i just got a barcoo grunter 9 inches. people say its a very agressive fish but so far 2 days now it has been well with my 3 -4 inch osacrs(2) and my 2-3 inch severums(5). will the barcoo grunter kill them later?? cause it hasnt eaten in 2 days but the person who i got it from says it eats like crazy