| 摘要: | 溪蟹科(Potamidae)是淡水蟹的其中一科，在全球有超過650個物種以及近100屬，並分為溪蟹亞科(Potaminae)及近溪蟹亞科(Potamiscinae)兩亞科。在台灣的淡水蟹則以明溪蟹屬(Candidiopotamon)、澤蟹屬(Geothelphusa)、南海溪蟹屬(Nanhaipotamon)所組成。在過去的研究多以粒線體基因序列來分析基因順序變化，並且溪蟹亞科的物種尚未發表，因此缺乏該亞科的分析。並且在台灣明溪蟹屬的兩物種，拉氏明溪蟹及蓬萊明溪蟹，兩者的粒線體序列均未被發表。本研究蒐集了新竹、花蓮以及台東的明溪蟹，利用次世代定序技術(Next generation sequencing，NGS)建構完整粒線體基因序列，並蒐集32種已發表的溪蟹科全粒線體基因序列，歸類出13種基因順序模式。此外使用了最大簡約法(Maximum parsimony，MP)、最大概率演化法( Maximum Likelihood，ML)以及貝葉斯法(Bayesian inference of phylogeny，BI)進行親緣關係樹分析，再結合遺傳距離與基因順序變化來探討演化關係。從拉氏明溪蟹及蓬萊明溪蟹的全粒線體基因序列分析發現，其遺傳距離僅略低於溪蟹科內種間的平均距離，表示其遺傳差異上支持為有效物種。然而在近溪蟹屬(Potamiscus)中，部分物種的遺傳距離甚至高於屬間平均，推測可能需要重新評估其分類關係。;The family Potamidae is a member of freshwater crabs, include over 650 species and nearly 100 genera worldwide. It is divided into two subfamilies: Potaminae and Potamiscinae. There are three genera of Potamidae in Taiwan: Candidiopotamon, Geothelphusa, and Nanhaipotamon. Previous studies primarily focused on mitochondrial gene sequences to discuss gene order evolution; however, species from the subfamily Potaminae have yet to be published, resulting in a lack of representation for this group. Furthermore, the mitochondrial genomes of the two Candidiopotamon species in Taiwan, Candidiopotamon penglai and Candidiopotamon rathbuni, remain unclear. In this study, Candidiopotamon samples were collected from Hsinchu, Hualien, and Taitung, and complete mitochondrial genomes were sequenced by next-generation sequencing (NGS). Additionally, 32 published Potamidae mitochondrial genomes were compiled, and a total of 13 gene order patterns were identified. Phylogenetic relationships were analyzed using maximum parsimony (MP), maximum likelihood (ML), and Bayesian inference(BI), in combination with genetic distances and gene order variation to study evolutionary relationships in the family Potamidae. This study successfully assembled the complete mitochondrial genomes of both Candidiopotamon species and found that their genetic distances were slightly lower than the interspecific average genetic distance within Potamidae, supporting their distinct taxonomy status. However, certain species within the genus Potamiscus interspecific genetic distances were greater than the genus-level average in Potamidae, suggesting that taxonomic re-evaluation may be needed. |
