Amphilius korupi, 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 : 50-52

Amphilius korupi sp. nov.

(Fig. 5)

Synonymy. Amphilius sp. [cf. A. brevis Boulenger, 1902 ]: Reid, 1989, 57.

Type material. Holotype, USNM 303621, SL 63 mm, Owaye River, just north of Mana River, Upper Ndian system, Korup ‘buffer zone A’, Cameroon, 5° 06'N, 8° 59'E, 4 February 1988, G. McG. Reid ; 42 paratypes: 1, USNM 365687, SL 37.7 mm, data as for holotype ; 29, USNM 304098, SL 37.4-65 mm, upper reaches of Bagodo River, tributary southern Munaya River, near Njeke Jalek village, Cross River system, Korup, Cameroon, 05° 37'N, 09° 12'E, 25 February 1988, G. McG. Reid ; 1, USNM 303568, SL 49 mm, female, Upper Ndian River bordering Korup, Cameroon, 05° 00'N, 08° 56' 30"E, 12 February 1988, G. McG. Reid ; 1, USNM 303862, SL 31.4 mm, Bake River below Nere Bifa Falls, tributary of Munaya River, Cross River system, Korup, Cameroon, 05° 15'N, 09° 10' 20"E, 4 March 1988, G. McG. Reid ; 1, SAIAB 79368, 49,7 mm SL, male, (K2) stream tributary of Akpa-Yafe River system, south-west Korup region, Cameroon, 05° 04'N, 08° 52'E, 1988, G. McG. Reid ; 7, SAIAB 79369, SL 20.7-59.6 mm, (K4) stream tributary of Akpa-Yafe River system, south west Korup region, Cameroon, 05° 06'N, 08° 47'E, 1988, G. McG. Reid ; 1, SAIAB 79370, SL 37.6 mm, (K1) Agpa-Yafe River system, south-west Korup region, Cameroon, 05° 04'N, 08° 52'E, 1988, G. McG. Reid ; 1, SAIAB 79371, SL 42,4 mm, (Q1) Upper reaches of Marube River, tributary Bake River, Cross River system, Cameroon, 05° 16' 30"N, 09° 11'E, 1988, G. McG. Reid .

Other material. MRAC 93-072-P-0768-0769, 2, SL 43.5-59 mm, Limbe River, Moussaka, CDC Camp, Limbe region, Cameroon, 04° 01'N, 09° 12'E, E. van den Bergh, 11 April 1993.

Diagnosis. A. korupi differs from A. pulcher , A. dimonika and A. mamonekensis in colour pattern, especially the large dark brown or black spot with yellow surrounds on the caudal fin, in having the eyes nearer the tip of the snout, longer barbels, and in being a more deep bodied species with a shorter, deeper caudal peduncle. It is most similar to A. nigricaudatus from the WCA region and A. brevis from the Congo River system. It shares with both these species similar overall morphology including a short head, eyes closer to tip of snout than to hind margin of head, long slender barbels and an emarginate caudal fin with 6+7 Principal rays and a fleshy epidermal fold across the caudal base. It differs from A. brevis in the position of the dorsal fin that reaches to above but not beyond the origin of the pelvic fins (in A. brevis the dorsal base extends beyond the origin of the pelvic base), and from A. nigricaudatus in that the anal fin is closer to the caudal fin base. Two specimens from further south in Cameroon (see other material MRAC 93-072-P-0768-69) appear close to A. korupi , but differ from the others examined in being more heavily built, have an adipose fin that is long low and confluent, and have longer barbels.

Description. Measurements and ray counts given in Table 3. Body stout and depressed anteriorly, caudal peduncle compressed. Head depressed, smooth above, broad and bluntly rounded in front, length 3.6-4.2 times in SL; branchiostegal membrane deeply cleft in ventral midline; mouth subterminal, broad, lips fleshy; teeth small, caniniform in square laterally tapered pad on premaxillae and narrow band on the mandible; barbels filamentous, maxillary longest, extending from lateral edge of upper lip to above pectoral base; mandibular barbels positioned laterally on ventral side of mandible, anterior pair medial but close to posterior pair, reach edge of branchiostegal membrane, posterior pair at lateral edge of mandible, reaching beyond branchiostegal membrane; snout relatively short, less than half length of head, nares on anterior half of snout, separated; eyes nearer tip of snout than posterior margin of head, small, widely spaced (interorbit 2.6-4 times orbit diameter), orbits confluent with head surface. Caudal peduncle short, 6.4-8.4 times in SL, relatively deep, 0.9-1.4 times longer than deep. Fins broad and well developed, origin of dorsal one head length behind head, dorsal base to above origin of pelvic base; dorsal obtusely rectangular with straight hind edge, leading ray shorter than leading edge of fin; pectoral fins broad and rounded, not reaching pelvic fins, leading ray pectinate and padded; pelvic fins not reaching base of anal, leading ray pectinate and padded; anal short and slender, extending to or close to base of caudal; caudal large and rectangular, trailing edge emarginate, caudal peduncle base with simple semi-oval epidermal fold; adipose fin low and elongate, or semi-elipsoid, base from before anal origin to behind anal base meeting procurrent ridge of caudal fin. Skin smooth; lateral line with irregular pores to base of caudal. Anus and genital pore close behind pelvic fin base. Reaches 65 mm SL.

Coloration. Uniformly dark brown dorsally and laterally, fin rays dark brown, membranes clear. Ventral surface from head to anal fin light brown. Caudal fin with large medial black spot and cream-yellow bands along base and distal edge.

Distribution. Coastal streams of north-western Cameroon including tributaries of the Cross, the Akpa-Korup and Ndian Rivers (Fig. 3).

Etymology. Named for the Korup National Park, Cameroon, where the species occurs.