Waipio Valley Stream Restoration Study

Molluscs: Introduced Species

Scientific name: Tarebia granifera
Common name(s): Thiarid snail, Quilted Melania

Scientific name: Tarebia granifera

Status: Introduced

Habitat: Thiarid snails live in variety of habitats, from fast-moving streams to brackish water canals. They can live in altered streams paved with concrete and in reservoirs and ponds. They like to burrow under the mud or sand.

Preferred Area of Stream: Can be found in a wide range of pools and runs, but not common in the fastest riffle areas. Also common in wetlands and kalo lo‘i.

Range in Hawai‘i: Common on all Hawaiian Islands

Diet: Detritus (rotting matter) and algae.

Predators: Ducks will eat snails, especially smaller young snails, some fish species.

Fact: These snails can be found in huge numbers. In some streams, they cover the stream bottom. All of the snails are female, so they can make eggs and give birth by themselves. Surprisingly, some native fish like to eat these non-native snails.