The Dusky Grouper (Epinephelus marginatus) is the best known grouper of the Mediterranean Sea and North Africa coast. It is said to have the best taste of all Mediterranean fishes.

The Dusky Grouper has a big body with a big mouth. One long dorsal fin and a rounded tail. Its color varies from brown to green depending on the season and the age. It is green during its juvenile phase. The adult is upper brown with yellow spots and lower yellow. On the Operculum there are three spines.

The dusky grouper is a solitary fish. It likes to live alone in rocks, at depths from the coast to 300 meters, but it's rare to find it below 60 meters. It has a barometric distribution, where the younger specimens are found near the coast and the older ones at the depths.

It normally has one cave considered as home and several other caves as temporary refuges. Its home has a minimum of two exits, and a size slightly bigger than the grouper, so no bigger animal can enter in. In case of biting attack or other force to extract it, the grouper opens its mouth, and the operculum spines wedge it inside the cave.