What a beauty! This is a Leleupi. They grow to be about 3-4” long and are known to be fiercely territorial. It is recommended to keep these fish in established pairs. If your aquarium is large enough, usually over 100 gallons, you may be able to keep a group of 6-8 of them. Be sure there are many hiding spaces for them and that there are a lot of decorations to break up the line of sight. If you want to be certain there will be no fights, keeping just one in your aquarium will be the easiest route. Despite being aggressive towards each other, they are fairly tolerant of other species. They can usually be kept with other lake Tanganyika cichlids or catfish that stay about their size. Feed them a high quality pellet and some meaty foods such as brine shrimp, bloodworms or black worms on the side to keep them healthy.