Cichlids and stingrays can add and subtract ‘one’ in the number space from one to five

Cichlids and stingrays can add and subtract ‘one’ in the number space from one to five

By V. Schluessel, N. Kreuter, I. M. Gosemann & E. Schmidt

Source: nature

3/31/2022

The numerical understanding of cichlids and stingrays was examined regarding addition and subtraction abilities within the number space of one to five. Experiments were conducted as two-alternative forced-choice experiments, using a delayed matching to sample technique.

On each trial, fish had to perform either an addition or subtraction, based on the presentation of two-dimensional objects in two distinct colors, with the color signaling a particular arithmetic process. Six cichlids and four stingrays successfully completed training and recognized specific colors as symbols for addition and subtraction.