A NEW MANTIDACTYLUS FROM SOUTH-EASTERN MADAGASCAR, WITH A REVIEW OF MANTIDACTYLUS-PERACCAE (RANIDAE, MANTELLINAE)

In the course of a herpetological survey in southern Malagasy rainfore st, a new species of the endemic genus Mantidactylus was discovered an d is here described as M. brunae n. sp. This frog is similar to M. per accae for which a redescription, new locality records, and natural his tory notes are provided. The examined M, peraccae specimens are slight ly warty dorsally, with small, dark protruding dots surrounding brown rounded patches on the light brown dorsum. Mantidactylus peraccae has a wide distribution in eastern Madagascar, occurring at elevations bet ween 900 and 1800 m. M. brunae n, sp, inhabits the low-altitude rainfo rest of Andohahela and differs from M. peraccae in its slender form an d smoother skin. In contrast to M. peraccae (which is arboreal), M. br unae n, sp. was found on the ground in crevices along rocky forest bro oks. Its acoustic repertoire consists of a rapid trill-like series of 3-4 click notes with a frequency ranging from about 1.4 to 6.7 kHz, wh ereas M, peraccae emits metallic sounds, single or in series, from ele vated positions. Morphological and bioacoustic differences between pop ulations attributed to M. peraccae indicate that they may constitute m ore than one species, but available data are insufficient to corrobora te taxonomic conclusions. A redescription of M. elegans, phenetically similar to M. brunae n. sp, and M. peraccae, is provided based on spec imens from Andringitra, together with a diagnostic key to the currentl y known species of the subgenus Spinomantis.