Sunday, April 17, 2011

Another New Tiny Frog From Borneo

The Borneo microhylid, Microhyla 
berdmorei. This species is larger
than the one described here, females
of this species reach 32 mm JCM
Frogs in the family Microhylidae are mostly small, ground dwelling species that specilize in feeding on ants - there are exceptions, some have adapted to life in the trees, others are burrowers, and some are semi-aquatic; and some have adapted to eating larger prey. The genus Microhyla is widely distributed from the Japan, Taiwan, and southern China, westward to Southeast Asia, and South Asia including Sri Lanka Currently, about 30 species are recognized. The island of Borneo contains five known species of Microhyla (M. berdmorei, M. borneensis, M. perparva, M. petrigena, and M. maculifera). Recently, Das and Haas described M. nepenthicola from Sarawak, emphasizing its small size as the Old World’s smallest frog, and recorded its unique nepenthiphilous breeding habits - depositing the eggs in water that collects in plants - when they described the species. In the description of M. nepenthicola they treated a sympatric, and sometimes syntopic, larger sized species as M. borneensis. Parker (1934) identified a nepenthiphilous larva from Kuching, near the type locality of M. borneensis. During herpetological fieldwork in Sarawak, Masafumi Matsui studied nepenthiphilous larvae and their parental species at various altitudes of Gunung (= Mt.) Serapi, including the type locality of M. nepenthicola (Das & Haas). Some specimens that keyed out to M. borneensis using Inger's (1966) key, except they had a smaller adult body size. At the same locality, specimens of Microhyla sympatric with the small form also keyed out to M. borneensis. However their body size better fits his description than the smaller form. Matsui also found the large form and larvae assigned to M. borneensis in ponds and stream-side pools in Sarawak and Sabah, and the literature led him to consider the small, nepenthiphilous form as true M. borneensis, and idea confirmed examination of the holotype of M. borneensis. This lead Matsui to described Microhyla malang, a new species of microhylid from Gunung Serapi, Matang Range, in the suburbs of Kuching, Sarawak.The name malang is a Malay word meaning "unlucky," and alludes to the long history of taxonomic confusion with its related species, M. borneensis.To date the new species is known from western Sarawak and eastern Sabah, Malaysian Borneo at altitudes of 50 to 555 m above sea level. M. malang is sympatric with M. borneensis around the type locality, in Kubah National Park. Tadpoles were found in ponds and in shallow, muddy pools in drying stream beds. Adult males are in the size range of 18 to 22 mm, making it one of the smallest frogs of the Eastern Hemisphere.

Matsui, M. 2011. Taxonomic revision of one of the Old World's smallest frogs, with description of a new Bornean Microhyla (Amphibia: Microhylidae) Zootaxa 2814:33-49.

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