So I have a 40 gallon fish tank with a pleco, an iridescent shark, and a fantail goldfish. The other day my friend gave 2 cichlads from her tank. She neglected to tell me (a novice) that the cichlads would attack my goldfish. I woke up this morning and the fantail goldfish's tail had been chewed off! He was still swimming around fine and didn't look sick at all, so I left him in the tank. A few hours later the cichlads ATE OUT THE EYEBALLS of my goldfish! That was probably one of the creepiest things I have even seen. Needless to say, I am really pissed at my friend and I am worried that those fish are going to attack my other fish. My iridescent shark is one of the coolest fish i've ever had. I'd be pissed if they attack him/her.