The threadsnake tangle: lack of genetic divergence in Epictia tenella (Squamata, Leptotyphlopidae): evidence for introductions or recent rafting to the West Indies

ABSTRACT

The confusion between the Neotropical threadsnakes Epictia albifrons (Wagler) and Epictia tenella (Klauber) has been ongoing for decades. The lost holotype of Stenostoma albifrons, a poorly detailed original description, and dubious type locality confound the problem. Recently an extant series of nine museum specimen from Belém, state of Pará, Brazil were selected as topotypes for Epictia albifrons Wagler. From this series a neotype was designated. Here we compare the morphology of the neotype to specimens from Trinidad and Guyana, confirming that they are Epictia tenella (Klauber) not E. albifrons (Wagler). We also compare four mitochondrial and one nuclear marker from Trinidad and mainland (Guyana) Epictia tenella populations and find E. tenella relatively widespread with minimal genetic diversification between island and mainland specimens. Hypotheses that may explain the low divergence for this small, fossorial snake are explored and discussed: over-water rafting, human-mediated dispersal, and avian-mediated dispersal.

KEYWORDS:

• systematics
• phylogeny
• Neotropics
• dispersal
• scolecophidian snakes

Acknowledgments

For the use of laboratory space and logistical support we thank Alan Resetar and Harold K. Voris at the Field Museum. For the loan of specimens, access to photographs of the type specimen we thank Darrel Frost and David Kizirian at the American Museum of Natural History (AMNH); Jonathan Losos and Jose Rosado at the Museum of Comparative Zoology (MCZ). Robert Murphy and Amy Lathrop at the Royal Ontario Museum (ROM). Robert Wilson, W. Ron Heyer and Kenneth Tighe at the Smithsonian (USNM).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

International Joint Research Project (National Institute of Ecology).