博士 / 國立中山大學 / 生物科學系研究所 / 104 / The flyingfish family Exocoetidae is widespread in tropical and temperate waters with about 35 species in six genera, four subfamilies in the northwestern Pacific. The phylogeny of the subfamily Cypselurinae including four genera and most species had controvsersy. In addition, research on population genetics of flyingfish in the northwestern Pacific is rare. The aims of this study were 1. to reconstruct phylogeny of flyingfishes from the northwestern Pacific Ocean based on morphology and two mitochondrial sequences; 2. to reconstruct the phylogeny of Cypselurinae using complete mitochondrial genome; 3. to investigate the population genetic structure of Hirundichthys oxycephalus in the northwestern Pacific Ocean. Six genera and 32 species were included in this study. Morphological phyologeny used 22 characters showed that the family Exocoetidae and three subfamilies were found to be monophyly. In Cypselurinae clade, Hirundichthys was at the basal place, but Cheilopogon + Cypselurus + Prognichthys formed a trichotomy which could not resolve the relationship of these genera. A total of 1637 bp of the partial COI gene (615 bp) and Cytb gene (1022 bp) was sequenced from 66 samples. Molecular phyologeny showed that the family Exocoetidae and three subfamilies were found to be monophyletic. Genus Hirundichthys was separated from Prognichthys + Cheilopogon + Cypselurus. Genus Cheilopogon was paraphyletic and divided into three clades. Genera Cypselurus + Prognichthys formed a sister group which was close to Cheilopogon clade III. According to molecular phylogeny, three clades of Cheilopogon corresponded with the five subgenera and new classification might need to be proposed. The complete mitogenomes of Cheilopogon unicolor, Ch. arcticeps and Ch. atrisignis were successfully determined by next-generation sequencing method. Partial mitogenomes of Ch. agoo, Ch. cyanopterus, Pr. brevipinnis and Hi.oxycephalus were determined by primer walking method. Phylogeny of Cypselurinae indicated that the Hirundichthys was ancestral genus than Cheilopogon + Cypselurus + Prognichthys, and Cypselurus + Prognichthys formed a sister group. Our results indicated that Cheilopogon was paraphyletic and can be divided into three clades. Future work should be designed to explore and classify the relationships of the subgenera within Cheilopogon. For the population genetic structure of H. oxycephalus, 156 specimens were collected and 616 bp of mtDNA COI gene were sequenced. Results indicated that the genetic differentiations among different localities were small and a high gene flow in the region with undergoing population expansion. Although phylogenetic trees showed two groups of H. oxycephalus in the northwestern Pacific Ocean, the separation was not geologically evident. However, due to high gene flow, an association of either group to a spatial distribution was not observed, and so the two groups may be considered as one population. Therefore, effective fishery management of H. oxycephalus requires joint efforts from countries within its population boundary in order to maintain sustainable exploitation.
| Identifer | oai:union.ndltd.org:TW/104NSYS5112020 |
| Date | January 2016 |
| Creators | Chang-en Chou, 周常恩 |
| Contributors | Hsueh-Wen Chang, 張學文 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 117 |
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