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Dorsal spines (total): 2-2; Dorsal soft rays (total): 5-6; Anal spines: 0-0; Anal soft rays: 9-9. Diagnosis: Chiloglanis dialloi is distinguished from C. normani, C. waterloti, C. longibarbis, C. occidentalis, C. kabaensis, C. kolente, and C. nzerekore in possessing more mandibular teeth in the functional row, and readily distinguished from C. polyodon and C. lamottei in having fewer mandibular teeth in the functional row; it can be distinguished from Chiloglanis aff. micropogon in possessing moderately long mandibular barbels vs. reduced or absent mandibular barbels; it is distinguished from C. tweddlei and C. pezoldi in having shorter pectoral and dorsal spines; it is distinguished from C. camarabounyi in having a shallower body depth at anus, 12.0-14.5% of standard length vs. 14.8-18.2%, and at the dorsal-fin origin, 15.3-17.7% of standard length vs. 16.3-22.5%, and a shorter dorsal spine; it can be distinguished from C. loffabrevum in having a smaller premaxillary tooth pad width, 15.1-16.6% of standard length vs. 16.9-20.2%, and length, 2.9-3.7% of standard length vs. 3.4-5.4%, a narrower anterior nare interspace, 4.1-4.3% of standard length vs. 4.5-6.3%, and a shorter pre-pectoral length, 29.0-32.6% of standard length vs. 31.9-37.1% (Ref. 116018).
Description: A moderate-sized Chiloglanis; 52.4 mm maximum observed standard length; body depressed anteriorly; laterally compressed posteriorly; pre-dorsal sloping ventrally towards orbit; pre-orbital convex; post-dorsal body sloping ventrally towards the caudal fin; pre-anal profile horizontal; post-anal horizontal to concave (Ref. 116018). Body covered with small unculiferous tubercles, more concentrated on head; lateral line complete; arising at level of orbit and sloping ventrally towards the caudal fin; urogenital papillae sexually dimorphic; males with an elongated and pointed papillae; shorter and separated from anus by shallow invagination in females (Ref. 116018). Head depressed; gill membranes broadly united; gill opening restricted; from near pectoral-fin origin to level of orbit; occipital-nuchal shield covered and visible through skin; eyes moderate; located in posterior half of head; horizontal axis longer; orbit without free margins; anterior and posterior nares mid-snout length; equidistant; posterior nares with elongated anterior and medial flaps (Ref. 116018). Mouth inferior; upper and lower lips united to form oral disc; oral disc moderate in size, width 20.3-22.5% of standard length; slightly wider than long; covered in papillae (Ref. 116018). Barbels in three pairs; maxillary barbel originating from posterolateral region of disc; unbranched and moderate in length, 12.5-22.5% of head length; lateral and medial mandibular barbels moderate; incorporated into lower lip and positioned on both sides of midline cleft on posterior margin of oral disc; lateral barbels, 3.6-10.8% of head length, usually twice the length of medial barbels (Ref. 116018). Primary premaxillary teeth "S"-shaped with exposed brown tips; 56-141 teeth in 3-5 rows on two ovoid tooth pads; secondary premaxillary teeth fewer; scattered on posterior surface of premaxillae; tertiary premaxillary teeth short and needle-like; bunched near midline of dorsal edge of toothplate; mandibular teeth in 1-2 rows; "S"-shaped and bunched near midline; functional, anterior, row usually contains 12 brown-tipped teeth (Ref. 116018). Dorsal-fin origin just posterior to anterior third of body; dorsal fin with small spinelet, spine, and 5-6 rays; dorsal spine relatively short, 11.2-13.2% of standard length; posterior margin of spine smooth; anterior margin with small notches distally; adipose fin moderate in length, 12.3-18.5% of standard length; margin convex with small notch at terminus; caudal fin forked with rounded lobes; lower lobe longer than upper lobe; count i,7,8,i; anal-fin origin posterior to adipose-fin origin; margin convex; count iii,6; pelvic-fin origin at vertical between dorsal and adipose fin; extending to anal-fin origin; margins convex; count i,6; pectoral fin with smooth spine; relatively short, 15.5-18.1% of standard length; count I,8-9 (Ref. 116018). Postcleithral process sexually dimorphic; elongate and spatulate in males; shorter and bluntly pointed in females; body size sexually dimorphic; females attaining a larger body size (Ref. 116018).
Colouration: In dorsal view, body medium brown; mottling of light brown to cream, patches of light brown at origin of dorsal fin and origin and terminus of adipose fin; head medium brown; mottling of light brown and small light unculiferous tubercles; in lateral view, body a cream ground colour with areas of medium brown; melanophores visible over lighter areas, light areas at origin and terminus of adipose fin, extending ventrally to origin and terminus of anal fin; in ventral view, body cream; few melanophores near origin of pelvic fin; oral disc and barbels cream (Ref. 116018). Pectoral and dorsal spine and rays cream to translucent; few melanophores near base of dorsal and pectoral fins; faint bars at mid-length; pelvic fins cream; adipose fin cream to translucent; few melanophores near base; anal fin cream to translucent; few melanophores near base and at mid-length; caudal fin cream to translucent; two areas of dark brown at mid-length of upper and lower lobes (Ref. 116018). |