清水溪魚類族群分布與海拔高度及溪流

Distribution of Fishes in Chinshoei Creek in Relation to Elevation and Stream Gradient

本研究於1992、1993年冬季枯水期在臺灣中部濁水溪支流清水溪流域14 個採樣站，共記錄鯉科、平鰭鰍科、鰍科、鮠科、鯰科、慈鯛科及　虎科等7科15種魚類。魚類群聚之魚種數和歧異度與海拔高度、溪流坡度有顯著之負相關，即魚種數和歧異度有從低海拔、坡度較緩的下游向高海拔、坡度較陡的上游減少的現象。所捕獲的15種魚類按海拔高度分布之不同可歸類為8群，第1群：鯰魚及高體　　，海拔高度200至280公尺；第2群：鯽魚、花鰍，海拔高度200至310公尺；第3群：粗首　、短吻鐮柄魚、莫三鼻口孵魚、埔里中華爬岩鰍及台灣鮠，海拔高度200至 570公尺；第4群：台灣石　、吻　虎，海拔高度200至890公尺；第5群：台灣間爬岩鰍，海拔高度200至950公尺；第6群：台灣馬口魚，海拔高度290至820公尺；第7群：台灣鏟頜魚，海拔高度 290至950公尺；第8群：台灣纓口鰍，僅在海拔560公尺及890公尺處發現。各群因魚種對棲地流速適應能力的不同致上游界限存在明顯的種間差異，下游界限出現之重疊現象則與清水溪及其主流濁水溪魚類族群之水域相連有關。 During the winter dry seasons of 1992-1993, a total of 15 species belonging to 7 families of fishes were collected at 14 samplings stations on Chinshoei Creek, a tributary to the Choshui River in central Taiwan. The number of species and the species diversity index were significantly negatively correlated to elevation and stream gradient. According to the distribution of the fishes in relation to elevation, they were divided into eight groups: 1)Parasilurus asotus and Rhodeus ocellatus at eletions of 200-280m, 2) Carassius auratus and Cobitis taenia at 200-310m, 3) Zacco pachycephalus, Abbotina brevirostris, Sarotherodon moss ambicus, Sinogastgromyzon puliensis and Leiocassis taiwanensis at 200-570m, 4)Accrossocheilus paradoxus and Rhinogobius spp. at 200-890m, 5 ) Hemimyzon formosanum at 200-950m, 6) Candidia barbata at 290-820m, 7) Varicorhinus barbatulus at 290-950m, and 8) Crossostoma lacustre only at 560m and 890m. The distributions showed obvious differences in the upstream ranges among the groups, reflecting the presence of different adaptation among the species to environmental conditions related to elevation and stream gradient. On the other hand, the downstream ranges were highly overlapped among the groups, indicating the strong association of the fishes in Chinshoei Creek with those in its main stem of Choshui River.