Redescription of Colostethus marchesianus (Melin, 1941) from Its Type Locality

Colostethus marchesianus was described from Missão Taracuá in Amazonas, Brazil, in 1941. Two specimens were collected in 1924 by Douglas Melin, a Swedish naturalist who led an expedition to the site. The name Colostethus marchesianus has since been applied to many populations of frogs in Amazonian Brazil, Colombia, Ecuador, Peru, and Bolivia. The type specimens are in poor condition; in addition, tadpoles, calls, and reproductive data were not obtained at the time of collection of the original specimens. Tadpoles and calls are critical in helping distinguish among morphologically similar species. Differences in morphology and calls from various widespread populations have led us and other workers to conclude that populations currently referred to as C. marchesianus represent a number of similar species. With the objective of obtaining adult frogs for redescription, tadpoles, and calls, two of us visited the type locality in April and May 2000. Only one species of Colostethus was present in the area. We obtained adults and recordings of the call and raised tadpoles (described elsewhere) taken from the backs of parent frogs. Colostethus marchesianus from the type locality differs from specimens from Colombia, Venezuela, Ecuador, and Peru based on a variety of characters described in the literature. Thus, frogs from those localities appear not to be the same species as C. marchesianus. The detailed redescription provided herein should help future workers distinguish populations of similar species from C. marchesianus.

Fig. 2.

Dorsal, ventral, and lateral views of a preserved male (A, C, and E; INPA 7977) and female (B, D, and F; INPA 7972) Colostethus marchesianus from the type locality at Missão Taracuá in Amazonas, Brazil. Note that the chin, chest, and belly of the male are pigmented; those surfaces on the female are unpigmented. Ventral gray areas on the female are eyes and internal organs showing through thin skin

Fig. 1.

Photograph of a male Colostethus marchesianus from the type locality at Missão Taracuá in Amazonas, Brazil. The photograph has some highlights obscuring the dark band on the side of the body, but small spots comprising the oblique lateral stripe can be seen. Photograph by A. P. Lima

Fig. 3.

Right hand and right foot of Colostethus marchesianus (INPA 7970) from the type locality at Missão Taracuá in Amazonas, Brazil. The small structure below the basal subarticular tubercle on Toe V is an extra toe

Fig. 4.

Spectrogram and waveform of advertisement call of Colostethus marchesianus (INPA 7970) from the type locality at Missão Taracuá in Amazonas, Brazil. At the time of recording, this frog was producing discrete calls. This call consists of 24 notes

Fig. 5.

Spectrogram and waveform of advertisement call of Colostethus marchesianus (INPA 7971) from the type locality at Missão Taracuá in Amazonas, Brazil. At the time of recording, this frog was producing an irregular train of notes

Accepted: 16 Jul 2001