Strain-specific alteration of zebrafish feeding behavior in response to aversive stimuli.

Behavioral management of risk, in which organisms must balance the requirements of obtaining food resources with the risk of predation, has been of considerable interest to ethologists for many years. Although numerous experiments have shown that animals alter their foraging behavior depending on the levels of perceived risk and demand for nutrients, few have considered the role of genetic variation in the trade-off between these variables. We performed a study of four zebrafish (Danio rerio (Hamilton, 1822)) strains to test for genetic variation in foraging behavior and whether this variation affected their response to both aversive stimuli and nutrient restriction. Zebrafish strains differed significantly in their latency to begin foraging from the surface of the water under standard laboratory conditions. Fish fed sooner when nutrients were restricted, although this was only significant in the absence of aversive stimuli. Aversive stimuli caused fish to delay feeding in a strain-specific manner. Strains varied in food intake and specific growth rate, and feeding latency was significantly correlated with food intake. Our results indicate significant genetic variation in foraging behavior and the perception of risk in zebrafish, with a pattern of strain variation consistent with behavioral adaptation to captivity.