Observations sur l'établissement du comportement de nage face au courant chez l'alevin de truite, Salmo trutta L., en ruisseau artificiel

Abstract

500 alevins were introduced into the gravel of an artificial stream. At the start of emergence, the activity of some alevins was recorded daily over 30 minutes.The essential elements of early activity are expressed as a swimming behaviour against the current so that a stable body position is maintained. At the beginning, the static swimming behaviour is shown in brief bursts. Later, these periods of static swimming become longer and less numerous. This static swiming behaviour precedes territorial behaviour.

Stratégies d'utilisation de l'habitat par les alevins post-émergents de truite commune (Salmo trutta) et de saumon Atlantique (Salmo salar)

“…De jour, la truite se détache du substrat dans les quelques jours qui suivent l'émergence pour adopter un comportement de nage intermittente ou de nage statique continue (HELAND, 1978). Dès que cette activité est établie, les captures deviennent fréquentes et les comportements agressifs courants, en particulier lorsque la densité est élevée (ici, au dessus de 8 individus par m^).…”

Social and spatial structure in brook chars (Salvelinus fontinalis) under competition for food and shelter/shade

“…Li and Brocksen (1977) also mentioned a growth increase in dominant Rainbow trouts (Salmo gardneiri), and noted how they sought sectors of the stream where the current was weaker. Héland (1971) and Li and Brocksen (1977) did not however distinguish between the respective influence of many variables which might explain the higher rate of growth for dominant subjects. In addition to the protection afforded by shelters, which may have contributed to a reduced energy expenditure for dominant subjects, the latter may have been able to benefit from greater nourishment than their conspecifics, but this was not verified in the said studies.…”

“…Hartman (1963) mentioned that brown trouts sought the protection of submerged rocks in artificial streams to a greater degree when current velocity was increased. Héland (1971), in his study of young fish of the same species, noticed that dominant trouts established territory over stream beds with most obstacles and shelters. The same author observed increased growth in dominant and territorial trouts, even though very few dominants established their territory upstream, where food was given out.…”

“…Locus dependent dominance seems to be at the basis of the formation of territorial mosaics and this state of affair, together with putative reversibility, satisfies the criterion for true territoriality, at least of an idealized concept of territoriality. The use of space by juveniles seems to conform to the territorial mosaic scheme in several salmonids (Hartman, 1963(Hartman, , 1965Hoar, 1951;Kalleberg, 1958;Keenleyside, 1962;Héland, 1971). Jenkins (1969) has suggested that this could be due to the relative uniformity of biophysical and ecological conditions which usually prevail during ontogeny: fish of equal size, age and hormonal development compete against each other over a substrate which is usually also very uniform.…”

Habitat De La Truite Commune (Salmo Trutta L.) Pendant La Période Juvénile en Ruisseau : Préférences, Mouvements, Variations Journalières Et Saisonnières.

“…Pour la truite commune, les comportements agonistiques qui apparaissent quelques jours après l'émergence conduisent rapidement à la stabilisation territoriale des individus (HÉLAND, 1971(HÉLAND, , 1977.…”