Corocoro

Found singly, or in small schools, during the day close to shelter, out at night hunting for food, over mud, rock and sandy bottoms of coastal waters.
Juveniles found in seagrass beds.

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.