Altolamprologus calvus, or the Calvus Cichlid, is a predatory cichlid from Lake Tanganyika, distinguished by its unique body shape and intriguing behavior. A species tank or carefully selected tank mates are necessary.
Overview
Altolamprologus calvus is one of the most recognizable endemics of Lake Tanganyika. Its high, laterally compressed body and elongated snout are evolutionary adaptations for hunting small fish and invertebrates in narrow rocky crevices. Several geographical morphs exist, differing in the intensity of their dark bands and the presence of yellow or white spots, such as "Black," "White Chaitika," and "Yellow." Despite its predatory lifestyle, it is a relatively calm and slow-moving cichlid, showing aggression mainly within its own species.
Tank Requirements
For a pair of Altolamprologus calvus, an aquarium of at least 40 gallons (150 liters) is recommended. The decor should consist of rock piles creating labyrinths of caves, grottos, and narrow crevices to mimic the rocky littoral zone of the lake. Fine sand is the best substrate. Plants are not essential, but hardy species like Anubias or ferns attached to rocks can be used.
Stable water parameters are crucial: a temperature of 75-81°F (24-27°C), pH of 7.8-9.0, and hardness of 10-20 dGH. Powerful filtration and aeration are necessary, along with weekly water changes of 20-30%.
Feeding and Diet
In the wild, A. calvus is a micropredator. The diet in an aquarium should primarily consist of frozen and live foods: brine shrimp, daphnia, cyclops, and small krill. They can be trained to accept high-quality sinking pellets or flakes with high protein content. It is important to avoid feeding meat from warm-blooded animals (like beefheart), as this can cause digestive problems. Feed moderately, once or twice a day, avoiding overfeeding.
Care and Maintenance
The key to keeping Calvus is maintaining a stable aquatic environment and providing a well-structured aquarium. They are shy fish that spend a lot of time in hiding, emerging mostly for feeding. They should not be kept with overly active and aggressive tank mates that will cause them constant stress. Observing their behavior, especially during hunting, is one of the most interesting aspects for an aquarist.
Compatibility
A species-specific tank is the ideal setup. If kept in a community tank, tank mates must be chosen very carefully. Other Tanganyikan cichlids of similar size and temperament that occupy different niches are suitable. Good tank mates can include species from the genera Julidochromis, Neolamprologus (less aggressive species), or shell dwellers like Lamprologus ocellatus. Avoid keeping them with fast and aggressive species, such as many Mbuna from Lake Malawi.
Breeding
Breeding Altolamprologus calvus is an interesting but not straightforward process. They are cave spawners, often laying eggs in very narrow crevices or empty shells of large snails (e.g., Neothauma). The female lays between 50 and 200 eggs and cares for them while the male guards the territory. The incubation period lasts about 3-4 days, and the fry start to swim freely after another 7-10 days. The initial food is baby brine shrimp. The fry grow very slowly, which is a characteristic feature of the species. Parents usually do not harm their offspring, and the fry can grow up with them in the same aquarium if there are enough hiding places.