Meeting Abstract

70.3  Thursday, Jan. 6  Comparative gross and sensory morphology of batoid tails NICHOLS, R.H.*; FISH, F.E.; BOETTGER, S.A.; BART-SMITH, H.; West Chester Univ., Pennsylvania; West Chester Univ., Pennsylvania; Univ. of Virginia, Charlottesville RN665540@wcupa.edu

Members of the superorder Batoidea, including skates, stingrays, electric rays, guitarfishes and sawfishes display an evolutionary trend in the transition from axial propulsion to locomotion based on the use of the enlarged pectoral fins. This transition has led to a reduction in the size of the tail, from basal batoids having a caudal fin and thick tail for swimming to recently derived batoids having a whip-like tail passively trailing the body. As the posterior lateral line extends into the tail, it is hypothesized that the whip-like tail of recently derived batoids functions as a passively towed sensory array system. This study investigated the relationship between tail morphology and superficial neuromast mechanoreceptor distribution, density, and morphology while exploring locomotion mode, habitat, phylogeny, and body morphology as potential covariates. Preliminary analysis showed no relationship between tail length and morphological body parameters, although Myliobatiformes had higher tail length variation than Rajiformes, Torpediniformes, and Pristiformes. The tail morphology, phylogeny, habitat, and locomotion mode may also be contributing factors to the distribution and density of superficial neuromasts. Histological analysis of the posterior lateral line and surrounding epidermal tissue in Dasyatis sabina displayed various sensory receptors, including superficial neuromasts, lateral line canals, and Vesicles of Savi, in the body and tail.