HomeFreshwater aquarium fishTetras & characinsFeatherfin tetra Featherfin tetra (Hemigrammus unilineatus) Scientific name: Hemigrammus unilineatus Gill, 1858 The Featherfin tetra (Hemigrammus unilineatus) is a freshwater fish of the family Characidae. In the aquarium it needs water at 23–28°C (73–82°F). Featherfin tetra care at a glanceTemperature23–28°C (73–82°F) BiologyUsually found in ponds, ditches, slow flowing streams, both clear and turbid, in both open and shaded areas. A voracious species which feeds on small crustaceans, insects and mollusks. Gregarious and non-aggressive, it is reputedly easy to rear and to reproduce in the aquarium. Maximum length questionable.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameHemigrammus unilineatusFamilyCharacidae (Characins)OrderCharaciformes (Characins)ClassActinopterygii (Ray-finned fishes)Maximum length5.3EnvironmentFreshwater;; pH range: 6.0 - 7.5; dH range: ? - 20 benthopelagicClimateTropicalDistributionCentral and South America: River basins of Trinidad, coastal river basins of Venezuela, rivers of Guyana, Suriname, French Guiana; Amazon and Guapor? River basins.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesAquarium: commercialResilienceHigh, minimum population doubling time less than 15 months (tm More tetras & characinsRummy-nose tetraHemigrammus rhodostomusEmber tetraHyphessobrycon amandaeOrnate tetraHyphessobrycon bentosiYellow tetraHyphessobrycon bifasciatusRosy tetraHyphessobrycon rosaceusRoyal tetraInpaichthys kerriSee all tetras & characins SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026