Underwater mathematicians - Can fish count?
Underwater mathematicians – Can fish count?
In search of an answer to this question, a team of scientists from the Universita degli Studio di Trento (Italy) studied the behavior of Archer Fish (Toxotes jaculatrix). These fish are often kept in aquariums, and their natural habitat is estuaries off the coast of India, Asia or Australia. The way they hunt is especially interesting. Well, thanks to the specific structure of the tongue and mouth, they shoot a column of water up to 1.6 m high from their mouth. Which precisely hits the insects hovering above it. The victims shot with this unusual weapon end up in the water, and then into the mouths of hungry archers.
As part of the research, fish were taught to spit water into a disc placed above the aquarium, on which a certain number of dots was visible (e.g. 5), for which they received a portion of food. After the training, it was time for the experimental part. Two discs with different numbers of dots (e.g. 5 and 3) are placed above the tank. It turned out that archers always aimed at the disc they had learned to recognize beforehand. The results obtained suggest that the fish somehow managed to count the dots and select the correct disc in anticipation of the reward.