Taxonomy & naming
Lethrinops sp. "Domira Blue" has no formal scientific description, no describing author, and no FishBase entry; the trade name combines a locality reference, most plausibly to Domira Bay in the South East Arm, with a blue breeding-male colour tag, following the standard convention for undescribed Lake Malawi cichlids of pairing a place name with a distinguishing colour. The genus Lethrinops was erected by Regan in 1922 and revised by Eccles and Trewavas in 1989; the South East Arm has produced numerous separately named, undescribed Lethrinops populations over the decades, and "Domira Blue" should be treated as its own distinct form rather than assumed identical to any other locally recorded Lethrinops.
Morphology
As implied by the trade name, breeding males of this form show blue colouration, though the precise extent, placement, and any accompanying pattern have not been formally documented, and this account does not go further than what the name records. Body form is presumed genus-typical: elongated and fusiform, with the oblique, protrusible sand-sifting mouth diagnostic of Lethrinops. Non-breeding males and females are expected to follow the genus-typical pattern of plain silver, offering little pattern away from the breeding grounds.
Habitat
The only recorded locality for this form is the South East Arm of Lake Malawi, a broad, shallow embayment at the lake's southern end with extensive open sand and silt substrate that supports a diverse community of sand-dwelling haplochromines, including several other undescribed Lethrinops populations. Like other sand-dwelling members of the genus, it is expected to occupy open sand away from rocky shoreline, at depths that vary by species. Water conditions there follow Lake Malawi's typical profile: warm, alkaline, and well-buffered.
Feeding
This form is presumed to be a sand-sifting invertivore in the manner typical of Lethrinops: patrolling just above the substrate, taking mouthfuls of sand, and filtering out small invertebrates such as chironomid larvae, ostracods and copepods through comb-like gill rakers before expelling the spent sand through the gills and mouth. No dedicated diet study exists for this specific population; the account here follows the well-documented feeding mode of the genus.
Mating
No study of courtship or territoriality has been published for this form. Lethrinops in general are expected to be non-territorial outside the breeding season but to establish a small display site on open sand once in colour, with the male's blue breeding dress signalling readiness to passing females. There is no pair bond; the social system is lek-like, with females moving between coloured males scattered across a patch of sand to choose where to spawn.
Breeding
Like every member of its genus, this form is presumed to be a maternal mouthbrooder: spawning takes place on open sand at or near the male's display site, and the female takes the fertilised eggs into her mouth immediately after laying, carrying them there through several weeks of development before releasing free-swimming fry. There is no male or biparental care beyond fertilisation. Clutch size has not been documented for this specific population; related sand-dwelling species typically produce clutches of a few dozen eggs.
In the aquarium
Lethrinops sp. "Domira Blue" is not established in the aquarium hobby and no husbandry record exists for it specifically. A keeper who obtained it should follow genus-typical Lethrinops practice: a soft sand substrate at least 2 in deep to support natural sifting behaviour, a tank of at least 47 in to allow a trio or small harem group, and water matched to Lake Malawi's chemistry — roughly 75–82 °F, pH 7.7–8.6, well-buffered. Because the form is undescribed and known from a single broad locality, keepers who acquire it should record and preserve the collection site rather than mixing stock from elsewhere in the Arm.
Conservation
No IUCN Red List assessment exists for Lethrinops sp. "Domira Blue", and none can until it receives a formal description. Sand-dwelling Lethrinops of the South East Arm face pressure from inshore trawling and seine-net fisheries, which take open-water and sand-associated haplochromines as bycatch far more heavily than rock-dwelling mbuna, and from sedimentation linked to catchment land use around the southern lake. No population-specific data exist to characterise this form's status beyond "unassessed".