HomeFish encyclopediaRay-finned fishesPerch-like fishGruntsPurplemouth grunt Purplemouth grunt (Pomadasys bayanus) Scientific name: Pomadasys bayanus Jordan & Evermann, 1898 The Purplemouth grunt (Pomadasys bayanus) is a freshwater fish of the family Haemulidae. In the aquarium it needs water at 21–30°C (70–86°F). Native range: Central and South America, Pacific drainages from Baja California, Mexico to Peru. Purplemouth grunt care at a glanceTemperature21–30°C (70–86°F) BiologyBody oblong, somewhat compressed, and not deep (depth contained 3.1 to 3.8 times in standard length); mouth large, terminal, and almost horizontal, its posterior edge located at the same level as the anterior rim of the eye; first gill arch with 7 to 9 gill rakers; dorsal fin notched, with 12 to 13 spines and 12 soft rays (XII-XIII, 12); pectoral fins short, not reaching distal edge of pelvic fins; second anal spine longer and thicker than third; back olive green; belly silvery; entire body iridescent.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific namePomadasys bayanusFamilyHaemulidae (Grunts)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length51.0Common length33.0EnvironmentMarine; freshwater; brackish; benthopelagicClimateTropicalDistributionCentral and South America: Pacific drainages from Baja California, Mexico to Peru.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesFisheries: minor 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