Afronemacheilus abyssinicus (Boulenger, 1902)

Family:  Nemacheilidae (Brook loaches)
Max. size:  5.07 cm SL (male/unsexed)
Environment:  benthopelagic; freshwater,
Distribution:  Africa: Lake Tana and Baro River (Ref. 31508, 58460). Specimens reported from Gojeb River, tributary of the Omo River (Ref. 31508, 58460), have been reidentified as Afronemacheilus kaffa (Ref. 94278).
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 10-14; Anal spines: 0-0; Anal soft rays: 9-12; Vertebrae: 35-37. Diagnosis: Afronemacheilus abyssinicus is distinguished from its congener A. kaffa by having usually 8 or 9 branched dorsal-fin rays (vs. usually 7); the anterior and posterior nares closely spaced (vs. well separated); the intestine straight (vs. with a single small loop), no contact between sphenotic and epiotic (vs. usually in contact); two pairs of pharyngobranchials and usually three basibranchials (vs. three and four, respectively); the dark spots on flank small and irregular becoming larger and transversely extended on dorsum (Ref. 94278). Description: Posterior naris situated immediately behind anterior one, or separated by less than half-diameter of posterior naris (Ref. 94278). Anterior maxillary barbel reaching base of mandibulary barbel or slightly beyond; posterior maxillary barbel reaching to, or slightly behind, vertical through anterior margin of orbit; mandibulary barbel reaching to or slightly beyond posterior border of orbit (Ref. 94278). Lips nearly smooth or only slightly crenulated; upper lip continuous or weakly incised in middle; lower lip interrupted and bearing rather short but pronounced mental lobes and one or two more or less deep grooves on each medial pad; dentiform process strong, matched by a corresponding incision on lower jaw (Ref. 94278). Head sensory pores very small; supraorbital canal with 7 pores, continuous or interrupted and composed of nasal and supraorbital portions, latter sometimes also interrupted; supraorbital and infraorbital canals not connected; infraorbital canal with 11-14 pores; preoperculo-mandibular canal with 8-9 pores, uppermost pore at horizontal line through mouth corner; supratemporal canal continuous or interrupted (Ref. 94278). Dorsal fin with 3-5 unbranched and 8-9 branched rays; dorsal-fin origin slightly closer to caudal-fin base than to tip of snout; dorsal-fin distal margin always distinctly convex because 2nd to 4th branched rays are longer than others; anal fin with 3-4 unbranched and 6-8 branched rays; distal margin of anal fin convex; pectoral fin with 1 unbranched and 10-12 branched rays; pelvic fin with 1 unbranched and 6-8 branched rays (Ref. 94278). Caudal-peduncle length/depth ratio 1.3-2.0 (Ref. 94278). Body entirely scaled; scales rather close to each other on most parts of the body, but not imbricate; scales on flanks below dorsal fin slightly deeper than long, with large focal zone (Ref. 94278). Vertebrae 4+35 to 4+37 (Ref. 94278). Colouration: Background very light, yellowish or creamy, overlayed with dense brown spotted pattern (Ref. 94278). Rather large and transversally broadened blotches on dorsum, 7-13 in number, from occiput to caudal-fin origin; these blotches usually expanded to dorso-lateral part of body, but before dorsal fin frequently becoming smaller, roundish, distributed irregularly or in staggered rows, and not expanded to dorso-lateral part of body; row of small blotches irregular in form along midlateral line; these blotches smaller in depth than distance from midline to dorsal outline, but less frequently these almost as deep as entire body depth; gaps between these lateral blotches equal to or larger than longitudinal dimensions of blotches themselves; dorsal blotches sometimes fused with lateral blotches, especially, behind dorsal fin (Ref. 94278). In addition to large blotches, flank speckled with small irregular spots and solitary melanophores, latter frequently producing a thin irregular line along mid-lateral septum; ventro-lateral surface of head and body before anal-fin origin light and not speckled, but becoming speckled caudally; one to three large spots sometimes present on ventral outline of caudal peduncle; dorsal and lateral parts of head densely speckled (Ref. 94278). Base of caudal fin with 0-4 rounded marks organized into vertical row; dorsal and caudal fins with pigment on membrane and rays; condensed in dark marks organized in more or less regular rows, much more pronounced on caudal fin; other fins transparent (Ref. 94278).
Biology:  Found on the bottom of Lake Tana and in patches of macrophytes along the shore of the lake, and along the banks of the Blue Nile (Ref. 94278).
IUCN Red List Status: Data deficient (DD); Date assessed: 01 May 2009 Ref. (130435)
Threat to humans:  harmless

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