Makobe Island located in Speke Gulf Tanzania, is rich in cichlid fauna. Haplochromis sp. "blue obliquidens" is found in the shallow protected surf zone around the island. It is particular in its choice of habitat. H. sp. "blue obliquidens" inhabitats near shore areas containing reeds and grasses. These locations are protected from surging waves by rock formations (breakers) located between the shoreline and open waters (Seehausen 1996). Other furu that share this biotype include species of Xystichromis and Neochromis lineages. Haplochromis sp. "purple yellow" also frequents this biotype.
Haplochromis sp. "blue obliquidens" is an opportunistic feeder. Examined gut contents contained diatoms and blue-green algae as well as may and caddis fly larvae. Plant matter and Bryozoa were found as well (Seehausen 1996). Both sexes appear in equal frequency with males claiming territories centered on and around a flat stone. In between defending the area they have claimed, males will join the females in grazing upon algae encrusted rocks.
At 9 cm, H. sp. "blue obliquidens" is not a giant by any means. The body shape is typical of a Lake Victoria haplochromine. It is laterally compressed somewhat with a convex cranial profile. The curved forehead is not a prevalent in younger fish but becomes pronounced as the fish ages. Between 6 and 8 vertical bars line the flanks. Upper and lower jaws extend equally with very little premaxillary indentation. The outer teeth are bicuspid with a blade-like structure. The distinct dental structure is also found in Haplochromis sp. "purple yellow" and Enterochromis sp. "red back scraper". Females have nondescript grey-silver body coloration. Males have a copper hued blue coloration. A black bar runs from the corner of the mouth, straight up to the left side of the eye. It then extends at a 45 degree angle through the eye, around the forehead, and continuing down the other side of the face. There are two bars crossing the muzzle between the primary bar and the mouth. Another wide bar extends up on the gill plate. The front of the dorsal fin is bright blue while the rear portion is dotted with red blotches. A red borders extends across the top of the dorsal. The caudal fin is crimson red. Pelvic fins are black with the first ray extending beyond the others. The anal fin contains between 4 and 6 yellow ocelli with clear orbits. The base of the anal fin is blue fading to yellow-orange. Pectoral fins are clear.
As noted by the field name, this species is thought to have a close affinity with the Haplochromis obliquidens. Superficially, H. sp. "blue obliquidens" shares a similar body pattern to Astatotilapia sp. "thick skin". It differs from H. obliquidens processing smaller eyes and smaller, more deeply embedded chest scales (Seehausen 1996). Astatotilapia sp. "thick skin" has differing dentition, a straighter forehead slope and more vibrant body coloration. So far as body shape and pattern similarity, H. sp. "blue obliquidens" shows a strong resemblance to Enterochromis sp. "red back scraper". Similar tooth structure is found in both species.
In the confines of an aquarium, Haplochromis sp. "blue obliquidens" is a social but aggressive species. The key to successful maintenance is providing enough space so that multiple males might have the room to develop and hold territories of their own. As in the wild, flat stones placed at intervals throughout the tank will allow these cichlids to display at their best. Males of similar size will continually defend their borders with open mouths and flared fins but actual contact is rare. Without these areas to defend, male coloration dulls and breeding is not frequent. Strands of Vallisneria sp. aid in reproducing the grassy strands preferred in the wild. The substrate should be natural colored sand or small grain gravel. Suitable tank mates include members of the Neochromis genus such as sp. "madonna", rufocaudalis, or omnicaeruleus. The Lake Tanganyika catfish Synodontis petricola is a lively little species that meld well with H. sp. "blue obliquidens". The reproductive process is typical of Lake Victoria haplochromines with the species being a maternal mouth brooder. Breeding does not seem to come as readily as in other furu. When it does occur, the fry are hearty and grow quickly reaching maturity in 10 months.
No special food requirements are needed for this cichlid. It will accept and prosper on commercial flake, pellet, frozen and live sources. A variety of the fore mentioned foods will help replicate the varied diet ingested in the wild.
The status of wild populations of Haplochromis sp. "blue obliquidens" appears stable. Its preferred habitat of sheltered planted locations may have helped protect it from the predatory Lates niloticus. Limited range makes this species venerable to environmental pressures that have hampered many other areas of Lake Victoria. Hopefully pristine areas will remain protecting Haplochromis sp. "blue obliquidens" for years to come.
Seehausen, Ole; 1996; "Lake Victoria Rock Cichlids"; Verduyn Cichlids