Phenotypic plasticity of fish muscle to temperature change

Abstract

The swimming performance of teleost fish is highly dependent on temperature. Natural selection has acted to adjust locomotory performance to particular thermal environments involving selective changes at the level of the genome. Johnston and co-workers have investigated muscle contraction associated with escape behaviour in teleosts from polar, temperate and tropical environments (Johnston, 1990). Force production shows perfect temperature compensation, whereas rate parameters, including force development, cross bridge cycle times and relaxation are significantly slower in Antarctic than tropical species (Johnston and Altringham, 1985; Johnson and Johnston, 1991a). It would appear that constraints to the adaptation of muscle proteins in low-temperature environments limit the maximum swimming speeds that can be attained (Johnston et al, 1991). Specialized biochemical adaptations to particular temperature regimes restrict the geographical ranges of polar and tropical species. Some, mostly temperate species, experience large seasonal changes in water temperature. In these species, phenotypic adaptations to temperature enable swimming performance to be adjusted to local conditions within certain limits (Johnston and Dunn, 1987). A fall in water temperature during the winter months may result in a dramatic reduction in the availability of prey species.