Diagnosis: juveniles and females light blue-beige to all yellow with bright yellow anal fin; males with black anal fin and black membranes in caudal fin; snout 27.7-36.6% head length; cheek depth 18.8-28.8% HL; caudal peduncle length of females 10.8-16.7% SL; body depth of females 32.9-38.8% SL (Ref. 76849).

Description: head decurved; dorsal head profile straigth to slightly concave in larger individuals; gape inclination of mouth about 20° to horizontal; jaws isognathous; teeth on dentary in 3-5 rows, outer row teeth bicuspid and procumbent, inner rows teeth tricuspid, erect to procumbent; part of upper dental arcade normally exposed when mouth is closed; tips of teeth in premaxilla and dentary in a V-shaped line with anteriormost in upper and lower jaw furthest apart and not touching when mouth is closed; angle of ethmo-vomerine block with parasphenoid of 3 indivduals 31-41°; 3-5 scale rows on cheek; 3-5 teeth rows on upper jaw, 3-4 on lower; 0-3 pored scales post lateral line (Ref. 76849).

Coloration: breeding males: head pale blue with black interorbital and two light-blue interorbital bands; cheek and chin rusty-red in males from Maleri and Chidunga, but blue in males from Nakantenga, Namalenje, and Thumbi West islands; body light-blue with 6-7 conspicuous black bars anterior to vent and 3 faint bars posterior to vent; belly rustybrown anteriorly and black posteriorly; dorsal fin pale blue with prominent submarginal black band, but black band lacking in some males of Thumbi West; all males with black membranes in rayed portion of dorsal fin and bars from body extend into dorsal fin, merging with submarginal band when present; lappets white; some males with small yellow-orange spots on distal margin of dorsal fin; caudal fin pale blue with black margins and black membranes; narrow yellow/orange distal margin; anal fin black with narrow white margin anteriorly, with 1-9 yellow ocelli; pelvic fin black with white or white/yellow leading margin; pectoral fin clear to gray; males at Maleri and Nankoma islands and at Chidunga Rocks have a rusty-red to orange patch on cheek and chin while such is absent in males of other populations (Ref. 76849). Females (Maleri Island and Chidunga): head yellow or pale yellow; body yellow to beige/yellow; dorsal fin light yellow with orange/yellow lappets and orange/yellow spots on distal margin; caudal fin yellow with tiny blue highlights on membranes; anal fin bright yellow to orange/yellow with narrow hyaline band proximally, without ocelli; pelvic fin yellow with white leading margin; pectoral fin with fine yellow pigment (Ref. 76849). Females (Thumbi West and Nakantenga): head gray/beige with 2 pale yellow/blue interorbital bars; green/blue highlights on postorbital region and green/blue to gray opercular spot; body light blue/beige with faint gray bars; dorsal fin light blue/beige with gray submarginal band and gray membranes in trailing portion and with lappets white/yellow proximally and orange/yellow distally; orange/yellow spots in rayed portion of dorsal fin; caudal fin gray with narrow upper and lower border yellow with white margin, trailing border yellow, and tiny blue highlights on membranes; anal fin bright yellow to orange/yellow with hyaline band proximally and 1-2 small yellow/orange spots on trailing edge; pelvic fin yellow with dark gray submarginal band and white leading margin; pectoral fin hyaline (Ref. 76849).