i got at least twenty jacks and half of them are at least half an inch maybe more, the rest very but aren't that much smaller. they are all the same age same batch. they love to eat cichlid pellets and fish flakes gold fish or tropical. they will even eat small fry like molly fry and platy fry. i have also cut a feeder in half and they ate it. but they wont yet attack anything else in my tank, i have mollys and mosqutio minows in there. i will sale the hole batch for ten bucks because i need the space in the tank so i can finish making it a comunity. a dollar a piece. heres a small vid with some shots.http://www.youtube.com/watch?v=yuuKvlJh3_U