Tree-climbing fish can also hop across water's surface

摘要

A SPECIES of fish known for its unusual ability to climb trees has now been spotted hopping across water. The team that made the find says it seems to be a previously unknown form of fish locomotion. "We already considered this fish to be very special since it was so adept at climbing trees and rock faces," says Parvez Alam at the University of Edinburgh, UK. "But the hopping was even more bizarre a finding than we had expected." Mudskippers are amphibious fish that can breathe out of water and use their pectoral fins to move about on land. They could be living examples of how organisms may have transitioned from water to land 350 to 400 million years ago. Alam and his colleagues originally went to the Indonesian island of Java to study how the dusky-gilled mudskipper (Periophthalmus variabilis) climbs inclined surfaces such as trees, rocks and mangrove roots. But when the researchers approached the mudskippers, the fish leapt from trees or rocks onto the neighbouring water and hopped across the surface.