Taxonomy & naming
Pseudotropheus sp. "Perspicax Likoma" is undescribed: no holotype, no publication, no entry in Eschmeyer's Catalog of Fishes. Generic placement follows Pseudotropheus Regan, 1922, the genus that until the late twentieth century held most of Lake Malawi's rock-dwelling mbuna before later revisions split off Metriaclima, Maylandia, Chindongo, Tropheops and others; whether this form would survive a future taxonomic split into one of those genera is not known. "Perspicax" is Latin for sharp-sighted or keen, a trade epithet whose precise motivation is not explained in any source available here. Two collection-point populations currently carry the name: this one, from Masimbwe Island near Likoma, tagged "Likoma", and a second from Gallireya Reef in the far north of the lake, tagged "Perspicax Hara". Whether the two represent one variable species collected at widely separated points or two genuinely distinct undescribed forms that happen to share a descriptive trade name has not been resolved by any source available here, and this account does not assume either answer.
Morphology
This form shows the standard Pseudotropheus body plan: a moderately elongate, laterally compressed mbuna with a sloped forehead and the short, closely packed dentition used to rasp algae from rock. Genus-typical adult length runs roughly 3–4.5 in, males somewhat larger than females. No detailed colour description specific to this population has been documented in the sources available here. As in other Pseudotropheus, dominant males are expected to carry the brighter, more saturated colouration and females and subordinate males the plainer pattern, following the near-universal mbuna rule, though the specific male display colour of this Masimbwe Island population is not documented here and should not be assumed to match the geographically separate Gallireya Reef population of the same trade name.
Habitat
Pseudotropheus sp. "Perspicax Likoma" is recorded from Masimbwe Island, a small rocky island close to Likoma Island in the open, mid-lake waters off the Mozambican side of Lake Malawi — a part of the lake with a cluster of small islands and offshore reefs that host a number of narrow-range mbuna forms. Like other rock-dwelling Pseudotropheus it is expected to hold territory among boulders and crevices in the shallow-to-intermediate littoral zone, roughly 7–49 ft, rather than crossing the open sand and deep water that isolate one island's rock fauna from the next. Water chemistry follows the Lake Malawi norm: warm, alkaline, and well-buffered, typically 75–82 °F and pH 7.7–8.6.
Feeding
As with other Pseudotropheus, this form is presumed to be a specialised aufwuchs grazer, using its rasping dentition to crop the mixed mat of filamentous algae, diatoms and associated micro-invertebrates that coats sunlit rock in the shallows. No feeding study specific to this population exists, but this diet is close to universal across rock-dwelling mbuna in the genus, and a territorial male typically defends a grazed patch of rock as a renewable food source in the same way he defends a spawning site.
Mating
Breeding behaviour is presumed to follow the standard mbuna pattern: polygynous and lek-like, with no pair bond. A dominant male holds and defends a patch of rock, often centred on a crevice or small cave, and displays to attract passing females rather than forming an exclusive pairing; subordinate males remain plainer and are largely excluded from the best territory. No behavioural documentation specific to "Perspicax Likoma" exists, and this account follows the well-established pattern for Pseudotropheus generally rather than direct observation of this population.
Breeding
Pseudotropheus sp. "Perspicax Likoma" is a maternal mouthbrooder, as is the entire genus. After spawning, the female takes the fertilised eggs into her mouth and incubates them for roughly three to four weeks, feeding little during that period, before releasing free-swimming fry that receive no further parental care from either parent. Clutch size has not been documented for this population; genus-typical Pseudotropheus of comparable size produce clutches in the range of a few dozen eggs.
In the aquarium
Pseudotropheus sp. "Perspicax Likoma" should be kept as a standard rock-dwelling mbuna. Dense, stable rockwork built into a tank of at least 47 in gives territorial males room to hold separate ground, with a sand or fine gravel substrate completing the setup. Water chemistry should replicate Lake Malawi: 75–82 °F, pH 7.7–8.6, consistently alkaline and well-buffered. Diet should be predominantly vegetable-based — a spirulina-forward flake or pellet as the staple — since mbuna are poorly suited to high-protein foods, which are strongly implicated in the digestive illness hobbyists call Malawi bloat. Keep a surplus of females per male to spread territorial attention, and house it with similarly robust mbuna. Because this is an undescribed, single-locality form, preserving accurate collection-point provenance and avoiding cross-breeding with the similarly named but geographically separate "Perspicax Hara" population is worthwhile for anyone maintaining a breeding group.
Conservation
No IUCN Red List assessment exists for Pseudotropheus sp. "Perspicax Likoma", and none can while it remains formally undescribed; no status, category or year should be attached to it. As a mbuna apparently restricted to a single small island's rocky shore, it carries the general vulnerability shared by narrow-range rock-dwelling cichlids around Lake Malawi — dependence on a small patch of intact rocky habitat and exposure to localised over-collection for the ornamental trade — but no population-specific study documents its actual abundance or trend. The accurate statement is that it is unevaluated.