Meeting Abstract
Acute temperature fluctuations are common in many nearshore marine habitats. Many small bodied reef fishes at temperate latitudes must cope with a wide range of thermal conditions as they do not migrate to follow optimal thermal regimes. Consequently, locomotor musculature must acclimate to a wide range of temperatures. Cunner is a small bodied labrid which occupy shallow reefs in the temperate Northwest Atlantic. This fish enters a state of hibernation in response to decreasing water temperatures. We aimed to demonstrate how this species copes with acute temperature changes to understand thermal tolerance of locomotor musculature. We hypothesized that cunner pectoral fin muscle would not differ in muscle kinetics when acclimated and tested at naturally occurring warm and cold temperatures. Following acclimation to warm (20°C) and cold (5°C) conditions, the pectoral fin abductor was tested in its acclimation and acute change temperatures. Cold and warm acclimated muscles did not differ in time to maximum twitch when subjected to an acute temperature change. When acclimated at the cold temperature and tested at the cold temperature muscles were slower to relax than the warm acclimated muscle tested at the cold temperature. Musculature acclimated at the cold temperature generally produced more power when at frequencies used during locomotion at the cold temperature. Cold acclimated muscle performed poorly when tested at frequencies commonly used during locomotion of warm acclimated fish. These experiments demonstrate that cues for hibernation in this species reduce overall muscle performance. Further work, with a large bodied congener will demonstrate the consequences of acute temperature changes on a large bodied temperate fish which migrates in response to decreasing temperature.
