Taxonomy & naming
Iodotropheus sp. "Londo" has no authority, no year of description, and no FishBase entry; it is known only by this informal field name, taken from Londo Bay, its recorded locality. Iodotropheus was erected by Michael Oliver and Paul Loiselle in 1972 for Iodotropheus sprengerae, the rusty cichlid, described from the lake's southeastern arm and restricted there to just four known sites — Boadzulu Island, Chinyankwazi Island, Chinyamwezi Island, and Makokola Reef. A second species, Iodotropheus stuartgranti, was later recognised from Gome on the western Malawian shore, once comparison across the sprengerae complex showed that populations from different stretches of coast differed enough in colour and proportions to warrant separate names. Londo Bay, on the Mozambican shore, falls outside the documented range of either described species, so this form cannot be assumed to be either one; it is best treated as its own unresolved population within a genus that has already proven to hold more hidden diversity than its long reputation as a single-species genus would suggest.
Morphology
Described Iodotropheus are dwarf mbuna with a Labidochromis-like build: a fusiform, laterally compressed body, a rounded muzzle, and a small terminal mouth. Iodotropheus sprengerae reaches a wild-caught maximum of roughly 3.5 in total length (larger in aquaria), with a warm rusty orange-brown ground colour in juveniles and females and a lavender-to-violet-blue flush over the flanks of dominant, breeding males; Iodotropheus stuartgranti is similarly small, with a muted, iridescent purple-brown to rusty base colour rather than sprengerae's more saturated rust-and-lavender contrast. No description specific to the Londo Bay population has been published, so this account does not assert which of these colour patterns, if either, it carries; it is presented as a genus-typical dwarf Iodotropheus pending a proper field account.
Habitat
This form is recorded from Londo Bay on the Mozambican shore of Lake Malawi, a locality outside the narrow, well-documented ranges of both described Iodotropheus species — Iodotropheus sprengerae confined to four sites in the lake's southeastern arm, and Iodotropheus stuartgranti known from Gome on the western shore. Iodotropheus as a genus is a rocky-shore fish, living over large rocks and slabs and in pockets of detritus and organic ooze between them, recorded across a broad depth band from the shallows to roughly 131 ft in the better-studied Iodotropheus sprengerae. No depth or micro-habitat figure specific to the Londo Bay population has been published, so the range given here reflects that genus-typical rocky-reef envelope. Water conditions follow Lake Malawi's usual hard, alkaline inshore chemistry.
Feeding
Described Iodotropheus graze aufwuchs — the felt of algae, diatoms, and small invertebrates coating lit rock surfaces — and behave as opportunistic omnivores rather than strict algae specialists; stomach-content work on Iodotropheus sprengerae found insect larvae and nymphs, benthic crustaceans, and blue-green algae all featured in its diet. No feeding study exists for the Londo Bay population specifically, so its diet is presented here as genus-typical aufwuchs grazing with an omnivorous lean, rather than a documented fact for this exact form.
Mating
In the wild, described Iodotropheus are not strongly site-territorial in the way many rock mbuna are: Konings found Iodotropheus sprengerae living alone or in small groups, with males chasing rivals from a feeding patch rather than defending a fixed cave, and courting males leading receptive females to a spawning spot rather than guarding a permanent territory. Whether the Londo Bay population follows this same loosely territorial pattern, and any courtship detail specific to it, have not been documented.
Breeding
As with every Lake Malawi cichlid, Iodotropheus sp. "Londo" is presumed to be a maternal mouthbrooder. In Iodotropheus sprengerae the female broods eggs and fry for roughly three weeks at around 77 °F, fasting throughout and recognisable by her distended throat, with reported brood sizes ranging from a handful up to several dozen. No clutch size or brooding data specific to the Londo Bay population have been published; the figures above are offered as genus-typical context rather than a documented count for this form.
In the aquarium
Iodotropheus sp. "Londo" is not established in the aquarium trade; the genus's hobby reputation rests almost entirely on Iodotropheus sprengerae, which has been bred in captivity for decades and is considered one of the gentler, more forgiving mbuna. A keeper who did obtain the Londo Bay form should follow the same broad template as its described relatives: a rock-built Malawi setup with plenty of caves and broken sightlines, a footprint of at least 35.5–47 in, and hard, alkaline water matching the lake — roughly 75–82 °F and pH 7.5-8.6. Diet should lean vegetable-forward, given the genus's aufwuchs-grazing habits, with rich, meaty foods offered sparingly to avoid the bloat risk common across mbuna-allied cichlids. No species-specific husbandry record exists for this form, and general Iodotropheus practice is offered here only as a starting point.
Conservation
Iodotropheus sp. "Londo" has no IUCN Red List assessment, since formal evaluation requires a validly published scientific name and none exists for this form. Iodotropheus sprengerae is assessed Near Threatened on the strength of its tiny four-site range, but that status describes a different, geographically documented population and cannot be extended to this unresolved Mozambican form. As a rock-associated cichlid apparently restricted to Londo Bay, it shares the general exposures documented across Lake Malawi's rocky-shore endemics — sedimentation from catchment disturbance, localised habitat pressure, and the ornamental collecting that targets many narrow-range Malawi mbuna — but no population-specific data exist to characterise its status beyond that general context.