Who will become dominant?
The roles of individual #behaviour, body size & environmental predictability in brown #trout fry hierarchies

European Journal of Ecology, 2017, 3(2), 123-133

Authors investigated performance of #browntrout fry with different behavioural characteristics, in environments differing in food predictability. They have hypothesised that more active individuals would be favoured by a predictable environment, as compared to an unpredictable environment, as a consequence of being more aggressive and likely to dominate the best feeding stations.

The hypothesis was not supported, as more active individuals instead tended to perform better, in terms of growth and survival, in unpredictable environments. However, this effect may stem from initial size differences, as more active fish also tended to be larger.

Näslund, J., Berger, D. & Johnsson, J. (2017). Who will become dominant? Investigating the roles of individual behaviour, body size, and environmental predictability in brown trout fry hierarchies. European Journal of Ecology, 3(2), pp. 123-133. doi:10.1515/eje-2017-0020

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The results highlight a potential advantage of more active and/or larger fry in unpredictable environments, while performance in predictable environments is likely depending on other phenotypic characteristics. General experimental approach can be useful for further developments in the investigation of performance of different ethotypes of brown trout fry.

Brown trout fry. Credit: authors