 259.4 cm (L50) and 234.6 cm (L50), respectively. Ova (eggs) are ovulated when they reach 25 mm in diameter. Reproductive pattern of Sphyrna zygaena is yolk sac placenta type with uterine compartment. Embryos´ data suggested a gestation period about 10 months and parturiting on May and June for this species. The predicted reproductive cycle is two years. Size at birth is approximately 55 cm total length (TL) and litter size varied from 13 to 37 with a mean value of 30.
| Identifer | oai:union.ndltd.org:TW/090NTOU0451017 |
| Date | January 2002 |
| Creators | 劉秀珠 |
| Contributors | 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 | 84 |
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