| Diagnosis: |
Dorsal spines (total): 15-16; Dorsal soft rays (total): 12-14; Anal spines: 3-3; Anal soft rays: 10-12. Diagnosis: Sarotherodon lamprechti is distinguished from all congeners by a lack of scales over the pectoral-fin base (Ref. 86429). Further distinguished from its sympatric sibling species, S. knauerae, and other S. galilaeus populations, by a combination of a prognathous lower jaw and an elongate ventral keel on the lower pharyngeal jaw; it also differs from the sympatric S. knauerae in a lower gill raker number, 20–25 vs. 24–30; longer pelvic fins reaching to or beyond first anal fin-spine, vs. not reaching beyond anus; from S. knauerae and other S. galilaeus populations and subspecies by long pectorals reaching the last anal fin-spine, vs. ending either in front of or at first anal fin-spine; upper lip large and prominent, upper lip length 22.5–28.4% of head length vs. 19.1– 25.4% in S. knauerae, 19.3–23.6% in neighbouring riverine S. galilaeus, 18.9–24.2% in S. g. borkuanus and 6.9–12.3% in S. g. multifasciatus; it differs from S. g. sanagaensis in lower preorbital depth, 16.3–25.2% of standard length vs. 25.0–27.8%; and from S. g. boulengeri in lower body depth, 36.3–40.4% of standard length vs. 44.5–50.0% (Ref. 86429). Finally it differs from phenotypically similar S. caroli and S. linnellii in lower gill raker number, 20–25 vs. 18–20 and 15–18; and from other Barombi Mbo Sarotherodon in higher number of dorsal fin-rays, 13–15 vs. 10–12 (Ref. 86429).
Description: Head large, conspicuously prognathous lower jaw, and prominent fleshy upper lips; head profile straight, sharply convex behind nape to dorsal fin; ventral head profile straight to ventral rim of opercle; greatest body depth in front of pectoral fin insertion; caudal peduncle elongate, longer than deep (Ref. 86429). Three scale rows on cheek, large scales along outer rim of opercle, with a few small scales scattered loosely over rest of gill cover; cycloid chest scales do not cover base of pectoral fin, which is naked; inter-pelvic area densely covered with minute scales, approximately half size of chest scales; smaller scales on ventral part of belly, lateral belly scales grading gradually towards lateral flank scales; upper branch of lateral line ascending to spiny dorsal fin and separated from it by 3 or 4 scale rows, ending 1 or 2 scale rows below fin, separated from lower lateral line by two scale rows, lower lateral line beginning in front of first anal spine and extending onto caudal fin, mean of two pored scales on caudal; basal third of caudal fin finely scaled (Ref. 86429). Dorsal fin XV-XVI spines, 12-14 branched rays; anal fin III spines, 10-12 branched rays; dorsal fin shallow, spines increasing in length to 5th, following spines of equal length; dorsal-fin lappets ending at tip of spines in females or a little produced in males; rayed dorsal and anal fins rounded, extending a little beyond caudal-fin base; pelvic fin spine about two thirds as long as first branched ray, fin pointed but not produced, reaching or almost reaching anus; pectoral fin pointed, branched rays increasing in length to 5th then gradually decreasing in length, fin reaches well beyond last anal spine in most specimens; caudal fin truncated and deeper than long (Ref. 86429).Total gill rakers on first arch 20-25; rakers stout, compressed, first 10 on lower branch small and stout, becoming more elongate towards angle of arch, epibranchial rakers strongly decreasing in size towards last (Ref. 86429). Lower jaw prognathous with 53-106 slender-necked bicuspid outer row teeth on upper and 26-62 on lower jaw; towards angle of jaws teeth with reduced minor cusps or fully unicuspid, upper half of outer row teeth with free necks; one to two rows of tricuspid inner teeth, deeply embedded in soft tissue on both jaws; lower pharyngeal bone gracile, ventral keel elongate, more than twice length of dentigerous area; dentigerous area densely covered with extremely slender unicuspid teeth; second pharyngobranchial not greatly inflated, moderately vacuolated, bearing two or three robust unicuspid teeth on posterior face (Ref. 86429).
