HomeFish encyclopediaRay-finned fishesPuffers and FilefishesFilefishesHairfinned leatherjacket Hairfinned leatherjacket (Paramonacanthus japonicus) Scientific name: Paramonacanthus japonicus Tilesius, 1809 The Hairfinned leatherjacket (Paramonacanthus japonicus) is a marine fish of the family Monacanthidae. Native range: Indo-West Pacific, southern Japan and northwest Australia to Papua New Guinea. BiologyDorsal spines (total): 2; Dorsal soft rays (total): 24-30; Anal spines: 0; Anal soft rays: 24 - 30; Vertebrae: 19. body width 2.0-2.6 in head length; body depth 2.0-3.1 in SL, head length 2.7-3.2 in SL; snout length 3.7-4.1 in SL; eye diameter 2.7-3.7 in head length; second dorsalmost caudal ray elongate and filamentous in male.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameParamonacanthus japonicusFamilyMonacanthidae (Filefishes)OrderTetraodontiformes (Puffers and Filefishes)ClassActinopterygii (Ray-finned fishes)Maximum length12.0Depth range34–46 m (112–151 ft)EnvironmentMarine; reef-associated; oceanodromous; depth range 34 - 46 mClimateTropicalDistributionIndo-West Pacific: southern Japan and northwest Australia to Papua New Guinea.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessResilienceMedium, minimum population doubling time 1.4 - 4.4 years (Fec = 3,300) SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026