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Dorsal spines (total): 17-17; Dorsal soft rays (total): 10-10; Anal spines: 3-3; Anal soft rays: 9-9. Diagnosis: Hemitaeniochromis brachyrhynchus is readily distinguished from its formal congener H. urotaenia, by its narrow lacrimal bone whose width, at the midpoint of the bone, is one-third of the orbit length, vs. nearly equal to the orbit length in H. urotaenia; by its snout being shorter than the orbit length, vs. longer in H. urotaenia; by its much larger eyes, the orbit length being about 36-38% of head length, vs. 22-28% in H. urotaenia; by its shorter lower jaw which is about 39-41% of head length, vs. 45-51% in H. urotaenia; and by its melanin pattern, which is composed of spots and line segments that are less well-defined than those of H. urotaenia (Ref. 91204). The narrow lacrimal and large eyes also distinguish H. brachyrhynchus from all other species that have sometimes been placed in Hemitaeniochromis (Ref. 91204).
Description: Body moderately elongate, dorsal profile evenly rounded from nuchal region of head to end of spinous dorsal fin, more convex than ventral body profile; head profile concave above snout (Ref. 91204). jaws rather short, gape steeply inclined, premaxilla nearly vertical when mouth widely opened; lower jaw apparently slightly projecting and inclined at ±50° to lateral midline when mouth is closed; lips slightly thickened but not lobate; snout distinctly shorter than orbit, 1.28-1.33 in orbit length; eyes large, orbit length 36-38% of head length; lacrimal bone narrow, its width at mid-bone only about one-third orbit length, its orbital and labial margins nonparallel, converging nearer each other ventrally than at dorsal end of bone (Ref. 91204). Caudal fin emarginate (Ref. 91204). Dental arcade of each jaw broad, semicircular in outline anteriorly; outer jaw teeth stout, the shafts conical; those of both jaws implanted with interspaces about as wide as the teeth or spaced more closely with interspaces about half as wide as teeth; crowns of outer upper jaw teeth are slightly incurved; the anterior teeth of the lower jaw have the crowns angled slightly forward and outward relative to their shafts, an unusual condition (Ref. 91204). Lower pharyngeal bone Y-shaped, delicate; all teeth laterally compressed, cuspidate, none enlarged, except those of posterior row near midline, nor submolariform; median suture straight, not sinuous (Ref. 91204). Gill rakers 10-12 on ceratobranchial, simple, unbranched, grading in length from longer posteriorly to short anteriorly; lightly pigmented with scattered melanophores (Ref. 91204). Scales ctenoid; lateral line discontinuous, the upper section kinked downward caudally so that the two sections are separated by a single scale without a canal or pore or by two scales, of which the upper has a pore but no canal and is situated below and behind the last true lateral line scale of the upper segment, and the lower has neither pore nor canal; squamation extending onto caudal fin between fin rays; bases of soft dorsal and anal fins partly covered by 1-3 irregular rows of small scales (Ref. 91204).
Colouration: In preservative dorsum, nuchal region, head above eye, and upper surface of snout dark brown; remainder of head and body with nearly uniform tan or light brown ground colour, becoming paler on hyoid area and branchiostegal membrane and silvery tan on belly; lacrimal brown, lacking distinct stripe; operculum with dark spot; no other distinct head markings; seven faint vertical bars below dorsal-fin base, darkest on upper body; traces of two further bars on caudal peduncle; four to five indistinct dorsal midline spots below dorsal-fin base; supralateral stripe situated just above upper lateral line, extending discontinuously between subdorsal bars 1-4, darkest at bar intersections and between bars 2 and 3; midlateral stripe just above level of lower lateral line, partly discontinuous, originating at subdorsal bar 2 and extending to end of caudal peduncle where it forms a more or less discrete small precaudal spot; this stripe darkest at bar intersections and most nearly continuous above anal fin; dorsal fin lacking a submarginal stripe; soft dorsal marbled with darker and lighter brown markings; caudal-fin membrane light to medium brown, without evident maculae; anal fin nearly uniform brownish; pectoral hyaline; pelvic brownish on anterior half, unpigmented on posterior 2 or 3 rays (Ref. 91204). |