CoMSES Catalog

Body size and shoaling in fish

Authored by J Krause, DJ Hoare, JGJ Godin, N Peuhkuri

Date Published: 2000

DOI: 10.1006/jfbi.2000.1446

Sponsors: Academy of Finland National Science and Engineering Research Council of Canada (NSERC) United Kingdom Natural Environment Research Council (NERC)

Platforms: No platforms listed

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

Shoaling behaviour ti generally described as a trade-off between the anti-predator benefits of living in groups and he costs of increased foraging competition. An individual's fitness varies as a function of shoal size and shoal composition, and this relationship is potentially body length dependent. As teleost fishes show indeterminate growth, many populations exhibit a broad range of individual body lengths. The latter is used as a criterion in active choice of shoaling companions, and shoals are often size-assorted. This reduces predation risk through minimizing phenotypic oddity, and may reduce competition between size-classes. There is some evidence for a positive relationship between shoal size and the body length of shoal members, although it remains unclear whether this is a result of active shoal-size choice or a by-product of the body length distribution of the population. Shoal membership is highly dynamic and individuals may maximize their fitness by switching frequently between groups of varying size and composition in response to changes in their physiological stage and the external environment. Fish shoals provide an excellent opportunity to investigate the functions and mechanisms of group living, and future studies should aim to take an integrated view of individual behaviours, group size and phenotypic composition when investigating group choice decisions. (C) 2000 The Fisheries Society of the British Isles.

Body size and shoaling in fish

Abstract

Tags