Fishbowl Adviser

How Do Fish Sleep: Everything You Need To Know

Sleep is an important part of our daily lives, It is essential for refreshing both the mind and body. And just like humans, nearly all animals sleep. And you can recognize that an animal is sleeping because their eyes are closed and they are motionless.

However, fish don’t have eyelids. Since they live underwater, they don’t have problems with dust getting in their eyes and therefore don’t have a use for eyelids. But fish do sleep. Some will sleep during the day and be awake at night, while others will sleep during the night and be awake during the day.

Grey fish

How Do Fish Sleep?

Unlike humans and other animals, fish do not close their eyes while they sleep, but you can still see that they are not awake. Just like all other animals, fish remain still while they sleep. Their breathing will slow down and you can even pick some up with your hand. But, even though most fish are motionless while they’re sleeping, there are some species of sharks that must move even during rest because they have to ventilate their gills.

Where Do Fish Sleep?

The place where fish sleep will vary from species to species. Some species will lay at the bottom of the water and tank, hide in caves and grottos, nest under aquarium plants, or even bury themselves in the sand. If you see your fish laying on the bottom like it might be stuck in an ornament or plant, there’s no reason to panic – many aquarium fish species do this while they sleep.

When Do Fish Sleep?

It is believed that most fish species have a regular sleep schedule like all animals. Most of them are diurnal, which means they will move during the day and sleep during the night. However, there are some species that are nocturnal and will prowl during the nightstand sleep during the day in a cave or crevice. Although fish sleep like all animals, there is one exception. Some fish might not sleep while they are caring for their young ones.

Do Fish Suffer From Sleep Disorders?

There isn’t much research on this topic, but a few studies have been done to see if fish have sleep disorders. It was discovered that Zebra Danios, when sleep-deprived for a few days (with a mild electrical current), will sleep more once they return to a normal cycle. However, in studies where the Zebra Danios were kept constantly under light for several days, they had normal sleep with a regular day/night cycle. It’s thought that light can inhibit the sleep hormone melatonin that Zebra Danios have, but there needs to be more research.

As for insomnia problems, so far it hasn’t been found among fish. However, there is one exception. If there is no darkness, zebrafish won’t be able to fall asleep. Luckily, they don’t experience sleep deprivation and all the effects that come with it.

How Do I Know If My Fish Are Sleeping?

Since fish don’t have eyelids and won’t have their eyes closed, it can be difficult to figure out when they’re sleeping. So what are some of the signs that your fish is sleeping?

The most obvious sign is that they will remain motionless for a while and won’t react to anything that’s going around them. They will also lay on the bottom of the water or in the aquarium. They can exhibit this behavior at any time of the day, but it will usually be the same time each day, probably when the aquarium light is turned off.

Corydoras fish

How Do I Make Sure My Fish Get Enough Sleep?

Just like all other animals, fish need to get enough sleep on a regular basis in order to stay healthy and live longer. The best way to make sure your fish get enough sleep is to make sure your aquarium light has a timer that will give them a sense of day and night routine.

In order to provide enough cover in the aquarium to make sure your fish will have a safe place to rest. And you should do regular aquarium maintenance to make sure nothing interferes with the health of your fish.


  1. Do Fish Sleep –
  2. Do Fish Sleep with Their Eyes Open? – Wonderopolis
  3. Fish Sleep Like Us, New Research Has Found – Scope


Related Posts

We will be happy to hear your thoughts

Leave a reply