Do goldfish really sleep?
They do indeed!
Most animals need some time to “recharge their batteries,” and goldfish are no exception.
FACT:
Goldfish actually sleep with their eyes open – because they don’t have eyelids!
This means suddenly turning on the lights can be quite a shock for them.
How do you know when your fish is catching some zzz’s?
Exactly How do Goldfish Sleep?
- Once it gets dark (and sometimes in the late evening), you may see your fish “hanging” in midwater – dorsal fin slightly relaxed, fins outspread gracefully.
- Every so often they might move their fins to keep their balance.
- Their colors might even fade a bit… but quickly return once they wake up.
Now:
Just how deeply do they sleep?
While we don’t know exactly, it would seem pretty lightly due to the two facts that:
- Unlike sleeping people, their brainwaves don’t change. Mammals have EEG waves that characterize that they are asleep.
- REM sleep, another sign of a very deep sleep, just doesn’t happen with cold-blooded animals such as fish.
They do have reduced activity and their metabolism slows, so there is definitely
It’s really important not to keep the goldfish’s light on in the aquarium 24/7. The natural day and night cycles are essential for their health, and has been proven to affect their immune system.
Sleep probably also serves other purposes for fish as well, some of which may not have yet been discovered. We know it serves to help restore their energy.
Get this:
In the wild, goldfish even have what seems to be a “yearly sleep” of hibernation when they don’t move around or eat much.
They spend the cold winter months near the bottom of the pond totally oblivious to everything, and seem to be living in slow-motion.
Tip:
Considering how important this period of nightly rest is, it’s a good idea not to do anything that might startle your fish unexpectedly and cause stress.
What About Other “Sleeping Positions?”
Sitting on the bottom of the aquarium isn’t a sign your fish is asleep, especially if that is happening during the day.
Actually, looking droopy at the bottom of the tank probably means your fish isn’t feeling well due to a problem in the aquarium or with the fish.
Bottom sitting could be an indication of issues with the water quality, infection and illness, or even constipation. Constipated goldfish may have trouble sinking to the bottom of the tank.
Does it look like your fish is sleeping upside down or on its side?
If so, chances are it might have swim bladder disorder or another health issue and is definitely not dozing.
A belly-up fish (if it is still alive) is not in a natural sleeping position at all, and is probably feeling stressed because it isn’t normal.
Swim bladder disorder can cause the fish to completely flip upside down and cause a lot of difficulty when swimming. This is due to the swim bladder organ being filled with air and unable to regulate itself properly.
You can click here to read more about Swim Bladder Disorder.
A fish laying on its side is usually having serious problems as well, and may be affected by an internal bacterial infection or caustic burns from high ammonia or nitrite levels.
The fish will usually be very lethargic, but that is because it is feeling bad rather than sleeping.
Goldfish Sleep FAQ
Q. How long do goldfish sleep?
It’s hard to know exactly, as some goldfish seem to enjoy taking a late afternoon siesta while others remain active all day until nightfall.
Most likely, their sleeping habits follow the day and night light cycle.
Q. Is your fish sleepy if it yawns?
Probably not.
Yawning is actually your fish clearing its gills by flushing water over them backwards, not necessarily a sign that it is feeling tired.
Q. Where do goldfish sleep?
Goldfish can sleep anywhere in the tank, but usually they stay in the mid to lower region of the aquarium. They will usually be suspended in the water no matter where they are.
Q. Are goldfish nocturnal?
While animals that are nocturnal sleep during the day and are awake at night, goldfish don’t fall into that category.
Not all fish sleep. Fish like the Tuna have to swim in order to respire.
Q. What about blind or visually impaired fish?
Though species of goldfish such as the Black Moor do not see as much as other varieties, they can still sense light and don’t rely completely on their vision to tell them when it is time to “go to bed.”
Wrapping it All Up
Now I’m turning it over to you…
Have you ever caught your fish in the middle of its sleep?
