HomeFish encyclopediaRay-finned fishesLightfishes and DragonfishesBristlemouthsSlender bristlemouth Slender bristlemouth (Cyclothone pseudopallida) Scientific name: Cyclothone pseudopallida Mukhacheva, 1964 The Slender bristlemouth (Cyclothone pseudopallida) is a marine fish of the family Gonostomatidae. BiologyDorsal spines (total): 0; Dorsal soft rays (total): 12-15; Anal spines: 0; Anal soft rays: 17 - 21; Vertebrae: 29 - 34. Light to dark brown in color. Branchiostegal rays: 14.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameCyclothone pseudopallidaFamilyGonostomatidae (Bristlemouths)OrderStomiiformes (Lightfishes and Dragonfishes)ClassActinopterygii (Ray-finned fishes)Maximum length4.6Depth range0–4938 m (0–16201 ft)EnvironmentMarine; bathypelagic; depth range 0 - 4938 m, usually 300 - 1400 mClimateDeep-waterDistributionAtlantic, Indian and Pacific: in deep water of tropical to temperate zones. Southern Ocean: between the Antarctic Polar Front and the Antarctic continental shelf of the Indian Ocean sector, near the Balleny Islands, and the Scotia Sea. Eastern Pacific: California Current region. South China Sea.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesFisheries: of no interestResilienceMedium, minimum population doubling time 1.4 - 4.4 years (Assuming Fec SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026