HomeFish encyclopediaRay-finned fishesCusk eelsViviparous brotulasTwinhook cusk Twinhook cusk (Diancistrus longifilis) Scientific name: Diancistrus longifilis Ogilby, 1899 The Twinhook cusk (Diancistrus longifilis) is a marine fish of the family Bythitidae. Native range: Western Pacific, Great Barrier Reef and Lord Howe Island. Species factsScientific nameDiancistrus longifilisFamilyBythitidae (Viviparous brotulas)OrderOphidiiformes (Cusk eels)ClassActinopterygii (Ray-finned fishes)Maximum length7.6EnvironmentMarine; reef-associatedClimateSubtropicalDistributionWestern Pacific: Great Barrier Reef and Lord Howe Island.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessResilienceLow, minimum population doubling time 4.5 - 14 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