Groupers are
teleosts, typically having a stout body and a large mouth. They are not built for long-distance, fast swimming. They can be quite large: in length, over a meter. The largest is the
Atlantic goliath grouper (
Epinephelus itajara) which has been weighed at and a length of , though in such a large group, species vary considerably. They swallow prey rather than biting pieces off of them. They do not have many teeth on the edges of their jaws, but they have heavy crushing tooth plates inside the
pharynx. They habitually eat fish, octopuses, and
crustaceans. Some species prefer to
ambush their prey, while others are active predators. Reports of fatal attacks on humans by the largest species, such as the
giant grouper (
Epinephelus lanceolatus), are unconfirmed. opening its jaws Their mouths and
gills form a powerful vacuum that pulls their prey in from a distance. They also use their mouths to dig into sand to form their shelters under big rocks, jetting it out through their gills. Research indicates
roving coralgroupers (
Plectropomus pessuliferus) sometimes cooperate with
giant morays in hunting. Groupers are also one of the only animals that eat invasive
red lionfish. ==Systematics==