Meeting Abstract
As non-migratory fishes, labrids from the Northwest Atlantic must be able to endure changes in temperature from 25 ° C to 0 ° C. During the winter both tautog (Tautoga onitis) and cunner (Tautogolabrus adspersus) enter into a state of extended torpor where metabolic activity is low. Cunner do this in inshore reefs while tautog make short migrations to deep reef/wrecks overwintering habitats. These habitats experience different temperatures throughout the winter with the inshore (cunner) habitat experiencing colder temperatures than the deep-water habitats. Additionally, the northern geographical range of cunner is far greater than the tautog. Given the differences in their overwintering behaviors and ranges, we predicted that muscle acclimation will differ between these species. We tested the hypothesis that cunner muscle will be better acclimated for operating in colder temperatures using workloop experiments on the primary locomotor muscle (abductor superficialis). We found that cunner muscle acclimated for cold temperatures was faster to contract and relax than tautog muscle acclimated at the same temperature. Additionally, cunner produced more force and more power at colder temperatures. Tautog muscle was more affected by temperature than cunner muscle, while showing less plasticity to acute temperature changes. Given their more southern range and more thermally stable overwintering habitats we conclude that tautog muscle cannot acclimate to temperature as well as cunner. Given the projected poleward shift of temperate animals we expect that cunner and tautog will begin competing for habitat and prey resources in northern latitude where this type of competition never occurred previously.
