2008年澎湖海域寒害後，珊瑚礁魚類可能回復的機制－以象魚為例

The Possible Restoration Mechanism of Coral Reef Fishes Following the 2008 Chilling Damage in Penghu Archipelago: Using Rabbitfish as an Example

郭金泉(Jin-Chywan Gwo) ； 鄭先祐(Hsien-Yu Cheng)

《國立臺灣博物館學刊》 63卷4期 (2010/12) Pp. 59-73

摘要

象魚(Siganus juscescens)是臺灣常見珊瑚礁魚類，並非臺灣目前養殖放流物種。此魚在2008年澎湖寒害受創嚴重，因此我們於2009年採集澎湖本島四個不同海域（外海：鎖港、成功；內灣：菜園、大倉）與臺灣基隆，共5個族群150個樣本，以擴增片段長度多樣性進行族群基因多樣性分析，嘗試以族群遺傳觀點解釋珊瑚礁魚類自然復育能力的機制。研究結果顯示，澎湖與臺灣基隆各採集族群間並無明顯遺傳之分化，顯示各族群有類似的族群基因結構，所以澎湖本島海域的象魚應可視為一個演化顯著單位。澎湖與臺灣東北角基隆的族群形成關聯族群，真有高度的連通性，至於此現象和範圍是否可推論至整個臺灣海域，還待採集更多地區分析更多樣本而定。物種生活史、仔稚魚補充擴散強弱、洄游途徑、產卵場與族群間的基因流程度、海流狀況、餌食與棲地條件等，都是影響關聯族群結構強弱的因素， 也可能都會決定2008年澎湖寒害後淺海珊瑚礁漁業資源自然復育速度的快慢。畢竟過去幾次的嚴峻歷史寒害，即使沒有放流水產生物種苗都沒有枯竭澎湖的漁業資源。

關鍵字

臺灣 ； 珊瑚礁 ； 分子標記 ； 遺傳多樣性 ； 擴增酶切片段長度多樣性

並列摘要

The rabbitfish or mottled spinefoot, Siganus fuscescens (Siganidae), is widely distributed in shallow coastal coral areas throughout the Pescadores (Penghu Archipelago) and Taiwan. The species is herbivorous and is not a target species for stocking in Taiwan. A massive fish kill by chilling damage happened during the winter of 2007- 2008. This abnormal cold spell had such a devastating impact on the Pescadores fishery industry that some Taiwanese researchers estimated it could take decades for the industry to fully recover. In 2009, the genetic variation of rabbitfish from Pescadores and Taiwan was assessed by using Amplified Fragment Length Polymorphism (AFLP) analysis. We tried to determine the recovery ability of the coral reef fish in terms of population genetics. A total of 150 samples caught from five localities (Soukang, Datsun, Tsaiyen, Chenkong and Keelung) were investigated using ten different AFLP primer sets. Both a Principal Component Analysis (PCA) and a neighbor-joining tree clearly showed low genetic variation among these five localities. The results of our genetic analyses also revealed that stocks from Pescadores and Taiwan might be panmictic; with high connectivity between the Pescadores and Keelung stocks. More samples from different locations are needed before expanding this metapopulation theory to the entire Taiwan coastal area. This study provides an explanation for the restoration mechanism which will serve as a useful reference for the fisheries management. In conclusion, despite not stocking fish fry into the ocean in the past, the Pescadores fishery resource remains in stable condition even after encountering several historical chilling damages, likely due to metapopulation structure.

並列關鍵字

Taiwan ； coral reef ； molecular marker ； Genetic diversity ； AFLP

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