Variation and taxonomic clarification of the large species of the Leptodactylus pentadactylus species group (Amphibia: Leptodactylidae) from Middle America, Northern South America, and Amazonia

Abstract

Variation of external morphology features and advertisement calls are analyzed for species currently identified as Leptodactylus knudseni, L. labyrinthicus, L. myersi, and L. pentadactylus from Middle America, the Pacific versants of Colombia and Ecuador, northern South America, greater Amazonia, and the corridor of open formations from Argentina to northeastern Brazil. Although there is noticeable geographic variation between eastern and western samples of L. knudseni, the variation is considered to be intraspecific in nature. Geographic variation within L. labyrinthicus is more pronounced and most consistent with recognizing three species: L. labyrinthicus (Spix, 1824), L. turimiquensis new species, and L. vastus A. Lutz, 1930. No new data are available for variation within L. myersi, which had previously been noted as possibly containing two species. Variation within L. pentadactylus is also pronounced and most consistent with recognizing four species: L. pentadactylus (Laurenti, 1768), L. peritoaktites new species, L. rhodomerus new species, and L. savagei new species. Some specimens that had been identified in collections as either L. knudseni or L. labyrinthicus from the Brazilian State of Pará are considered to represent an undescribed species, herein described as L. paraensis new species. Standard simple statistical tests of significance for sexual dimorphism in members of the study group may not indicate biological significance. Adult morphological and advertisement call differentiation patterns among the species recognized in this paper do not provide completely reliable information for identifying the species involved, suggesting a different pattern of differentiation than occurs in the Leptodactylus fuscus species group. Larval morphological variation and habitat differentiation may be important in the evolution of species differentiation in the taxa dealt with in this paper.