The 5 Weirdest Ways Aquatic Animals Sleep
The ways aquatic animals sleep are understandably different those of terrestrial species. Sea creatures often have to get creative to catch some shuteye.
When you’re a sea creature, sleeping can be a challenge. How do you avoid drifting away in the current? How can you be sure a predator won’t come along while you’re sleeping? To solve these problems, adaptation has resulted in myriad bizarre and creative ways aquatic animals sleep. Let’s look at five.
- 1. Sperm whales sleep vertically.
Sperm whales sleep for 10 to 15 minutes at a time, with their bodies frozen straight up and down. Scientist don’t actually know why these whales sleep vertically. Because sperm whales are social animals, they typically move in groups, and seeing a group of sperm whales sleeping together is breathtaking.
- Dolphins sleep while swimming.
Dolphins can sleep one of two ways: a deep sleep while staying still at the surface of the water, or a light sleep while swimming slowly. Mother dolphins have to use the second technique in the weeks after they give birth.
Very young dolphins cannot swim independently yet, and they also do not sleep. To prevent her baby from sinking, Mom has to catch her Z’s on the go.
- Sharks sleep in strong currents.
Scientists still don’t understand exactly how sharks sleep, but a video captured by a team of shark researchers in 2016 provides some clues. The video shows a great white shark named Emma facing into a strong current with her mouth open. Because she is swimming very slowly, the researchers think she is sleeping.
Many shark species need to constantly keep water moving over their gills to ensure their bodies stay oxygenated, so they can’t ever stop swimming completely.
But they may be able to sleep by swimming very slowly into a strong current, like Emma does, so that water keeps flowing over their gills.
- Walruses can sleep anywhere.
The walrus is the one animal that may literally be able to “sleep on a picket fence.” Walruses have been observed sleeping in very odd positions, such as floating in the water vertically with their heads sticking out. They have even been seen sleeping in the water while using their tusks to hang onto ice floes.
Walruses usually sleep for short periods of time in the water; but when they fall asleep on land, they can sleep for up to 19 hours. They can also stay awake for a staggering 84 hours, a length of time that may be unprecedented in the animal kingdom.
- Sea otters hold hands.
You might already know this one. Sea otters sleep in the water, so they have a couple of techniques to ensure they don’t drift away. One is to hold hands with their buddies. Another is to wrap themselves with a piece of kelp that is tethered to the seafloor.
Of all the ways aquatic animals sleep, sea otter techniques are the cutest.