Taxonomy & naming
Alticorpus sp. "Mentale Bicuspid" 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. Its trade name signals a resemblance to the genus's type species, Alticorpus mentale - described by Stauffer and McKaye from a Monkey Bay holotype and named for its projecting bony chin (Latin mentum) - while "Bicuspid" flags the dental character, bicuspid outer-jaw teeth, that field workers use to keep this Senga Bay population separate from the described mentale population itself rather than folding it in as the same fish. The two have not been formally compared in a taxonomic publication, and this account does not assert that they are, or are not, closely related beyond that resemblance. 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. "Mentale Bicuspid" 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
Alticorpus sp. "Mentale Bicuspid" follows the general Alticorpus build - a fusiform, laterally compressed body of moderate depth, with the genus's diagnostic head bearing enlarged sensory pores and widened lateral-line canals across the snout, cheek and lower jaw. Like the type species Alticorpus mentale, it is reported to carry a projecting mental process - a jutting bony chin at the front of the lower jaw - which is the basis for the trade-name resemblance; unlike confirmed mentale material, its outer-jaw teeth are bicuspid rather than matching the described species' dentition, which is the character field workers use to keep it apart. Colour has not been documented for this population; deep-trawled Alticorpus rarely show the bright breeding dress of shallow-water cichlids. No published measurements exist specific to this form.
Habitat
Alticorpus sp. "Mentale Bicuspid" is recorded from the Senga Bay area on the central-western shore of Lake Malawi, distinct from the type locality of Alticorpus mentale itself, which was described from material trawled off Monkey Bay in the south of the lake. As with other Alticorpus, material assigned to this form is understood to come from offshore trawl work over open sand and mud rather than Senga Bay's shallow, sandy nearshore. The genus-typical depth range runs from roughly 59–492 ft, with most species living below about 197 ft; the specific depth of this population has not been separately documented. It shares the warm, hard, alkaline water column typical of Lake Malawi generally, with temperature and light both falling well below surface levels at depth.
Feeding
This form is presumed to feed as other Alticorpus do - a benthic micro-feeder of the soft offshore floor, using enlarged cranial sensory pores to detect small invertebrates in the sediment where vision is of little use in the dim deep water. Alticorpus mentale itself, the species this form's name evokes, sits at a documented low trophic level of about 2.7 and shows a long lower jaw, low gill-raker count and cavernous head pores consistent with sifting the soft floor for diatoms, detritus and small invertebrates - a reasonable analogy for this form, though no feeding study specific to it has been published.
Mating
Courtship has never been observed in this form, for the reason true of the whole deep Alticorpus group: the fish lives below diving depth and is known chiefly from trawl catches. By analogy with Alticorpus mentale and the wider Lake Malawi haplochromine flock, it is presumed polygynous with no lasting pair bond, males holding spawning sites on or near the soft offshore floor while females move between them to select a mate. The absence of documented bright breeding colour is consistent with a fish that spawns in water too dark for the visual courtship of shallow-water relatives.
Breeding
Alticorpus sp. "Mentale Bicuspid" is treated as a maternal mouthbrooder, consistent with its genus and with essentially the whole Malawi haplochromine radiation. No clutch counts, egg sizes or fry data specific to this form have been published. Alticorpus mentale itself has no published clutch data either; the related, better-studied congener Alticorpus macrocleithrum has been shown by South West Arm trawl work to spawn seasonally with clutches on the order of a hundred to a few hundred eggs, offering the best available analogy for how this form most plausibly reproduces.
In the aquarium
For practical purposes this is not an aquarium fish. Like Alticorpus mentale itself - a species FishBase's broad trade tags notwithstanding never really makes it into the ornamental hobby - this form is a deep-water specialist known from trawl surveys rather than ornamental collection. An animal adapted to life well below 197 ft is in genuine trouble on the way up, and even a healthy specimen would need cool, dark, soft-floored conditions no bright, warm Malawi display tank can provide. It belongs on a serious keeper's mental map of the lake's full cichlid diversity, not in their tank.
Conservation
Alticorpus sp. "Mentale Bicuspid" has not been evaluated by the IUCN. As an undescribed form it carries no Red List status of any kind - a statement about taxonomy, not safety. Its close relative Alticorpus mentale is assessed Least Concern on the strength of a broad distribution through the deep southern lake, but that assessment cannot simply be extended to this separately recorded Senga Bay population. As a deep-water, soft-bottom form it sits within reach of the demersal trawl fishery that works Lake Malawi's offshore waters for food fish, a pressure that bears more directly on deep communities than on the shallow reef fauna most conservation attention focuses on. No conservation status beyond "not assessed" should be attached to it.