HomeFish encyclopediaRay-finned fishesPerch-like fishSquaretailsSmalleye squaretail Smalleye squaretail (Tetragonurus cuvieri) Scientific name: Tetragonurus cuvieri Risso, 1810 The Smalleye squaretail (Tetragonurus cuvieri) is a marine fish of the family Tetragonuridae. BiologyDorsal spines: 15 - 21; Dorsal soft rays: 12-15; Anal spines: 1; Anal soft rays: 11 - 13; Vertebrae: 52. Pectorals and pelvic fins small. Dark brown, paler at base of tail and on head, otherwise almost uniform throughout.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameTetragonurus cuvieriFamilyTetragonuridae (Squaretails)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length70.0Depth range1–800 m (3–2625 ft)EnvironmentMarine; bathypelagic; oceanodromous; depth range 1 - 800 mClimateDeep-waterDistributionEastern Pacific: Aleutian Islands, Alaska to Baja California, Mexico; Chile. Western Pacific: Japan, New Zealand and Australia. Western Indian Ocean: Natal, South Africa. Atlantic Ocean, including the Mediterranean.Conservation status (IUCN)Not EvaluatedThreat to humansReports of ciguatera poisoningResilienceLow, minimum population doubling time 4.5 - 14 years (K=0.10) SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026