i picked up a 3" ARTC about a month ago and it's now maybe 3 1/2", i thought it wouldn't get aggressive until about 8" but so far i've had out of the 20L tank dissappear (1) baby green sunfish which was bigger than its head, might have jumped (2) pepper loaches that i don't think he could have eaten (3) darters, which i was incredibly excited to get and about to move out of the tank shortly before they disappeared and they even nipped at the cat when i first added him and (2) gambusia that were mostly put in for future food, i had (4) baby 3" ID sharks in the tank but when i went to move them yesterday i found one dead and another was missing the top half of his tailfin. has my ARTC already turned into a psychopathic killer? i did look at him every chance i got and he didn't seem to be fat enough to have eaten any of the fish, i actually worried about him because the ID sharks usually got all the food before he came out, even with the lights out, so i've always thought he looked a bit skinny.