Stream Toads / Slender Toads
This genus of toads currently includes about two dozens of recognized species distributed from Myanmar to Sundaland and the Phillippines, many more are expected to be discovered. Species of this genus have long and slender appendages and slender bodies. These toads are small to medium in size. Most species have a brownish coloration and a relatively dry, keratinized, warty skin, sometimes with small spines on warts. They lack a distinct parotoid gland.
These toads are found along streams. Their tadpoles are rheophilous, i.e., live in the flowing waters. The tadpoles of different species show a variable degree of adaptation to strong currents. On the island of Borneo, they are often encountered with tadpoles of the ranid genus Meristogenys on the same rocks. Tadpoles are active day and night, but are more exposed during the night when they feed on top of overflown rocks in the current.
The taxonomy of this genus ist still in a state of flux, because several species have not been described so far and some species are not easy to identify. As a result the true diversity of Ansonia is probably not yet known.