i was wondering which of my fish is doing the killing, i currently have 2 12" oscars, a 13-14" florida gar, a 20" clown knife, 2 6" pacu, and a 10" pictus catfish. which of these would you think would do this damage to a goldfish? i dont think it is the oscars or the pacu, they were in the pond with the goldfish for a month without touching them.