Systematics and biogeography of Eastern Caribbean frogs (Leptodactylidae: Eleutherodactylus), with the description of a new species from Dominica

Populations of Eleutherodactylus on the island of Dominica, West Indies, differ from other Lesser Antillean members of the genus by their vocalizations, morphology, sexual size dimorphism, allozymes, and chromosomes. Thus, these populations comprise a new endemic species, closely related to E. johnstonei and E. martinicensis. The new species is most abundant in montane forest habitats at elevations of more than 500 m. Females commonly attain snout–vent lengths of more than 35 mm, making them the largest Lesser Antillean Eleutherodactylus. Frogs are brown during the day, but change color to dark orange when active at night. This species is the ninth Eastern Caribbean Eleutherodactylus species and the fifth single-island endemic. A phylogenetic analysis of external and internal morphological characteristics shows that Eastern Caribbean Eleutherodactylus are members of two distinct clades, one of South American origin, the other of Greater Antillean ancestry. We suggest that the present distribution of these species results from the dispersal of elements of the larger herpetofaunas from the Greater Antilles and South America, and that rapid divergence of the Eastern Caribbean Eleutherodactylus fauna may be continuing. The phylogenetic analysis also confirms that morphological characters of Eleutherodactylus species can be highly homoplastic.