Affiliation: | School of Biological Sciences, University of Birmingham, Birmingham, B15 2TT, U.K. |
Abstract: | Eurythermal crustaceans survive seasonal, diurnal or tidal changes in environmental temperature by developing several capacity and resistance adaptations to change their behaviour, physiology, growth and metabolism. In temperature climates, marked physiological differences have been observed between summer and winter crayfish with seasonal changes in haemocyanin oxygen affinity and changes in the relationship between pH and temperature. Rates of protein synthesis in the leg and abdominal muscles of the native British crayfish, Austropotamobius pallipes, decreased with temperature at an exaggerated Q10 value of 5–10 suggesting metabolic depression at the low winter temperatures. A similar response was noted in the stenothermal Antarctic isopod, Glyptonotus antarcticus, as whole animal rates of protein synthesis were extremely low in this species when compared to data collected from the temperate marine isopod, Idotea rescata. This was due to the relatively high energetic cost of protein synthesis in G. antarcticus in association with low rates of oxygen uptake. Temperature also has an effect on rates of transcription of several proteins in the muscle, including actin and myosin heavy chain (MHC), with an increase in levels of expression as temperature increases in temperate and Antarctic species. The potential role of heat shock proteins as an additional strategy in the response of temperate crustaceans to thermal stress is discussed. |