Amphilius mamonekenensis, Paul H. Skelton, 2007

Paul H. Skelton, 2007, New species of the amphiliid catfish genera Amphilius, Doumea and Phractura and the taxonomy of Paramphilius from West Central Africa (Siluriformes, Amphiliidae)., Zootaxa 1578, pp. 41-68 : 52-53

Amphilius mamonekenensis sp. nov.

(Fig. 6)

Synonymy. Amphilius lamani non Lonnberg & Rendahl, 1920: Mamonekene & Teugels, 1993, 44 (in part, specimens from the upper Mpoulou River).

Type material. Holotype, MRAC 91-068-P-1206, SL 71.6 mm, male, Mpoulou River, tributary of the Loubomo River, Kouilou River system, ‘pont 1 sur la piste de Dimonika à Makaba, avant le village de Koulila ’, Republic of Congo, 04°11 'S, 12°26'E, G.G. Teugels and V. Mamonekene, 12 August 1991 ; 17 paratypes, 2, MRAC 91-068-P-1207-1208, SL 45.7-71.3 mm, Mpoulou River, ‘au pont de l’ancien Carrefour PassiPassi, après Makaba’, Republic of Congo, 04°09'S, 12°24'E, G.G.Teugels and V. Mamonekene, 11 August 1991 ; 1, MRAC 91-068-P-1209, SL 63 mm, male, Mpoulou river, ‘au camp Banina, à 1 km de Makaba, direction Carrefour Passi-Passi’, Republic of Congo, 04°08'S, 12°23'E, G.G.Teugels and V.Mamonekene ; 6, MRAC 91-068-P-1271-1276, SL 31-66 mm, Mpoulou River, ‘pont 1 sur le piste de Dimonika à Makaba, avant le village de Koulila’, Republic of Congo, 04°11'S, 12°26'E, 11 August 1991, G.G.Teugels and V. Mamonekene ; 4, AMNH 240490 (ex MRAC 91-068-P-1281-1284), 34.5-47.6 mm SL, same data as MRAC 91-068-P-1271-1276 ; 4, SAIAB 79510 (ex MRAC 91-068-P-1277-1280), 31.6-58.8 mm SL, same data as MRAC 91-068-P-1271-1276 .

Diagnosis. An Amphilius species distinguished by its light body colour, clear large dark brown or black scattered spots and vermiculations and lightly pigmented caudal fin. The coloration and in particular the lack of a large dark spot on the caudal fin distinguishes the species from species most similar in body form, especially A. nigricaudatus , a species widespread within the WCA region, and also A. korupi . It differs from A. longirostris in the key character of caudal fin Principal rays (6+7 vs.7+8) and head features such as the position of the eyes. It has a deeper caudal peduncle than A. caudosignatus and is further distinguished from that species by the caudal fin coloration (plain vs.dark with a white oblique bar). It differs from A. pulcher in pigment pattern, (spotted vs.striking dark brown blotches and saddles) and in having a smaller adipose fin (distinct gap between dorsal fin and origin of adipose vs.origin of adipose close to hind margin of dorsal fin).

Description. Measurements and fin ray counts given in Table 4. Body depressed and ovoid in cross-section anteriorly, caudal peduncle compressed. Head length 3.8-4.25 times in SL, head longer than wide, depressed, flat below; branchiostegal membrane deeply cleft in midline; mouth broad, subterminal, lips fleshy, teeth caniniform in pad on premaxillae and narrow band on mandible; barbels filamentous, maxillary longest, reaches from lateral edge of upper lip to base of pectoral fins; mandibular barbels reach to edge of branchiostegal membrane, anterior pair on ventral side of mandible, medial to outer (posterior) pair that extend from lateral corner of mouth; snout less than half length of head, nares in mid snout, separated; eyes small, moderately widely spaced (interorbit 2.3-3.4 times orbit diameter), confluent with head (orbits without free margins), positioned slightly nearer anterior edge of snout than posterior margin of head. Caudal peduncle short, 5.9-6.8 times in SL, 1.2-1.5 times longer than deep. Fins well developed, origin of dorsal less than one head length behind head, dorsal fin base extends to above origin of pelvic fins, dorsal fin rectangular with straight hind edge, longest simple ray shorter than leading edge of fin; pectoral and pelvic fins about equal sized, large and rounded, with leading ray curved, pectinate and padded; pectoral fin not reaching pelvic fins, pelvic fins not reaching anal origin; anal fin short based and rounded, nearly reaching ventral base of caudal; caudal fin large, truncate or slightly emarginate, crenellated epidermal fold over base; adipose fin long, low, extending from before origin of anal to procurrent ridge of caudal. Skin smooth; lateral line to base of caudal. Anus and genital pore close behind pelvic fins. Reaches 71.5 mm SL.

Coloration. Light brown with dark brown spots and vermiculated markings dorsally and laterally; intensity of spots varies individually, some specimens considerably more spotted than others; plain creamish ventrally from head to anal fin. Fins plain pale brown or clear with occasional spots, caudal fin light brown, with a feint mid-band or bar.

Distribution. Upper Mpoulou River, tributary of the Kouilou River within the Dimonika Biosphere Reserve, Republic of Congo (Fig. 3).

Etymology. Named for Victor Mamonekene, one of the collectors of the type series of this species, and who has contributed much to understanding the fishes of the Republic of Congo in recent times.