Cory catfish are among the most popular bottom-dwelling fish that people buy. These fish are easy to take care of, but you still might be worried about making mistakes if you’re new to the hobby of keeping fish.
Walking into the room with your fish tank and seeing a fish laying on its side might be alarming. Many people assume that the fish has died when they find it in such a position.
Is this normal for cory catfish or is it something to be concerned with? Should you try to do something to help the fish or is it best to leave it alone?
Below, you’ll learn about why cory catfish lay on their sides. You’ll better understand the fish and its sleeping habits after getting all of the details.
The Cory Catfish Is Likely Just Resting
It’s actually normal for cory catfish to lay down like this. Often, you’ll see cory catfish laying down like this when they want to get some rest.
These fish are a little bit unusual when it comes to how they sleep, too. They’re technically considered to be diurnal fish, but they don’t sleep for long periods of time. They actually just take “naps” when they feel that they need to.
When a cory catfish feels that it needs to rest, it’ll take a little nap. Often, you’ll find the cory catfish napping on its side for five minutes at a time.
The fish might lean against a rock or it might sleep on the sandy substrate in the tank. These fish will sleep at random times during the day and night.
Since they’re diurnal fish, they are more active during the day than they are at night. They just don’t have a traditional day and night cycle like many other fish do.
Swim Bladder Issues
Swim bladder issues might cause a cory catfish to lay on its side for long periods of time. If you notice that the fish just lays on its side most of the time, then it might be having a hard time swimming around normally.
Try tapping the glass to see if you can get the fish to move and swim around. Observe the cory catfish and note how it swims.
Is the fish swimming around erratically or as if it has very little control over its movements? Some people describe swim bladder issues as fish looking like they’re drunk.
Some fish might swim in circles while others will swim sideways or upside down. It’s a problem that can make it tough for fish to get around, and some fish won’t even be able to eat normally.
If the fish isn’t swimming in a normal fashion, then it’s likely that a swim bladder issue is to blame. Overfeeding and poor water quality have the potential to cause swim bladder problems.
You can treat this issue by giving the fish swim bladder medications. It should help to clear things up so long as you’re following the instructions that came with the medication.
Be sure to solve any issues in the fish tank as well. Monitor the water parameters and do your best to keep the tank clean by doing regular water changes.
When feeding the fish, do your best to avoid overfeeding it. You’re supposed to feed cory catfish twice per day, and each time you should be feeding them as much as they can eat in three minutes.
Constipation can cause swim bladder issues quite easily. One easy remedy is to feed the cory catfish a boiled pea to make it poop.
Overcrowding and Stress
Another thing to consider is whether the fish tank is overcrowded. Sometimes fish can act strange when they’re put in stressful situations.
A fish might lay on its side more than normal if something is wrong in the tank. Overcrowded fish tanks might make it harder for the water parameters to stay in the right range.
When tanks are overcrowded, it’s easy for them to get very dirty. You might see that the fish will start to suffer if the ammonia, nitrate, and nitrite levels get too high.
There are many other sources of stress that can cause cory catfish to do odd things, too. For instance, not being kept in a large enough group can stress the cory catfish.
Cory catfish are supposed to be kept in groups of six or more. These are schooling fish that don’t do well when kept in tanks by themselves.
Even keeping just two or three of these fish won’t be enough for them to feel comfortable in a fish tank. It’s possible that some of the fish might start looking lethargic if they aren’t happy in the tank.
This is why it’s imperative to do your best to make the fish feel comfortable. Keep them in groups of at least six and give them big enough fish tanks that they will be able to thrive.
Remember that you want to pick out appropriate tank mates for these fish, too. Cory catfish are so peaceful that they can get bullied by aggressive fish.
Aggressive tank mates could easily cause cory catfish to feel stressed. It’s always important to research tank mates before setting up a community tank.
If your cory catfish is just laying on its side sometimes, it’s nothing to worry about. These fish will nap throughout the day, but they do so in five-minute intervals.
Cory catfish like to lay on their sides. It’s not unusual to see them do this.
The fish could be experiencing swim bladder issues if it seems lethargic and can’t swim normally. In this situation, you’ll want to fix water quality issues and do what is necessary to keep the fish from becoming constipated.
Stress issues can cause the fish to act lethargic as well. Try to look into anything that might be causing the fish to feel stressed so that you can change things for the better.
So long as you’re doing your best to take care of the fish, it’s likely that everything will be fine. Just keep an eye on the fish to ensure that its behavior is normal.
Jeff has always enjoyed having pets, but as a child, he was drawn to his family’s fish tank. Being able to maintain a small ecosystem and observe the behaviors and interactions in the underwater world peaked his interest early on and has kept him hooked until this day. On Avid Aquarist, Jeff shares everything he’s learned about helping aquatic life survive and thrive in a home aquarium.