Bastard grunt

Found in large schools, during the day close to shelter, out hunting for food at night close to the bottom, over hard sandy areas of estuaries, lagoons and reefs.

In some areas of the world 'Grunts' are better known as 'Sweetlips' distinguished from other species by their very large rubbery lips.
'Grunts'because they "grunt," the grunting sound is produced by their flat teeth plates rubbing together and this is amplified by their air bladders.
Found either singly or in schools hovering or motionless over the reef during the day, becoming nocturnal predators.