About two weeks ago I bought a senegalus bichir that was about 4", now he's about 7". I feed him krill, formula one frozen cubes, shrimp pellets and blood worms. But since I've had him he's also eaten about 10 neon tetras, a 2 inch black ghost knife, three platies, five fancy guppies and three 1 inch cory catfish. I feed him once a night, and he eats everything! Is this normal? Like I said before, I'm pretty new to fish keeping. I'm not complaining at all about him eating, because it's my favorite fish that I have, but do they normally grow this fast?