Fish can do maths.
Fish are capable of doing maths
The creatures are not known for their sharp brains but a new scientific study has revealed that they can get their heads around sums involving numbers one to five.
They were trained to recognise that yellow symbols represented adding by one and blue symbols meant subtracting by one.
If the fish were shown three blue shapes they would discover a treat by adding one to three and swimming through a gate displaying four shapes.
The tests - carried out on freshwater stingrays at the University of Bonn in Germany - and found that they were right between 69 and 94 per cent of the time.
Dr. Vera Schluessel told the journal Scientific Reports: "It could help them recognise individual fish by counting their stripes or spots."
Mathematical ability has also been found in other animals including gorillas, dolphins and elephants.