Remarks: Roseline Sharks, also called Denison's Barbs, are one of the most popular aquarium fishes for a reason. These peaceful barbs shoal back and forth across the tank constantly and make great tankmates for Rainbowfish, most schooling fish, and peaceful cichlids. If kept in small numbers, it is likely for this fish to become stressed and nip the fins of tankmates. The best way to prevent this is to keep them in groups of 6 or more so they are preoccupied with displaying and sparring rather than harassing other species.