Zebra mbuna (a species of cichlid fish) and stingrays can add and subtract one from the numbers one to five, according to a study published in Scientific Reports.

Stingrays and zebra mbuna fish can add and subtract, scientists say Tests were carried out to ensure animals were not simply memorising patterns, Sam Hancock reports Friday 01 April 2022 21:24 BST ...

Vera Schluessel at the University of Bonn in Germany and her colleagues designed tests to work out whether ocellate river stingrays (Potamotrygon motoro) and zebra mbuna (Pseudotropheus zebra) can ...