Meeting Abstract

P2.50  Saturday, Jan. 5  Thermal effects on jumping kinematics in plethodontid salamanders WHITENACK, LB*; RYERSON, W; Allegheny College; University of Connecticut lwhitena@allegheny.edu

Many plethodontid salamanders must endure a wide range of environmental temperatures, yet still be able to escape and feed despite the strong effects of temperature on muscle function and performance. On the other hand, ballistic movements, which rely more on elastic recoil of structures, have been found to be thermally independent. Jumping is typically described as a ballistic movement powered by elastic recoil of structures loaded by muscle contractions, and is used by plethodontid salamanders as a means of escape. We examined jumping behavior in Plethodon cinerus and Desmognathus ochrophaeus across a temperature range of 5-25°C in order to understand how the jump is affected by temperature and to elucidate muscular versus elastic contributions to jump mechanics. Salamanders were filmed at 500 fps jumping over a 5 cm gap, with five trials per temperature (5, 15, 25°C) per individual. Q10 (or R10) values were calculated for bending and unbending angular change, durations, and angular velocities. Preliminary results indicate that the while the much of the bending kinematics were unaffected by changes in temperature, unbending duration and velocity were significantly higher than 1 (Q10 = 1.6 and 1.4 respectively), suggesting that jumping in plethodontids may not be powered by elastic recoil as it is in other organisms.