Meeting Abstract
The Florida sand skink’s, Plestiodon (= Neoseps) Reynoldsi, use of limbs and tail in surface sand swimming and burying locomotion is of particular interest because of this animal’s greatly reduced limbs. The forelimbs retain only a single digit while the hindlimbs bear two digits. Previous work suggested that forelimbs are of little use during sand locomotion (Andrews, 1994). We conducted preliminary locomotion trials using two adult skinks that we hand-captured at the Archbold Biological station, Florida. Using a Canon 600D camera, we recorded their behavior in an indoor sand-filled test arena. Preliminary observations suggest that the skink leaves characteristic tracks when swimming on the sand’s surface, contradicting reports that tracks were a result of sub-surface swimming (Andrews, 1994). This suggests that both sets of limbs are actively used during locomotion and appear to move in a stereotypical gait, alternating diagonally-paired limbs. The skink also appears to generate thrust with its tail in certain sand burying situations. This often occurred when the skink dipped its head off to the side of its longitudinal axis to initiate the burying process. The tail whips anteriorly to such an extent that it may contact the side of the head, and the process is repeated on the opposite side. Based on our trials, it is plausible that the hindlimbs are used to push against the sand to help produce this whipping motion. Although the function of lateral tail whipping during burial is unclear, during the burying trials we observed ½ to 2 complete body undulations before full submersion. Early observations suggest the skink uses its reduced limbs during both surface sand-swimming and burial but more experimentation is required to determine the role of the tail and limbs.
