Taxonomy & naming
Pollimyrus cuandoensis was described by Bernd Kramer, Monique van der Bank and Michael Wink, published online in 2013 and in print in 2014 in the Journal of Natural History (volume 48, issue 7–8, pages 429–463). The holotype, ZSM 41805, is held at the Zoologische Staatssammlung München; it was collected on 25 August 1999 from the Kwando River at Kongola Bridge, Caprivi Strip, Namibia (17°47'33"S, 23°20'33"E), which serves as the type locality. The species belongs to the family Mormyridae within Osteoglossiformes, the ancient bonytongue lineage, in the genus Pollimyrus — the dwarf stonebashers.
The description places Pollimyrus cuandoensis in a narrow contact zone on the lower Kwando River between two sibling species: Pollimyrus castelnaui, centred on the Okavango system, and Pollimyrus marianne, from the Zambezi. The authors distinguished it from both using genomic fingerprinting (ISSR-PCR) alongside differences in electric organ discharge, and a cytochrome b analysis places P. castelnaui as sister to a clade containing P. cuandoensis and P. marianne together. Some sources note that the P. cuandoensis type series shows little morphological difference from P. marianne, leaving open the possibility that further study could revise how the two are separated; no formal synonymy has been proposed.
Morphology
Pollimyrus cuandoensis is a small fish, reaching about 2.5 in in standard length according to FishBase. The body is short and deep with a compressed cross-section, a build shared across the genus and suited to maneuvering through rock crevices rather than open water. Fin-ray counts given for the species are 15–18 soft rays in the dorsal fin and 21–24 in the anal fin.
As in all mormyrids, a weak electric organ in the caudal peduncle generates a pulse-type discharge, read through electroreceptors distributed over the skin. The discharge recorded for Pollimyrus cuandoensis has five phases, and the original description found considerable variation in its waveform among samples taken from different points on the lower Kwando River — variation the authors suggested might reflect hybrid introgression at the contact zone with the neighboring species. That same discharge is what chiefly separates Pollimyrus cuandoensis from Pollimyrus castelnaui and Pollimyrus marianne, since outward appearance alone does not reliably do so.
Habitat
Pollimyrus cuandoensis is known from Namibia and Angola, in the lower Kwando (Cuando) River of the Caprivi Strip and in the Angolan reaches of the upper Zambezi system. The type locality is the Kwando River at Kongola Bridge.
It is a benthopelagic freshwater fish of the tropical zone, recorded over rocky substrate offering crevices and holes to shelter in, and occasionally among weed beds where these are present. FishBase describes it as a concealment-seeking fish that is nonetheless often found high in the water column, sometimes at the surface beneath water lily leaves in bright sunlight — a habit that puts it in shaded cover rather than in open, exposed water even when it is not hugging the bottom. Specific temperature and pH data have not been published for this species.
Feeding
No dedicated diet study has been published for Pollimyrus cuandoensis. FishBase computes a trophic level of about 3.2 for the species, consistent with a carnivorous diet, and the genus as a whole is understood to forage on small benthic invertebrates located by electrolocation. Nothing about feeding behavior in the aquarium has been documented for this species specifically.
Mating
No courtship behavior has been described for Pollimyrus cuandoensis. The species was distinguished from its close relatives largely on the basis of its electric organ discharge waveform, which fits a broader pattern in the genus of the EOD acting as a signal in mate and species recognition — a mechanism proposed for related dwarf stonebashers such as Pollimyrus castelnaui and Pollimyrus marianne at the same contact zone. Whether that holds for Pollimyrus cuandoensis specifically has not been tested. In the wider genus, males carry a modified anal fin with a distinctive notch used in an anal-fin reflex thought to assist in handling and fertilizing eggs during spawning, but this has not been confirmed in Pollimyrus cuandoensis by direct observation.
Breeding
Breeding in Pollimyrus cuandoensis is unrecorded. No wild or captive spawning account for this species has been published, and mormyrids generally are rarely, if ever, bred in the aquarium — fish reaching the trade are almost always wild-caught. Nothing can be said about egg-laying sites, clutch size, or parental care in this species without extrapolating past what is actually known.
In the aquarium
Pollimyrus cuandoensis has no documented history in the aquarium hobby; it is not named in the general mormyrid-care literature, and it should be treated as effectively absent from the trade rather than as a known quantity. Anyone attempting to keep it would be working from general mormyrid husbandry rather than species-specific experience: a soft sand or fine-gravel substrate to protect the sensitive facial skin used in electrolocation, dim lighting, and ample cover such as rockwork, driftwood, or roots standing in for the crevices this species uses in the wild.
Mormyrids as a group are known to be sensitive to poor water quality and to many common medications, so stable water and cautious dosing matter more here than with typical community fish. At 2.5 in this is a small species that would not need a large footprint on size grounds alone, but the complete absence of a captive record means any care regime for it is an extrapolation from the wider genus rather than an established practice.
Conservation
No IUCN Red List assessment has been located for Pollimyrus cuandoensis. The species is known only from a limited stretch of the lower Kwando (Cuando) River and the adjacent upper Zambezi system straddling the Namibia–Angola border, and its conservation status has not been formally evaluated.
No species-specific threats are documented. Rivers of the Kwando–Okavango–Zambezi system face general long-term pressures from water abstraction, damming, and habitat change elsewhere in the basin, and a narrow-range species restricted to a small stretch of one river system would be more exposed to such changes than a widely distributed one, but this is a general concern rather than a documented threat to Pollimyrus cuandoensis itself.