Microsympatry in cryptic lowland salamanders (Caudata: Plethodontidae:BolitoglossasubgenusNanotriton) from north-western Honduras: implications for taxonomy and regional biogeography

The taxonomy of the diminutive bolitoglossine salamanders of the subgenus Nanotriton has previously been a source of confusion among specialists. At various times, at least three different species of Nanotriton have been reported to occur in Honduras: Bolitoglossa nympha, B. occidentalis and B. rufescens. Phylogenetic analysis of 16S and cyt b from samples from three localities in Honduras (departments of Yoro, Copan and Cortes) confirms that most populations are assignable to B. nympha. Nine samples collected from a single locality on the northern slope of the Sierra de Omoa, between 120 and 190 m in elevation, were found to represent two distinct taxa: B. nympha and B. rufescens. Field examination of these nine specimens found them to be morphologically indistinguishable, including a lack of maxillary teeth in all specimens. As such, in situ identification of the two species in north-western Honduras is problematic given the occurrence of the two taxa in microsympatry in at least one locality. The discovery of yet another divergent lineage of B. rufescens highlights the need for a taxonomic reassessment within this species complex.