Picture courtesy of: Claire Goiran

Actinopterygii (Gigaclass) > Actinopteri (Class) > Teleostei (Subclass) > Perciformes (Order) > Percoidei (Suborder) > Epinephelidae (Family) > Epinephelus (Genus)

Mérou demi-lune, Chinaman rockcod, Charlie court cod, Chinaman cod, Chinaman rock-cod, Dotted groper, Green-finned rock-cod, Halfmoon grouper, White-dotted cod, Garoupa meia-lunada, Mero medialuna, Halfmaan-klipkabeljou, Shimofurihata, シモフリハタ, 半月石斑魚, 玫瑰斑, 纹斑石斑鱼, 霜點石斑魚, لُؤز نصف قمر, Cá Mú kè,

Synonymes
Epinephelus grammatophorus (Boulenger, 1903)
Epinephelus homosinensis (Whitley, 1944)
Epinephelus matterni (Fowler, 1918)
Epinephelus raymondi (Ogilby, 1908)
Epinephelus rhyncholepis (Bleeker, 1853)
Epinephelus spiramen (Whitley, 1945)
Serranus rhyncholepis (Bleeker, 1853)
Serranus rhyncolepis (Bleeker, 1853)
Serranus rivulatus (Valenciennes, 1830)
Serranus viridipinnis (De Vis, 1884)

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Description
Dorsal spines (total): 11; Dorsal soft rays (total): 16-18; Anal spines: 3; Anal soft rays: 8. Pectoral fins rays: 17-19 fleshy; Gill rakers: 6-8 + 14-16; Lateral line scale: 48-53; Lateral scale series: 86-102. Body scales ctenoid except cycloid anterodorsally above lateral line, on nape, thorax and abdomen; Body with auxiliary scales only anterodorsally behind zone of small cycloid scales; Greatest depth of body: 2.7-3.2 in SL (fish 12-35 mm SL); Rounded caudal fin; Pelvic fins: 1.9-2.4 in Head Length; Head length: 2.3-2.6 in SL; Flat to slightly convex interorbital area, dorsal head profile convex; Snout length: 4.0-5.0 in HL; Angular preopercle, with enlarged serrae at angle; Straight upper edge of operculum, almost horizontal; Posterior and anterior nostril subequal in size; Maxilla reaches to or past vertical at rear edge of eye, ventral edge with slight step at distal expansion; Rows of teeth on midlateral part of lower jaw: 2-3; Pyloric caeca. Max. length: 50.0 cm TL; Max. published weight: 4.0 kg; Max. reported age: 13 years. Depth range 1 - 150 m.

Color
Body red-brown to green-brown, with pale spot on each scale; Four irregular dark bars usually on body and extending onto dorsal fin base (3rd and 4th bars run from soft-rayed dorsal fin to anal fin and often join midlaterally), 5th dark bar on peduncle; Two dark red or red-brown bands on chest and dark brown spot on front of isthmus; Head dark, with irregular pale blotches and vermiculations, and 4 pale spots ventrally; Fins green-yellow or grey-brown; Dorsal fin with dark streak along base (may be restricted to spinous base), margin of interspinous membranes yellow to reddish next to spines, transparent posteriorly, with pale stripe below triangular tips of fin; Pectoral fins dusky, with dark red or red-brown semicircular blotch at base of rays; Some fish with white dots on operculum and on body.

Etymology
Epinephelus: from prefix Greek, epi = upon, on, over, near, at, before, after + from Greek, Nephos = cloud. Referring to film or membrane eye of most if not all groupers known to Bloch (although modern accounts mention only a transparent cornea protruding slightly through the orbit); Bloch also provided three vernacular names that describe the eyes: Blödaugen, German for “stupid eyes” or “bleary eyes,” depending on the translation, the English “Wall-eye,” and the French Tayes (per Bloch 1797), from taie, an opaque spot on the cornea.
rivulatus: from Latin, rivulatus = provided with small brooks. Referring to 3-4 wavy brown lines on cheek below eye.
Original description: Serranus rivulatus Valenciennes, 1830 - Type locality: Réunion island, western Mascarenes, southwestern Indian Ocean.

Distribution
Indo-West Pacific: Eastern Cape and KwaZulu-Natal (South Africa), East Africa, Socotra (Yemen), Comoros, Madagascar, western Mascarenes (La Réunion, Mauritius), east to Tonga, north to Ogasawara Islands (Japan), south to Western Australia, Queensland (Australia), New Caledonia and northern New Zealand.

Biology
Sedentary reef-associated species. Occurs on coral reefs, areas with rocky substrata, algal flats and seagrass beds. Feeds on fishes and crustaceans. A protogynous hermaphrodite. Forms spawning aggregations. A monandric species. Sedentary, solitary, and easily approached by divers; Has been seen to face a diver and display its large pectoral fins so the red spot at the bases appear as eyespots of a larger fish.