Originally introduced in several streams on O'ahu in 1922; in the Nu'uanu Reservoir in 1940, and then in several irrigation reservoirs on Maui; not as common as before; small populations recently found in streams and ditches draining into Kawainui Marsh, Waiawa Springs and Kapakahi Stream (Ref. 44091, 58302). Known from low-elevation freshwater habitats of all types on Maui and O'ahu (Ref. 58302).