Body depth distinctly less than head length, depth contained 3.0 to 3.6 times in standard length. Head length contained 2.5 to 2.9 times in standard length; interorbital area convex; preopercle angular, with 3 to 6 large spines at the angle, the lowermost directed ventrally; eye diameter equals interorbital width in fish of 20 to 25 cm standard length and is distinctly less than interorbital in larger specimens; rear nostrils slightly bigger than front ones; maxilla reaches about to vertical at rear edge of eye; midlateral part of lower jaw with 2 rows of teeth. Gill rakers 8 to 10 on upper limb, 15 to 17 on lower limb, total 23 to 26. Dorsal fin with XI spines and 14 to 16 rays, third or fourth spine longest, the interspinous membrane only slightly incised between the spines; anal fin with III spines and 8 (rarely 7 or 9) rays; pectoral-fin rays 18 or 19, longest contained 1.5 to 1.7 times in head length; pelvic-fin origin below base of pectoral fins; caudal fin rounded. Body scales ctenoid; lateral-line scales 67 to 72; lateral-scale series 98 to 102. Pyloric caeca 12 to 14.
Colour: Greenish bronze, the fins darker, brownish violet, bordered with white or pale mauve; 3 or 4 pale blue (or white) lines across operculum, the lowest from rear end of maxilla to interopercle, the next from eye across preopercle just above the angle and onto subopercle, the uppermost line from eye to upper end of preopercle where it usually bifurcates and continues to rear edge of operculum. Juveniles with faint dark spots on body forming 5 indistinct dark bars; fins also with faint dark spots. In large adults the white lines on the head may be indistinct.

E. aeneus occurs throughout the southern Mediterranean and along the west coast of Africa to southern Angola. Heemstra (1991) mentioned reports from the Canaries and Cape Verde Islands (based on the distribution map of Cadenat, 1935:fig. 29), but these records are unsubstantiated. Brito (1991) did not include E. aeneus in his catalogue of the fishes of the Canaries, and he informed Heemstra and Randall (1993) that although this species is often seen in the markets there, the specimens invariably emanate from the continental coast of Africa. The seasonal migration of E. aeneus off the coast of Senegal is influenced by the seasonal upwellings off Senegal and Mauritania (Cury and Roy, 1988). The description of Perca robusta Couch (1832) was apparently based on a stray individual that was caught off the south coast of England.

Adults are found on rocky or mud and sand bottoms in depths of 20 to 200 m; juveniles have been taken in coastal lagoons and estuaries. In west African waters, Longhurst (1960) found that E. aeneus feeds on fishes (58%), stomatopods (21%), crabs (10%), and cephalopods (10%). Bruslé (1985) summarized the published information on the ecology, distribution, and biology of this species. E. aeneus is a protogynous hermaphrodite that matures first as a female at 50 to 60 cm total length and a weight of about 3 kg for Tunisian fish. Most females change sex at about 9 kg, but smaller males (of 3 to 5 kg) are occasionally found. Total potential fecundity was estimated to range from 789 436 ova in a 44 cm standard length fish of 2.2 kg to 12 589 242 ova in a 87 cm standard length fish of 12.6 kg. Vadiya (1984) estimated “absolute fecundity” of a 93.5 cm, 8.6 kg E. aeneus at 3 873 271 ova. Ezzat et al. (1981) used annular rings on scales to determine age and growth of E. aeneus in Egyptian waters; they found that a 9.7 kg fish was 8 years old. Bouain et al. (1983) studied age, growth, and reproduction of the Tunisian population: the largest fish was 115 cm total length, 25 kg, and was estimated to be 17 years old; females were mature at 5 to 7 years (1.5 to 3.0 kg, 50 to 60 cm total length); and sex change occurs at 10 to 13 years (6 to 15 kg, 80 to 110 cm total length). Development of larvae (2.16 to 8.96 mm standard length) and a prejuvenile of 22.4 mm standard length were illustrated by Aboussouan (1972).

Maximum total length 120 cm; weight 25 kg.

Perca robusta Couch, 1832 was listed as a synonym of “Epinephelus guaza” (= E. marginatus) by C.L. Smith (1971), but Heemstra (1991) considered this species a synonym of E. aeneus.