HomeFreshwater aquarium fishSouth & Central American cichlidsFlag cichlid Flag cichlid (Mesonauta festivus) Scientific name: Mesonauta festivus Heckel, 1840 The Flag cichlid (Mesonauta festivus) is a freshwater fish of the family Cichlidae. In the aquarium it needs water at 25–34°C (77–93°F). Flag cichlid care at a glanceTemperature25–34°C (77–93°F) BiologyReported to reach around 10 cm SL. Tapajos (NRM) specimens were taken from a sandy shore at Aveiro and a small creek at Santarem, close to vegetation and with mud and sand bottom; Vila Bela da Santfssima Trinidade (NRM) specimens were seined in the shadow of the ferry, in shallow water with much aquatic vegetation; while from Madre de Dios, one sample was seined from a pool in a stream with clear, slightly tinted water and no vegetation; another, mixed sample came from a small stream and nearby cattle pool.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameMesonauta festivusFamilyCichlidae (Cichlids)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length8.2EnvironmentFreshwater;; pH range: 6.0 - 8.0; dH range: 4 - 6 benthopelagic; non-migratoryClimateTropicalDistributionSouth America: Paran? River basin, in the Paraguay River drainage in Brazil and Paraguay; Amazon River basin, in the Guapor? (Brazil and Bolivia), Madre de Dios (Peru), Mamor? (Bolivia), Jamari and Tapaj?s (Brazil) River drainages.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesAquarium: highly commercialResilienceHigh, minimum population doubling time less than 15 months (tm More south & central american cichlidsUmbrella cichlidApistogramma borelliiDemon eartheaterSatanoperca jurupariGoldeneye cichlidNannacara anomalaRed discusSymphysodon discusUaruUaru amphiacanthoidesFlag acaraLaetacara curvicepsSee all south & central american cichlids SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026