We’ve all thought about it: how do marine animals sleep without drowning? Well, sit back, because we’ve got the answers for you.
Whales live and breathe in the water day in and day out. So how do they breathe while slipping off into dreamland? Well, they don’t slip away – oceanic mammals keep half of their brain awake while the other half takes a snooze. (This helps them stay alert for predators and obstacles in their path, among other things.)
The reason for this is that marine animals, such as dolphins and whales, are conscious breathers, which means they have to voluntarily remember to take each and every breath. After a couple hours, whales will rise to the surface for some fresh air and then head back down for some more shuteye – this time turning off the opposite side of the brain.
Furthermore, since marine mammals are always half awake, they tend to sleep in the craziest positions. Whales sleep vertically or horizontally right below the water’s surface in a position called logging. They can also sleep while swimming next to another animal…talk about a great way to workout. Baby whales can even eat next to their mom and sleep at the same time. Classic midnight snacking!
A couple more underwater creatures with crazy sleeping habits are sharks and walruses. Most sharks need water constantly moving over their gills to receive oxygen. They have something called spiracles, which are small openings behind their eyes that lead to the respiratory system and help pump water over the gills while it’s sleeping.
Walruses might be the most unusual sleepers of them all. They sleep by using their tusks to anchor themselves to huge pieces of ice while their body hangs in the water and sleeps. They also have sacs in their neck, which inflate with air to the size of basketballs and act as personal floaties to keep their heads up and their bodies afloat during slumber.
The more you know!