ON THE IDENTITY OF HOG-NOSED PIT-VIPERS FROM WESTERN PANAMA: A REVIEW OF SPECIMENS OF PORTHIDIUM LANSBERGII (SCHLEGEL, 1841) IN LOWER CENTRAL AMERICA.

Porthidium lansbergii is a relatively abundant pit viper in semiarid environments from eastern Panama, through the Caribbean plains and Magdalena Valley in Colombia to northeastern Venezuela. Like other members of this genus, P. lansbergii exhibits great variation in scutellation and other morphological characters, a situation that has complicated the taxonomy and identification of populations assigned to the species. In Lower Central America, P. lansbergii is known to inhabit seasonally-dry environments of the Pacific slopes of western Panama. Here, we aimed to clarify the taxonomic status of some enigmatic specimens collected in western Panama, with morphological ambiguity, resembling P. lansbergii. We used the mitochondrial marker cytochrome oxidase b to perform a Bayesian phylogenetic analysis, to evaluate the affinities ofthese specimens with P. lansbergii individuals from central and eastern Panama, and Venezuela. We also analyzed meristic morphological characters to discriminate among populations of P. lansbergii in Panama, including other species of the Porthidium genus. Our analyses indicate that the enigmatic individuals do not differ from others individuals identified as P. lansbergii, thus forming a monophyletic group. We conclude that P. lansbergii has a more extended range than currently recognized including the western Pacific in Panama.