HomeFish encyclopediaRay-finned fishesSwallowers and GulpersOnejawsPaddletail onejaw Paddletail onejaw (Monognathus ahlstromi) Scientific name: Monognathus ahlstromi Raju, 1974 The Paddletail onejaw (Monognathus ahlstromi) is a marine fish of the family Monognathidae. Native range: Eastern Central Pacific, California, USA. Species factsScientific nameMonognathus ahlstromiFamilyMonognathidae (Onejaws)OrderSaccopharyngiformes (Swallowers and Gulpers)ClassActinopterygii (Ray-finned fishes)Maximum length4.9Depth range0–2000 m (0–6562 ft)EnvironmentMarine; benthopelagic; depth range 0 - 2000 mClimateTemperateDistributionEastern Central Pacific: California, USA.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