A new study shows zebrafish have rhythm, and it may be a survival mechanism. After being taught a "rhythm" using flashes of light, the larvae "remembered" the beat pattern for 20 seconds after the flashes ceased. This finding suggests that the fish possess a sort of mental metronome that can help them evade predators.
With each light "beat", the baby zebrafish wiggled their tails and experienced activity in their brains that possess visual information, the optic septum. When the researchers turned the lights off, the fish continued to wag their rears and show signs of brain activity in time with the rhythm.
Dragonfly larvae are the chief predators of zebrafish babies. By learning the dragonflies' rhythm, zebrafish may anticipate their enemies' next moves and act to escape the attacks.