Leptodactylid frogs of the genus Eleutherodactylus from the Andes of southern Ecuador

Abstract

The frog fauna of the Andes of southern Ecuador consists of no fewer than 21 species of eleutherodactylines belonging to the genera Eleutherodactylus and Phrynopus. A single species of Phrynopus and twenty species of Eleutherodactylus occur in the Andes south of the Nudo de Azuay and north of the Huancabamba depression in northern Perú. Of the eighteen representatives of the unistrigatus group of Eleutherodactylus found in the region, sixteen are named as new species. With a single exception, the affinities of the 20 species of Eleutherodactylus are with high altitude and moderate altitude species found in northern Ecuador and southern Colombia. Eleutherodactylus bromeliaceus is most similar to a species of the Amazon basin, E. lacrimosus. The greater diversity of eleutherdactylines in the andes of southern Ecuador as compared to northern Ecuador may be a function of 1)the Pleistocene vulcanism of northern Andean Ecuador , 2) habitat contiguity in northern Andean Ecuador, or 3) the invasion of subparamo habitats in southern Ecuador by species found on the Andean slopes at more northern latitudes. In general, the andean species of Eleutherodactylus are parapatrically distributed, and the distribution areas of the southern species are smaller than those of the largely sympatric representatives of the genera Atelopus, Gastrotheca, and Telmatobius. These observations suggest that Eleuterodactylus are less vagile and more sensitive to ecogeographic barriers than are the frogs of the genera Atelopus, Gastrotheca, and Telmatobius, all of wich are larger than mst Eleutherodactylus and have restrictions on oviposition sites (all have aquatic tadpoles)