Variation of groove counts in Caecilia thompsoni (Gymnophiona: Caeciliidae) suggests gene flow between distant populations and calls for an updated diagnosis

Abstract

Caecilia thompsoni is a Colombian endemic species known from the Magdalena Valley that reaches a large body size (1767 mm maximum total length). To clarify some taxonomic concerns, we studied variation of the primary grooves, secondary grooves, grooves interrupted by the vent, total length, body width at mid-body, and length/width. We examined 77 specimens from four populations within the Magdalena Valley and found significant variation in the east–west direction for the humid (north) and dry (south) populations. We provide a redescription for the species and comment on the taxonomic challenges that currently affect the genus Caecilia