Habitat for hihiwai (Neritina granosa), a freshwater snail endemic to the Hawaiian Islands, may be declining due to changes that have resulted from shading by invasive, non-native riparian vegetation. Once common throughout the Hawaiian Islands, N. granosa have diminished in numbers and are now found only in relatively undisturbed streams. This study examined N. granosa distribution, density, feeding behavior, and the effects of light availability in shaping benthic algal assemblages which may affect N. granosa habitat in Hawaiian streams. Results indicated that stream substrate beneath open-canopy had greater densities of N. granosa than beneath closed-canopy. Based on chlorophyll a pigment analysis, open-canopy stream areas had higher levels of algal biomass than shaded regions. Algal community composition also differed between the open-canopy and closed-canopy areas with green algae dominant in the open and diatoms dominant in the closed. In feeding choice trials, N. granosa preferred algae grown in open sunny reaches of streams (green algae-dominated) to closed-canopy shaded reaches (diatom-dominated).