Is my clownfish sick?

Bittwee · May 31, 2026

Darwin ocellaris clownfish I got from saltwateraquarium.com two days ago. Just noticed he has a small patch of white towards the back of his body. Could this be some type of parasite or bacterial infection?

Tahoe61 · May 31, 2026

A great resource.
@Jay Hemdal

Jay Hemdal · May 31, 2026

Bittwee said:
Darwin ocellaris clownfish I got from saltwateraquarium.com two days ago. Just noticed he has a small patch of white towards the back of his body. Could this be some type of parasite or bacterial infection?

Welcome to Reef2Reef!

It could be an infection, but more likely it is a minor injury, either from shipping damage, or fighting with fish in the new tank (clowns often don’t mix well).

I’d watch it for now. Look for other general symptoms like not eating, rapid breathing, ripped fins, this spot getting larger, or new spots starting.

Do you have a treatment tank? If not, you might want to get some ruby reef rally pro. It is safe to use in your display and covers a couple of common causes for lesions like this. Then, you’ll have it on hand in case things worsen.

Bittwee · May 31, 2026

Jay Hemdal said:
Welcome to Reef2Reef!

It could be an infection, but more likely it is a minor injury, either from shipping damage, or fighting with fish in the new tank (clowns often don’t mix well).

I’d watch it for now. Look for other general symptoms like not eating, rapid breathing, ripped fins, this spot getting larger, or new spots starting.

Do you have a treatment tank? If not, you might want to get some ruby reef rally pro. It is safe to use in your display and covers a couple of common causes for lesions like this. Then, you’ll have it on hand in case things worsen.

Thank you Jay!
The clowns are in good shape in terms of their behavior, but for sure I’ll continue to keep an eye on them. The tank they’re in right now is their quarantine tank, so I could get by with any type of treatment but I’ll definitely look into the ruby reef rally pro. Thanks for the quick response!