Haplochromis (Yssichromis) pyrrhocephalus males sparring. These fishes were from Chester Zoo's old breeding stock of these beautiful and highly endangered Lake Victoria cichlids. I looked after these fishes for a couple of years until they died of old age, allowing the Zoo's aquarists to concentrate on successive generations.
bongorob told me this week that one of my photos of this species appears in Volume 34 of the International Zoo Yearbook, which I did not know.