西北太平洋鱸鰻族群遺傳結構之研究

Population genetic structure of Anguilla marmorata in the Northwestern Pacific

鄭志成(Chih-Chen Cheng)

指導教授 ： 曾萬年

國立臺灣大學/生命科學院/漁業科學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.02019

摘要

中文摘要
鱸鰻為熱帶性淡水鰻，廣泛分佈於印度太平洋及太平洋地區。西北太平洋鱸鰻族群的分佈範圍南起菲律賓，北達日本南部，跨距達2000公里。和日本鰻一樣，成熟的鱸鰻會從西太平洋區陸地的溪流中洄游至馬里亞那群島附近產卵。孵化後的鱸鰻柳葉鰻會經由北赤道洋流、黑潮再輸送回西北太平洋陸棚區，經變態為鰻線後進入沿岸河川中成長。日本鰻已發現無時空上的遺傳分化，在西北太平洋同一洋流系統輸送的鱸鰻是否會有空間和時間上的遺傳分化情形則不清楚。本研究以微衛星DNA為工具，分析了柳葉鰻漂送過程中必經的菲律賓、臺灣及日本三地的223條鱸鰻的遺傳變異性及族群遺傳結構。結果顯示西北太平洋的鱸鰻並無族群分化的現象， FST = 0.002 (P > 0.05)。即使是已經相隔10年的日本樣本，其族群的遺傳結構也和最近從臺灣、菲律賓所採集的樣本無明顯差異。此結果顯示西北太平洋的鱸鰻族群遺傳結構不論是在空間或時間上都相對的穩定。鱸鰻柳葉鰻漂游期間的逢機擴散及熱帶鰻終年產卵的特性可能是抑制鱸鰻族群分化的主因。
關鍵字：柳葉鰻、微衛星DNA、族群遺傳結構、黑潮

關鍵字

柳葉鰻 ； 微衛星DNA ； 族群遺傳結構 ； 黑潮

並列摘要

Abstract
Anguilla marmorata is a diadromous fish that grows in the freshwater and spawns in the ocean and is widely distributed in Indo-Pacific and Pacific Ocean. The distribution of A. marmorata in the Northwestern Pacific Ocean ranges from the Philippines to the south of Japan with an approximate separation distance of 2000 km. The spawning ground of A. marmorata was assumed to be in the west of Mariana Islands. After hatching the leptocephalus passively drifts with the North Equatorial Current and Kuroshio Current and metamorphoses into glass eel in the continental shelf of the 3 aforementioned countries. They become pigmented elver in the estuary and grow to yellow eel in the rivers. After maturation, they migrate downstream to the ocean to spawn and die. The spatial and temporal population genetic structure of A. marmorata in the Northwestern Pacific Ocean is still unclear. In this study, 5 microsatellites loci were used to analyze the genetic variability and population genetic structure of 223 A. marmorata collectedfrom the Philippines, Taiwan and Japan. The result showed that A. marmorata in the Northwestern Pacific did not have significant population genetic differentiation, FST = 0.002 (P > 0.05), even if the Japan specimens were collected 10 years ago. Their population genetic structure was also similar to that of the specimens recently collected from Taiwan and the Philippines. This study indicated that the spatial and temporal population genetic structure of A. marmorata in the Northwestern Pacific is stable. The mixing of their leptocephalus during long distance dispersal and their year round spawning behavior might inhibit the population differentiation.

並列關鍵字

leptocephalus ； Microsatellite DNA ； Population genetic structure ； Kuroshio Current

參考文獻

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