Sleep in a schooling fish, Tilapia mossambica

There are only a few infra-mammalian studies on sleep. For this reason, behavioural sleep in the fish T. mossambica was investigated and the increased response threshold to electrical and feeding stimuli measured. The results of these studies afford little evidence for REM-like sleep; however, the possibility of this kind of sleep is not precluded. Behavioural sleep is established for this species of fish.