Clownfish died, damsel looking rough

[itgoeson]

I have a mature 180G that has been doing well for a couple of years. Four days ago (July 1), my female clownfish (who I’ve had for 4 years, my first fish in my first tank that I later upgraded), was swimming briefly head down. She started swimming normally again and I thought maybe she was just picking at food on the rocks or something.

The next day, she was swimming sideways and had white stringy poop. Yesterday, dead.

I added a new fish April 21, a filefish from another hobbyist’s tank. No other new fish for over a year. No new coral or inverts since March.

The rest of the tank (male clown, filefish, hippo, sailfin, foxface, mandarin, flame hawk, four azure damsels) looked fine. Until today. Now one of the damsels looks really beat up. They do have occasional squabbles, so maybe he’s just beat up, but now I’m worried I’ve got something running through the tank.

Coral are fine, including some SPS (green slimer, acro echinata). However, about a month ago, I had a very large pink nephthea (that I grew from a small frag) melt completely to nothing.

My biggest issues up to now have been BTAs and aiptasia taking over the tank. Everything has been stable and happy for a long time. Could this be something contagious? Should I treat the tank with something?

 

[Sharkbait19]

The damsel definitely looks like the victim of aggression. Between the tangs, clown, and other damsels, there are plenty of culprits.
Did you notice any split fins or other injuries on the clown?

 

[itgoeson]

The damsel definitely looks like the victim of aggression. Between the tangs, clown, and other damsels, there are plenty of culprits.
Did you notice any split fins or other injuries on the clown?

No, I didn’t see any injuries. She is (was) the boss of the tank and no one messed with her. She looked a little thin to me… not like THIN but just not as fat as she normally did. I thought maybe an internal parasite from frozen food (I feed Reef Frenzy and some pellets daily)?

One of the other damsels has a little fin damage so I’m wondering if those two went at it.

 

[Sharkbait19]

I wouldn’t really expect any parasites to come in on food, if so other fish may be showing signs too.
Keep an eye on the others and see if they start acting/looking off.
At this point the issue could just be specific to the clown.

 

[itgoeson]

I wouldn’t really expect any parasites to come in on food, if so other fish may be showing signs too.
Keep an eye on the others and see if they start acting/looking off.
At this point the issue could just be specific to the clown.

I hope so! Thank you!

 

[Jay Hemdal]

I hope so! Thank you!

I agree, I think the damsel is showing aggression and the clown had done other issue. If the filefish brought something into the tank, it should have been one of the first to show symptoms.