Colouration: Live colouration of males: base body colour golden with golden iridescence on flanks and head, but not on nape towards dorsal fin or laterally along dorsal fin base; nuptial males dusky blackish ventrally, blotchy dark brown above lateral line and along dorsal fin base, belly black except for light coloured anus and genital papilla; head black ventrally, upper lip, ethmoidal area, dorsal head surface, nape and upper parts of preorbital and pre- and postopercle orbit metallic golden-green; nine or ten thin vertical stripes present in juveniles and subadults, retained in nuptial males sometimes as irregular black blotches, which may extend onto belly; iris brown with narrow golden inner rim; dorsal fin reddish turning dark brown in nuptial males; caudal fin golden-reddish proximally, dusky greyish distally (Ref. 86429). Live colouration of females: overall colouration golden-grey, with golden iridescence over flanks; belly white, anus and genital papilla in mature females extruded and white; adult females sometimes with eight or nine thin lateral stripes extending from lateral line to dorsal fin base, ending in small dark grey or black irregular blotches over 2 or 3 scale rows below dorsal fin; if visible, last stripe on caudal peduncle broader and more prominent than lateral flank stripes, if not then overall colouration black, opercular blotch with blue iridescence, rest of opercle greenish-golden; head below orbit in some females dusky grey black, but not as intensively so as in males, otherwise golden-greenish; upper lip metallic golden-green; iris as in males; dorsal fin with distinct light grey blotches, forming more or less regular diagonal stripes, distally with black margin; fin membranes red-brownish, colouration becoming more distinct caudally; caudal fin yellowish-golden medially, becoming transparent distally; anal fin reddish-brown, pelvic fin-spine with golden iridescence (Ref. 86429). Preserved colouration of males: body brown to dark greyish brown dorsally, upper lip dark brown, lower lip dark brown anteriorly, ventral and laterally light brown; interorbital brown, becoming darker towards nape and in front of dorsal fin; cheek brown, dorsal gill cover translucent brown, opercular blotch prominent; branchiostegal membranes, interopercle, ventral part of preopercle, and opercle light brownish beige; six or seven black, sometimes broad, lateral blotches, often merging into a single fine line above lower lateral line; dorsal fin membrane light brown, spinous fin lappets dark brown to blackish, no markings in rayed fin; 'tilapia spot' not present in adult males; caudal fin membranes brownish beige, darkening proximally in some specimens; anal fin beige, darkening near fin base, some males displaying a broad dark brown to blackish band near fin base; pelvic fins beige brown with prominent dark brown pigmentation becoming denser along spines and towards free fin tips; pectoral fins beige brownish and translucent, pectoral fin-base darkly pigmented; sexually mature males with dark brown body colouration while belly and produced starkly white anus; upper lip dark brown, anterior rim of lower lip dark brown, brown or grey towards ventral border; interorbital area, nape and predorsal dark brownish black; branchiostegal membranes dark brown to black anteriorly, interopercle, ventral preopercle and opercle dark brown (Ref. 86429). Preserved colouration of females: overall colouration brown; upper lip brown, darker anteriorly; lower lip beige; interorbital and nape brown, darkening towards dorsal fin insertion; cheek brownish grey, opercle translucent with prominent opercular blotch; lower part of opercle beige; branchiostegal membranes pale beige with darker pigmentation anteriorly; if present, vertical bars reduced to broad lateral blotches over four to six lateral scales; chest light beige; belly creamy white, black peritoneum visible; lateral belly with brownish hue, ventrally between inter-pelvic region and anus white; dorsal fin membrane beige to greyish, finely pigmented; spines brownish; lappets dark brown distally; caudal fin brownish-beige, darker proximally; anal fin beige and finely pigmented, brownish near fin base; pelvic fins beige, pectoral fins beige-brownish and translucent, pectoral fin-base slightly pigmented (Ref. 86429). |
