Papyrocranus congoensis (Nichols and LaMonte, 1932)
Species overview
Typical knife fish with rather straight back and convex base of anal fin, by external characters hardly to separate from P. afer, except for a shorter and wider head and a darker colour. The areas of distribution obviously are not overlapping.
Size observed: 60 cm.
Taxonomic description
-Body strongly laterally compressed, its greatest depth slightly behind origin of anal fin.
-Head about 1/6 of body length, width of head about 1.5 times head-width of P. afer .
-Upper profile of head straigth, underside convex.
-Mouth terminal, its edge slightly behind posterior rim of eye.
-Opercular cleft long, round. Origin of pectoral fin at level of edge of mouth, fin extending to base of anal fin.
-Pelvic fins absent.
-Dorsal fin with short base.
-Base of anal fin very long, 104-118 fin-rays, merging in the caudal, 12 fin-rays, without apparent border. 66-73 vertebrae.
-Coloration, >... entire body and anal fin covered with numerous relatively large black spots, usually joined to form oblique marbling or wavy stripes.<
Type locality
>Lower Congo at Lukolela<, 1° 03'S 17° 12' E
Distribution
>... apparently is restricted to the Congo basin.<