Waipio Valley Stream Restoration Study

Fish: Native Species

Scientific name: Stenogobius hawaiiensis
Common name(s): ‘O‘opu naniha

Stenogobius hawaiiensis

Status: Endemic

Habitat: ‘O‘opu naniha are not the best waterfall climbers and are found in the lower parts of the stream and in estuarine reaches of streams.

Preferred Area of Stream: Deep pools and slow to moderate velocity runs.

Range in Hawai‘i: Found on all Hawaiian Islands .

Diet: Worms , small shrimp, insects, and algae

Predators: Birds such as ‘auku‘u (black-crowned night-herons). Many species of native fish such as āholehole, ulua (Caranx spp.), moi (Polydactylus sexfilis) and kākü (Sphyraena barracuda) eat ‘o‘opu when the hinana return from the ocean. Fish introductions such as Mexican mollies and mosquitofish have added more hazards as they have brought in new parasites and also eat young ‘o‘opu.

Fact: These fish lay 6000-8000 eggs, which are guarded by the male until they hatch, and after the eggs hatch the small larvae are washed down into the ocean, where they will live for up to half a year before returning to the stream, where they spend the rest of their life.