I had 2 clownfish that died(i can't give details because this was awhile back) on the same day. I had 2: A stripeless oceallaris and a striped oceallaris. I bought the stripeless first and the striped next. I kept the striped for about a month and I kept the stripeless for about 2 months. They both ate and were very healthy. Neither of them were picked on by any of the other fish nor did they pick on each other(tbh they liked each other). About a 2 weeks before they died I began noticing problems. The striped clownfish began building some mucus on it's body. The clownfish was breathing fast and I blew it over as oxygen problems because multiple fish in the aquarium(yellow tang, 4 stripe damsel, and both clowns) were breathing fast. The striped stopped swimming and just kinda idled on the bottom until he died, and ate the remainder of his days until the day before he died he stopped eating. The stripeless did the same thing except he kept swimming. The day they died, I woke up and found the striped clownfish on the bottom of the aquarium, dead. The stripeless clownfish looked TERRBILE. His scales were falling off, he had mucus on his body, he had red blotches on his body, and he was breathing fast. He could barely swim, his body looked like he could barely move. We went to the saltwater store and came back to find that the stripless clownfish had died. What was weird about this is that both clownfish died in the SAME spot...(just thought that was interesting fact)

During this entire time, I had a 4-stripe damsel breathing fast also and not swimming. About 3 days after the clownfish died, this fish died also. He was on the bottom of the aquarium when I got home from school and he was not swimming much. A lot of his fins were gone, they were just bone. The thing about this fish is that I the yelow tang was picking on it.

I have 2 ideas on why they died:
-Brooklynellosis
-Another fish killed them

I would just like your opinions on what killed these fish.. thanks.

***Please remember that this happened awhile back, so i'm not sure about tank details at the time. I do remember that I had high nitrates and high salinity***