HomeFish encyclopediaRay-finned fishesPerch-like fishSea basses: groupers and fairy bassletsKoester Koester (Acanthistius sebastoides) Scientific name: Acanthistius sebastoides Castelnau, 1861 The Koester (Acanthistius sebastoides) is a marine fish of the family Serranidae. Native range: Southeast Atlantic, Namibia to East London, South Africa. BiologyDorsal spines (total): 11 - 13; Dorsal soft rays (total): 15-17; Anal spines: 3; Anal soft rays: 7 - 8. Head and body with small orange spots and few scattered dark brown blotches; caudal and anal fins dark grey, pelvic fins dusky yellow. Lower GR with 4-6 rudiments.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameAcanthistius sebastoidesFamilySerranidae (Sea basses: groupers and fairy basslets)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length35.0Depth range1–30 m (3–98 ft)EnvironmentMarine; demersal; depth range 1 - 30 mClimateSubtropicalDistributionSoutheast Atlantic: Namibia to East London, South Africa.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesFisheries: commercial; gamefish: yesResilienceMedium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.) SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026