HomeFish encyclopediaRay-finned fishesPerch-like fishSea basses: groupers and fairy bassletsHalfmoon grouper Halfmoon grouper (Epinephelus rivulatus) Scientific name: Epinephelus rivulatus Valenciennes, 1830 The Halfmoon grouper (Epinephelus rivulatus) is a marine fish of the family Serranidae. BiologyDorsal spines (total): 11; Dorsal soft rays (total): 16-18; Anal spines: 3; Anal soft rays: 8Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameEpinephelus rivulatusFamilySerranidae (Sea basses: groupers and fairy basslets)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length39.0Depth range1–150 m (3–492 ft)EnvironmentMarine; reef-associated; depth range 1 - 150 mClimateSubtropicalDistributionIndo-West Pacific: East Africa to the western Pacific, southward into temperate waters of South Africa, Australia, and New Zealand. Not known from the Red Sea or Persian Gulf.Conservation status (IUCN)Least Concern (LC)Threat to humansHarmlessUsesFisheries: minor commercialResilienceHigh, minimum population doubling time less than 15 months (K=0.4) SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026