Egyptian Butter Catfish

Diagnosis: 13-16 gill rakers on lower limb of first gill arch; 57-75 branched anal-fin rays; eyes positioned dorso-laterally; adipose fin always absent (Ref. 43912, 57127, 81643). Often with a post-occipital hump, a character also sometimes found in Schilbe intermedius whose head profile is extremely variable (Ref. 57127, 81643). Posterior nostrils closer to each other than are anterior ones; nasal barbel at maximum reaching to midway between eye and opercle, but generally shorter; inner side of pectoral spine feebly serrated (Ref. 43912).Description: 50-57 vertebrae, 45-52 non-fused vertebrae; 8-10 branchiostegal rays on one side of head; caudal peduncle generally deeper than long, in some cases as long as or slightly longer than deep; nasal barbel reaches at maximum to midway between eye and opercle but in larger specimens it is much shorter and does not even reach beyond orbit; maxillary barbel reaches at least to middle of eye and at maximum to posterior border of opercle; inner mandibular barbel short and reaches at maximum to just beyond orbit; outer mandibular barbels reach at least to midway between eye and opercle and at maximum to posterior border of opercle; in many specimens upper profile of head nearly horizontal and nape ascends very abruptly from occiput to dorsal fin, thereby forming a well-defined hump (Ref. 43912). Schilbe uranoscopus is closely related to S. intermedius from which it can be distinguished by the higher number of gill rakers on the lower part of the anterior arch (13-16 against 7-14 in S. intermedius), the higher number of branched anal fin rays (57-75 versus 41-66 in S. intermedius) and by the supero-lateral position of the eyes (Ref. 43912).Coloration: Juveniles: sides more or less silvery, head and postcephalic area irregularly mottled (Ref. 43912, 57127, 81643) as well as sides, just behind opercle (Ref. 43912). In adults, head and back, as well as all fin-bases, dark brown; sides yellowish or whitish; anal fin sometimes black-edged (Ref. 43912, 57127, 81643). Dark blotch present behind head, where swimbladder comes close under skin; brown median stripe may be present along caudal peduncle (Ref. 43912).

Distinct pairing (Ref. 205).

Potamodromous. Migrating within streams, migratory in rivers, e.g. Saliminus, Moxostoma, Labeo. Migrations should be cyclical and predictable and cover more than 100 km.

Dorsal spines (total): 1; Analsoft rays: 59 - 73; Vertebrae: 50 - 57

Adapted to riverine and lacustrine conditions; appears to live mainly in the open waters; predatory, carnivorous but not strictly piscivorous; young essentially entomophagous (Ref. 43912). Oviparous, eggs are unguarded (Ref. 205). Especially in the Chad basin of some economic value to the fishermen (Ref. 43912). Maximum reported total length 45 cm (Nile basin)(Ref. 43912).

fisheries: minor commercial