Observations on Fossorochromis rostratus

The first time I've got to see Fossorochromis rostratus was in January 1995 in Moscow, when I visited a comrade looking for new fishes for my tanks. Among other species F. rostratus were allocated first of all. Because of their size at that time, about 14 cm (~5''), the males had not adult coloration yet, and I was told they were still young fish. I wondered then that if this fish were still teenagers, which is the size of an adult fish?. Among other things about this fish I thought that because of their longer snouts it was possible for them to make deeper digs in the sand, at least in comparison with other representatives of the Haplochromine assemblage of species in Lake Malawi. The fish showed an extraordinary high mobility. My personal opinion is that F. rostratus would leave far behind such fish as Tropheus species on speed of movement.

Observing their behavior in a tank (150x60x40 cm), I could see clearly that this is a fish of open water. In lake Malawi they live on open sand patches together with Cyrtocara Moorii and do not require the cover of rocks. Fishes living at rocks (for example mbuna) are not as mobile as F. rostratus. The whole day my Fossorochromis rostratus would dig in the substrate of the tank, using their powerful mouths for the purpose. Very similar behavior have South-american's Satanoperca species, which as well constantly dig at the bottom.

Today, two years after I obtained the fish, the adult ones have reached 18 cm for the males and 15 cm for the females. My tank contains not too many stones as I consider that F. rostratus need the maximum free space for navigation. The water has the following parameters: pH 8.5 and a hardness of 18 German degrees, which I meassured using a Tetra® test kit.

Fossorochromis rostratus, sub-adults an Mbenji island, Malawi. Photo by Ad Konings.

At an early stage the fish were fed with frozen cyclops and mosquito larvae, dry food was also provided in the form of Germany manufactured Tetra Cichlid food. Since an age of 10 months I started to feed F. rostratus with frozen mosquito larvae and dry floating Sera® Cichlid sticks (This is very convenient, as the floating food gets quickly eaten and does not takes load to the biofilter). Their voracity is extraordinary, a fish can eat so much that their bellies become shaped like a ball.

Fossorochromis rostratus are polygamous. For breeding purposes it is desirable to have a large flat stone in the tank for they to spawn. After spawn, this Haplochromines get divorced as the majority of Malawian cichlids do. F. rostratus are mouthbrooders, and females incubate the eggs inside of their mouths. The average quantity of juveniles produced in each breeding attempt goes around 40. Situations were the female eats the fry are usual, therefore, applying artificial incubation to prevent losses of fry is very convenient. Raising the juveniles has no complexities. I give my fish cyclops and dry Tetramin® flakes. It is necessary to note that males F. rostratus get ready to breed much older than females do, about 3 or 4 months. Therefore the first 6 to 8 spawns can appear as abortive.

In my tank I use FLUVAL® mod.3 canister filters, two automatic 200 watts heaters of Italian, illumination is provided by means of a fluorescent 1x36W.lamp. For substrate I use a thin layer (4...6 mm) of small gravel. I use large decorative stones with caves I have collected in the Black Sea. Plants are only artificial.

Some authors tell about different maximum length for adults Fossorochromis rostratus. A. Kochetov in his book "Aquarium fish-breeding" gives an adult size of 20 cm and Achim Bruhlmeyer "Buntbarsche aus dem Malawi-see" tells about 25 cm. My opinion is that the maximum length of the fish depends first of all on the correct conditions and the size of the tank where they are kept, but certainly under certain limits (some species like Labeotropheus trewavase grow in aquarium conditions more than it does in nature).

I hope that my experience with F. rostratus will be useful for fans who desire to get acquainted with this interesting cichlid more closely. If you can add anything to my observations, I would be glad to hear from you, e-mail me to [email protected].