Like other rainbowfish, Boeseman’s rainbowfish is a small, freshwater fish with a rather compressed body, large scales, and, as the name suggests, bright colouration (3). The colour pattern of the male Boeseman’s rainbowfish is unusual in that the head and front half of the body are a bright blue-grey, sometimes almost blackish, while the fins and rear half of the body are a contrasting vivid orange-red. Between these two areas are alternating light and dark vertical bars (2) (4) (5). Boeseman’s rainbowfish has two dorsal fins, both of which have a white outer margin, and the second of which is long and, unlike the first, lacks spines (3) (5). The anal fin is also long (3). In contrast to the male, the female Boeseman’s rainbowfish is much less brightly coloured, and has shorter and less elaborate dorsal fins (2) (3) (4) (5).
- Length: up to 12 cm (2)