Dominance in demand‐feeding behaviour in Arctic charr and rainbow trout: the effect of stocking density

The effects of stocking density on the demand feeding behaviour of Arctic charr Salvelinus alpinus and rainbow trout Oncorhynchus mykiss were evaluated using demand feeders in combination with a monitoring system based on automatic passive integrated transponders. The proportion of total bites accounted for by top-ranked charr and trout decreased from 87 to 15% and from 66 to 15%, respectively, when moving from the lowest to the highest densities, indicating that the ability of the highest-ranked fish to monopolize the demand feeders was reduced at high densities. However, when the individuals were grouped into quartiles, based on their individual rank, both charr and trout ranked within the upper quartile accounted for the majority of bites independent of stocking density (87 and 72% of the total, respectively). Instead of there being a single dominant individual, as was the case under low density conditions, a small group of individuals dominated the actuation of the trigger at high densities. The two species responded differently to crowding, with the total daily bite activity of charr increasing linearly with increasing density, whereas the corresponding relationship was quadratic for rainbow trout, with a peak value at 24 to 36kg m−3.

[1]  A. Alanärä.  The effect of temperature, dietary energy content and reward level on the demand feeding activity of rainbow trout (Oncorhynchus mykiss) , 1994 .

[2]  E. Brännäs,et al.  Effect of reward level on individual variability in demand feeding activity and growth rate in Arctic charr and rainbow trout , 1994 .

[3]  E. Jørgensen,et al.  Effects of stocking density on food intake, growth performance and oxygen consumption in Arctic charr (Salvelinus alpinus) , 1993 .

[4]  E. Brännäs,et al.  Monitoring the feeding activity of individual fish with a demand feeding system , 1993 .

[5]  R. Srivastava,et al.  The effect of stocking density on the behaviour of Arctic charr (Salvelinus alpinus L.) , 1992 .

[6]  Anders Alanärä,et al.  The effect of time-restricted demand feeding on feeding activity growth and feed conversion in rainbow trout (Oncorhynchus mykiss) , 1992 .

[7]  Dominic F. Houlihan,et al.  The effect of feeding hierarchy on individual variability in daily feeding of rainbow trout, Oncorhynchus mykiss (Walbaum) , 1992 .

[8]  P. Elvingson,et al.  Comparison of rainbow trout (Oncorhynchus mykiss) strains for body weight, length and age at maturity in different Swedish production systems , 1992 .

[9]  T. Boujard,et al.  Demand‐feeding behaviour and diel pattern of feeding activity in Oncorhynchus mykiss held under different photoperiod regimes , 1992 .

[10]  Y. S. Svendsen,et al.  The combined effects of stocking density and sustained exercise on the behaviour, food intake, and growth of juvenile Arctic charr (Salvelinus alpinus L.) , 1992 .

[11]  Malcolm Jobling,et al.  The behaviour and the relationship between food intake and growth of juvenile Arctic charr, Salvelinus alpinus L., subjected to sustained exercise , 1990 .

[12]  J. Holm,et al.  The effect of fish density and feeding regimes on individual growth rate and mortality in rainbow trout (Oncorhynchus mykiss) , 1990 .

[13]  M. Vijayan,et al.  High stocking density alters the energy metabolism of brook charr, Salvelinus fontinalis , 1990 .

[14]  F. Huntingford,et al.  Social dominance and body size in Atlantic salmon parr, Salmo solar L. , 1990 .

[15]  E. Jørgensen,et al.  Feeding modes in Arctic charr, Salvelinus alpinus L.: the importance of bottom feeding for the maintenance of growth. , 1990 .

[16]  J. Huner,et al.  Crawfish culture in the southeastern USA. , 1990 .

[17]  M. Vijayan,et al.  Effect of stocking density on the growth and stress-response in brook charr, Salvelinus fontinalis , 1988 .

[18]  J. C. Wallace,et al.  The effects of stocking density on early growth in Arctic charr, Salvelinus alpinus (L.). , 1988 .

[19]  T. Storebakken,et al.  Growth rate estimates for cultured Atlantic salmon and rainbow trout , 1987 .

[20]  C. Schreck,et al.  Effects of rearing density on indices of smoltification and performance of coho salmon, Oncorhynchus kisutch , 1985 .

[21]  M. Jobling,et al.  Influence of body weight and temperature on growth rates of Arctic charr, Salvelinus alpinus (L.) , 1983 .

[22]  J. R. McBride,et al.  Stress-Related Effects of Hatchery Rearing Density on Coho Salmon , 1981 .

[23]  R. Jakubowski,et al.  Effect of stock density on growth and survival of rainbow trout (Salmo gairdneri Rich.) , 1981 .

[24]  Robert W. Brocksen,et al.  Approaches to the analysis of energetic costs of intraspecific competition for space by rainbow trout (Salmo gairdneri) , 1977 .

[25]  T. Refstie.  Effect of density on growth and survival of rainbow trout , 1977 .

[26]  T. Refstie,et al.  Effect of density on growth and survival of artificially reared Atlantic salmon , 1976 .

[27]  Gary Wedemeyer,et al.  Physiological response of juvenile coho salmon (Oncorhynchus kisutch) and rainbow trout (Salmo gairdneri) to handling and crowding stress in intensive fish culture , 1976 .

[28]  P. Mccart,et al.  Bulbodacnitis alpinus sp. nov. (Nematoda: Cucullanidae) from Arctic char, Salvelinus alpinus L., with notes on other species of Bulbodacnitis. , 1974, Canadian journal of zoology.

[29]  K. O. Allen.  Effects of stocking density and water exchange rate on growth and survival of channel catfish Ictalurus punctatus (Rafinesque) in circular tanks , 1974 .

[30]  Owen C. Fenderson,et al.  Effects of crowding on the behaviour of juvenile hatchery and wild landlocked Atlantic salmon (Salmo salar L.) , 1971 .