Yeah, reminds me of an episode of "River Monsters," where Jeremy Wade went in search of a fish that had reportedly killed somebody by biting and castrating him. Jeremy caught the type of fish responsible, a Pacu. A fish native to the Amazon, where they need their molar-like teeth to crack into the tough cases of nuts and seeds. The Pacu was introduced in Papua New Guinea years ago as a resource for fishing, and are now able to grow to 40 lb because their diet now consists of meat instead of a vegetarian only diet.