碩士 / 國立中興大學 / 生命科學系所 / 95 / Gray mullet, Mugil cephalus Linnaeus is one of the most important economic fish in the coastal waters of Taiwan. In order to understand the population differentiation and genetic structure of gray mullet in Taiwan, cytochrome b (Cyt b, 1137 bp) of 95 individuals and phosphoglucose isomerase A (Pgi-A, 1662 bp) of 30 individuals were amplified by PCR or RT-PCR methods and subsequently sequenced. Phylogenetic trees reconstructed with Cyt b sequences and results of ΦST suggested the existence of three populations (Group 1, Group 2, and Group 3) of gray mullet around the coastal waters of Taiwan. Between-group genetic distances were 5.29 % (± 0.62 %), 6.96 % (± 0.71 %), and 6.51 % (± 0.73 %) for Group 1 and Group 2, Group 1 and Group 3, and Group2 and Group3, respectively. Within-group genetic distances were 0.30 % (± 0.08 %), 0.03 % (± 0.01 %), and 0.52 % (± 0.12 %) for Group1, Group2, and Group3, respectively. Neutrality tests and mismatch distributions indicated that Group 1 and Group 2 had experienced population expansion. In the Cyt b gene, because phylogenetic relationships among the three groups are different among the trees reconstructed by Baysian, maximum likelihood, maximum parsimony, and neighbor joining methods, the relationships among them were not resolved. Phylogenetic trees reconstructed with Pgi sequences were not completely congruent with that of Cyt b sequences. Specifically, only the Group 3 was monophyletic but the Group 1 and Group 2 were paraphyletic. This result suggests Group 1 and Group 2 are interbreeding. For estimating relative abundance of juveniles of the three groups, a PCR-RFLP method was developed. The results of RFLP showed that juveniles of Group1 and Group 3 can be found as early as November but juveniles of Group 2 were not found until February. Because adult specimens of Group 1 and Group 2 were mainly collected during December, January, and February and Group 1 and Group 2 contained the adult specimens from China and Japan, respectively, I propose that Group 1 and Group 2 are migratory populations from the coastal waters of China and Japan during the spawning season. Because Group 3 is the most abundant group in November and adult specimens were not found between November and February of the next year, I propose that Group 3 is a resident population found only in Taiwan.
| Identifer | oai:union.ndltd.org:TW/095NCHU5105036 |
| Creators | Huei-Mien Ke, 柯惠棉 |
| Contributors | 高孝偉 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 53 |
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