Clown fish, famously known as Nemo’s species, are territorial sorts that aren’t well suited to living with more than one of their own kind in captivity.
Clownfish will eat any other clownfish that are small enough to fit in their mouths. This means fry will get eaten almost immediately, even by their parents. Adult clownfish, on the other hand, aren’t at risk of getting eaten but may still be attacked by other, more aggressive clownfish.
Let’s talk more about when clownfish might get eaten, why they might be attacked, and what you can do to protect them.
Do Clownfish Eat Other Clownfish?
Clownfish absolutely do eat other clownfish. Not necessarily in the way you think, however. Let’s break this down starting from freshly hatched clownfish and moving forward to talking about adult clownfish.
While clownfish have a reputation of being great parents, that reputation ends as soon as their eggs hatch.
Once the clownfish fry emerge from their eggs, any clownfish in the aquarium – including their parents – will eat them with no remorse. It’s basically just open season.
If you don’t separate out the young from the other fish in the tank, any that can’t hide until they’re too big to get eaten will get eaten.
Juveniles are a bit safer from other clownfish due to their larger size, but they are still open to being eaten by other clownfish if they’re not careful.
Clownfish in a saltwater aquarium can get to be 6-7” long, and they’re likely to eat a young clownfish if it can easily fit in their mouths.
Clownfish typically eat small foods like algae or krill, but they’re omnivores, so they aren’t above eating another clownfish if it looks like an easy meal.
The juvenile clownfish themselves may eat fry if those fry are small enough, for the same reason.
An adult clownfish isn’t really at much risk of getting eaten by another clownfish because of how big they typically get.
That doesn’t mean that they aren’t in danger from other clownfish, however. As I said above, clownfish are extremely territorial and don’t like any other clownfish to get anywhere near them.
Clownfish may live peacefully together for a while, but eventually one pair will end up killing every other clownfish in the same aquarium. It’s in their nature.
This is especially true with the more aggressive types like the maroon clownfish.
Why Are My Clownfish Fighting?
Clownfish are extremely territorial and will fight each other over space in an aquarium. If they both want to host in the same anemone or in an area that is too close to each other, they will fight for dominance. It’s best to keep no more than 2 clownfish in a tank to avoid fighting.
Clownfish don’t necessarily need a reason to fight. Other clownfish being in their aquarium is enough of a reason, to be perfectly honest.
Sometimes young clownfish can live in peace with each other for a while. That almost always changes, however.
Most likely what will set them off is spawning. When they start spawning clownfish get much more aggressive, and to protect their nest they will attack other clownfish that might be nearby.
Even ones they lived peacefully with before are not necessarily safe once a pair of clownfish in the aquarium begin spawning.
Harem tanks are a bit safer of an option, but even those usually don’t end well.
This is why the best advice for aquariums is to never keep more than one pair in a tank, regardless of whether it’s a 10 gallon or a 100 gallon aquarium.
How Do I Stop My Clownfish From Fighting?
The only guaranteed way to stop clownfish from fighting is to separate them out into their own tanks. If you don’t have an extra tank, rearranging the aquarium so that areas where your clownfish host aren’t visible to each other might buy you some time, as can using an aquarium divider if possible.
You have to be extremely vigilant, because it doesn’t take long for one clownfish to kill another, and it could happen even if you only have 2 in the aquarium if they don’t pair well.
Either one fish will bully the other to death or the weaker of the two clownfish will jump out of it’s aquarium to try to get away (and die on the floor).
If at all possible, the best way to stop your clownfish from fighting is to separate them into their own tanks.
This is the only guaranteed way of stopping them from killing each other if they’ve started fighting.
If you have a refugium but don’t have multiple tanks, you can remove the aggressive clownfish and drop it into your refugium where it can’t harm anything else. Leave it there for a few days, and then you can try reintroducing it to the tank.
This may help reduce your clownfish’s aggression, but it’s not a sure thing.
If you don’t have a refugium, you can get an aquarium divider and separate them out into their own halves of the tank if your layout supports it. (If it doesn’t you might try moving some of your hardscape around.
If neither of those works, you can try rearranging your aquarium to make the territory look different and provide more separation between hosting areas, but most likely you’re looking at either setting up a new tank or taking the aggressive one back to your local fish store.
Sad, but unfortunately true.
Clownfish can be aggressive little things, that’s why the best way to stop your clownfish from fighting with each other is to avoid putting them in the same tank to begin with.
This is especially important for smaller clownfish that are at risk of getting eaten by the bigger ones.
If you’re having problems with a clownfish attacking or trying to eat another clownfish, the best thing you can do is provide separation. Whether this means another tank, your refugium, a tank divider, or anything you can pull together at a moments notice, this is your best bet to avoid one of your clownfish getting killed.
Good luck saving your clownfish!