Matang narrow-mouthed frog

Appearance

''Microhyla borneensis'' is a very small species with a snout to vent length of about 18 mm for females and around two thirds of this for males. It has a broadly triangular body that is flattened dorso-ventrally. The snout is obtusely pointed, the eyes are small and have round pupils and there are no visible tympani. The skin on the dorsal surface may be smooth or bear tubercles and that of the ventral surface is always smooth. The limbs are short. The hands are unwebbed and the outer digits are spatulate. The digits of the feet are partially webbed. The dorsal surface of this frog is reddish-brown, the throat is mottled brown and the ventral surface is pale.

Distribution

''Microhyla borneensis'' is known from the Matang Range in Sarawak, Borneo, but it is presumably widespread in suitable habitats in the lowlands of northern Borneo.

''M. borneensis'' is found near Mount Serapi in Kubah National Park, Sarawak, Borneo. It spends much of its life cycle in the traps of the pitcher plant ''Nepenthes ampullaria'', after which it is named. It is therefore considered a nepenthebiont. This is not particularly unusual; in fact, it shares this environment with a species of crab spider, ''Misumenops nepenthicola'', which is also commonly found in ''Nepenthes'' pitchers, and is similarly named for this reason. ''Microhyla nepenthicola'' has less webbing on its feet than most frogs, which may be beneficial when trying to climb the sides of the pitcher plants, which can be slippery.

Status

This frog is seldom seen, perhaps because of its small size and inconspicuous appearance. Its numbers are thought to be in slow decline but the IUCN rates it as being of "Least Concern" as it considers that the rate of decline is insufficient to justify listing it in a more threatened category. No particular threats to this species have been identified.

Behavior

''Microhyla borneensis'' breeds in the water-filled pitchers of ''Nepenthes ampullaria'', a pitcher plant that is a feature of the floor of the Borneo rainforest. Multiple clutches may be laid in the same pitcher which may contain tadpoles of different ages. Metamorphosis takes place about a fortnight after the eggs are laid.

Habitat

''Microhyla borneensis'' is known from the Matang Range in Sarawak, Borneo, but it is presumably widespread in suitable habitats in the lowlands of northern Borneo.

''M. borneensis'' is found near Mount Serapi in Kubah National Park, Sarawak, Borneo. It spends much of its life cycle in the traps of the pitcher plant ''Nepenthes ampullaria'', after which it is named. It is therefore considered a nepenthebiont. This is not particularly unusual; in fact, it shares this environment with a species of crab spider, ''Misumenops nepenthicola'', which is also commonly found in ''Nepenthes'' pitchers, and is similarly named for this reason. ''Microhyla nepenthicola'' has less webbing on its feet than most frogs, which may be beneficial when trying to climb the sides of the pitcher plants, which can be slippery.