Acrobats: walking on one’s toes

The Banded Leaf Monkey is found in Singapore and the southern end of Peninsular Malaysia.

The Banded Leaf Monkey is not found outside of ASEAN. Within ASEAN it is only found in southern Peninsular Malaysia and Singapore.

Rhyacobates constrictus Tran & Nguyen, 2016
Rhyacobates gongvo Tran & Yang, 2006

If water skaters have an extreme sports category, species of Rhyacobates will fit perfectly as their champion athlete. Water skaters or water striders are known for their ability to skate on water surfaces of streams, rivers, ponds, lakes and even open oceans. Although most water striders are considered fast skaters, only a few can skate against very fast torrents like these two species.

Rhyacobates individuals are extremely hard to observe as they skate very swiftly at the middle of the stream, where the water current is the fastest, and possess reflective pubescence on their relatively small body (length ca. 6–10 mm). Thus, they can “camouflage” well with the turbulent stream surfaces. When not skating, they usually rest on partially submerged rock in the middle of the stream.

Rhyacobates are extremely skittish, so they jump off from their resting places and skate away hastily when disturbed. Their elusive behaviour contributes to their ability to successfully evade the notice of most field biologists.

Before 2006, only nine species of Rhyacobates were recognised. Recent studies have added five more species. Both these species of Rhyacobates are only known from Vietnam and are not found outside of ASEAN.