How to Identify Wallago

To identify Wallago (Wallago attu), look at these key features.

Physical Characteristics

Body shape

eel-like

Coloration

Dorsal surface typically dark grey to brownish-green, fading to silvery-white on the ventral side. May have irregular dark blotches or spots, especially in younger individuals. Fins are generally dusky.

Scale type

none

Mouth position

superior

Distinctive features

Extremely elongated and compressed body, particularly towards the caudal fin., Very large, wide mouth extending beyond the eye., Two pairs of barbels: one pair of long maxillary barbels reaching beyond the pectoral fin, and one pair of short mandibular barbels., Small, widely spaced eyes located dorsally., Absence of an adipose fin., Anal fin is exceptionally long, extending from behind the anus almost to the caudal fin.

Dorsal fin

Very small, with 5 soft rays, located far forward, anterior to the pelvic fins.

Tail fin

Forked, with pointed lobes.

Pectoral fin

Relatively large and pointed, with a strong, serrated spine.

Distinctive fins

Anal fin is extremely long, with 77-97 soft rays, confluent with the caudal peduncle but not joined to the caudal fin.

Identification Tips

1. 1

   Body Shape

   Look for the distinctly elongated, compressed, and eel-like body, especially the posterior half.

2. 2

   Mouth and Barbels

   Observe the very large, wide, superior mouth and the two pairs of barbels, particularly the long maxillary barbels.

3. 3

   Dorsal Fin

   Note the extremely small dorsal fin located far forward on the body.

4. 4

   Anal Fin

   Identify the exceptionally long anal fin that runs almost the entire length of the posterior body.

5. 5

   Absence of Adipose Fin

   Confirm the lack of an adipose fin, which is common in many other catfish species.

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