HomeFish encyclopediaRay-finned fishesSmeltsPencil smeltsSlender argentine Slender argentine (Microstoma microstoma) Scientific name: Microstoma microstoma Risso, 1810 The Slender argentine (Microstoma microstoma) is a marine fish of the family Microstomatidae. BiologyDorsal spines (total): 0; Dorsal soft rays (total): 10-12; Anal spines: 0; Anal soft rays: 7 - 9; Vertebrae: 44 - 45. Body silvery, darker near tail. Swim bladder faintly colored. Adults mostly silver.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameMicrostoma microstomaFamilyMicrostomatidae (Pencil smelts)OrderOsmeriformes (Smelts)ClassActinopterygii (Ray-finned fishes)Maximum length21.0EnvironmentMarine; bathypelagicClimateDeep-waterDistributionProbably worldwide in tropical and subtropical seas. Eastern Atlantic: southern Ireland, scattered records in western Mediterranean, also Madeira Islands. Western Atlantic: Gulf of Mexico. Western Pacific: Australia and New Zealand.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesFisheries: of no interest SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026