Frogs of the Genus Colostethus (Anura; Dendrobatidae) in the Andes of Northern Peru

Abstract

Seventeen species of the dendrobatid frog genus Colostethus are recognized in the Andes and adjacent lowlands in northern Peru. Nine of the species have been reported previously from the region and eight are described as new. Tadpoles of eight species are described and illustrated, and growth trajectories of six species of tadpoles are compared. The greatest diversity of Colostethus is in humid montane forests in the northern part of the Cordillera Central, where five species occur at elevations above 1600 m; six other species occur at elevations below 1000 m. Two of these also range into the valley of the Rio Maranon, where two additional species occur. Colostethus elachyhistus is widespread in the Andes in southern Ecuador and in the northern part of the Cordillera Occidental, including the Cordillera de Huancabamba, the higher parts of which are inhabited by C. sylvaticus. Colostethus elachyhistus and C. nexipus are the only species that occur in Ecuador and northern Peru. Seven instances of sympatry reveal slight differences in size between co-occurring species at most of these sites.