First record of cleaning behaviors of common carp, Cyprinus carpio, on grass carp, Ctenopharyngodon idellus, in large aquarium tank

Abstract

Cleaning behaviors of the common carp, Cyprinus carpio, on the grass carp, Ctenopharyngodon idellus, in a large aquarium tank were described for the first time. When a young common carp pecked at the body of an adult grass carp, the grass carp stopped swimming, raised its head slightly upward, and tilted its body at an angle. These actions of the grass carp were supposedly for requesting cleaning from the common carp. This was a rare case of cleaning behaviors among freshwater fishes.