Meeting Abstract

70.4  Thursday, Jan. 6  The effect of tail autotomy on locomotor performance in the long tailed grass lizard, Takydromus sexlineatus MCELROY, E. J.; College of Charleston mcelroye@cofc.edu

The effect of tail autotomy on locomotor performance has been studied in a number of lizard species, from arboreal geckos to generalized terrestrial lizards. These studies show that tail autotomy can have a positive or negative effect on locomotor performance with a variety of mechanisms proposed to explain these findings. This study examines the effect of experimentally-induced tail autotomy in the arboreal lacertid lizard, Takydromus sexlineatus. Two aspects of this study make it unique with respect to previous investigations. First, Takydromus sexlineatus has a tail that is relatively longer (80% of total body length) and heavier (35% of body mass) than most other lizard species; suggesting that this structure should exert a more significant mechanical load than in the species previously studied. Second, this is the first study to quantify acceleration performance as it relates to autotomy. Given the extreme size of the tail in this lacertid; it was hypothesized that the removal of the tail would result in an increase in running speed and acceleration performance on both horizontal and vertically oriented racetracks. To test this hypothesis, six individuals were run on a flat and then a vertically oriented racetrack before and after autotomy. On the flat, running speed was unaffected but acceleration was significantly reduced following tail autotomy. On the vertical, autotomy significantly reduced both running speed and acceleration. Thus, it appears that the heavy load which Takydromus sexlineatus carries does not reduce locomotor performance; rather it seems that the tail plays an important role in enhancing performance and the mechanism is likely different with respect to substrate.