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Dorsal spines (total): 16-18; Dorsal soft rays (total): 8-10; Anal spines: 3-3; Anal soft rays: 6-8; Vertebrae: 28-29. Diagnosis: Haplochromis vanheusdeni can be distinguished from all species of the genus Orthochromis except O. torrenticola by the presence of egg spots on the anal fin in both males and females vs. no egg spots, and by hypuralia 1 and 2 and hypuralia 3 and 4 either clearly separated or separated by a clearly visible seam vs. never fused into a single seamless unit (Ref. 97348). It can be distinguished from Orthochromis kalungwishiensis, O. kasuluensis, O. luongoensis and O. torrenticola by having fewer caudal vertebrae, 14-16 vs. 17; and fewer total vertebrae, 28-30 vs. 31-33; from O. rugufuensis and O. uvinzae by having fewer total vertebrae, 28-30 vs. 31-33, and dorsal fin spines, 16-17 vs. 19-20; from O. polyacanthus and O. rubrolabialis by having fewer inner series of teeth in the lower jaw, 1-2 vs. 3-5, and fewer dorsal fin spines, 16-17 vs. 18-20; and from O. malagaraziensis by having more scales between the lateral line and the dorsal fin origin, 3-4 vs. 5-6; from O. machadoi, O. mazimeroensis, O. stormsi and Haplochromis bakongo by having a scaleless chest vs. a scaled chest; from O. mosoensis by having small cycloid scaled on the belly vs. no scales; from O. luichensis by the different stripe and bar patterns on the head ; from Schwetzochromis neodon by the presence of lachrymal stripes and fewer inner teeth rows in both jaws, 1-3 vs. 4-6; from Haplochromis snoeksi by having fewer scales on the horizontal line, 26-29 vs. 30-31, and on upper lateral line, 20-22 vs. 23, and in having fewer caudal vertebrae, 14-16 vs. 17 (Ref. 97348).
Description: A moderately elongate species with maximum body depth close to insertion of first dorsal spine (Ref. 97348). Head length about one third of the standard length; dorsal head profile straight between upper lip and eye region, then becoming gently curved towards dorsal fin origin; no prominent nuchal gibbosity (Ref. 97348). Eye diameter larger than or rarely equal to interorbital width (Ref. 97348). Jaws slightly retrognathous; posterior tip of maxilla reaching slightly beyond anterior margin of orbit; lips well developed, upper lips becoming thinner posteriorly (Ref. 97348). Anterior jaw teeth of outer rows of upper and lower jaw large, closely set and bicuspid or subequally bicuspid; posterior teeth more widely set caudally becoming unicuspid and smaller; brownish crown of single bicuspid teeth slightly expanded, with uncompressed, narrowly set cusps; neck of the bicuspid teeth stout; tooth counts of outer row of upper jaw between 30-38 and of outer row of lower jaw 14-26; two, rarely one, inner upper and lower jaw teeth rows with small and tricuspid, rarely bicuspid or unicuspid teeth (Ref. 97348). Dentigerous triangular surface of lower pharyngeal bone about 1.5 times broader than long, with 10+10 teeth along posterior margin and seven teeth along midline; posterior row and midline teeth larger than lateral teeth; pharyngeal teeth weakly bicuspid; posterior row teeth enlarged compared with more slender, bevelled anterior teeth (Ref. 97348). Dorsal fin with 16-18 spines and with 8-10 rays; first dorsal spine always shortest; dorsal fin base length between 49.3-57.7% of standard length; posterior end of the dorsal fin rays extending slightly beyond caudal fin base; posterior tip of anal fin ending slightly before or at caudal fin; caudal fin outline subtruncate to truncate; anal fin with 3 spines with 3rd spine longest and 6-8 rays; anal fin base length between 16.4-19.8% of standard length; pectoral fin with 15 or rarely 14 rays; pectoral fin length between 19.0-24.0% of standard length; longest pectoral ray not reaching level of anus; first upper and lower pectoral fin rays very short to short, especially first upper ray hardly recognizable; pelvic fin with 1st spine thickly covered with skin and 5 rays; pelvic fin base always behind pectoral fin base; longest pelvic fin reaching