HomeFish encyclopediaRay-finned fishesLive bearers, Killifishes and RivulinesPoeciliidsSouthern mountain swordtail Southern mountain swordtail (Xiphophorus monticolus) Scientific name: Xiphophorus monticolus Kallman, Walter, Morizot & Kazianis, 2004 The Southern mountain swordtail (Xiphophorus monticolus) is a freshwater fish of the family Poeciliidae. Native range: North America, Mexico. BiologyA species characterized by a longer caudal appendage, sword index 0.25; fainter orange stripes that fade in older individuals and pronounced melanophore pigmentation at the edges of the dorsal and ventral sword margins (in males).Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameXiphophorus monticolusFamilyPoeciliidae (Poeciliids)OrderCyprinodontiformes (Live bearers, Killifishes and Rivulines)ClassActinopterygii (Ray-finned fishes)Maximum length5.0Depth range2–3 m (7–10 ft)EnvironmentFreshwater; pelagic; depth range 2 - 3 mClimateTropicalDistributionNorth America: Mexico.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