Fossorochromis rostratus

Fossorochromis rostratus is a large, elongated hap that lives on the wide sandy flats of Lake Malawi. Its name means "digger": when in danger it dives into the sand and within moments buries its body almost completely. Juveniles and females carry regular dark blotches on a silvery background; males in breeding condition, on the other hand, take on a completely different look with dark blue tones and bright colors. Because of its adult size, it is only suitable for very large aquariums.

• At least 700 liters and 200 cm in length for an adult group; a wide floor area is essential.
• A deep, fine sand substrate; coarse gravel is not used because of its sand-diving behavior.
• A few sturdy rocks and a wide open area; plants get uprooted.
• Hard and alkaline water (pH 7.8–8.5), strong filtration and weekly 40–50% water changes.

Carnivorous; in the wild it takes sand into its mouth and sifts it, picking out the small invertebrates within. It is fed sinking large cichlid pellets, frozen mysis, krill and shrimp.

Despite its large size, it is a calm and skittish fish; at sudden movements it may dive into the sand or dart quickly around the aquarium. It should not be kept with aggressive species.

Good companions: large, calm haps such as venustus, livingstoni, blue dolphin cichlid and Malawi eye-biter, large Synodontis catfish suited to hard water.

Avoid: aggressive mbuna, small fish that fit in its mouth, community fish, shrimp, snails and planted setups.