Do sponges sleep?

The goal of the proposed project is to shed light on the early evolution and function of sleep by investigating physiological and behavioural rhythms of sponges. Sponges hold an important place in the evolutionary history of animals as one of the oldest extant lineages. Importantly, it is one of the few animal groups without a nervous system. Our hypothesis is that sponges do display sleep-like behaviour and that sleep is not a feature of neurons only. If our team can demonstrate sleep or sleep-like behaviour in sponges, it would be highly unconventional since most existing ideas on the function of sleep relies on the presence of nerve cells. Consequently, demonstrating cycles of sleep and wakefulness in sponges could potentially revolutionize our view on the original functions of sleep.