[Sleeping upside-down jellyfish Cassiopea andromeda]
[Waves crashing against the sand]
[Lewes Beach Patrol lifeguard handling and educating beachgoers on moon jellyfish]
[Divers passing through a school of fish]
[Timelapse showing pulsation behavior of the upside-down jellyfish Cassiopea andromeda]
Oren Levy (interview): “The key finding is that you have a very basic organism, doesn’t have brain or eyes. They still can sleep. We see them sleeping for eight hours per day, and I think they’re doing that; I don’t think we know they’re doing that in order to reduce the DNA damage that is accumulating when they are active. When you sleep, even if you sleep in fragments, you don’t sleep for the total eight hours. But you sleep, in fragments during a one hour, for example, but when you sum all the fragments when you are resting or sleeping, it can be coming for eight hours, it’s helping to reduce this DNA damage in the sense.”
[Timelapse showing movement and contraction of the sea anemone Nematostella vectensis in wake and sleep periods]
Lior Appelbaum (interview): “When we studied, we used video tracking, IR video, infrared video tracking during the day and during the night, and we basically follow the movement of either the sea anemone or the jellyfish. So if we take the jellyfish, we found that they reduce their pulsation rate during the night and increase during the day. Of course, like you said, I mean, this is a simple animal with simple nerve net, and maybe they just reduce activity, not just (when they) sleep.”
[Cassiopea andromeda in its natural habitat underwater]
Lior Appelbaum (interview): “We applied a very specific stimuli. It can be light, it can be sound, it can be food, I mean smell. And then we measure the response to the stimuli. So for example, if you’re awake, but don’t move, and I do that, and you respond. But if you will be sleepy, I will need to increase the arousal threshold, that stimuli, and because your arousal threshold is increased. So it’s exactly the same thing we do to the jellyfish and the sea anemone, we use various stimuli to show that during sleep they demonstrate increase of arousal threshold.”
[Confocal image of the nerve net of the sea anemone Nematostella vectensis]
[Fluorescent image of an adult Nematostella vectensis, showing neurons in orange highlighted by a transgenic fluorescent reporter line]
Oren Levy (interview): “This study and other studies in my lab, we know that what we call sensory pollutants, so for example, you use your phone during nighttime or you have what we called light pollution from urban areas or you have a light interfering your sleeping, it can cause what we know as sleep deprivation. So, the more we reduce these sensory pollutants or these stressors on our sleep, and we sleep better, the chance for us is to do DNA repairing is much much better. And I think that this can help our health for the longevity of the people.”
[Jellyfish on the sand at the beach]
[Lewes Beach Patrol lifeguard handling and educating beachgoers on moon jellyfish]
This script was provided by The Associated Press.