Marilyn sez, "In an experiment at the U. of Padua last year, female mosquito fish preferred to join shoals that were larger by just one fish, 'preferring shoals of four fish rather than three fish, and consistently preferring shoals of three fish over those containing just two.'"
This means that they have similar counting abilities to those observed in apes, monkeys and dolphins and humans with very limited mathematical ability.
Christian Agrillo, an experimental psychologist at the university of Padua in Italy said: "We have provided the first evidence that fish exhibit rudimentary mathematical abilities."
(Thanks, Marilyn!)
