| Diagnosis: |
Vertebrae: 28-30. Diagnosis: Haplochromis bwathondii is a small sized (less than 9 cm standard length), micrognathic species with a normal to relatively slender body outline, body depth 29.7-35.7% of standard length; with bicuspid and tricuspid teeth in the oral jaws and a moderately curved dorsal head profile; it has a melanin pattern of dusky, interrupted, longitudinal bands and vertical bars, producing a so-called 'chess board pattern'; this pattern also occurs in several oral shelling molluscivores, insectivores and algae scrapers, but these species generally are larger, have a strongly curved dorsal head profile and a lower jaw length/width ratio of less than 1.5, whereas in H. bwathondii it ranges from 2.0 to 2.8 (Ref. 85523). Haplochromis bwathondii differs from other small species with a 'chess board pattern' and a lower jaw length/width ratio of more than 1.5, H. sphex and H. sauvagei, in live colouration of sexually active males, by having red in the rostral part of the body; further, it differs from H. sphex by having a deeper body and a larger eye (Ref. 85523). On first impression the colours of sexually active males of H. bwathondii and H. sauvagei look alike; however males of H. bwathondii have a less distinct 'chess board pattern', are less yellow and have a silvery iridescent area on each scale, giving them a silvery appearance; furthermore H. bwathondii has a larger eye, thinner lips, a narrower lower jaw and less stout teeth with a relatively larger flange than H. sauvagei (Ref. 85523).
Description: Body relatively slender to normal; dorsal head profile straight to moderately curved; premaxillary pedicel not prominent (Ref. 85523). Mouth oblique; lips not thickened; medial part of premaxilla not expanded; caudal part of the maxilla not bullate; the vertical through the caudal tip of the maxilla runs through the iris; lower jaw isognathous and obtuse; jaws equal anteriorly, lower jaw slightly protruding in a few specimens; mental prominence not pronounced; retro-articular processes of right and left mandible halves occasionally touching, slightly interrupting the ventral outline; eye approximately circular; a small aphakic aperture may be present; cephalic lateral line pores not or slightly enlarged (Ref. 85523). Cheek, gill cover, dorsal head surface, greater part of dorsum and caudal fin base covered with cycloid scales, the remaining part of the body with ctenoid scales; a gradual size transition between scales of chest and flank; four to six scales between the upper lateral line and the dorsal fin origin, four to six between the pectoral and the pelvic fin bases (Ref. 85523). Pelvic fins reaching the anal fin origin; first soft rays of pelvic fins slightly produced, occasionally filamentous; anal fin just or just not reaching the caudal fin origin; caudal fin outline truncate to slightly emarginate (Ref. 85523). The number of gill rakers on the lower part of the first gill arch is 10 to 11; the lower two to four rakers are reduced; next one to two rakers are short; these are followed by three to five long rakers, their shape is pointed to acutely pointed; the remaining upper two to four rakers are long, their shape is acutely pointed to bluntly pointed or bifid; the rakers on the first gill arch generally are touching each other; the number of gill filaments on the lateral hemibranch of the first gill arch ranges from 88 to 97 (Ref. 85523). Premaxillary dentigerous arm as long as ascending arm in males, slightly shorter in female; the angle between the two arms is 87° to 91°; the ascending arm is slightly broader than the dentigerous arm; lower jaw relatively elongated; the upper half of the dentary has a distinct outwardly directed flare; mental prominence not pronounced; both premaxilla and lower jaw generally show an admixture of unequally bicuspid and tricuspid teeth in the rostral part, ca. 2/3 of dentigerous area, caudally mostly tricuspid teeth are found; the caudal-most teeth in the premaxilla are not enlarged, tricuspid, occasionally bicuspid; the number of tricuspids in the premaxilla may vary from just a few to all teeth; in the lower jaw relatively less teeth are tricuspid; in bicuspid teeth, the shape of the major cusp is isoscelene to subequilateral, sometimes obliquely truncated, especially in females; a flange is present, which may be very large in rostrally positioned teeth; the tip of the major cusp is generally not elevated above the flange; the cusp gap is