刺鯧之遷徙及族群遺傳結構

Migration and population genetic structure of Japanese butterfish (Psenopsis anomala)

林庭宏(Ting-Hung Lin)

指導教授 ： 蕭仁傑

國立臺灣大學/理學院/海洋研究所/碩士(2020年)

https://doi.org/10.6342/NTU202000182

摘要

刺鯧(Psenopsis anomala)，又名肉魚，為臺灣重要的經濟性魚種，但是漁業年報的統計資料顯示，臺灣海域的刺鯧產量逐年遞減。本研究針對刺鯧的耳石微化學，測定耳石核心到邊緣的氧同位素值變化，再以matlab進行分析數據，比對海水溫度及鹽度，來推測刺鯧可能的棲息海域，並以粒線體DNA之cytb與COI基因串聯作為分子標記，探討刺鯧之族群遺傳結構。
樣本取自兩個國家六個樣點，分析其耳石穩定氧同位素來了解族群之間可能的移動路徑，結果顯示臺灣及日本的族群都會隨著季節有不同分布，春季分布於臺灣海峽及南海，夏季會向北移動到黃海及東海一帶，秋季開始向南移動，冬季則會回到臺灣海峽及南海，推測刺鯧的分布和溫度24-27°C分布帶有密切關係，魚群可能隨著大陸沿岸流及黑潮在黃海、東海及南海之間遷移。族群遺傳分析發現46個單倍型，遺傳變異分析顯示族群具有高單倍型歧異度(h = 0.85)和低核苷酸歧異度(π = 0. 00099)。分子變異分析(AMOVA)顯示主要的變異來自於族群中的個體(92.98%)。中性檢定之Fu’s Fs各族群皆為顯著負值，與族群變異分布分析皆支持近期族群歷史變動有擴張的現象。重建最大似然親緣關係樹(Maximum likelihood tree)及中點連接網狀圖(Mediam joining network)皆顯示沒有明顯分群。分子證據顯示刺鯧經歷族群擴散，且各族群基因交流頻繁。

關鍵字

刺鯧 ； 耳石 ； 穩定氧同位素 ； 季節性分布 ； 粒線體DNA ； 族群遺傳結構

並列摘要

Japanese butterfish (Psenopsis anomala) is one of the most important commercial fish in Taiwan. According to the statistics of the fishery annual report, the catch of the Japanese butterfish in Taiwanese waters has been decreasing in recent years. This study estimated the migration and distribution of Japanese butterfish by analyzing the stable oxygen isotope values in the otolith, which was used to refer the experienced seawater temperature and salinity. The population structure of the Japanese butterfish was also analyzed using the mitochondrial cytb and COI genes. The samples were collected from six sample sites in two countries. The result showed that the seasonal distribution can be discovered in both populations of Japanese butterfish in Taiwan and Japan. The seasonal distribution of Japanese butterfish was closely associated with the mean water temperature of 24-27℃, which might be influenced by the Kuroshio and China coastal current. We also found 46 haplotypes among the 109 individuals, the populations had high haplotype diversity (h = 0.85) and low nucleotide diversity (π = 0. 00099). Analysis of molecular variance (AMOVA) reveals that the main variation (92.98%) was among individuals within populations. Fu’s Fs test of all locations indicates no significant difference, and the mismatch distribution both supports the recent expansion of population historical dynamic. No population can be distinguished by maximum likelihood tree and median-joining network. Molecular evidence showed that the Japanese butterfish have had little to no geographic population genetic structure.

並列關鍵字

Japanese butterfish (Psenopsis anomala) ； otolith ； stable oxygen isotope ； seasonal distribution ； mtDNA ； population genetic structure

參考文獻

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