Do you think your goldfish has dreams in the wee hours of the night?
I want to hear your thoughts in the comments section below.
Featured image credit: seaonweb, Shutterstock
Well my Bubbles is now sleeping (i guess) almost out of the tank! xdd so her back is slightly touching the top of water ot the aquarium. She seems very relaxed and not moving. I think she is doing this more often now as i did not notice before. I IWONDER if its normal .
That doesn’t sound like normal sleeping behavior to me, Sara, I’d recommend testing your water
Hi~ Actually I’m quite worried with my goldfish sleeping time… I mean I’ve turn off the light and the room supposed to be very dark, however my goldies which are Shubbies don’t wanna sleep that much… they kept on playing all night even though it’s really dark. I peeked at them once before… and they were playing… I mean swimming around… and during the day there were times where they’ll just float in the middle of the tank, like in sleeping mode, moving only their fins to balance themselves while floating. One day I tried to just dim the light a bit and they tend to be more relaxed. So do you think I should just dim the light like that every night? or make it totally dark?
I would recommend keeping it totally black at night, no light, and leave the light on in the day. They may just wake up if they see you looking at them. Hope this helps 🙂
Thank you for the advice, I’ll make it totally dark from now on??
My Sparky has been so lazy for a few days. It doesn’t even move! (unless I force it too) I even changed water and put a little peace of ice in it. What should I do?
P.S: nice website by the way!!!
It’s possible Sparky isn’t feeling well. You might want to start by a water test. 🙂
I’ve caught my two Orandas Bubbles and Splash sleeping side by side in the middle of their tank mostly at night . They are the cutest I dont know if they are male or female but they practically are inseparable. I just love them❤
How adorable!
So i had 4 goldfish in my tank and they seemed very happy, always swimming around, rarely ever laid at the bottom of the tank. I decided to buy a baby sucker fish and it all seemed fine and not even two days later my sucker fish was dead which i don’t even know why. And literally the next day the biggest of all my goldfishes dies, and then i noticed the rest of my goldfish started laying on the bottom way more often then usual. I sadly thought that maybe the sucker fish had something and that all of my fish were going to die. It’s been about three days and they haven’t died thankfully, they’re starting to swim more but they only swim for a little while then they all lay at the bottom of the tank together then they start swimming again. They dont look sick and they definitely eat all of their food and their water is just fine but i’m just so confused on why the sucker fish died and one of my goldfish died the very next day and then the rest of my goldfish are less active then usual. Was it due to stress for adding that sucker fish? I have no idea or maybe i’m just over thinking, please help lol
The baby sucker fish could have brought in some pathogen.
Should i try to clean the tank again? I really don’t know what to do, now there scales have all these flakes on them, it doesn’t look like ich because it doesn’t just happen over night?
Ich can happen overnight.
so they ended up having a really bad case of ich and ended up dying, im very upset but now i know what it was and shouldve known not to buy fish at petsmart
I’m sorry alysia 🙁 Yeah pet store fish are almost guaranteed to have parasites which they don’t tell you. I had to learn that lesson the hard way too. Now I treat all new pet store fish for ich from the first day I get them.
I am quite worried about my Oranda, Dame Judi Dench. I went to turn her light off the other night and say goodnight when I found she wasn’t moving. We changed the water just in case and she sprung back to life again. However, since then, she keeps going into what looks like these ‘deep sleeps’. She is near the top of the tank, very still. But then once I can get her attention, she will start swimming around like nothing has happened. I don’t know what’s going on!
You might need to test the water and make sure the levels are correct.
N
I have three calico fancy goldfish in a huge tank. Had four but the 4th is a female and they tortured her by chasing. She had a growth problem and they exhausted her so she has her own apartment now, lol. I bought two together initially and then another two (the female included) a few months later. At bedtime, the two that I bought first, sleep beside each other every night in one specific spot and the other sleeps alone in his specific spot. During the day, they are all buddies and having fun.I think its fascinating! This happens every single night. Does anyone else see pairing it bonding in their goldfish?
