Remarks: Japanese trapdoor snails are, as their common name implies, a species native to Japan but they have also been introduced to certain parts of North America. They are very popular among those with ponds as they have a voracious appetite for algae, are very tolerant of cold weather, and are unlikely to overpopulate due to their slower reproductive cycle. Instead of laying egg clusters on surfaces, these snails keep their eggs in a brood chamber until they hatch into tiny baby snails. Their clutches are rather small for a snail, only typically having anywhere from 1 to 15 babies at a time. Whether you plan to keep this species in a tank or a pond, they make a great addition to almost any clean-up crew.