yeah! your definatly right, they do have teeth! I have two pacu's. there both the same age (Im asuming, they were the same size when I got them) anyways....the smaller of the two (about ten inches) has 4 sharp teeth on the bottom jaw. its kinda strange, two on the outside and two in the middle. the rest are blunt and flat like ours. I will take some pics and post it. hopefully by tomorrow. but the larger pacu 15" has the typical flat teeth for eating seeds and vegatation in the wild. from my experence; he bite me one day and it made a blood blister on my finger. oh!yeah! they got teeth!