The research group led by Prof. Dr. Vera Schluessel from the Institute of Zoology at the University of Bonn has proven that Cichlids and stingrays can perform simple addition and subtraction up to the number five. The researchers still do not understand how fish use this ability.
What makes this very interesting is that fish do not have the part of the brain that allows them to perform complex cognitive tasks and these species of fish do not need the ability to count in the wild. Other species of fish do pay attention to the number of eggs in their clutch.
Author’s Note: It is always amazing to learn that fish and animals have more intelligence than humans assumed that they have. It makes it exciting to think of what is yet to be discovered and should make people pause the think about how we treat other species.