Blue gularis

The blue gularis, Fundulopanchax sjoestedti, is a large and colourful killifish from the swampy coastal rainforests of the Niger Delta in Nigeria and Cameroon. Males grow to around 13 centimetres, far bigger than most killifish, with blue-green bodies marked by red striping and a distinctive three-pronged tail. It is sometimes sold as the golden pheasant or red aphyosemion. Despite the killifish label, this is a powerful, robust fish rather than a tiny, short-lived nano species.

Blue gularis is a predator. It feeds on aquatic invertebrates and small fish in the wild, so it is not safe with dwarf shrimp or with fish small enough to be eaten. Keep it instead with peaceful tankmates too large to be prey, such as larger characins, corydoras, and calm cichlids. Males are aggressive toward one another and need room, while females do better kept two or three per male to spread out his attention. Offer meaty foods like bloodworm and daphnia and other live or frozen items, since dried foods are taken only reluctantly.

Provide a 100 litre or larger tank with dark substrate, dense planting, driftwood, and a tight cover, because this fish jumps. Keep the water soft, slightly acidic to neutral, and around 22 to 26 degrees Celsius. The species is a substrate spawner that lays its eggs in the bottom layer, and those eggs can pass through a resting period before they hatch. In a community tank you are unlikely to see surviving fry, since eggs and young get eaten; raising them takes a dedicated breeding setup with peat or spawning mops and separate incubation of the collected eggs.