Both of my males fight any other FRT. One of my females ripped the lower jaw off of another female and I had to put the maimed one down. All of my FRTs chase down fish and bite them. Back when I thought my FRTs were OK with fish (before they were 2 years old) I found out the hard way that their habits change. A male killed an AUL by biting its back clear through the spine. My smallest female took some dorsal fins and the top of the caudal fin and peduncle from one of my polys. Since then, all the turtles have been in solitary confinement.