HomeFish encyclopediaRay-finned fishesPerch-like fishWormfishesFlagtail wormfish Flagtail wormfish (Clarkichthys bilineatus) Scientific name: Clarkichthys bilineatus Clark, 1936 The Flagtail wormfish (Clarkichthys bilineatus) is a marine fish of the family Microdesmidae. Native range: Eastern Central Pacific, off Cabo San Lucas, Baja California and off Nayarit. Mexico to northern Colombia and the Galapagos Islands. BiologyInhabits rocky, exposed tide pools and shallow rock and coral reef areas. Spawns upon reaching 3.4 cm SL. Oviparous.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameClarkichthys bilineatusFamilyMicrodesmidae (Wormfishes)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length6.2Depth range8 m (26 ft)EnvironmentMarine; reef-associated; depth range ? - 8 mClimateTropicalDistributionEastern Central Pacific: off Cabo San Lucas, Baja California and off Nayarit. Mexico to northern Colombia and the Galapagos Islands.Conservation status (IUCN)Data deficient (DD)Threat to humansHarmless SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026