HomeFish encyclopediaRay-finned fishesSilversidesNeotropical silversidesBigmouth silverside Bigmouth silverside (Chirostoma sphyraena) Scientific name: Chirostoma sphyraena Boulenger, 1900 The Bigmouth silverside (Chirostoma sphyraena) is a freshwater fish of the family Atherinopsidae. Native range: North America, endemic to the Lerma River basin, Mexico. Species factsScientific nameChirostoma sphyraenaFamilyAtherinopsidae (Neotropical silversides)OrderAtheriniformes (Silversides)ClassActinopterygii (Ray-finned fishes)EnvironmentFreshwater; benthopelagicClimateTropicalDistributionNorth America: endemic to the Lerma River basin, 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