HomeFish encyclopediaRay-finned fishesCharacinsCharacinsSemaphore tetra Semaphore tetra (Pterobrycon myrnae) Scientific name: Pterobrycon myrnae Bussing, 1974 The Semaphore tetra (Pterobrycon myrnae) is a freshwater fish of the family Characidae. In the aquarium it needs water at 23–26°C (73–79°F). Native range: Central America, Pacific drainages of southern Costa Rica, Jicote and Rincon rivers and the Esquinas River of Osa Peninsula. Semaphore tetra care at a glanceTemperature23–26°C (73–79°F) BiologyAquarium specimens reach 7.0 cm TL. Inhabits creeks of low to high current velocity. Collected in sites between elevations of 10 to 80 m, insectivorous.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific namePterobrycon myrnaeFamilyCharacidae (Characins)OrderCharaciformes (Characins)ClassActinopterygii (Ray-finned fishes)Maximum length3.9EnvironmentFreshwater;; pH range: 6.0 - 7.0; dH range: ? - 15 benthopelagicClimateTropicalDistributionCentral America: Pacific drainages of southern Costa Rica, Jicote and Rincon rivers and the Esquinas River of Osa Peninsula.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessResilienceHigh, 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