Silurus glanis |
Linnaeus, 1758 
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Factsheet
001 |
| Synonyms: |
Siluris glanis, Silurus silurus, Silurus glanis aralensis |
| Common Name: |
Wels Catfish, this being [Wels] the German name for catfish |
| Family: |
Siluridae |
| Subfamily: |
Silurinae |
| Distribution: |
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| Size: |
475cm ( 16ft) |
| Temp: |
04-20°c (35-67°f) |
| pH.: |
6.0-8.0 |
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Russia,Lake
Aral, Central and Eastern Europe.
Germany,
in the upper Rhine.
his 'beasty' can grow up to 16ft in the wild and is definitely not an aquarium fish unless kept in an indoor pool! where it could grow to 9ft.
There is actually 12 known species the world over, and glanis is the type-species.
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This is Europe's largest freshwater fish and is only one of two catfish indigenous to Europe the other from the same genus, Silurus aristotelis from the River Akelhoos in Greece. This species looks like the other wels, but its dorsal fin is smaller, and it has just two pairs of barbels. The caudal fin is distinct from the anal fin.
The Common name for glanis is the 'Wels Catfish' and is found in the Rhine River in Germany eastwards to the Black and Caspian Seas.The elongated wels body consists of a powerful forebody and a laterally greatly compressed tail shaft; the prominent anal fin merges with the caudal fin. This fish, with its calm undulating tail movements normally has its long pair of upper jaw barbels pointing straight forward, while the four smaller barbels of the lower lip hang down. The dorsal fin, consisting of just four rays, seems small for such a powerful animal.
What intrigues me most about this fish is the small size of the dorsal (which is common in the Siluridae family) compared to the size of the body and the long anal fin. Identification of the Silurus genus relates to the long anal fin, small dorsal fin with four or five rays without a spine, and minus an adipose fin. The caudal fin is usually round to emarginate.
The name Silurus was used for some time for all naked catfishes until Bleeker identified the distinguishing characters of the various currently recognised groups. Silurus glanis was actually the first catfish to be scientifically recorded and it is synonymous to ScotCat as it is the first factsheet to be produced. It had been introduced sporadically to Lakes in England during the latter part of last century where clubs have been formed, relating only to these fish, with videos being produced of them being caught for sport in England, and other parts of Europe.
A friend of mine actually went of to Spain to fish for them in a Lake where they were seemingly introduced by a German ichthyologist and he had a rare old time!. Altogether I think a very interesting animal.
Characteristics: Dorsal 1/4; Anal 90-92; Pectorals; 1/14-17. Body elongate, cylindrical anteriorly, compressed posteriorly. Head large and depressed. Gape very wide. 3 pairs of barbels; the maxillary pair are especially long and when laid back, reach to beyond the pectorals. The dorsal fin is very small and inserted well forward. Adipose fin absent. Anal fin-base very long.
Colour: Colouration extremely variable; usually fairly dark, the upperside dark olive-green to blue-black and the flanks paler, occasionally with a red-brownish sheen. Underside, especially the belly, pale. Upon this ground colour are imposed cloudy or spotted marblings. Entirely black-blue and quite pale individuals also occur. Fins dark, red-brownish to brown-violet.
Compatibility: Not to be trusted with any other fish. Not suitable for aquarium keeping when it is going through the juvenile/adult stages.
Breeding: In their native habitat in the spring (May-July), the eggs are laid in a shallow depression excavated by the male, the eggs can total into the thousands and the growth is very rapid, with them becoming sexually mature at between 4 and 5 years old and living up to 20 or 30 years. There are even reputed reports of them living to 80 years old!
Feeding: You can of course keep small Wels Catfish in an aquarium where feeding is no problem as they will eat anything ( just keep an eye on your household ‘cat’), but where would it go after outgrowing your tank as Public Aquariums have probably their full quota. In the wild they have been known to eat ducks where they rush up behind them at night, sucking them into their mouths with a vortex motion. In their native habitat they feed on other fishes mainly eels,
burbot, tench and roach, but it also takes water voles as well as the ducklings.
Etymology: Silurus; From 'silouros', a kind of river fish. Silurus, sheetfish, catfish. According to Lacepéde (1803) this word indicates the rapidity with which Silurus can move its tail.
glanis; The name of a kind of fish.
References: Wheeler, Alwyne; Freshwater Fishes of Britain and Europe 1983
Grzmeck's Animal Life Encyclopedia Volume 4 Fishes 1, 1963
Sterba's Freshwater fishes of the World Vol.1
Photo Credits: Hans Reinhard
