Discovery of the Frog Genus Anomaloglossus in Panama, with Descriptions of Two New Species from the Chagres Highlands (Dendrobatoidea: Aromobatidae)

The occurrence in Panama is documented for the South American frog genus Anomaloglossus (Dendrobatoidea: Aromobatidae). Two species are described from a low, forested uplift in eastcentral Panama, just northeast of Panama City. These low mountains, unnamed on maps, are designated the “Chagres Highlands” because a large part of the uplift lies in the Río Chagres drainage (which provides water critical to lock operation in the Panama Canal). The Chagres Highlands may be a lower montane forest refuge for some amphibians and reptiles, including the two Anomaloglossus and Atelopus limosus, and the rare snakes Atractus depressiocellus, A. imperfectus, Geophis bellus, and Rhadinaea sargenti. Several other rare species are not endemic but include the Chagres Highland area as part of their individually fragmented or mosaic distributions (Adinobates fulguritus, Anolis kunayalae, Coniophanes joanae, Geophis bracycephalus, Dipsas nicholsi). The two new frogs are at least broadly sympatric in the Chagres Highlands, but both species are rare. Anomaloglossus astralogaster, new species, is known only from the adult female holotype (22 mm SVL). Its ventral surfaces are covered overall with whitish dots (≤ 0.1 mm) somewhat similar to large chromatophores but possibly glandular; there is no appearance of glandular structure at ×50 magnification, but the edges of some of the pale dots can be “felt” with a fine (0.1 mm diameter) teasing needle and histological examination is needed. The other taxon is Anomaloglossus isthminus, new species, which is described from six specimens including four adult males (19–21 mm SVL), one adult female (23 mm SVL), and a juvenile female. Dorsal surfaces are basically brown mottled with darker brown. Small pale yellowish spots located proximally above the insertions of arm and thigh are not well defined and tend to disappear after preservation (unlike normal dendrobatid flash markings). Ventral surfaces are pale blue with some dark mottling but no pale dots. The vocalization of A. isthminus resembles calls of some South American species in being a train of “peeplike” notes, but there are fundamental interspecific differences in frequency modulation, note repetition rate, and call length.