The dusky grouper inhabits rocky reefs in the Mediterranean Sea, eastern and south-western Atlantic and western Indian Ocean. It is a large fish, measuring up to 1.5 metres in length and occasionally reaching over 50 kilos in weight.

Its big head, wide mouth and jutting lower jaw give the dusky grouper a slightly prehistoric look, and the distinctive fungus-like blotches on its skin add to its strange appearance.

Dusky groupers favour habitat with a rocky bottom. Territorial, and largely solitary outside the spawning season, they are mainly ambush feeders, sucking in their prey and swallowing it whole.

One of the most remarkable characteristics of this and other grouper species is that every fish begins life as a female before turning into a male once it has attained a certain age and size. This gender reversal most frequently occurs at around 12 years old.