HomeMarine aquarium fishWrassesMcCosker's flasher McCosker's flasher (Paracheilinus mccoskeri) Scientific name: Paracheilinus mccoskeri Randall & Harmelin-Vivien, 1977 The McCosker's flasher (Paracheilinus mccoskeri) is a marine fish of the family Labridae. In the aquarium it needs water at 25–28°C (77–82°F). Native range: Indo-West Pacific, western Indian Ocean to Fiji. Questionable record from Indonesia. McCosker's flasher care at a glanceTemperature25–28°C (77–82°F) BiologyOnly the first dorsal soft ray prolonged in adults; penultimate dorsal soft ray of males 1.6-2.0 in HL; a single short dark stripe beneath pectoral fin.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameParacheilinus mccoskeriFamilyLabridae (Wrasses)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length8.0EnvironmentMarine; reef-associated, usually 5 - 40 mClimateTropicalDistributionIndo-West Pacific: western Indian Ocean to Fiji. Questionable record from Indonesia.Conservation status (IUCN)Least Concern (LC)Threat to humansHarmlessUsesAquarium: commercialResilienceHigh, minimum population doubling time less than 15 months (Preliminary K or Fecundity.) More wrassesSpot-lined flasherParacheilinus lineopunctatusPink flasherParacheilinus carpenteriRed Sea eightline flasherParacheilinus octotaeniaFilamentous wrasseParacheilinus filamentosusLong green wrassePseudojuloides elongatusSmalltail wrassePseudojuloides cerasinusSee all wrasses SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026