or slightly exceeding anus (Ref. 97348). Two separate lateral lines; flanks above and below the lateral lines covered with comparatively large ctenoid scales, except for cycloid scales of the anterior dorsal and lowermost ventral area; belly with very small cycloid scales; chest scaleless; chest to flank transition with small, deeply embedded cycloid scales; snout up to eye level scaleless, nape and occipital region with medium sized cycloid scales, interorbital scales deeply embedded; cheeks devoid of large, externally visible scales, but small deeply embedded cycloid scales may be present; cycloid scales on operculum of variable size and shape; opercular blotch partially covered with medium sized scales, but posterior margin always scaleless; upper lateral line scales 19-22 and lower lateral line 6-12; horizontal line scales 25-28 plus no or one pored scale on caudal fin; upper and lower lateral lines separated by two scales; at level of last dorsal fin spine on large ctenoid scale below one small dorso-ventrally compressed cycloid scale; anterior part of the caudal fin covered with 3-4 columns of small cycloid scales, with median scales being slightly larger; scaled area of caudal fin caudally extended at upper and lower area with minute, interradial scales; scales around caudal peduncle 14-16 (Ref. 97348). Caudal peduncle rather short but always longer than deep, the ratio of caudal peduncle length to depth 1.13-1.78 (Ref. 97348).
Colouration: Body ground colouration pale brown to grey; back, flanks and caudal peduncle towards chest and belly light beige to yellowish; dorsal head surface brownish-grey, cheeks greyish, especially the lower part; ventral side of head beige; branchiostegal membrane beige to yellowish; operculum yellow-orange to brownish with a black opercular spot extending rostrally as a broad dark grey-brown stripe almost to the posterior edge of the eyes; another grey element, an oblique bar, originating from the opercular spot crossing the preoperculum and operculum finally reaching to the ventral margin of the opercular complex (Ref. 97348). Turquoise hues around pectoral fin base and between preoperculum and operculum; a dark grey lachrymal stripe, gradually extending and widening from its origin at the anterior-ventral margin of the orbit to before the edges of the nostrils and almost reaching the upper lip margin ; across snout above upper lip margin lachrymal stripes of both sides fusing, resulting in a U-shaped frontal face mask; supraorbital stripes starting from rear dorsal orbit margins towards dorsal fin origin but deviating after a short distance anteriorly where both stripes at the forehead fuse centrally and form a flattened 'M' in the rostral view; no nostril stripe present; dark grey interorbital stripe present; a dark greyish and less distinctive nape band connected with the first vertical stripe above the operculum (Ref. 97348). Upper and lower lips brownish-grey, rostrally bright yellow, caudally orange, and lower lip lighter coloured than upper lip (Ref. 97348). A greyish mid lateral band starting from the opercular blotch to the caudal fin, becoming more distinctively edged on caudal peduncle; this band further extending onto the scaled part of the caudal fin, where splitting into three to five horizontal streaks on the caudal fin membranes: mid lateral stripe crossed by 6-7 greyish bars, sometimes Y-shaped and sometimes extending into the dorsal fin (Ref. 97348). Dorsal fin ground colouration a mixture of whitish and black elements; dorsal fin membrane margins orange, followed submarginally by first a white and then black element; anal fin yellow-greenish, anteriorly and towards the margins of the anal fin yellow; 1-4 orange egg spots, located on the posterior two thirds of the upper anal fin, here centred between anal rays; caudal fin yellowish-greyish towards base of caudal fin orange, above and below the extensions of the mid lateral band brownish to orange; outer caudal fin rays with black margin; pectoral and pelvic fin greyish to brownish (Ref. 97348). |