Citation Adams CE, Huntingford FA, Turnbull J, Arnott S & Bell A (2000) Size heterogeneity can reduce aggression and promote growth in Atlantic salmon parr. Aquaculture International, 8 (6), pp. 543-549. https://doi.org/10.1023/A%3A1009255612529
Abstract Aggression in groups of 0+ Atlantic salmon (Salmo salar) was monitoredat weekly intervals in two tanks containing 100 fish each. Three 1 + salmonparr were added to one of these. After 5 weeks, fish weights were measuredin both tanks and the conditions reversed. At ten weeks, weights of fish inboth tanks were measured again. In both populations, levels of aggressionamong the smaller fish were significantly lower and growth ratessignificantly higher when the large fish were present. Although the largefish attacked the small ones, the rate at which they did so was an order ofmagnitude lower that the rate at which small fish attacked each other in theabsence of larger conspecifics. This raises the possibility that levels ofaggression among farmed salmon might be reduced by the addition of a fewlarge conspecifics.