Meeting Abstract
Winter conditions in the North West Atlantic cause cunner Tautogolabrus adspersus to enter a state of extended torpor when water temperatures drop below 10° C. As one of the northern most species in the primarily tropical family, Labridae, this species has adopted a form of hibernation as a physiological response to low temperatures. We examined the impact of acclimation temperature (5, 10, 15, 20° C) on steady swimming in cunner. We hypothesized that maximum sustainable swimming speed and gait transition speed would increase with increasing temperature. Conversely, cost of transport and fin beat frequency at a given speed would not change across temperature. Through swimming step trials we found that maximum sustainable swimming speed and gait transition speed increased significantly with increasing temperature. Both cost of transport and pectoral fin beat frequency were highest at the warmest temperature tested. Low oxygen carrying capacity at high temperatures as well as an elevated standard metabolic rate were likely responsible for the increasing cost of transport with increasing temperature. At warmer (15 and 20° C) temperatures fish were capable of reaching higher velocities, causing the increase in pectoral fin beat frequency with increasing temperature. Low metabolic output and locomotor capabilities were observed at ≤ 10° C, supporting the observation of a behavioral shift at this temperature. Observations made in this study demonstrate the physiological cost of performance through an ecologically relevant temperature regime. Additionally, this work suggest that further warming in the North West Atlantic will increase the physiological cost of overwintering.
