Meeting Abstract

82.2  Monday, Jan. 6 10:45  Thermal response of prey-capture kinematics in teleost fishes departs from physiological expectations SLOAN, T.J.*; TURINGAN, R.G.; Florida Institute of Technology tsloan2009@my.fit.edu

As poikilotherms, the physiological performance of fishes is expected to reach optimum levels at a narrow temperature range. As a consequence of the direct effects of environmental temperature on the contractile properties of skeletal muscle, it is expected that the rate of motion in muscle-driven mechanisms doubles for every 10°C change in ambient temperature (i.e., Q₁₀=2.0). This study examined the variation in Q₁₀s of prey-capture kinematic velocities among cyprinodontiform, scorpaeniform and perciform species, as well as among a size series of cyprinodontiform and scorpaeniform fishes, in an attempt to address the question, “How does temperature affect whole-organism performance in teleost fishes?” Size-corrected Q₁₀s for gape, hyoid, lower-jaw displacement, and cranial rotation velocities in fish feeding at 20°C and 30°C ranged from 0.56 to 1.44 in all three species. Intraspecific analyses revealed that the Q₁₀s for the same kinematic variables were 1.0-1.50 in pike killifish (17-101mm SL) and 1.02-1.40 in lionfish (36-107mm SL). These results indicate that prey-capture performance remains largely unaffected by temperature at both interspecific and intraspecific levels of investigation. In the light of the climate-change phenomenon, it is imperative that we advance our understanding of the mechanisms that underlie whole-organism performance in different temperature regimes.