碩士 / 國立臺灣大學 / 海洋研究所 / 102 / Shark fin is the most valuable part in a whole shark body, the custom of eating shark fin is very popular in East and South-East Asia, and it has been counted a traditional noble delicacy in China for centuries. This study aims to analyze constitution of species in Taiwan market fins. We collected or purchased shark fin samples from fishing ports or metropolis in Taiwan, including fresh fin, dried fin, soaked fin, canned fin, and pack fin. Because of lacking key features, it is impossible to identify species of the samples by morphological method. We used the molecular tool- DNA barcode (the gene marker is mitochondrial COI gene) to accomplish it. The results showed that this method is appropriate in species identification of fresh fin, dried fin, and soaked fin, but inappropriate in canned fin and pack fin. In the results of species analysis, we found 46 species in the 686 successfully indentified samples of the all 1170 samples. The 46 species belong to 8 orders, 14 families, and 21 genera. In all the samples we analyzed, the most plentiful species is Blue shark, subsequently are Silky shark, Shortfin mako, Bigeye thresher, Scalloped hammerhead, and Pelagic thresher. In status of conservation, according to the evaluation and classification by IUCN, critically endangered species account for 2.2 %, endangered species account for 4.3 %, vulnerable species account for 32.6 %, near threatened species account for 39.1 %, least concern species account for 15.2 %, data deficient species account for 4.3 %, not evaluated species account for 2.2 % in all the species we found in this study.
In addition to species identification, we also calculated evolutionary distances of the COI sequences. The results showed that within-species distances ranged from 0.002 to 0.035, with the mean value on 0.007; within-genus distances ranged from 0.003 to 0.102, with the mean value on 0.029; and within-family distances ranged from 0.003 to 0.105, with the mean value on 0.054. Furthermore, all the species can be perfectly separated in phylogenetic trees which are constructed by the haplotypes, it indicated that capability of COI gene in species identification of chondrichthians is very good. Moreover, phylogenetic analyses showed regional genetic divergences in Pelagic thresher, Thresher, Silky shark, Scalloped hammerhead, and Smooth hammerhead; but no divergence in Bigeye thresher, Oceanic whitetip shark, and Great hammerhead.
We affirmed that using mitochondrial COI gene as a DNA barcode to identify chondrichthian species is a fast, effective, and accurate method, which will be helpful for fishery management and species conservation.
| Identifer | oai:union.ndltd.org:TW/102NTU05279041 |
| Date | January 2014 |
| Creators | Chien-Kang Huang, 黃建綱 |
| Contributors | Jen-Chieh Shiao, 蕭仁傑 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 76 |
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