Above ABOVE: Tyranochromis nigriventer male. BELOW RIGHT: Tyranochromis nigriventer Female. Photos by Rick Borstein.
Tyranochromis nigriventer is mouthbrooding Malawian cichlid first typed by Maréchal in 1991. A synonym for this fish is Haplochromis macrostoma.
Males achieve a length close to a foot in the aquarium and sport an overall beautiful blue scheen on the falnks with white tips to the dorsal fin. This is a large impressive fish.
Females (see picture at left) top out at seven to eight inches and are blotchy in appearance with a yellow streak on the nose.
Tyranochromis nigriventer is decidedly piscivorous and has been observed preying on adult mbuna in the wild. It is an ambush predator, waiting stealthily behind a rock or outcropping. It then darts out to attack. In the aquarium, it will exhibit hunting behavior and will eat any other fish small enough for it to swallow.
In the lake, Tyranochromis nigriventer is found over open, sandy areas in shallow depths from 5 to 30M. According to Ad Konings, it has a lake-wide distribution.
Tyranochromis nigriventer is not demanding, but it grows large so you will need a big tank. My adult fish were kept in a 125-gallon tank serviced by a wet/dry filter. I performed 50% water changes weekly. My water is standard Chicago water; 7.2pH and very hard.
Tyranochromis nigriventer is easy to feed. Smaller fish will eat flake and small pellets. Adult fish greedily consume large pellets and Tetra Cichlid Sticks. I occasionally fed my fish excess fry and feeders (rosy reds) which Tyranochromis nigriventer will chase down with delight.
I obtained ten young fish from fellow GCCA member Sam Miller and housed them in a 55-gallon tank. They grew quickly and after seven months I moved them to a 125-gallon tank. The fish reached adult size at about 18 months of age.
Tyranochromis nigriventer take quite a while to become sexually mature. My male did not color up and get interested in spawning until he was eighteen months old. At this time he also got interested in harassing (and ultimately killing) a rival. The battles escalate quickly and within hours death may occur for an unlucky male. These fish are fast swimmers and will butt each other causing extensive internal damage.
Thus, whether you plan it or not, you will need to have a single male and several females.
Provide a flat slate for the breeding area for the fish. Breeding takes place in typical mouthbrooder fashion and the eggs are fertilized in the mouth of the female.
Brood sizes are large; over 50 medium-szed eggs. I stripped my first batch of eggs at two days and tumbled them with succes. Subsequent spawns have shown me that the females are good holders.
I started the fry out on newly hatched baby brine shrimp and they grew quickly.
Once your breeding group starts spawning, they can be very productive.
Tyranochromis nigriventer is not an expensive fish in the hobby. Two inch fish go for $8-10 each. Fully-colored adult males can be expensive. Expect to pay $30-40 for a show-quality adult male.
Tyranochromis nigriventer is rarely found in pet stores. Sub-adult fish are not very colorful and thus don't sell well. Few pet stores are wiling to bring in expensive adult fish. For the moment, this fish remains a cichlid hobbyist's fish with little chance of becoming popular at retail. Still, young fish are occasionally available on wholesaler's lists, so you may be able to ask your local store to order some in for you.
Report August 2003 by Rick Borstein