Parauchenoglanis longiceps (Boulenger, 1913)

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 : 799-800

Parauchenoglanis longiceps (Boulenger, 1913)

(figure 8f)

Auchenoglanis longiceps Boulenger, 1913 .

Auchenoglanis maculosus Holly, 1927 (new synonymy).

Parauchenoglanis longiceps: Teugels et al., 1991 .

Diagnosis. Head height smaller than preorbital head length. Interorbital distance more than twice horizontal orbital diameter. Barbels short, with maxillary barbel never reaching base of pectoral fin spine, external mandibular barbel at most reaching halfway along pectoral fin spine. Anterior margin of pectoral fin spine largely smooth (not serrated). Minimal height of caudal peduncle slightly greater than horizontal distance between bases of adipose and caudal fin, but never twice as great.

Description. Based on eight specimens including holotype (see below). See also table 4. Body low and slender. Snout relatively long, giving head elongate appearance. Posterior margin of pectoral fin spine serrated; anterior margin smooth except for few serrae distally. Humeral process narrow and pointed, with width at base being smaller than length of process. Eight pectoral fin rays.

Overall coloration brown or reddish, with head as dark as, or slightly darker than rest of body. Head and body covered with numerous small dark dots, those on head being as large as those on body. Dorsal, caudal and adipose fins densely spotted as well. Other fins usually uniformly brown or grey. Belly pale, without any dots.

Note on the synonym. Holly (1927) stated that P. maculosus could be distinguished from P. longiceps by means of the ‘mightier’ head, the shorter external mandibular barbel, the smaller eye, the larger number of anal fin rays and the more numerous gill rakers. Both syntypes of P. maculosus are very large, compared to the holotype of P. longiceps , and so the first two cited differences may be due to allometry. The numbers of anal fin rays and gill rakers vary considerably even between individuals that originated at the same location. None of these four cited characteristics, nor any other, can be used to discriminate the nominal species, which are thus considered synonyms.

Distribution (figure 10). This species is restricted to the basin of the Nyong River (Central to South Cameroon).

Maximum size recorded. The maximum size recorded is 411 mm SL.

Material examined. Eight specimens. NHM 1913.10.29:12 (holotype): Nyong River at Akonolinga ( Cameroon); 3°46∞N, 12°15∞E; 160 mm SL. NMW 7800–7801 (syntypes of P. maculosus ): Cameroon ; two spm, 318–411 mm SL. MRAC 73- 2 -P-1797: Nyong River near Ebogo ( Cameroon); approx. 3°24∞N, 11°28∞E; 182 mm SL. MRAC 73-18 -P-2244: Ebogo, Nyong River ( Cameroon); 3°24∞N, 11°28∞E; 285 mm SL. MRAC 73-29 -P-1455–1457: Ebogo, Nyong River ( Cameroon); 3°24∞N, 11°28∞E; three spm, 163–265 mm SL .