How to Identify Wels Catfish

To identify Wels Catfish (Silurus glanis), look at these key features.

Physical Characteristics

Body shape

eel-like

Coloration

Highly variable. Dorsal side typically dark olive-green to black, often mottled or marbled with darker spots. Flanks are lighter, greenish-brown to yellowish-white, with a pale, often yellowish or whitish belly. Albino and xanthic forms exist.

Scale type

none

Mouth position

superior

Distinctive features

Very long, scaleless body, Broad, flattened head with a wide mouth, Two very long barbels on the upper jaw (maxillary barbels), Four shorter barbels on the lower jaw (mandibular barbels), Small, widely spaced eyes, Extremely long anal fin extending to the caudal fin, Very small, almost vestigial dorsal fin

Dorsal fin

Very small, with 3-5 rays, located far forward on the body.

Tail fin

Rounded or slightly emarginate, confluent with the anal fin.

Pectoral fin

Relatively large and rounded, often used for propulsion and steering.

Distinctive fins

Anal fin is exceptionally long, extending from behind the anus almost to the caudal fin, with 83-92 rays. Pelvic fins are small.

Identification Tips

1. 1

   Body Shape and Size

   Look for an exceptionally long, cylindrical, and scaleless body. Adults can reach lengths of over 2 meters and weights exceeding 100 kg, making them unmistakable in their native range.

2. 2

   Head and Barbels

   Observe the broad, flattened head with a very wide mouth. The presence of two very long maxillary barbels and four shorter mandibular barbels is a key identifier.

3. 3

   Fin Configuration

   Note the tiny dorsal fin and the extremely long anal fin that runs almost the entire length of the posterior body, merging with the caudal fin.

4. 4

   Coloration

   While variable, the mottled dark olive-green to black dorsal coloration with lighter, often yellowish, flanks and belly is typical.

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