Get smart curated videos delivered to your inbox every week.      
The Kid Should See This

Do jellyfish sleep?

At first glance, humans seem to have very little in common with Cassiopea, a primitive jellyfish. Cassiopea is brainless, spineless, and spends essentially its entire life sitting upside down on the ocean floor, pulsating every few seconds. However, Caltech scientists have now discovered that, as different as our daily schedules may seem, humans and jellyfish actually start and end their days with the same behavior: sleep. This finding that jellyfish sleep implies that sleep is an ancient behavior, largely untouched by millennia of evolution.

From CalTech.edu: Listen to graduate students and study co-authors Ravi Nath, Claire Bedbrook, and Michael Abrams as they discuss their research on the Cassiopea jellyfish and its sleep-like behaviors—”the first example of sleep in animals without a brain.” Their nightly behaviors include a decrease of rhythmic bell pulsing, slower reactions to changes around them, and when kept active at night, a decrease in activity the next day.

Watch them without narration:

Related listening at SciFri: What Is Sleep? A ‘Superpower,’ a ‘Power Cleanse’.

Follow this with the benefits of a good night’s sleep and why do we sleep and how do different animals sleep? Plus: More jellyfish.

This Webby award-winning video collection exists to help teachers, librarians, and families spark kid wonder and curiosity. TKSST features smarter, more meaningful content than what's usually served up by YouTube's algorithms, and amplifies the creators who make that content.

Curated, kid-friendly, independently-published. Support this mission by becoming a sustaining member today.

🌈 Watch these videos next...

How do jellyfish sting?

Rion Nakaya

A swarm of hungry moon jellies

Rion Nakaya

Hawksbill turtle snacks on a jellyfish

Rion Nakaya

Why do we sleep and how do different animals sleep?

Rion Nakaya

A Surprising Appetite for Dead Jellyfish

Rion Nakaya

Amazing Jellies

Rion Nakaya

The Mindfulness of the Jellyfish

Rion Nakaya

Yawns, a collection film by The Mercadantes

Rion Nakaya

How Life Begins in the Deep Ocean – TED Ed

Rion Nakaya