wide, occasionally the minor cusp is only slightly smaller than the major cusp; in labial view, the neck is moderately slender, the crown slightly to moderately expanded; in lateral view, the crown is compressed; the outer row teeth of both premaxilla and lower jaw are slightly to strongly recurved; the inner row teeth are tricuspid; teeth are relatively small and slender (Ref. 85523). Dental arcade rounded and U-shaped; premaxilla has two to four inner rows anteriorly, none posteriorly; lower jaw two to three inner rows anteriorly, none posteriorly; there are 46 to 57 teeth in the outer row of the upper jaw; teeth of premaxilla and lower jaw closely set, the most caudally positioned teeth may be somewhat more widely set; outer row teeth of premaxilla erect, inner row teeth recumbent; lower jaw outer row teeth slightly procumbent, inner row teeth erect (Ref. 85523). Lower pharyngeal element relatively slender; as broad as long, or slightly longer than broad; the dentigerous area is broader than long; the suture is straight; there are 29 to 37 pheryngeal teeth in caudal-most transverse row, 10 to 11 teeth in medial rows; caudal-most transverse row hooked, major cusp only slightly incurved and blunt; other teeth pronounced or bevelled; all teeth are relatively fine and slender, medial teeth are not coarser than other teeth (Ref. 85523). The total number of vertebrae is 28-30, comprising 13-14 abdominal and 15-16 caudal vertebrae (Ref. 85523).
Colouration: Live colouration of males: snout, dorsal head surface and dorsum dark grey to light gold-brown, a bluish sheen is generally present; lips light grey to grey, often with a bluish sheen; lower jaw ivory to light grey; the eye has a dark grey outer ring and a golden-yellow inner ring; the cheek is light brownish to grey with a red flush; interoperculum and gill cover red; the rostral part of the flank is grey with a red flush, the caudal part and the caudal peduncle grey with a green-yellow flush; belly, chest and rostral part of ventral side ivory with red, remainder of ventral side ivory with a green-yellow flush; nostril-, interorbital-, lachrymal-, and preopercular vertical stripes and nape band present; the supraorbital stripe may be interrupted; the lachrymal- and supraorbital stripes are prominent; opercular blotch present; an additional blotch often present dorsal to the pectoral fin base; there are five to six dark grey to black vertical bars on the flank; an interrupted mid-lateral- and dorsal lateral band are present, as well as traces of a dorsal medial band, all dark grey to black; due to the crossing of horizontal bands and vertical bars the so-called 'chess board pattern' may emerge, although not distinct; pectoral fins hyaline, pelvic fins with a black lateral side; medial side dusky with a reddish flush; anal fin hyaline-grey with two yolk-yellow egg dummies surrounded by a hyaline ring; caudal fin base often coloured as caudal peduncle, with an extension of the mid-lateral band in the medial part; on the distal part of the caudal fin reddish to disky maculae may be present; dorsal fin faint hyaline to light greyish, with reddish to dusky streaks and spots; rostral lappets dusky (Ref. 85523). Live colouration of females: snout dark grey; dorsal head surface, dorsum and flank olive-green, the colour gradually becoming less intense caudally and ventrally; dorsum and flank with a bluish sheen; lips olive-green; lower jaw, chest, belly and ventral side ivory to silver; an opercular blotch and a preopercular vertical stripe are present; the remainder of the stripe pattern is faint, three to five vertical bars, and an interrupted mid-lateral band may be visible; pectoral fins hyaline, pelvic fins hyaline-yellow; caudal fin hyaline-grey, anal fin olive-green to hyaline, generally with one faint yellow spot; dorsal fin hyaline-grey with an olive-green base, lappets dusky (Ref. 85523). Preserved colouration of males: dorsal parts darker brown, ventrally khaki-brown; markings are the same as in sexually active, live males; pectoral fins hyaline, pelvic fins black laterally, medially hyaline-brown to dusky; anal fin brownish-hyaline occasionally with dusky spots; caudal fin brownish-hyaline with an extension of the mid-lateral band over a part of the fin; dorsal fin brownish-hyaline, lappets on the rostral part dusky (Ref. 85523). Preserved colouration of females: coloured like preserved males, but the markings are less distinct and the pelvic fins are hyaline (Ref. 85523). |