How adorable, Tina! Thanks for sharing!
We have a 45litre tank containing a small black moor, a calico fan, 2 white cloud minnows and 4 shrimps. about 4 weeks ago the two goldfish started to lay side by side on the bottom. they would occasionally swim around the tank and eagerly come up for food. after about a week they reverted to normal swimming and foraging in the gravel. then about 3 days ago they started to lay on the bottom again. I regularly test the water which is perfect, do water changes and change filter pads monthly using stress coat and quick start. The fish appear to be quite healthy, dorsal fins erect when on the bottom and are about 3 months old. could this behaviour possibly be a mating routine?
Great website!!
It sounds like there could be some illness going on. Some parasites take a while to build up and affect the fish’s activity levels. Flukes comes to mind.
Thanks Meredith will check that out
My gold fish are staying on the bottom corner during the day idk what is wrong plz help they don’t swim around only at night
Sounds like its not feeling well, could be a water quality issue or disease
RE: Black Moor, about 5 years old, only one in a 10 gallon tank…Lately I’ve noticed he hovers in back corner, midway down, stays very still, head upward. Wondering if this is a sleep position, I googled it, only to read they sleep just the opposite, with head down. Do they ever sleep, head up? Any feedback appreciated. Thanks. ?
Yes, they can.
I just recently got a goldfish and it appears that my fish is sleeping at the bottom of the tank on the rocks, but seems fine when he starts moving around again. What should I do?
Please see this post 🙂
Hey, my goldfish sleeps all-day and is active at night. Why does she do that? Is it okay?
She may not be feeling well. You might want to check this post.
I have 2 black moors in a 20 gallon planted tank, the water always looks clean, I have a filter and a bubbler on a timer from 9am- 3pm, I turn the light on around 8 and off when the sun starts to set, they look healthy and are about 4 years old? They both sleep rested on the bottom and always have, I have a tall octagonal tank about 2 feet tall,
The thing that worries me is the strange behavior my male has, he likes to point head down in the same corner of the tank after his breakfast, then he goes back to normal after doing that for a little, the female does not do that, he also likes to nap wedged into the plants, neither of them have a swim bladder problem, they have perfect swimming and balance, they just have odd behaviors, it’s never gotten any worse and I guess that’s just how they are? They also sleep a lot, during the day, they are napping right now and it’s mid day, if there not foraging for food on the gravel they are napping, when they aren’t napping they act completely active and normal so idk, should they be this lazy?
The filter always runs, just the bubbler is on a timer
Older fish tend to do this more. 4 is considered pretty old for a black moor.
Help. I brought a sand gravel but it’s clouding up and n Pi t sure I cycle the tank properly. I’m concern. How do I clear up the cloudy tank? The fish are already in the tank might have new tank syndrome. Not sure. My children and I are learning but my son made a mistake of throwing out all the fish water, he dump the sand in first and added new water then he added new tank liquid. I’m worried.
Sponge filters can help. In the future, washing the sand first is ideal. 🙂
I have a very small Ryukin goldfish, I’m not sure how old. As with my previous goldfish, he sits on the bottom of the tank from time to time, upright, no clamped fins, and perks up and swims around as soon as he sees anyone. Is this sleeping or sickness? He has a great appetite as well. He spends most of the day doing normal goldfish behavior-swimming around, rooting around the substrate and plants, etc.
Old fish will bottom sit sometimes, especially fancies.
I think my Ryukin is very young, based on his very small size. Knowing that, Is this still normal behavior?
No, not normal. Young fish are supposed to be active.
He is mostly active. Once in a while I’ll catch him sitting on the bottom upright, with no clamped fins. I wasn’t sure if maybe he just sleeps without hovering?
Sounds normal if he is eating and otherwise healthy.