According to the study, published in the journal Scientific Reports, cichlids and stingrays can add and subtract up to five.
The Bonn zoologist Vera Schlüssel had both species carry out simple additions and subtractions in her study. “They had to increase or decrease an initial value by one,” Key explained. To do this, she and her team used methods that have already been tried and tested in other animal species to test mathematical abilities.
They presented the fish with a collection of geometric shapes, such as four squares. If these were colored blue, it meant “add one”. Squares colored yellow meant “subtract one”. After that, the tasks were hidden and the animals were shown new pictures – one with five and one with three squares. If they swam to the right picture – i.e. when adding five blue squares instead of four – they became fish rewarded with food. If they answered wrong, they got nothing.
Learning success under water
To test whether the fish When they were able to apply their knowledge to new tasks, the researchers changed their tasks after the learning phase. It has been shown that the fish could now also solve the tasks three plus one and three minus one. Also in a combination of several geometric shapes such as square, triangle and circle fish calculated correctly.
The researchers were also surprised by the performance of the perch and ray because they do not have a cerebral cortex. In humans, this is responsible for most complex cognitive tasks. In addition, it is not known that the two fish species require a good understanding of numbers. The head of the study, Schlüssel, sees the result of her work as confirmation that humans tend to underestimate other species.
Source: Nachrichten
