Diagnosis: The presence of predominantly tricuspid teeth in both the upper and lower jaws that are visible when the mouth is closed clearly places Petrotilapia microgalana in the genus Petrotilapia (Ref. 78421). Pigmentation and colour patterns of P. microgalana distinguish it from all described species of Petrotilapia; the black submarginal band in the dorsal fin distinguishes P. microgalana from P. tridentiger and P. chrysos; males of P. microgalana have a bright blue ground colour along the flanks with 5-7 faint black vertical bars and a blue head; males of P. genalutea have a dull blue ground colour laterally with orange colour along the flanks, 5-7 black vertical bars, and orange/yellow cheeks, while males of P. nigra are predominantly black with 7-10 gray/brown vertical bars (Ref. 78421).

Description: Jaws are isognathous; 6-10 rows of teeth in upper and 5-10 rows in lower jaw; most teeth in outer and inner rows tricuspid (Ref. 78421). Pectoral fins with 12-14 rays (Ref. 78421). Scales along lateral side ctenoid; 32-33 lateral-line scales; 1-2 pored scales posterior to hypural plate; 3-4 scale rows on cheek (Ref. 78421). Gill rakers on first ceratobranchial 10-11 with 3 on the epibranchial (Ref. 78421).

Colouration: Lateral body colouration of territorial males blue with 5-7 faint black vertical bars; chest and belly yellow or orange; head blue with one broad black interorbital bar, black opercle spot, and faint yellowish orange gular region with micromelanophores; proximal two-thirds of dorsal fin gray with black submarginal band, light blue lappets, and orange tips; caudal fin with blue membrane, gray rays, and orange tips; anal fin clear with melanophores and 3 orange ocelli; pelvic and pectoral fins gray with pale blue leading edge (Ref. 78421). Females with light brown to bright gold lateral body colouration with 5-7 faint brown vertical bars below dorsal fin and series of dark brown blotches running mid-laterally along body (Ref. 78421). Juveniles bright yellow (Ref. 78421).