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Do Betta Fish Sleep – Where, When And For How Long?

If you’re new to keeping betta fish, you may be wondering if your pet ever sleeps.

Do fish sleep is not a silly question!

After all, how can a fish sleep without sinking to the bottom of the tank? And, don’t fish need to keep swimming to breathe?

Well, in this article, we answer those questions, as well as telling you everything else that you need to know about your betta’s sleeping habits.

Do Betta Fish Sleep?

man's hand holding a glass of water with betta fish inside

All fish sleep, including bettas.

But how do fish sleep?

Fish do not sleep in the same way that people and animals do, although most fish species do rest.

Many fish species can slow down their metabolism and reduce activity levels while still remaining on the alert for potential danger. Some species float motionless, others burrow into the substrate or hide in a rock crevice, while some choose a suitable nest in which to snooze.

Research indicates that these periods of “suspended animation” help the fish to recuperate and rest, just as sleep does in mammals.

When Do Betta Fish Sleep?

Some species of fish are nocturnal, spending the day hiding and resting, and then coming out at night to feed. Betta fish are most active during the day, primarily sleeping at night. That said, bettas are notorious for taking short “catnaps” during the daytime too.

Best Betta Tanks—A Complete Buyer’s Guide - Two betta fish put inside on a separate tanks.

So, do fish sleep with their eyes open?

With the exception of the freshwater pufferfish, most other fish species do not have eyelids, so they can’t close their eyes when they sleep.

So, why don’t fish have eyelids? Well, the eye first appeared in the ancestors of fish. The eye’s surface needs to remain moist constantly, making it well-suited to an aquatic environment. That’s why fish do not have eyelids; they simply don’t need them. However, eyelids have evolved in land-dwelling creatures to prevent the eyes from drying out.

For that reason, you should limit the number of hours that your tank light is switched on during the daytime, and always make sure that the tank is in darkness at night. That means that your betta will understand when it’s daytime and when it’s night time when he should be sleeping.

How to Tell if a Fish is Sleeping?

Beginner’s Guide to Betta Fish_ Facts, Tips and Advice for a Healthy Betta Set-Up- Betta fish in black background.

Some species of fish are nocturnal, spending the day hiding and resting, and then coming out at night to feed. Betta fish are most active during the day, primarily sleeping at night. That said, bettas are notorious for taking short “catnaps” during the daytime too.

Betta fish can sleep in several locations and positions, which can be confusing. Take a close look at your fish. If he is motionless but his mouth and gills are slowly moving as he breathes, then he is most likely asleep.

Some experts maintain that bettas’ colors appear less vivid while the fish is sleeping. Conversely, the colors become brighter when the fish is spawning or displaying aggression.

If you notice those signs at night, it’s a pretty good sign that your betta is sleeping. However, don’t forget that betta fish also like to nap during the daytime. So, an inactive betta is most likely asleep, no matter what time of day or night it is.

Betta Fish Sleeping Behavior

Fighting fish (Betta splendens) Fish with a beautiful array of colorful beauty.

So, how do betta fish sleep?

Betta fish show a variety of different sleeping behaviors, which can be confusing, especially if you’re a new owner.

In this section of our guide, we take a look at betta fish sleeping behavior so that you can tell if what your pet is doing is normal or if it’s a cause for concern.

Do Betta Fish Sleep On Their Sides?

Bettas do sometimes sleep on their sides, usually when provided with a comfy “bed” of thick leaves or a special betta hammock.

Usually, movement near to the tank will disturb the betta, and he’ll swim away. However, if your fish spends a lot of time laying on his side, he could have a health problem, such as ammonia poisoning, swim bladder disease, or temperature shock.

Do Betta Fish Sleep On the Bottom of the Tank?

Feeding Baby Bettas in the Aquarium with Frozen Baby Brine Shrimp

As bettas spend most of their time in the upper area of the water column, feeding and periodically gulping air from the surface, you may be somewhat alarmed to see your pet laying on the bottom of the tank.

Don’t worry! It’s not uncommon for betta fish to take a nap on a comfy area of the substrate, especially if you use sand.

However, be alert to potential issues that could be causing your betta to sleep on the bottom.

In their natural habitat, betta fish live in very slow-moving water in rice paddies, marshes, and water ditches. So, if the filter current in the tank is too powerful, your betta may be buffeted around too much for comfort, so he will sink to the bottom to avoid the pump’s flow.

Also, the temperature in the tank may not be consistent throughout, and your fish could be relocating to a spot where he’s more comfortable.

Colorful with main color of blue betta fish, Siamese fighting fish was isolated on black background.

By placing the heater next to the filter outlet, you’ll ensure that warmed water is pushed evenly throughout the tank. Position your thermometer at the end of the tank farthest away from the heater. That way you can tell if the temperature is equal at both ends.

Do Betta Fish Sleep On Leaves?

Betta fish do like to sleep while resting on broad-leaved plants. The plants act as a comfy hammock, supporting your betta while he snoozes.

The best plants for betta fish include Anubias, whose leaves form a cuplike bed that’s perfect for a sleepy betta. If you don’t have live plants in your tank, you could invest in a betta leaf hammock. These silk faux-leaves are inexpensive and most bettas love them.

