Distribution of freshwater amphipods, Jesogammarus jesoensis and Eogammarus kygi, in the Chitosegawa River system, Hokkaido, northern Japan
スポンサーリンク
概要
- 論文の詳細を見る
We studied the distribution of freshwater amphipods in the water system of the Chitosegawa River, showing that Eogammarus kygi (Derzhavin) inhabits the river itself, Jesogammarus jesoensis (Schellenberg) its tributaries, and Sternomoera yezoensis (Uéno) spring-fed brooks. In addition, an intensive study of E. kygi and J. jesoensis in the Naibetsugawa River, a tributary of the Chitosegawa, showed that (1) the distribution boundary of the two species was clear with little overlap, (2) there was a significant difference in the biomass of salmon carcasses between the waters upstream and downstream of the boundary, and (3) animal fragments, especially of amphipods, were observed more frequently in the gut of E. kygi than in that of JJ jesoensis. Based on these facts, we discussed three probable explanations for the distribution of the two species, i.e., (1) E. kygi extended its distribution from the lower to the upper reach of the Chitosegawa previously inhabited by J. jesoensis, (2) E. kygi, which feeds more often on animal detritus, inhabits the area where salmon carcasses are available, driving J. jesoensis away to areas where they are not, and (3) each species inhabits its own exclusive area due to some direct interspecific interactions, such as predation.
- 日本陸水学会の論文
日本陸水学会 | 論文
- キイロカワカゲロウの孵化におよぼす水温の影響〔英文〕
- キイロカワカゲロウ羽化の経日・日周変化〔英文〕
- Studies on Taxonomy and Distribution of the Freshwater Snails,Genus,Semisulcospia in the Three Islands inside Lake Biwa
- びわ湖南湖におけるタテヒダカワニナおよびカゴメカワニナの分布とその決定要因について
- ちりとり型金綱による河川底生動物採集上の問題点