HomeFish encyclopediaRay-finned fishesCharacinsCharacinsCroaking tetra Croaking tetra (Mimagoniates inequalis) Scientific name: Mimagoniates inequalis Eigenmann, 1911 The Croaking tetra (Mimagoniates inequalis) is a freshwater fish of the family Characidae. Native range: South America, blackwater tributaries of lower Jacu? River and blackwater coastal streams and swamps of Rio Grande do Sul, Brazil. BiologyInhabit small to moderate-sized streams or rivers.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameMimagoniates inequalisFamilyCharacidae (Characins)OrderCharaciformes (Characins)ClassActinopterygii (Ray-finned fishes)Maximum length3.3EnvironmentFreshwater; benthopelagicClimateTropicalDistributionSouth America: blackwater tributaries of lower Jacu? River and blackwater coastal streams and swamps of Rio Grande do Sul, Brazil.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessResilienceHigh, minimum population doubling time less than 15 months (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