i got a "blue" crayfish off my friend cause he was eating a neon one day when he got home. i but him in my 10 gollon and hes eating a fish a night is this normal ? hes about 2 1/2 inches
yes crayfish will eat small fish they can even eat a fish if it's slightly bigger than itself, IMO keep them with much larger fish, fish which could easily escape the clutches of there nippers, or if the fish is too big the crayfish may not even bother with it.
Crayfish don't last long in my tank, because my puffers kill them. I make sure to break their claws so they don't hurt the fish. He is going to eat fish and plants, thats what they do. What did you do with him?