Taxonomy & naming
Alticorpus sp. "Bicuspid Bis" is not a formally described species. It has no scientific name of its own, no describing author, no year of publication, and no entry in Eschmeyer's Catalog of Fishes. It belongs to Alticorpus, a genus of deep-water Lake Malawi cichlids erected by Jay Stauffer and Kenneth McKaye in 1988 around the type species Alticorpus mentale, and currently containing about six valid, formally described species (among them A. macrocleithrum, A. mentale, A. peterdaviesi, A. profundicola and A. geoffreyi), all confined to the deep, offshore, soft-bottomed water of the lake rather than the rocky shallows of the mbuna or the weedy margins of the shore-associated haps. A cluster of such deep-water forms with bicuspid outer teeth has been recorded from the Senga Bay area on the central-western shore, and where more than one distinct bicuspid population turns up at the same site, field references distinguish them with an added qualifier rather than inventing a new descriptive name for each - here "Bis," Latin for "twice" or "second," marking this as a second, separately recognised bicuspid-toothed form at Senga Bay alongside others such as Alticorpus sp. "Bicuspid Small-scale." Because so many deep-water Alticorpus specimens taken by trawl cannot be confidently matched to a described species using external anatomy alone, field workers and trawl-survey literature have long grouped unassigned material by working characters such as outer-jaw tooth shape - unicuspid, bicuspid (two-pointed) or tricuspid - alongside locality and depth. Alticorpus sp. "Bicuspid Bis" is one such bicuspid-toothed, Senga Bay-recorded population, recognised informally through the malawi.si database and Ad Konings's field surveys rather than through a taxonomic publication. Until a formal revision addresses the group, no authority or date should be attached to it.
Morphology
This form follows the standard Alticorpus body plan: a fusiform, laterally compressed body of moderate depth, carrying the genus's diagnostic head, in which the lateral-line canals and sensory pores of the snout, cheek and lower jaw are enlarged into conspicuous open pits. The working character that separates it from other unassigned Alticorpus material is dental - the outer row of teeth in both jaws is bicuspid, each tooth ending in two points rather than one (unicuspid) or three (tricuspid), a pattern used across the trawl-survey literature to sort otherwise similar deep-water specimens. Colour has not been documented for this population; fish taken by trawl from well below the photic zone rarely show the vivid breeding dress of shallow-water cichlids, and the genus as a whole is not known for strong sexual dichromatism. No published measurements exist specific to this form.
Habitat
Alticorpus sp. "Bicuspid Bis" is recorded from the Senga Bay area on the central-western shore of Lake Malawi. Senga Bay itself is a shallow, sandy embayment familiar to visitors, but Alticorpus is a genus of the offshore soft bottom, and material assigned to this form is understood to come from trawl work further out from shore, over open sand and mud rather than the rock reefs closer in. Genus-typical depth range runs from roughly 59–492 ft, with most species living below about 197 ft; where in that range this particular bicuspid-toothed form sits has not been separately documented. The surrounding water is the warm, hard, strongly alkaline chemistry typical of Lake Malawi's water column, though temperature and light both drop with depth well below what the sunlit littoral experiences.
Feeding
As with other Alticorpus, this form is presumed to be a benthic micro-feeder of the soft offshore floor, using its array of enlarged cranial sensory pores to detect small invertebrates moving within or on the sediment in dim or dark water where vision is of limited use. The genus generally sits at a low trophic level, consistent with a diet weighted toward detritus, diatoms and small invertebrates sifted from sand and mud rather than active fish-hunting. No feeding study specific to this bicuspid-toothed Senga Bay population has been published; this account follows the well-documented genus pattern rather than direct observation of the form itself.
Mating
Courtship has never been observed directly in this form, for the same reason true of most deep Alticorpus: the fish live below diving depth and are known chiefly from trawl catches. By analogy with the wider Lake Malawi haplochromine flock, of which Alticorpus is a deep-water offshoot, it is presumed to be polygynous with no lasting pair bond, males competing for and defending spawning sites on or near the soft floor while females move between them. The apparent absence of bright breeding colour in deep Alticorpus is consistent with a fish that pairs in water too dark for the visual courtship displays used by shallow-water relatives.
Breeding
Alticorpus sp. "Bicuspid Bis" is treated as a maternal mouthbrooder, in keeping with its genus and with essentially the whole Malawi haplochromine radiation. The female is presumed to take fertilised eggs into her mouth and brood them through to free-swimming fry, releasing a small number of relatively large, well-provisioned young rather than a large clutch of small ones. No clutch counts or fry data have been published for this specific form. South West Arm trawl studies of the better-known congener Alticorpus macrocleithrum have documented seasonal spawning with moderate clutches on the order of a hundred to a few hundred eggs, and this form most plausibly follows a broadly similar pattern, though that remains an inference rather than a documented fact.
In the aquarium
This is not a fish encountered in the aquarium hobby in any meaningful sense. Alticorpus sp. "Bicuspid Bis" is known from scientific trawl surveys rather than from ornamental collection, and the deep, cold, dark, soft-bottomed water it occupies is nothing like the conditions of a display tank. A fish adapted to life well below the sunlit littoral is also poorly suited to survive the pressure change of being hauled up in a trawl net, which is part of why Alticorpus as a genus barely registers in the trade despite containing some sizeable, striking-looking species. The realistic way to place this form is as one of several unassigned, working populations that trawl surveys and field references use to track the genus's real diversity below the depths hobbyists can access - a fish for the record, not the tank.
Conservation
Alticorpus sp. "Bicuspid Bis" has not been evaluated by the IUCN. As an undescribed form without a published scientific name it has no Red List category, status, or assessment of any kind - that is a statement about its taxonomy, not about its safety in the wild. As a deep-water, soft-bottom form of the central lake it is exposed to the same broad pressures affecting other offshore Alticorpus: the demersal trawl fishery that works Lake Malawi's deeper water for food fish sits squarely in this fish's habitat in a way inshore net and hook-and-line fishing does not, and the deep lake community generally is far harder to survey and monitor than the shallow reefs. No conservation status beyond "not assessed" should be attached to it.