Experimental study of the influence of presence and predation by sculpin,Cottus gobio L., on the drift of emergent brown trout, Salmo trutta L.
Gaudin, Philippe; Caillere, Louis
Archiv für Hydrobiologie Volume 147 Number 3 (2000), p. 257 - 271
published: Feb 3, 2000
ArtNo. ESP141014703001, Price: 29.00 €
In two complementary experiments carried out in artificial channels, brown trout larvae, Salmo trutta L., introduced into the gravel resorbed their yolk sac and emerged in the presence or absence (control) of sculpin, Cottus gobio L. The presence of sculpin induced an earlier and greater trout drift during the night. This phenomenon was observed during the few days following the emergence period, then the frequency of displacements resumed a normal level. It is suggested that the drift of trout alevins was not only the result of disturbance due to sculpin locomotory activity by night, but was an avoidance of predation by sculpin as, during these few days of perturbation, the predation by sculpin was also high. The emergence period and the following days appeared to be a very vulnerable period in the early life of trout, during which the mechanisms allowing alevins to cohabit with potential predators are installed.