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Study on the reproduction of Paramyxine nelsoni (Myxinidae)from the southwestern coast of Taiwan

This study investigates the reproductive biology of Paramyxine nelsoni which distributes in some areas off the southwestern coast of Taiwan.
Specimens were captured by shrimp traps. Body weight and body length were measured. Maturation stages of female, adult male and immature were recored. Egg length¡Bnumber of egg, gonad weight and GSI for mature females were measured.
Results showed that P. nelsoni spawned all year round. However, a drastic increase of GSI in June and a drop in July, was noticed suggesting that reproduct in summer. Sex ratio was female¡Gmale¡Gimmature = 0.68¡G0.20¡G0.11; male/female = 0.30 . Number of females was fewer in July, suggersting a possibility that female foraging activity reduce after spawning.
The minimum maturature sizes for both sexes were 16 cm. The maximum size of female was larger than that of male. Results showed that P. nelsoni is not proatndrous. Small female smaller than 20 cm did not contained eggs longer than 3 mm. Some of females longer than 20 cm might involve in spawning activity.
According to the frequency distribution of egg length, it was confirmed that P. nelsoni were synchronous spawner and reproduct iteroparous. Eggs were in one to two discontinuous size classes. Mature females produced only 3-7 ripe eggs at a time.
Anchor-like hooks appeared in both tipa of 20~27 mm eggs. Mechanism controlling the development of these hooks remains unclear.
Date12 February 2003
CreatorsHung, Li-Yueh
ContributorsMeng-Hsien Chen, none, Hin-Kiu Mok
Source SetsNSYSU Electronic Thesis and Dissertation Archive
Detected LanguageEnglish
Rightsunrestricted, Copyright information available at source archive

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