A new study by research students at the California Institute of Technology has unveiled it’s not just creatures with brains that snooze – even the brainless jellyfish need their zzz’s, reports Dogo News.
Ravi Nath, Michael Abrams, and Claire Bedbrook began by populating a home aquarium with 23 specimens of the Cassiopea jellyfish. The largely immobile creatures spend their lives on the seabed, or clinging to other surfaces, with their stinging tentacles facing upwards to catch any unsuspecting prey that swims past.
The researchers, who used cameras to record the movement of the jellyfish for six days and nights, observed that the animals were 30 percent less active at night. They not only pulsated less frequently, but also underwent periods of between 10 to 20 seconds of no movement at all.