Body length rather than routine metabolic rate and body condition correlates with activity and risk-taking in juvenile zebrafish Danio rerio.
In this study, the following hypotheses were explored using zebrafish Danio rerio: (1) individuals from the same cohort differ consistently in activity and risk-taking and (2) variation in activity and risk-taking is linked to individual differences in metabolic rate, body length and body condition. To examine these hypotheses, juvenile D. rerio were tested for routine metabolic rate and subsequently exposed to an open field test. Strong evidence was found for consistent among-individual differences in activity and risk-taking, which were overall negatively correlated with body length, i.e. larger D. rerio were found to be less active in a potentially dangerous open field and a similar trend was found with respect to a more direct measure of their risk-taking tendency. In contrast, routine metabolic rate and body condition were uncorrelated with both activity and risk-taking of juvenile D. rerio. These findings suggest that body length is associated with risk-related behaviours in juvenile D. rerio for which larger, rather than smaller, individuals may have a higher risk of predation, while the role for routine metabolic rate is relatively limited or non-existent, at least under the conditions of the present study.
Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Muggelseedamm 310, 12587, Berlin, Germany. polverino@igb-berlin.de.
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Polverino
Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Muggelseedamm 310, 12587, Berlin, Germany.
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Bierbach
College of Medical, Veterinary and Life Sciences, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, U.K.
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Killen
Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Muggelseedamm 310, 12587, Berlin, Germany.|Division of Genetics and Physiology, Department of Biology, University of Turku, Itäinen Pitkäkatu 4, Turku, 20014, Finland.
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Uusi-Heikkilä
Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Muggelseedamm 310, 12587, Berlin, Germany.|Division of Integrative Fisheries Management, Faculty of Life Sciences, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany.
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Arlinghaus
D000818:Animals; D001481:Basal Metabolism; D049628:Body Size; D046352:Freezing Reaction, Cataleptic; D012309:Risk-Taking; D015027:Zebrafish / Q000378:metabolism*
allometry; behavioural type; body size; boldness; metabolism; personality