Silurus glanis, Linnaeus, 1758

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 599

Silurus glanis

Common name. European catfish.

Diagnosis. Distinguished from S. triostegus by: ● always two pairs of mental barbels / ● maxillary barbel longer than head length / ● anterior mandibular barbel present, longer than posterior mandibular barbel / ● one patch of vomerine teeth / ● pectoral spine not or slightly serrated on its inner margin. Size up to about 2600 mm SL and 148 kg.

Distribution . Lake Urmia basin, Black, Caspian, North, Baltic, and Aral basins, as far north as southern Sweden and Finland; Aegean basin, in Maritza and from Stuma to Sperchios drainages. Not native to Persian Gulf and Mediterranean basins of West Asia. Widely introduced and translocated in Anatolia, Europe, Hari drainage, and Lake Balkhash basin ( Kazakhstan). Occasionally stocked in Persian Gulf basin but does not appear to have established (yet).

Habitat. Large and medium-sized lowland rivers, reservoirs, backwaters, and well-vegetated lakes. Spawns in shallow, warm, and well-vegetated riverine habitats without current.

Biology. Lives up to 80 years in wild. Spawns first time at 2–3 years and 1–2 kg, April–June, in northern areas until August, when temperatures reach about 20°C. Female lay about 30,000 eggs per kilogram of body weight. At spawning sites, males defend small territories and build nests of plant material, dig shallow depressions, or clean spawning substrate such as willow ( Salix ) roots. Males defend nest until larvae emerge.

Spawns in pairs. Male embraces female during spawning. Eggs hatch in 2–3 days, and larvae remain in nest until yolk sac is absorbed (2–4 days). A nocturnal predator, feeding near bottom and in water column. Very sensitive to extraaquatic sounds. Head sensory canal system allows tracking of wakes (a trail of hydrodynamic and chemical signatures left by a swimming fish) of prey up to 10 seconds old over distances up to 55 times length of prey. Larvae and juveniles benthic and negatively phototactic, feeding on a wide variety of invertebrates and fish. Adults feed on fish and other aquatic vertebrates, documented to feed on pigeons at water edge by lunging out of water during daylight.

Conservation status. LC; one of most important invasive species in the Western Palearctic.

Further reading. Mohr 1957 (biology); Kobayakawa 1989 (description); Pohlmann et al. 2004 (wakes).

Figures

Silurus glanis

Distribution