The Dusky Grouper, also known as Merou or Dusky Perch, is s species in the order of the Perciformes and thus belongs to the superclass of bony fish. The stock of Epinephelus marginatus is threatened by overfishing and is classified as highly endangered by the IUCN.
Description
The Dusky Grouper has a high-back and a laterally compressed body with a big mouth that extends behind the eyes. In addition, the lower jaw surpasses the upper jaw. The back and sides are brown to violet coloured, with yellow or white marbling. The abdomen is also yellowish.
It reaches a maximum size of 150cm in length and a maximum weight of 60kg.
Habitat and Distribution
Epinephelus marginatus can be found over rocky reefs with many hiding places, such as caves and gaps, down to a depth of 200m.
When diving in the Canaries you can observe it frequently. The large specimens are, however, more likely to be seen on Lanzarote, Fuerteventura and El Hierro. It is also found in the eastern Atlantic to the southern tip of Africa, the Mediterranean Sea and the western Atlantic on the coasts of Brazil, Argentina and Uruguay and in the western Indian Ocean.
Biology
The Dusky Grouper lives solitary and is territorial. While older specimens are deeper at around the 30m, one finds juveniles closer to the coast, in shallower water.
Their diet consists of small fish, crustaceans, cephalopods and other invertebrates.
Furthermore Epinephelus marginatus reaches an age of more than 60 years.
Reproduction
Epinephelus marginatus is a protogyne hermaphrodit. That means that it changes sex from female to male at a maximum size of 80cm or at the age from 12 to 17 years. The Dusky Grouper reaches its sexual maturity with about 5 years. In the north-eastern Atlantic it spawns from March to June. Small Groups of them gather and the sperm and eggs are released into the open water. The eggs are accordingly pelagic with the current until they hatch.