Meeting Abstract
Understanding the impacts of temperature on ectotherm muscle is important for understanding thermal effects on whole organism performance. Much of the work to this point has been predicated on thermal acclimation of muscle via myosin isoform regulation. The duration of acclimation, however, has varied greatly in the literature. As a result, we aimed to address the effects of acclimation on fish locomotor muscle. By comparing thermally acclimated fish to fish taken and tested immediately from the wild we addressed the effects of acclimating fish to a specific thermal environment in the lab. Our study species was tautog (Tautoga onitis), a labrid fish found along the eastern coast of North America in waters that range from 5°C to 20°C. Locomotor muscle fiber kinetics and power output of the abductor superficialis muscle were measured in a group of tautog acclimated at 20°C and a group of tautog collected once water temperatures reached 20°C in the wild. Muscles were tested at 5°C, 10°C and 20°C. 20°C acclimated tautog locomotor muscle produced more power when tested at 5°C than the power produced by natural 20°C tautog when tested at 5°C. This finding suggests that increased exposure time to warmer waters allows tautog abductor superficialis muscles to perform better at colder temperatures. At colder temperatures, both 20°C acclimated and 20°C natural tautog showed a longer time to maximum twitch and time to relax when compared to that of warmer temperatures. This suggests that duration of acclimation did not impact muscle performance, rather, performance was effected by exposure to cold temperatures.
