Typically stout bodied and a large mouth fish. They are not built for long-distance fast swimming. They can be quite large, with lengths over a meter and weight up to 100 kg.
Epinephelus fuscoguttatus is a medium-sized fish which grows up to 120 cm, but the average size mostly observed is 50 cm.Its body has a stocky and robust aspect, is compressed laterally and has a sharp profile for the head. The mouth is big and has a superior position with many small teeth and canine in front. The background coloration is pale yellowish-brown with many irregular in size and shape dark brown or Grey blotches. The body is also covered with many small dark brown spots. All the fins are large and round.
The brown-marbled grouper can be easily confused with its close relative Epinephelus polyphekadion. The differences are more obvious on adults specimen. The distinctive characters of the brown-marbled grouper are: a small black saddle on the top of caudal peduncle, when observed on the side a notch above the eyes and the front head is clearly visible, its body is quite thick from the front of the dorsal fin to the bottom of the fish below the pectoral fins.