Blackeye Goby are common inhabitants of coral reefs and rocky habitats along the Eastern Pacific Ocean coasts of Mexico, the United States, and Canada, although they are hardly noticed, as they often rest motionless near their shelters. Blackeye gobies are highly territorial. Each male usually guards a harem of two to eight females and a small territory around a shelter. They are diurnal and mostly prey on small crustaceans and mollusks. They are protogynous hermaphrodites, with all individuals being born females and turning into males once they reach a certain size under the correct conditions. Source: https://en.wikipedia.org/wiki/Rhinogobiops