25 October 2016, Askham Bryan Wildlife and Conservation Park. The aquarium is signed, but this one wasn't, so all can say is it is a cichlid (from Lake Malawi).
Male Pseudotropheus crabro, fishkeepers usually just call it crabro, but pretentious folk have started to call it the hornet cichlid (translating the Latin name) which is silly because that is the traditional name of Tilapia buttikoferi.