HomeFish encyclopediaRay-finned fishesFlatfishesTonguefishesWestern Pacific Tonguefish Western Pacific Tonguefish (Symphurus thermophilus) Scientific name: Symphurus thermophilus Munroe & Hashimoto, 2008 The Western Pacific Tonguefish (Symphurus thermophilus) is a marine fish of the family Cynoglossidae. In the aquarium it needs water at 19–22°C (66–72°F). Western Pacific Tonguefish care at a glanceTemperature19–22°C (66–72°F) BiologyOccurs on a variety of substrata only within active hydrothermal vent sites.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameSymphurus thermophilusFamilyCynoglossidae (Tonguefishes)OrderPleuronectiformes (Flatfishes)ClassActinopterygii (Ray-finned fishes)Maximum length8.7Depth range239–733 m (784–2405 ft)EnvironmentMarine; demersal; depth range 239 - 733 mClimateTropicalDistributionPacific: an endemic species in the western Pacific Ocean collected at several active hydrothermal vent sites with a disjunct distribution over a wide geographic range from Kaikata Seamount (26?42.30'N, 141?04.70'E; near Bonin Island, off southeastern Japan) to the Rumble 3 Submarine Volcano (35?44'S, 178?72?79'W) on the Kermadec Ridge, northern New Zealand.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesFisheries:ResilienceHigh, minimum population doubling time less than 15 months (Preliminary K or Fecundity.) SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026