How agressive are clownfish?

pseudorand · Nov 26, 2019

I picked up two medium to large (2-3") Clarkii clowns with some live rock from craig's list for my new 120g. I had to take them so they wouldn't be homeless, but I'm not really a fan of clowns or nems. A quick google search listed them as semi-agressive before I took them, but in doing some more research I suspect "semi" may be generous. I don't mind being their retirement home unless they keep me from getting the fish I really want.

They're now sharing the tank with a 3-stripe damsel that I picked up under similar circumstances with a second batch of live rock. The damsel does get chased, but he has plenty of places to hide that the much larger clowns can get to. He also holds his own and even chases back once in a while. I won't be too surprised to find him missing one day though.

Does anyone know how aggressive clarkii clowns really are? Can I expect them to murder anything smaller than them? Flame angel? Royal Gramma? Fire goby? Ruby red blenny? Smaller puffers (Canthigasters)? Copperband Butterfly?

I assume they're just territorial and won't bother inverts like shrimp or linckia stars? Does that sound right?

vetteguy53081 · Nov 26, 2019

Clowns are and can be quite nasty, territorial and nip the hands that feed them

TriggersAmuck · Nov 26, 2019

Every clown or clown pair can be different, and they will often respond to the environment. A 120 gallon tank is a good start for mitigating clown wars. I had a mated pair of Maroon clowns for well over a decade in a 125g tank, and they pretty much stayed near their anemone and didn't bother anyone (except they would let me know when I was cleaning too close to their digs). And I currently have a pair of flame (red saddleback) clowns, known for being very feisty, which leave a Royal Gramma, cryptic wrasse, and several tiny gobies alone, all in a 14 gallon cube. (That could change over time, of course, and I have a plan in place for both temporary and long term separation should the facts on the ground change).

If the Clarkiis aren't laying eggs yet, then they could well get more aggressive when they start mating. I would say that if you really aren't a fan, then finding a local fish store or reef club member in your area to re-home them would be doing right both the fish and your longer term tank plans. If that is impossible not all is lost necessarily. Make sure you get some type of in-tank acclimation tank (held in place by magnets or whatever) to be able to slowly introduce new fish over a week's time or so or separate hostile ones should war break out. Or else get some plastic lighting egg crate from Home Depot to cordon off a portion of the tank for new additions, provided they aren't small enough to sneak through the crating.

EmdeReef · Nov 26, 2019

Clarkiis are among the more aggressive clowns + they get pretty big. The good news is that they’ll usually settle in one part of the tank and won’t bother fish that don’t venture there. Eventually most fish learn to avoid clown nests IME.

Phildago · Nov 26, 2019

They can be deadly. I find that they are very territorial, so they don't necessarily continue the hunt outside of their territory. If the other fish learns to stay away they're usually fine, if not they die

pseudorand · Nov 29, 2019

My three-line damsel is still alive. When he was first introduced, they chased him terribly. I even have two groups of live rock (with more on the way) and I made what I though was a great hiding place for him on the far side of the tank from the Clarkiis. But he preferred to hang out with them. They still chase him every once in a while, but he can come out and about without being constantly harassed.

Feeding time is also great. The Clarkiis are more interested in food than the damsel, and he seems to get plenty to eat.

I'll still be introducing new tank mates slowly, but I'm hopeful. They are cool fish with plenty of personality. They're just a bit...big.

AC1211 · Nov 29, 2019

I actually am more concerned with the damsel becoming a bully that the clowns killing anything.

GoldeneyeRet · Nov 29, 2019

Clark can get very mean, as will the 2 stripe damsel.

fcmatt · Nov 29, 2019

I imagine a pair of clarkii will prob be more aggressive then a single. If I was you I would just find a good day to find a new home for them. Better off getting the mix of fish you want.

S.Pepper · Nov 29, 2019

pseudorand said:
I picked up two medium to large (2-3") Clarkii clowns with some live rock from craig's list for my new 120g. I had to take them so they wouldn't be homeless, but I'm not really a fan of clowns or nems. A quick google search listed them as semi-agressive before I took them, but in doing some more research I suspect "semi" may be generous. I don't mind being their retirement home unless they keep me from getting the fish I really want.

They're now sharing the tank with a 3-stripe damsel that I picked up under similar circumstances with a second batch of live rock. The damsel does get chased, but he has plenty of places to hide that the much larger clowns can get to. He also holds his own and even chases back once in a while. I won't be too surprised to find him missing one day though.

Does anyone know how aggressive clarkii clowns really are? Can I expect them to murder anything smaller than them? Flame angel? Royal Gramma? Fire goby? Ruby red blenny? Smaller puffers (Canthigasters)? Copperband Butterfly?

I assume they're just territorial and won't bother inverts like shrimp or linckia stars? Does that sound right?

There was a recent discussion on this. Here's a link to it: https://www.reef2reef.com/threads/clownfish-are-savages.665309/unread