Stingrays (left) and cichlids (IMAGE) University of Bonn Caption can perform simple additions and subtractions in the number range up to 5. Credit Photo: Prof. Dr. Vera Schlüssel/University of Bonn Usage Restrictions This image may be used together with the press release. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.