I have a reticulated ray which i guess is also called the teacup. (correct me if i am wrong) But i have him living with 2 oscars 2 jacks 2 convicts a clown knife 2 angels and 2 plecos and i haven't had any problems with them trying to kill him. However i do agree that you should do the research 1st and then make a educated decision based on that research. Like it was said before it may work for some and not for others