How Else Do Bettas Sleep?

Bettas have individual sleeping preferences. Some like to sleep on their side, some sleep vertically, and some wedge themselves between the side of the aquarium and the filter housing. As long as the behavior is repeated regularly and the fish is eating and otherwise active, that’s fine.

Does Your Betta Need A Bed?

betta fish, siamese fighting fish in aquarium

Not all bettas need something to sleep on. Many are content to sleep on the substrate or resting on clumps of plants, and some simply float while they sleep. As you get to know your pet, you will quickly see his preferences.

Do Bettas Need Darkness To Sleep?

Your betta is similar to you in that he needs a certain amount of darkness each day so that he knows when to sleep.

Ideally, you should provide your fish with between eight and 12 hours of daylight and 12 to 16 hours of darkness each day. You should certainly not leave the light on in your tank at night. After all, could you sleep with the lights on and your eyes wide open? Read our article “Do Betta Fish Like Light?” for more information.

How Long Do Fish Sleep?

As you’re asleep at night yourself, it’s hard to estimate how much time your betta spends sleeping. However, even if your fish is active for part of the night, he will make up for that by taking small naps during the day.

However, if you notice that your fish is very inactive during the daytime, that could indicate a health problem.

Is Your Betta Oversleeping?

Wild nature betta splendens or wild siamese fighting fish with black background.

Bettas are usually fairly active, social fish, coming to the surface when you approach the tank or interacting with tankmates.

If your betta seems to be sleeping constantly during the daytime, you should check that there isn’t a problem. There are a few things that could be causing your betta to oversleep:

Temperature shock

Bettas are very sensitive to changes in temperature. If the water in the tank is too cold, your pet could go into temperature shock or his metabolism could slow down so that he is much less active than he should be.

If the water temperature drops below 72 degrees Fahrenheit, your fish will be too cold. You’ll need to warm the water gradually. Don’t suddenly heat the tank or you risk making your betta’s condition worse. Gradually raise the temperature over an hour or so. You should see your betta “waking up” once he’s warm.

siamese fighting fish , betta isolated on white background

You should have a heater for your tank so that the water temperature can be maintained at a constant 78 degrees Fahrenheit. Be sure to buy a tank thermometer and check the temperature daily.

The Tank Lighting is Too Dim

Fish determine when to sleep depending on how much light there is in their environment.

Therefore, if you have your lights off for too many hours, or your aquarium lights are too dim, your betta will assume that he should sleep more.

Your Betta is Bored

Although many people assume that fish are not particularly bright, bettas are highly intelligent and require plenty of mental and physical stimulation to keep them from becoming bored.

R2 Fish School Complete Fish Training Kit

Be sure to include plenty of decorations in your betta’s tank, including floating logs and plants to explore. Also, bettas are very interactive fish and even enjoy taking part in fish training sessions!

However, we do not recommend using mirrors. Betta mirrors are designed to encourage your betta to flare by making him think that a rival male is invading his territory. Although the display might look impressive, Aggravating your betta in this way will stress him, which may cause health problems.

Although you can’t keep two male bettas together as they will fight, you can include a few peaceful tankmates to create a community and provide company for your lonely betta. Corydoras catfish make good tankmates for bettas, as do small Gouramis.

Your Betta is Sick

If your betta suddenly begins sleeping a lot and everything in the tank is fine, it’s possible that he is sick.

Take a close look at your fish to see if he has any ulcers, fluffy white growths, white spots, or obvious lumps and bumps on his skin that could indicate a bacterial infection or disease.

Betta Fish swimming

Bettas can be prone to developing constipation if they are overfed or if their diet is not correctly balanced.

A constipated fish will usually rest on the substrate or appear unable to keep himself on an even keel while he’s swimming. In that case, do not feed your betta for 24 hours, and then offer him a small portion of frozen or live bloodworms. In my experience, that usually solves the problem.

Is Your Betta Old?

Bettas generally have a lifespan of up to four years, sometimes less. If your fish is in his senior years, you should expect him to sleep more.

Don’t be unduly concerned. Just let the old-timer have his rest as and when he needs it.

You Have a Lazy Betta!

Yes, just like some people, you can get bettas that are just plain lazy!

Betta Fish swimming

You could try providing your fish with some entertainment in the form of tankmates and toys, and you could try some training activities with him to coax your fish into being more active.

It’s important that you encourage your betta to take some exercise, as these fish are prone to obesity, which can cause serious health issues, potentially shortening your pet’s lifespan.

Final thoughts

Understanding your betta fish’s sleeping patterns and habits is crucial if you are to keep your pet in good health so that he thrives.

Betta fish need sleep just like their owners do. So, be sure to provide your pet with something to rest on and limit the hours of daylight in the tank to encourage your betta to sleep at night.

Provide your betta with a few tank mates or toys so that he doesn’t become bored and inactive, and always make sure that the water temperature in the tank is correct.

Alison Page has been an avid fish keeper for over 35 years and has owned many different species of freshwater tropical fish including bettas. Currently Alison has two large freshwater tanks. The first tank has two huge fancy goldfish who are almost ten years old and still looking as good as ever. In the other, she has a happy community of tiger barbs, green tiger barbs, corydoras catfish, platys, and mollies.

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