Do Goldfish Sleep?

Last updated: March 29, 2019

Overview

Do goldfish sleep? This is a common question and something that I’ve asked myself before. Back when I was still a child, I’ve always wondered how come I’ve never seen a goldfish sleeping. They always have their eyes wide open. Don’t they ever get tired of always being awake? How come they don’t have any eye bags from being awake for 24 hours?

Sleeping with eyes wide open

Yes, goldfish sleep. All animals sleep and a goldfish is no exception. The difference lies in how long they sleep and how they look while they’re asleep. For humans, we interpret sleeping as someone resting with their eyes closed. A goldfish also needs rest but they don’t have eyelids so they cannot close their eyes. Only a few species of fish have functioning eyelids. A shark is one example of a fish with eyelids.

Goldfish also do not lie down whenever they go to sleep. They just become less immobile or inactive. When a goldfish sleeps, it stays in just one place. You will see some signs of movement, but these movements are almost unnoticeable. The little movements that they do are meant to keep themselves stable while they sleep.

How does a goldfish look while it sleeps?

Observing a goldfish in a clear tank or fishbowl is the best way to take note of how a goldfish really look like while sleeping. When a goldfish sleeps, you will notice that it stays near the bottom of the fish bowl or tank. They hover about an inch from the bottom. You can also observe that its head points slightly downward.

A goldfish also changes color while it sleeps. Its color will slightly fade. The said color will return to its normal brightness when it is awake. This change in color is a survival mechanism. A dull color makes it less noticeable to predators. Maintaining a bright color while sleeping is like waving a dinner sign to predators.

There is another difference between goldfish and humans when it comes to sleep. The brainwaves of a goldfish remain unchanged while it sleeps. Unlike humans, goldfish don’t experience periods of deep sleep. Humans experience Rapid Eye Movement sleep or REM sleep. This is the sleep stage where a human body heals itself. This is also the stage of sleep where the human brain makes new memories. Maybe this is the reason why we often hear it said that a goldfish doesn’t have any memories.

When does a goldfish go to sleep?

They don’t need it to be nighttime for them to sleep. So why do they sleep at night? What they need to sleep is a dark and quiet environment. And if the goldfish is kept at a human house, nighttime is the best time to achieve these requirements. Nighttime is usually the time when a house is dark and quiet.

You can perform a little experiment to witness this firsthand. If you have a fishbowl at home, place it in a quiet room. You can then close all the curtains in that room to darken the entire room. You will notice that after a few minutes, the goldfish will become still and exhibit the signs of sleep. It will become active again if you let daylight in or if you make a loud noise. This is the reason why you should keep the noise level down if you want your pet goldfish to sleep.

Notice that if you make a loud noise when the fish is sleeping, it will startle awake. You may have also observed that some fish will hide behind plants or tank ornaments. Those places provide some cover of darkness and will allow them to sleep.

Can I make my goldfish sleep at night?

Yes, you can do this by making the environment conducive to sleep. This is easy to do if you keep a light on in your fish tank. Turn off the light in the fish tank before you go to bed at night. If you turn on and off the light on a schedule, your goldfish is more likely to follow the said schedule. It will sleep at night and stay awake during the day. Just make sure that you don’t keep the light on for more than 12 hours a day. This is to make sure that your goldfish gets enough rest each day.

Is it bad if a goldfish doesn’t get sleep?

Yes, sleeping is important for goldfish too. They’re like humans who need sleep to restore energy to their body systems. Sleeping also helps maintain their immune system. When a goldfish don’t get enough sleep, it loses its ability to fight off infections. Sleeplessness also slows down its metabolism.

They are unlike humans though, who needs at least 6 hours of sleep every day. The amount of sleep that a goldfish needs depend on the fish itself. You will notice that some goldfish take naps in the afternoon. Others stay awake the entire night. It is important for a goldfish to be exposed to a consistent day and light cycle. This will help your pet goldfish get enough sleep and maintain its health.

How do I know that my goldfish is just sleeping and not sick?

Since a goldfish doesn’t close its eyes while it sleeps, we need to rely on other signs that it is sleeping. When a goldfish sleeps, you can see it in a stationary but upright position. It shouldn’t be sideways or upside down. If you see your pet fish upside down, leaning, or lying on the bottom, there is a huge possibility that it is sick.

A fish has a swim bladder. This is the organ that helps keep them afloat or buoyant. A fish that float sideways or upside down has a disease of the swim bladder. Another symptom of this disease is if the fish has difficulty swimming.

If your pet fish is lying on the side, it is also possible that it has a bacterial infection. This can also be a result of high concentrations of nitrite or ammonia in the water. Transfer the fish to a clean container. This will allow you to clean the tank and replace the water. Check if the fish will still exhibit the same behavior in the clean tank with fresh water. If it still does, you should have your fish checked by a veterinarian as soon as possible.

How do I make sure that my pet goldfish gets enough sleep and stays healthy?

A simple way of ensuring that your fish tank doesn’t have a high concentration of ammonia is by ensuring that it is free of any dirt or too many algae. Although a goldfish can survive in algae-filled water, it still needs room to swim. Depending on the species, a goldfish can grow to between 6 and 18 inches. You should not keep a goldfish in a bowl that is too small for it. Such a small tank or fish bowl allows nitrates to build up rapidly. This can potentially poison your pet fish.

You should also limit the amount of fish food that you give to your pet. This doesn’t mean that you need to starve it. You just need to make sure that it can consume the food you give it. Uneaten food dirties water in the tank. This can result in an algal bloom. When this happens, there will be an excess of carbon dioxide in the water. Fish need oxygen and not carbon dioxide.

I know it can be time-consuming to always transfer a fish to another container so you can clean the entire tank.

A simple and efficient way of keeping your tank clean is by frequently removing half of the water. No need to remove the fish. Just scoop out half of the water and throw it away. You can then replace the same amount of water you removed with clean water. This will not prevent algal bloom but it will slow it down to a point where you don’t need to clean the entire tank every week.

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