Photo/IllutrationChimpanzees forage for freshwater crabs in a stream. (Provided by Kathelijne Koops, a researcher of the University of Zurich in the international team)

  • Photo/Illustraion

Researchers who discovered that chimpanzees living in the rainforests of Guinea in West Africa are fond of eating freshwater crabs said the finding may reshape perceptions of early human ancestors.

Until now, it was commonly accepted that anthropoid apes, the closest species to humans, shy away from water and shun aquatic creatures in their diet.

The finding offers pointers on how man's distant ancestors came to feast on aquatic creatures.

An international research team, which involved members from Kyoto University, announced their findings in the online edition of Journal of Human Evolution, a British science publication, on May 29.

Team members found evidence in 2012 that chimps had rolled over stones in a stream and scratched them with their fingers in the Nimba Mountains of Guinea.

The team set up cameras at four locations through April 2014, which captured images of chimps eating freshwater crabs on 181 occasions. In many cases, female chimps came with their young.

Traditionally, it was assumed that man's distant ancestors began to eat aquatic life around 2 million years ago when they began to leave deep forests and settle near flowing water.

Tetsuro Matsuzawa, a distinguished professor of Kyoto University and a primatologist, said, “This indicates the possibility that ape-men living in deep forests were already eating aquatic creatures more than 4 million years ago.”