I have a 38 gallon tank with 2 angelfish, 3 turquoise rainbowfish, and an electric blue acara. I know the tank is too small, and the angels were the only ones I was planning on keeping and rehoming the rest with a friend soon. Anyways, I walked in and noticed the one of the angelfish was dead and a rainbow was swimming as if it’s spine had been broken. When I removed the angel, it looked like there was a tear in its side. It wasn’t very big, but still torn. I also noticed on the other angelfish that one of the pectoral fins were smaller as if the bottom portion was gone. Also last week I tried to introduce a new angelfish and it died within the hour but all the other fish were fine and I haven’t had any problems. So I took the fish back and bought another from a different store the next day, yet this one died too. Could the EBA be the one causing the problems? I haven’t noticed any signs of aggression in any of the fish, other than when I first got the acara a few months ago and he chased the others and even nipped at their fins. But I haven’t seen him doing this lately. I’ve also never seen any nipping of any of the other fish and I’ve had them for months, maybe even a year or so. Edit; attached is a photo of the acara.