Taxonomy & naming
Cyprichromis sp. "Leptosoma Jumbo" is a working name for an undescribed Cyprichromis. The quotation marks and "sp." mark a trade and database label, not a validated species. It has no describing author, no year and no type specimen, and none should be attached to it. The atlas's own article on Cyprichromis leptosoma treats the "jumbo" as a larger form that is likely a separate species, and that is the position taken here: probably distinct, but not formally shown to be.
tanganyika.si files it as "Cyprichromis sp. 'leptosoma jumbo'" with locality variants, including Cape Chaitika (listed there as "Blue Orchid"), Cape Mpimbwe and Kipili. A store listing seen by the atlas offers a Mpimbwe "Black Bee" form; that is a trade name for one population, and what distinguishes it from other jumbo populations is not documented in the sources used here.
Morphology
No measurements or colour descriptions for this form were available in the sources behind this article. The atlas's Cyprichromis leptosoma article puts true leptosoma at roughly 3.5–4 in and the jumbo at about 4.5 in, which is the basis for the "jumbo" name. That is a hobby-level comparison, not a published measurement series.
Genus context: Cyprichromis are slender, torpedo-shaped open-water cichlids, and males are brightly coloured while females are plain silvery. Which colours the jumbo populations carry, and how they differ between collection points, is not recorded here.
Habitat
tanganyika.si records the form at 39 collection points. By the countries named in the atlas's locality records these fall in Tanzania (for example Bondola Bay, Kipili, Cape Mpimbwe, Kekese and Kafungi), Zambia (for example Cape Kachese, Chimba, Funda, Isanga Bay and Kasenga) and DR Congo (Kamakonde, Kapampa, Livua, Moliro and Tembwe). Several points, such as Cape Chaitika, Karema (South) and Lwasase, are listed without a country or coordinates in the atlas data. The records thus span the southern half of the lake and reach both sides of it.
Many of the sites are rocky capes and islands. Cyprichromis in general live in open water above steep rock slopes, in shoals that can be large. Depth and water chemistry for this particular form are not recorded; Lake Tanganyika as a whole is alkaline and hard, and the atlas's lake-level figures apply.
Feeding
No feeding observations specific to this form were found. Genus-wide, Cyprichromis are plankton feeders that pick zooplankton from midwater, and the atlas's account of C. leptosoma describes the same behaviour. Its feeding has not been described separately from that of C. leptosoma.
Mating
Not documented for this form. Cyprichromis males are known to display in open water in front of females, in the way described for C. leptosoma in the atlas. Whether the jumbo differs in any detail is not recorded.
Breeding
Genus-level only. Cyprichromis are maternal mouthbrooders that spawn in open water, and females brood small clutches of large eggs for about three weeks. The atlas's C. leptosoma article gives clutches of roughly 9-20 eggs. Nothing specific to the jumbo has been found, and no clutch figure is claimed for it.
In the aquarium
The form is traded in small numbers, including the Mpimbwe "Black Bee" population seen in a specialist store listing. Care follows other Cyprichromis: a long tank, open swimming space with rockwork at the sides, hard alkaline Tanganyika water, and a shoal with several females per male. Fish of the same genus may hybridise, so keeping only one Cyprichromis form per tank keeps local lines recognisable.
Sellers' claims about size and colour for a named population should be treated as the seller's own statement. The atlas has no form-specific husbandry data for the jumbo.
Conservation
An undescribed form cannot be assessed by the IUCN, so there is no Red List category for it. That says nothing about its population in either direction. Its range, as recorded on tanganyika.si, is wide, but no survey data for it were found.