Yes, goldfish do sleep, but not in a conventional way that we as humans do. It is certainly no secret that goldfish are one of the most popular freshwater fish in the hobby, being extremely versatile, relatively low maintenance, hardy, and full of endearing behavior.
In this article, we are going to delve into not just the fact that goldfish sleep, but when they sleep, how they sleep, how long they sleep for, and whether you need to turn the lights off at bedtime for them!
How Do Goldfish Sleep?
Humans and goldfish have very different sleeping methods, which is understandable considering one resides in water and the other on land. Goldfish do not lie down on their front or side and simply rest their eyes, in fact, they do not have eyelids despite not being able to see in the dark!
When sleeping, goldfish will become much less active, typically residing in one place and moving very slowly, keeping themselves balanced and stable whilst they rest.
Do Goldfish Sleep at the Bottom of the Tank?
Yes, they tend to stay around an inch or less off the bottom of the tank almost hovering with their heads pointing slightly downward. Whilst there are many different types of goldfish, they all share the same sleeping patterns.
Do Goldfish Sleep with their Eyes Open?
Goldfish do in fact sleep with their eyes open. While it may seem weird to us, goldfish, and most fish for that matter do indeed sleep with their eyes open. This is because their brains are very much functioning at a high rate whilst sleeping, meaning they never "deep sleep" or enter REM sleep as most humans do.
Additionally, if you notice the color of your goldfish fading slightly when sleeping, do not be alarmed, this is pretty common and it will likely revert back to being bright and colorful once awake again. It is actually super clever why they do this, they change their color to protect themselves from predatory fish whilst they are sleeping.
When Do Goldfish Sleep?
In the wild, goldfish do not sleep at nighttime, however, they are extremely adaptable to almost any sleeping time or schedule. For most goldfish owners, it makes sense to get them used to sleeping at night, due to this coinciding well with most people's sleeping schedule.
How Long Do Goldfish Sleep?
Goldfish will typically sleep for anywhere between 8 to 12 hours during a 24 hour period. Usually this isn't 8 or 12 hours of straight sleep, they tend to do so in short bursts, never spending too long sleeping at any given time.
Do Goldfish Need the Light off at Night?
Goldfish tend to sleep much better when it is dark and quiet, which is the same with most fish in captivity. You can ensure this by keeping the tank light off during the night, or whenever you want your goldfish to sleep.
Noises and lights being on whilst your fish are trying to sleep will only cause them to become startled and have a disruptive sleep, which you certainly don't want to cause. So, for the best night's sleep for your goldfish, turn off your tank light and any other light in the room when your goldfish are sleeping.
The great thing about goldfish is their adaptability, which makes them very beginner-friendly. In this case, you can train your goldfish to sleep when you do, simply by turning your fish tank light off when you go to bed or whenever you want them to sleep and turning it back on when you wish them to wake. They will get used to this sleeping pattern very quickly.
How Long Should their Light be on?
Your aquarium light should be on for a maximum of 12 hours per day, so, keep that in mind when you are organizing your goldfish's sleep schedule.
Goldfish will find ways to sleep even if your tank is light, by hiding away in plants and tank decorations to get some darkness and ultimately sleep. However, this can cause them to feel stressed and it may lead to them not getting enough rest, you should certainly remove the light and create a dark atmosphere for them.
What Will Happen to your Goldfish if it Doesn't Get Enough Sleep?
Sleep and rest are abundantly important for pretty much most living things, and this is no different with goldfish. They require adequate sleep just like we do so that they can restore energy and maintain healthy immune systems.
By not getting enough sleep, they will naturally become weaker and less healthy, making them far more susceptible to catching diseases and fish infections.
Difference Between a Sleeping Goldfish and a Sick Goldfish
When sleeping, fish remain stationary, however, they are still upright, not turning sideways or upside down, and they do not look like they are in any sort of discomfort.
If your goldfish is lying at the bottom of your tank either on its side or upside down, it is a good sign that it might be sick. Additionally, your goldfish will be sleeping during its sleeping time of the day, if you notice yours constantly at the bottom of your tank even in the daytime or times it shouldn't be, something will likely be wrong and you should investigate further!
The swim bladder is the organ that helps fish keep buoyant in the water, so, if your fish is floating sideways or upside down, or has problems swimming in general, it is likely they have adopted a swim-bladder disease.
If your goldie is lying on its side it is likely a bacterial infection or a high concentration of nitrate or ammonia in the aquarium water. If you notice any of these symptoms on any of your fish, it is crucial that you take it to the vet as soon as you can. Alternatively, if your goldfish is acting a little different from usual, it could be pregnant.
If you see your beloved goldfish hovering around at the bottom of your fish tank with a slightly paler complexion than usual, do not panic! This is just a sign that your fish is tired and is looking to have a well-earned sleep. So, turn off the lights, and let your fish recharge its batteries, just like you do.