The bluegill bully (Gobiomorphus hubbsi) is a fish in the family Eleotridae endemic to New Zealand. It is a specialist of shallow, fast-flowing riffles and torrents, where it lives amongst the gravels. It has a similar distribution to the other endemic riffle specialist, the torrentfish. The bluegill bully is the smallest of the Eleotrids, commonly reaching only . It is named for the bright blue edge to the operculum or gill cover, which is present in both sexes. It eats aquatic invertebrates and has an upturned mouth, allowing them to pick invertebrates off the stones above them. They are amphidromous. The eggs are laid in fresh water and, on hatching, larvae are carried to sea for the first stage of their development. The young fish return to fresh water after a few months and continue to slowly migrate upstream as they get older. Thus the largest bluegills are found furthest upstream. References External links Photograph of male bluegill bully Endemic freshwater fish of New Zealand Taxa named by Gerald Stokell bluegill bully