HomeMarine aquarium fishGobies, blennies & dottybacksOnespot wormfish Onespot wormfish (Gunnellichthys monostigma) Scientific name: Gunnellichthys monostigma Smith, 1958 The Onespot wormfish (Gunnellichthys monostigma) is a marine fish of the family Microdesmidae. In the aquarium it needs water at 23–27°C (73–81°F). Onespot wormfish care at a glanceTemperature23–27°C (73–81°F) BiologyDorsal spines (total): 21 - 22; Dorsal soft rays (total): 39-42; Anal spines: 0; Anal soft rays: 38 - 43. Diagnosis:Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameGunnellichthys monostigmaFamilyMicrodesmidae (Wormfishes)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length15.0Depth range1–20 m (3–66 ft)EnvironmentMarine; reef-associated; depth range 1 - 20 m, usually 6 - 20 mClimateTropicalDistributionIndo-Pacific: East Africa to Marquesan and Society islands, north to Ryukyu Islands, south to the southern Great Barrier Reef. Record from Mauritius requires verification.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesAquarium: commercial More gobies, blennies & dottybacksYellowhead jawfishOpistognathus aurifronsFire gobyNemateleotris magnificaYellow prawn-gobyCryptocentrus cinctusPersian blennyEcsenius midasCurious wormfishGunnellichthys curiosusY-bar shrimp gobyCryptocentrus fasciatusSee 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