HomeFish encyclopediaRay-finned fishesPerch-like fishGobiesKaalpens goby Kaalpens goby (Coryogalops william) Scientific name: Coryogalops william Smith, 1948 The Kaalpens goby (Coryogalops william) is a freshwater fish of the family Gobiidae. Native range: Western Indian Ocean, Xora River mouth, South Africa to Inhaca Islands, Mozambique. BiologyDorsal spines (total): 7; Dorsal soft rays (total): 10-11; Anal spines: 1; Anal soft rays: 9. Color variable, usually dark; scale edges darker; dark crescent at caudal base.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameCoryogalops williamFamilyGobiidae (Gobies)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length6.0EnvironmentMarine; freshwater; brackish; demersal; amphidromousClimateSubtropicalDistributionWestern Indian Ocean: Xora River mouth, South Africa to Inhaca Islands, Mozambique.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