HomeMarine aquarium fishGobies, blennies & dottybacksBlue devilfish Blue devilfish (Assessor macneilli) Scientific name: Assessor macneilli Whitley, 1935 The Blue devilfish (Assessor macneilli) is a marine fish of the family Plesiopidae. In the aquarium it needs water at 24–26°C (75–79°F). Native range: Western Pacific, Great Barrier Reef in Australia and New Caledonia. Blue devilfish care at a glanceTemperature24–26°C (75–79°F) BiologyAdults are found in lagoon and seaward reefs, aggregate in caves, often upside down. Males incubate the eggs mass in their mouth. Minimum depth reported from.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameAssessor macneilliFamilyPlesiopidae (Roundheads)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length6.0Depth range2–20 m (7–66 ft)EnvironmentMarine; reef-associated; depth range 2 - 20 m, usually 2 - 15 mClimateTropicalDistributionWestern Pacific: Great Barrier Reef in Australia and New Caledonia.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesAquarium: commercialResilienceHigh, minimum population doubling time less than 15 months (Preliminary K or Fecundity.) More gobies, blennies & dottybacksYellowhead jawfishOpistognathus aurifronsFire gobyNemateleotris magnificaYellow prawn-gobyCryptocentrus cinctusPersian blennyEcsenius midasYellow tilefishHoplolatilus luteusYellow-spotted tilefishHoplolatilus fourmanoiriSee all gobies, blennies & dottybacks SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026