Cory catfish and betta fish are potentially compatible species.
However, a community tank with these species depends on the specific betta’s personality.
Here’s what you need to know about the requirements and possible risks related to keeping these two fish in the same aquarium.
Can I Put a Catfish in with My Betta?
You might be able to keep Cory catfish and betta fish together. This mostly depends on how aggressive your betta fish is since Corys are a generally friendly species.
Plus, betta fish tend to direct their aggressive behavior toward other fish of the same species. Bettas can live peacefully with a handful of fish species.
Many people tend to include Cory catfish in this compatible group, mainly because Corys stick to the tank’s bottom, sifting through the substrate.
Bettas, on the other hand, will swim around in the middle and top of the water. However, they can also venture to the bottom too.
Many betta fish do this when merely exploring or looking for food that’s drifted to the tank’s bottom. This is where the biggest problems can arise.
Betta fish can get aggressive when valuable resources are present, specifically:
- Potential mates
If your betta perceives the Cory catfish as competitors for any of these three things, chances are it will behave aggressively.
Unfortunately, there’s no reliable way to predict this. If possible, the only thing you can do is know your betta’s personality ahead of time.
This can be risky, as you don’t want to give your betta too much time in the aquarium alone before introducing a new tank mate.
For example, take the study observing betta’s aggression of the resources, referred to in the list above.
The fish were only given one week to acclimate to their tanks before they displayed these behavioral patterns.
Who knows how much more time they’d need to become entirely incompatible with Cory tank mates?
Aside from behavior, you’ll also need to think about the logistics of keeping bettas and Cory fish in the same aquarium.
One of the most important things to consider is the tank size. Since Corys prefer to live in a colony, it would be best to give them at least 20 gallons.
As far as water temperature, they require similar ranges to live comfortably. A Cory catfish prefers temperatures between 74-80°F, while a betta likes 76-81°F.
So, there’s a good amount of overlap to keep them both happy.
How Do You Introduce a Cory Catfish to a Betta?
As you’ve learned so far, housing a Cory catfish school and a betta fish in the same aquarium is a tricky business.
Unless you know your betta fish very well, it’s challenging to predict how it will respond to new tank mates.
Because bettas grow possessive of their living space rather quickly, it’s best to introduce the fish to an existing community tank. To do this safely, follow the instructions below:
- Quarantine your betta fish. Keeping the betta in quarantine for at least two weeks will allow you to observe its behavior and physical health. Signs of bad health* include:
- Bloated abdomen
- A lack of interest in eating
- Fungal growth on the body
- Damaged fins
- Slimy film on the body
- Clean the community tank. Get rid of excess algae and other debris in the water column or soil. A clean tank makes for happy animals that get along well!
- Double-check the water conditions. Make sure the water is within the appropriate temperature and pH range (7-7.5 for Corys and bettas together).
- Acclimate the betta. Float your betta in the new community tank inside a small plastic bag for 15 minutes. This way, it can see the other fish and get used to the water.
- Submerge the betta. Roll the sides of the bag down and gradually add water to the bag. This will slowly submerge the betta into the new tank without shocking it.
- Monitor the fish. Watch the fish very closely to ensure none are behaving dangerously. If there are signs of fighting, chasing, fin nipping, etc., you should remove the betta.
*If you notice any of these signs of poor health, take your betta fish to the vet right away. Do not add it to the community tank.
What to Know About Cory Catfish Behavior
Before you get to know the Cory catfish’s general behavioral profile, understand that there are many variations of this fish.
In this way, this group of aquatic animals is much like betta fish.
There are numerous variations. However, they all adhere to a generally applicable temperament range, share required living conditions, dietary necessities, and more.
With that said, much of the current academic knowledge on Cory catfish behavior is based on studies of the bronze Cory catfish, Corydoras aeneus.
This catfish, like many, lives in a close-knit social structure. In the wild, this helps the fish to avoid being eaten by a predator.
However, in domestic life, the Cory catfish retain their instinctual predator evasion tactics. When living in groups, or “schools,” Cory catfish can perceive more in their environment.
Researchers have referred to it as “seeing through their group-mates’ eyes.”
For example, imagine if you were traveling with a group of friends.
Together, you will hear and see more in your environment and share that information with each other, keeping you all equally safe and informed.
In this circumstance, you would all be much safer and better prepared for safety risks than you would be alone.
This is one of the many reasons that Cory catfish prefer to live in schools. Their sociality is one trait that greatly distinguishes them from the betta fish.
One of the hallmark characteristics of the betta fish is that it prefers to live in solitude.
You may be able to make community tanks work for bettas and Corys.
However, Corydoras’ group wariness and evasive tendencies are just two reasons why you must be mindful of a tank containing both cory catfish and bettas.
This issue might become quite a headache to deal with if you have a Cory school in your aquarium.
If the betta fish becomes aggressive with one fish, the whole school could go into a brief frenzy.
On the other hand, some types of Cory catfish prefer to live on their own. Although this won’t result in the panicked school behavior of social types, it could be disastrous for their safety.
They’re not very aggressive fish, and will most likely submit to a bullying betta fish, resulting in injury or death.
In general, experts recommend housing a minimum of six Cory catfishes at a time. Interestingly, the more you have, the different their behavior becomes.
You can get up to 50 of these intriguing fishes for a lively group.
Betta Fish Behavioral Norms
There’s a reason that one of the betta fish’s alternate names is the Japanese or Siamese “fighting fish.” It’s no secret that these fish can be aggressive, provoked or not.
This is the main reason why they’re recommended to live alone. This rule of thumb more so applies to the males.
However, it may be best to heed that suggestion for your female bettas, too.
Keep in mind that this rule mainly applies to this species sharing company with other betta fishes.
Veterinarians state that it’s usually fine to house them with other types of fish.
Dr. Krista Keller, a board-certified zoological medicine specialist at the University of Illinois Veterinary Teaching Hospital, stated:
“There are a variety of other species of tank mates that can be safely added to a betta’s tank, such as snails, ghost shrimp, certain species of fish, and African dwarf frogs.”
Now, this isn’t to say that you should throw all caution to the wind when keeping a betta. It’s still possible that the fish will display aggression toward another.
With that said, when you give your betta a tank mate, make sure they have enough space to avoid one another.
That way, you can keep the peace, even if your betta is feeling a little grumpy.
Dr. Keller recommends at least a five-gallon glass or plastic tank for keeping a betta comfortable on its own. So, you’ll need to bump up the size if you’re thinking of adding a few Corys to the aquarium.
Further, various betta fish types differ in their aggression levels.
More specifically, the fish’s sex and genetic line dictate how aggressive it might be, as this trait is inherited and not only a product of its environment.
- Fighter: The fish mostly focuses aggressive behavior toward males.
- Lover: The fish primarily displays courtship behaviors toward females.
- Divider: The betta splits its behavioral tendencies between males and females.
“Lovers” and “dividers” tend to be less aggressive than their “fighter” counterparts.
If you want to be sure of what behavioral profile you can expect from your betta, it’s best to buy from a reputable, experienced breeder.
Otherwise, their aggression levels can be a bit unpredictable. You don’t want to place your Cory in with a betta experimentally, only to find out too late that they don’t get along!
Betta fish and Cory catfish can live in the same tank if you have a friendly betta. However, there are many risks to housing them in a community tank.
Bettas are known to be aggressive, and bad breeding can make the problem worse.
Buy your betta fish from a reputable breeder and introduce the animals carefully to ensure they all stay safe.
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