Taxonomy & naming
Pseudotropheus sp. "Tursiops Mbenji" is undescribed: no holotype, no publication, no entry in Eschmeyer's Catalog of Fishes. Generic placement follows Pseudotropheus Regan, 1922, provisionally, pending any future revision. The trade epithet "Tursiops" borrows the genus name of the bottlenose dolphin (Tursiops truncatus); the precise reason a collector or trader chose it for this fish is not explained in any source available here, but it parallels other Lake Malawi cichlid nicknames built on a resemblance to dolphins — most notably Cyrtocara moorii, the widely traded "Malawi blue dolphin", named for its blue-grey body and prominent nuchal hump. Whether "Tursiops Mbenji" was named for a similar rounded head profile, a comparable grey-blue tone, or some other trait is not documented, and no single explanation is asserted here as confirmed. "Mbenji" is the collection-point tag, for Mbenji Island.
Morphology
This form follows the standard elongate, laterally compressed Pseudotropheus body plan, with a moderately sloped forehead and the closely packed dentition used to rasp aufwuchs from rock. If the "Tursiops" epithet does allude to a dolphin-like appearance, a grey-to-blue body tone with a smoothly rounded head profile would be the expected diagnostic feature, paralleling the far larger, unrelated Cyrtocara moorii — but this remains an interpretation of the trade name rather than a documented description, and the fish's actual colour and markings have not been detailed in the sources available here. Genus-typical adult length runs roughly 3–4.5 in, males somewhat larger than females.
Habitat
Pseudotropheus sp. "Tursiops Mbenji" is recorded from Mbenji Island, an offshore island in the central-western part of Lake Malawi that sits well out from the mainland shore and is well known among hobbyists and collectors for large, dense mbuna populations and comparatively clear water. 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. 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 Mbenji Island's dense mbuna community is well documented as supporting many co-occurring algae grazers that partition the resource by grazing angle and rock texture.
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 "Tursiops Mbenji" exists, and this account follows the well-established pattern for Pseudotropheus generally rather than direct observation of this population.
Breeding
Pseudotropheus sp. "Tursiops Mbenji" 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. 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. "Tursiops Mbenji" 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 Malawi bloat. Keep a surplus of females per male, and house it with similarly robust mbuna rather than gentle community fish. Because this is an undescribed, single-locality form, preserving accurate collection-point provenance is worthwhile for anyone maintaining a breeding group.
Conservation
No IUCN Red List assessment exists for Pseudotropheus sp. "Tursiops Mbenji", 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 island's 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.