HomeFish encyclopediaRay-finned fishesCusk eelsViviparous brotulasBighead brotula Bighead brotula (Grammonus opisthodon) Scientific name: Grammonus opisthodon Smith, 1934 The Bighead brotula (Grammonus opisthodon) is a marine fish of the family Bythitidae. Native range: Southeast Atlantic, South Africa. BiologyTwo specimens known, one of which was collected from a depth of 22 m.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameGrammonus opisthodonFamilyBythitidae (Viviparous brotulas)OrderOphidiiformes (Cusk eels)ClassActinopterygii (Ray-finned fishes)Maximum length5.0Depth range22 m (72 ft)EnvironmentMarine; demersal; depth range ? - 22 mClimateSubtropicalDistributionSoutheast Atlantic: South Africa.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