ok. i have a 55 gallon aquarium, and i put a 4" red lobster (crayfish???) well they said it was a lobster in the tank. since then, i have lost like 4 fish in one week. WTF? they said it was not aggressive. what's going on here? any ideas??? TIA

Axiom M60Ti Infinity 2000.6 x 4 Infinity RS1 rear Infinity CC200 HSU VTF3 - MKII