HomeFish encyclopediaRay-finned fishesHalosaurs and deep-sea Spiny eelsHalosaursHalosaur Halosaur (Halosaurus johnsonianus) Scientific name: Halosaurus johnsonianus Vaillant, 1888 The Halosaur (Halosaurus johnsonianus) is a marine fish of the family Halosauridae. In the aquarium it needs water at 4–11°C (39–52°F). Native range: Eastern Atlantic, southern Spain and Portugal to Mauritania including the Azores and Canary Islands. Halosaur care at a glanceTemperature4–11°C (39–52°F) BiologyFound on the continental slope. Feeds on copepods. Minimum depth reported taken from.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameHalosaurus johnsonianusFamilyHalosauridae (Halosaurs)OrderNotacanthiformes (Halosaurs and deep-sea Spiny eels)ClassActinopterygii (Ray-finned fishes)Maximum length50.0Depth range680–2200 m (2231–7218 ft)EnvironmentMarine; bathydemersal; depth range 680 - 2200 mClimateDeep-waterDistributionEastern Atlantic: southern Spain and Portugal to Mauritania including the Azores and Canary Islands.Conservation status (IUCN)Not EvaluatedThreat to humansHarmless SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026