HomeFish encyclopediaRay-finned fishesFlatfishesTonguefishesTonguesole Tonguesole (Symphurus nigrescens) Scientific name: Symphurus nigrescens Rafinesque, 1810 The Tonguesole (Symphurus nigrescens) is a marine fish of the family Cynoglossidae. Native range: Eastern Atlantic, Angola, St. Helena and Ascension islands northwards to Portugal (including Azores) and Mediterranean. BiologyOccurs on mud or sand bottoms of the continental slope and shelf.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameSymphurus nigrescensFamilyCynoglossidae (Tonguefishes)OrderPleuronectiformes (Flatfishes)ClassActinopterygii (Ray-finned fishes)Maximum length12.0Depth range20–1140 m (66–3740 ft)EnvironmentMarine; demersal; depth range 20 - 1140 mClimateSubtropicalDistributionEastern Atlantic: Angola, St. Helena and Ascension islands northwards to Portugal (including Azores) and Mediterranean.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesFisheries: commercialResilienceHigh, 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