Wels Catfish (Silurus glanis) Care Guide
Silurus glanis is one of the largest freshwater fish in Europe, a cold-water predator suitable only for public aquaria.
Overview
Silurus glanis, the wels catfish, was described by Linnaeus in 1758. It is a large predatory catfish native to Europe and parts of western Asia, and one of the largest freshwater fishes in Europe. Owing to its eventual size it is suitable only for very large public aquaria and ponds, not home tanks.
Taxonomy
- Family: Siluridae
- Genus: Silurus
- Scientific name: Silurus glanis
Habitat
FishBase records the species from the North, Baltic, Black, Caspian and Aral Sea basins, as far north as southern Sweden and Finland, and it has been widely introduced across Europe. It inhabits large and medium lowland rivers, backwaters and well-vegetated lakes, and can tolerate brackish water in the Baltic and Black Seas.
Tank requirements
- Minimum volume: 5000 L or more; realistically a public-aquarium or pond species
- Temperature: 4-24 °C (39-75 °F); FishBase lists 4-20 °C
- pH: 6.5-8
- GH: 8-20 °dGH
- Depth in nature: 0-30 m (FishBase)
- Lifespan: about 8-15 years in care; FishBase records a maximum age of 80 years
Diet
FishBase classifies it as a nocturnal predator: juveniles eat invertebrates and small fish, while adults prey on fish and aquatic vertebrates. Wikipedia notes large specimens also take crayfish, eels, frogs, rodents and even aquatic birds. It is a carnivore best fed once daily on meaty foods.
Compatibility
This is an aggressive, bottom-dwelling predator that will consume any tankmate small enough to swallow. It should not be combined with small fish. Only similarly large, robust species in very large systems are appropriate, and it is largely nocturnal.
Conservation status
IUCN Red List: Least Concern (FishBase cites an assessment dated 29 May 2022). Wikipedia notes the species is locally declining in northern peripheral populations such as Sweden, while being regarded as invasive where introduced.