Silurus glanis Linnaeus, 1758
Wels catfish
Silurus glanis
photo by Hartl, A.

Family:  Siluridae (Sheatfishes)
Max. size:  273 cm TL (male/unsexed); max.weight: 130 kg; max. reported age: 80 years
Environment:  benthopelagic; freshwater; brackish; depth range 0 - 30 m, non-migratory
Distribution:  Europe and Asia. North, Baltic, Black, Caspian and Aral Sea basins, as far north as southern Sweden and Finland; Aegean Sea basin in Maritza and from Struma to Sperchios drainages; Turkey. Absent from the rest of Mediterranean basin. Now widely introduced and translocated throught Europe and Lake Balkhash basin in Kazakhstan. Several countries report adverse ecological impact after introduction.
Diagnosis:  Dorsal spines (total): 1-1; Dorsal soft rays (total): 4-5; Anal spines: 1-1; Anal soft rays: 83-95. Distinguished from all other freshwater fishes in Europe by the following unique characters: two pairs of mental barbels; and anal fin with 83-91½ rays. Differs further from the following combination of features: body naked; large, depressed head; dorsal fin with 2-4½ rays; caudal fin rounded or truncate; no adipose fin; and anal rays almost touching caudal (Ref. 59043). Caudal fin with 17 rays (Ref. 2196).
Biology:  The maximum length of the species has been recorded as 5 m for a long time and the maximum weight as 306 kg . It has been demonstatred that misidentifications and problems of measurment units have led to these numbers. The recorded maxima with evidence are 2.73 m and 130 kg (Ref. 123627). Inhabits large and medium size lowland rivers, backwaters and well vegetated lakes (Ref. 59043). Occurs mainly in large lakes and rivers, though occasionally enters brackish water in the Baltic and Black Seas (Ref. 9988). Found in deep waters of dams constructed on the lower reaches of rivers (Ref. 9696). A nocturnal predator, foraging near bottom and in water column. Larvae and juveniles are benthic, feeding on a wide variety of invertebrates and fish. Adults prey on fish and other aquatic vertebrates. Attains first sexual maturity at 2-3 years of age (Ref. 59043). Spawns in the salt water of the Aral Sea (at Kulandy) (Ref. 1441). Marketed fresh, canned and frozen; can be pan-fried and baked (Ref. 9988). Locally threatened due to river regulation destroying shallow spawning sites (Ref. 59043).
IUCN Red List Status: Least Concern (LC); Date assessed: 01 January 2008 Ref. (130435)
Threat to humans:  potential pest
Country info:   
 


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