Waipio Valley Stream Restoration Study

Molluscs: Native Species

Scientific name: Neritina granosa
Common name(s): Hīhīwai, Wī

N. granosa

Status: Endemic

Habitat: Hīhīwai like clean, fast-running streams with boulders and a gravel bottom. They are most active at night.

Preferred Area of Stream: Clean, cold fast water areas such as riffles and cascades

Range in Hawai‘i: Found in high-quality streams on Kaua‘i, Maui , Moloka‘i, and Hawai‘i. They are uncommon on O‘ahu.

Diet: Algae growing on rocks in fast water

Predators: Hīhīwai are a favorite for native birds such as ‘ulili (wandering tattler) that pick them off the rocks, with piles of eaten shells sometimes lining the streambanks. Surprisingly, native fish such as ‘o‘opu akupa have been found with their stomachs full of hīhīwai.

Fact: Hīhīwai immatures spend a year in the ocean and then march single file back up the stream. They don’t like dirty or altered streams, which is why they are uncommon on O‘ahu.