TAXONOMIC STATUS OF HYLOMYS-PARVUS AND HYLOMYS-SUILLUS (INSECTIVORA, ERINACEIDAE) - BIOCHEMICAL AND MORPHOLOGICAL ANALYSES

The genus Hylomys was thought to be represented by a single widespread species. Biochemical and morphometric analyses of several Southeast A sian populations reveal that Sumatra is inhabited by two distinct spec ies, the dwarf gymnure (H. parvus) and the lesser gymnure (H. suillus) . The absence of interbreeding between these two groups along with the ir relatively ancient common origins are documented by several diagnos tic loci and a large Nei's genetic distance (D = 0.353 +/- 0.035). The dwarf gymnure has been reported only from the slopes of the Mt. Kerin ci volcano in Sumatra, where the species lives at higher elevations th an its potential competitor, the lesser gymnure. Other populations of Hylomys from Java, Borneo, and Malaysia are more closely related to th e Sumatran sample of H. suillus, but they exhibit strong interpopulati onal genetic differentiation (D = 0.165 +/- 0.040) that may be account ed for by their isolated montane habitat. In addition, a principal-com ponents analysis based on 16 measurements of the skull clearly separat es adult specimens of both species. There is little overlap in the mea surements between H. suillus (which is larger) and H. parvus. On Sumat ra where both species may be sympatric, the notched space between prem axillary tips, soft texture of the fur, and more delicate skull and de ntition are diagnostic of H. parvus.