Presence of sculpins (Cottus gobio) reduces drift and activity of Gammarus pulex (Amphipoda) |
| |
Authors: | K. G. Andersson C. Brönmark J. Herrmann B. Malmqvist C. Otto P. Sjörström |
| |
Affiliation: | (1) Department of Animal Ecology, University of Lund, Helgonavägen 5, S-223 62 Lund, Sweden;(2) Present address: Department of Ecological Zoology, University of Umeå, S-90187 Umeå, Sweden |
| |
Abstract: | Introduction of sculpins into a stream previously devoid of these predators significantly reduced drift rate of Gammarus pulex. The drift of insect larvae was not affected. High amounts of exudates after implantation of sculpins were probably responsible for the low number of drifting G. pulex specimens. Laboratory experiments confirmed reduced locomotory activity of G. pulex when exposed to caged sculpins, an observation that excludes reduced drift activity as a result only of predation.The average size of drifting G. pulex specimens was larger during the night than during the day. This result is in accordance with the hypothesis that large individuals should, in relation to small ones, turn nocturnal because of greater predation risk during daytime. Presence of sculpins did not alter the size composition of drifting G. pulex. |
| |
Keywords: | Gammarus pulex sculpin drift anti-predatory behaviour |
本文献已被 SpringerLink 等数据库收录! |
|