Meeting Abstract

S5-2.4  Thursday, Jan. 5  Low genetic diversity across the Pacific Ocean in the pelagic sea snake, Pelamis platurus SHEEHY III, C.M.*; LILLYWHITE, H.B.; PFALLER, J.B.; Univ. of Texas at Arlington; Univ. of Florida; Univ. of Florida

The Yellow-bellied sea snake, Pelamis platurus, inhabits warm tropical waters of the Pacific and Indian Oceans and is the only extant sea snake species to have colonized the New World. At present, intraspecific patterns of genetic diversity are unknown in these snakes. Although this species is morphologically conserved, two distinctly different color patterns are observed off the northern (N) and southern (S) Pacific coast of Costa Rica. We used two mitochondrial gene fragments, ND4 (632 bp) and Cytb (1109 bp), to compare sequence divergence among individuals from Costa Rica, Panama, and Australia, and to address two questions: 1) is genetic variation correlated with color pattern in the Costa Rican populations? And 2) are large-scale patterns of genetic variation in P. platurus associated with geographic distribution in these wide-ranging snakes? Our preliminary results suggest extremely low mitochondrial diversity among comparisons of all populations. Sequence divergence between individuals from N and S Costa Rica ranged from 0.10–0.31% (Cytb) and 0.0–0.32% (ND4). Sequence divergence between Australian, Panamanian and Costa Rican individuals ranged from 0.0–0.41% (Cytb) and 0.0–0.32% (ND4). Several individuals from Costa Rica and Australia (ca. 16,000 km apart) shared identical haplotypes. These low levels of genetic variation may be explained by the natural history of P. platurus. Unlike other sea snakes, this species appears to drift passively with surface water currents, which may facilitate movement over large distances and helps to explain our preliminary genetic results. Based on these results, we plan to use more rapidly evolving genetic markers to further investigate population genetics in these pelagic snakes.