Do fish sleep at night?
Fish do sleep at night, for sure, but not like we humans sleep. For fish, there is not a long rest period dedicated to sleep. They slow down for a few seconds several times throughout the day, and during the night or, better, when there is very little light, they slow down for more extended periods.
So, how to tell if a fish is sleeping? Stay with me.
In the same way humans keep breathing while they sleep, fish keep breathing and swimming while they sleep (more slowly than when awake).
In this video, you can see a neon probably sleeping.
Night Predator Fish
Night Predator Fish, like most of the Owls, Moths, Foxes, Bats, etc., hunt at night and sleep during the day.
Check this amazing page about Nocturnal Wildlife.
Why fish don’t sleep like we sleep?
There are different reasons why fish don’t sleep like humans (for long hours). One of them is sleeping could mean death, as predators always surround. That is why some fish and other livestock, like shrimps, wedge themselves into some secure spot while resting.
For sharks, for example, swimming is not just a way of getting around but also part of their breathing movement, as when they move, the water is forced to circulate over their gills so they can get the oxygen they need.
How to tell if a fish is sleeping?
You can tell if a fish is sleeping by looking at its movements back and forth, up and down, and side to side. If he is still, such as floating, without moving forward or back for more than a few seconds, he is sleeping.
Can fish sleep?
Yes, fish can sleep, and this is the moment when they grow, regenerate tissues, and improve their health. They slow down for a few seconds several times throughout the day.
References
The US NOAA National Ocean Service has an interesting article here.
Learn more about fish
I have a couple of very interesting articles about fish that I want to share with you.
In the Fish Tank Basics, I answer some of the very initial questions one could have like for example, how much time will I need to spend taking care of my aquarium or maybe Why would I have a fish tank, not a cat or dog? Should I get a freshwater or saltwater tank?.
Another good article is the How to setup a Freshwater aquarium. Before you head to the store, you must know what is necessary; otherwise, you will buy things you don’t need, or you will need to return to the store later as something is missing.
If you have questions or suggestions, reach out to me here.
