Identity of Two Andean Eleutherodactylus with the Description of a New Species (Amphibia: Leptodactylidae)

Abstract

Field work on the high eastern slopes of the Ecuadorian Andes resulted in the col- lection of specimens of two species of Eleutherodactylus heretofore known only by holotypes from Equator. The species are redescribed based on fresh material and are compared with other Ecua- dorian Eleutherodactylus. Eleutherodactylus devillei is a member of the surdus group, and E. glan- dulosus is a member of the curtipes group. The specimens of E. devillei are all females and in ex- planation of the unbalanced sex ratios observed in this and two other species of Andean leptodac- tylids from Ecuador the hypothesis is advanced that the unbalanced sex ratios may reflect the col- lectors' bias. Eleutherodactylus chloronotus is named on the basis of material collected in the valley of the Rio Papallacta, Napo Province, Ecuador. Breeding was observed in March but not in July. The non- polymorphic species occurs at high elevations (2500-3350 meters) and is related to E. devillei and E. surdus. Young specimens characteristically have a bright green dorsal stripe which fades with an increase in size. * * * Frogs of the genus Eleutherodactylus make up a conspicuous element of the Neotropical fauna. Approximately 300 species are presently recognized, and a large number of South American species probably remain to be described. The most recent synopsis of the genus, Boulenger's (1882) catalogue, included 45 species; in the ensuing 40 years about half of the now recognized species of the genus in northwestern South America were named by Boulenger from Ecuador. Few of these were illustrated and the descriptions were lists of those characters that Boulenger considered im- portant. Many of the nominal species were based on specimens with inexact locality data (e.g., Andes of Ecuador, western Ecuador, or eastern Ecuador); the only descriptive data available are those included by Boulenger in the species diagnoses. Incomplete descriptions, inaccurate locality data, lack of figures, and the diversity of the genus have contributed to the difficulty of identifying frogs of this genus, which are notorious for the subtle species differences available in preserved material. It will ultimately be necessary to redescribe most, if not all, of the species named by Boulenger, if we are to gain an understanding of the composition of the genus. This paper was prompted by the rediscovery of the first two species of the genus named by Boulenger (H. devillei and H. glandulosus) on the eastern slopes of the Andes in Napo Province, Ecuador. Neither species has been collected at elevations above 3000 meters in spite of intensive field work above Papallacta, Napo Province, Ecuador.