Dusky grouper

Photo: Sylvain Le Bris · CC BY-NC

The dusky grouper — known locally as the mérou brun — is one of the most charismatic species of the Mediterranean rocky reef. Protogynous hermaphrodites, all individuals begin life as female and the largest, oldest animals transition to male. Inside the Calanques reserve, grouper are so habituated to divers that individuals approach within arm's reach, making this one of the few places in Europe where close natural behaviour can be observed. They are apex predators of octopus, fish, and crustaceans, and their population recovery is a marker of reserve health.