農業部水產試驗所全球資訊網

午仔魚中的兩個物種，四絲馬鮁 (Eleutheronema tetradactylum) 與多鱗四絲馬鮁 (E. rhadinum)是沿近海漁業及養殖漁業的重要經濟性物種。四絲馬鮁與多鱗四絲馬鮁鑑別特徵主要是藉由側線鱗片數量進行區分，但外觀上仍不易分辨，而魚卵、魚苗及水產加工品更無法藉由外觀進行鑑定，雖然基因定序可以區分兩物種，但時間及成本的花費高。本研究旨在根據四絲馬鮁與多鱗四絲馬鮁細胞色素c氧化酶I (cytochrome c oxidase I, COI) 基因序列上的差異，建立物種專一性引子 (species-specific primer) 技術，依聚合酶連鎖反應 (polymerase chain reaction, PCR) 擴增片段的大小不同，即能快速準確鑑定物種。結果顯示物種專一性引子的物種鑑定結果與外觀鑑定及基因定序結果一致，證實物種專一性引子能夠快速準確的鑑定此兩物種。本研究採集之臺灣周邊海域野外午仔魚樣品為多鱗四絲馬鮁，而養殖場取得午仔魚、魚卵及魚苗樣品為四絲馬鮁。無論是基礎研究、種原保存或現場應用皆需快速且準確的檢測方法來進行物種鑑定，本研究將有助於四絲馬鮁屬 (Eleutheronema) 魚類的遺傳背景研究、物種資源保護及午仔魚的養殖產業開發。

摘要abstract(英) The two species of fourfinger threadfin fish, Eleutheronema tetradactylum and Eleutheronema rhadinum, are economically important species in coastal fisheries and aquaculture. They are primarily distinguished by the number of lateral line scales, rather than appearance alone. Additionally, the fish eggs, fry, and processed aquatic products cannot be identified based on appearance. Although gene sequencing can distinguish between the two species, it is time-consuming and costly. This study aims to develop species-specific primers based on the differences in the cytochrome c oxidase I (COI) gene sequences between E. tetradactylum and E. rhadinum. The two species can be identified quickly and accurately by amplifying different fragment sizes through polymerase chain reaction. The results showed that species identification using species-specific primers was consistent with both morphological identification and gene sequencing, demonstrating that the primers can achieve fast and accurate species identification. Field samples of threadfin fish collected from the waters around Taiwan were identified as E. rhadinum, while samples of threadfin fish, eggs, and fry obtained from aquaculture farms were identified as E. tetradactylum. A fast and accurate detection method is necessary for species identification in basic research, germplasm conservation, or field applications. This study contributes to the genetic background research, species resource conservation, and aquaculture industry development of Eleutheronema threadfin fish.