Exercise, agonistic behaviour and food acquisition in Arctic charr, Salvelinus alpinus
- Colin E. Adams 1
- Felicity A. Huntingford 2
- Jaroslav Krpal 3
- Malcolm Jobling 4
- Scott J. Burnett 5
- 1) Fish Behaviour and Ecology Group, University Field Station, Rowardennan, G63 OAW, Glasgow, Scotland, UK
- 2) Fish Behaviour and Ecology Group, Zoology Department, University of Glasgow, G12 8QQ, Glasgow, Scotland, U.K.
- 3) University of J.E. Purkynè, Brno, Czech Republic
- 4) N F H, University of Tromsø, 9037, Tromsø, Norway
- 5) Department of Human Sciences, Brunel University, Uxbridge, Middlesex, England, U.K.
Synopsis: Although swimming is energetically costly, a number of studies on salmonid species have demonstrated increased growth rates in fishes forced to swim for prolonged periods at moderate speeds (typically 1–2 body lengths per sec). This suggests that additional energetic costs of swimming are more than met by alternative compensatory gains. The mechanisms underlying such effects are not fully understood. In this paper, we describe an experiment designed to examine one possible mechanism, namely a swimming-induced inhibition of aggression, with consequent beneficial effects on growth. The study used Arctic charr,Salvelinus alpinus, a species for which a positive relationship between exercise and growth has been clearly established. Using direct behavioural observations on small groups, we demonstrate that individuals displaying high levels of aggressive behaviour are able to monopolise access to food and that enforced swimming at a moderate speed (1 body length per sec) reduces the incidence of aggression although not the degree of monopolisation of food shown by aggressive individuals. These results suggest that the enhanced growth rates accompanying enforced swimming may reflect lower energetic costs of reduced aggressive activity rather than improved access to food by subordinates.
- 1 - sciences appliquees, technologies et medecines
- 2 - sciences biologiques et medicales
- 3 - sciences biologiques fondamentales et appliquees. psychologie
- 4 - ethologie animale
- 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Aquatic Science
- 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Ecology, Evolution, Behavior and Systematics