Well I was thinking that light could impact the availability of their food source and so what the researchers interpret as sleep is just some other form of ener

Well I was thinking that light could impact the availability of their food source and so what the researchers interpret as sleep is just some other form of energy conservation, but the 'groggy' behavior of the jellyfish in their one experiment made me think that their energy conserving state does involve their neurons and so at that point it's hard to distinguish energy conservation from sleep.