this is a rather sad tale about losing tails. I bought 4 goodeid, they were sold to me as a good community fish, but that they would stick together instead of hanging out around the tank. My small amount of research said that they had an extremely overblown reputation as being fin nippers. THIS WAS FALSE. Within 2 days they had completely torn the tails off of a number of fish. The people at the store were shocked to hear this. I think that my tank (55 gallon) was not big enough to keep them at a comfortable distance from the other species. I would recommend a single species tank to anyone who is interested in these misleadingly labeled fish.