Parauchenoglanis ngamensis (Boulenger, 1911)

Geerinckx, T., Adriaens, D., Teugels, G. G. & Verraes, W., 2004, A systematic revision of the African catfish genus Parauchenoglanis (Siluriformes: Claroteidae), Journal of Natural History 38 (6), pp. 775-803 : 798-799

Parauchenoglanis ngamensis (Boulenger, 1911)

(figure 8e)

Auchenoglanis ngamensis Boulenger, 1911 .

Parauchenoglanis ngamensis: Teugels et al., 1991 .

Diagnosis. Humeral process of cleithrum, which is visible through the skin, bluntly triangular, with its width at base nearly as great as its length, with width being at least as great as orbital diameter. In adult specimens its upper margin usually becomes somewhat serrated. Head height greater than, rarely as great as, preorbital head length. Barbels relatively short, with external mandibular barbel never reaching beyond tip of pectoral fin spine. Caudal peduncle significantly higher than long, with minimal height much greater than horizontal distance between bases of adipose and caudal fins.

Description. Based on 20 specimens including holotype (see below). See also table 4. General shape of body and head moderately elongate. Pectoral fin spine coarsely serrated on both margins, anterior margin being slightly less rough than in P. punctatus . Seven or eight pectoral fin rays.

The overall colour of this species varies considerably from bright to virtually blackish brown. Purple hue occasionally present. Belly brown to whitish. Zambezi and Okavango specimens are characterized by five to seven vertical rows of blackish spots on background of lighter spots all over body. Kasai specimens typically lack background pattern, though intermediate forms may be found.

Distribution (figure 9). Parauchenoglanis ngamensis has been found in the tributaries of the Kasai River, as well as in the upper Zambezi River basin and in the Okavango Delta ( Angola, Zambia, Botswana).

Maximum size recorded. The maximum size recorded is 207 mm SL.

Material examined. Twenty specimens. NHM 1910.5.31:35 (holotype): Okavango River near Lake Ngami , Botswana; 20°45∞S, 22°55∞E; 186 mm SL. MRAC P.142057: tributary of upper Zambezi River at Chavuma ( Zambia) ; 13°06∞S, 22°42∞E; 141 mm SL. MRAC P.142072: tributary of upper Zambezi River at Monga ( Zambia) ; 14°05∞S, 22°24∞E; 104 mm SL. MRAC P.161663, 161665: tributary of Luachimo River (Kasai basin, Angola) ; 7°23∞S, 20°50∞E; two spm, 106–154 mm SL. MRAC P.161707: Cavuemba River ( Angola) ; 87 mm SL. MRAC P. 161712–161714: Lake Calundo (Zambezi basin, Angola) ; 11°43∞S, 20°48∞E; three spm, 103–208 mm SL. MRAC P.161718: Luita River at Cuilo Xà-Ua (Kasai basin, Angola) ; 8°02∞S, 19°25∞E; 74 mm SL. MRAC P.161719: Uamba River near Mabete (Kasai basin, Angola) ; 8°07∞S, 18°09∞E; 125 mm SL. MRAC P.161725–161727: Mololo River (tributary of Chiumbe River, Kasai basin, Angola) ; 7°49∞S, 21°05∞E; three spm, 98–145 mm SL. MRAC P.161765–161766: Luenda River ( Angola) ; two spm, 51–66 mm SL. MRAC 78-6 -P-875: Lomboma , Luembe River (Kasai basin, Angola) ; 7°53∞S, 21°24∞E; 175 mm SL. MRAC 78-6 -P-876–878: Cafunfo , Cuango River (Kasai basin, Angola) ; 7°37∞S, 15°43∞E; three spm, 48–60 mm SL.