THE NOTHOBRANCHIUS SITE

RMCA 2016-027-P-00024, male, 23.3 mm SL; DR Congo: lower Luapula drainage: upper Lubi system: ephemeral marsh in the river floodplain, about 25 km southwest of Kasenga township (10°31.2’ S, 28°27.3’ E); B. Nagy, A. Chocha Manda & G. Petneházy, 15 Apr 2016 (field code: CD 16-20).

RMCA 2013-022-P-0001–3 (3), RMCA 2016-027-P-00025–8, (4).

Nothobranchius poppi differs from all congeners, except N. malaissei, its only sympatric congener in the lower Luapula drainage, by sharing the following combination of male colour pattern characteristics: light blue scales with red-brown posterior edge, creating a broad reticulation pattern on body; median fins with brown-red spots proximally; caudal fin with an overlaying light blue iridescent distal band, covering approximately the distal one-third of the caudal fin, and interspaced with brown-red fine lines parallel to fin rays. It is, however, distinguished from N. malaissei in male colour pattern characteristics by having: an anal fin without subdistal and distal bands (vs. with a slender light blue to orange subdistal band and slender to broad red-brown distal band in N. malaissei); a relatively short head length, 29.4–32.5% SL (vs. longer, 32.7–35.4% SL); and a short snout length, 19–21% HL (vs. longer, 22–28% HL).

Subgenus: Zononothobranchius

Species group: N. brieni group

Nothobranchius poppi was established as a species by Nagy, Chocha Manda & Vreven in 2026.

DR Congo: lower Luapula drainage: upper Lubi system: ephemeral marsh in the river floodplain, about 25 km southwest of Kasenga township (10°31.2’ S, 28°27.3’ E)

This species is endemic to seasonal freshwater habitats in south-eastern Democratic Republic of the Congo. It is known from the type locality and four other nearby sites, all being ephemeral marshes of the upper Lubi system in the lower Luapula drainage.

Bangweulu–Mweru (544)

977–982 m

Personal observation at type locality:

Water temperature: 27.5 °C

pH: 6.1

TDS: 64 ppm

None

The species has an annual life cycle.

Embryonic development under captive conditions in peat moss is about three to five months at room temperature.

Maximum size reported: 40.0 mm SL (RMCA 2013-022-P-0001-0003, paratype, male)

The karyotype has a diploid number 2n = 49 for males and 2n = 50 for females with NF = 68/68 (as N. sp. Kasenga in Krysanov et al., 2016).

Karyotype structure unique in the genus.

The specific name is given in honour of Thomas Popp (Germany) who, together with collaborators at the Université de Lubumbashi (UNILU: DR Congo), discovered the species during the course of a scientific field expedition. A noun in the genitive case.

Not evaluated. Recommended as Endangered in Nagy et al. 2026.

    Krysanov, E., T. Demidova & B. Nagy. 2016. Divergent karyotypes of the annual killifish genus Nothobranchius (Cyprinodontiformes; Nothobranchiidae). Comparative Cytogenetics, 10: 439-445.  [as Nothobranchius spec. Kasenga, chromosomes]

    Nagy, B. 2025. Review of cyprinodontiform fishes in the upper Congo drainage with descriptions of four new species of seasonal Nothobranchius (Nothobranchiidae) and a new species of ‘Lacustricola’ Lampeye (Procatopodidae) in South-Eastern DR Congo. Ecology and Diversity, 2 (2), 10006. [as Nothobranchius spec. from upper Lubi, phylogeny]

    Nagy, B., Chocha Manda, A. & Vreven, E.J.W.M.N. 2026. Nothobranchius poppi, a new species of seasonal killifish (Cyprinodontiformes: Nothobranchiidae) from ephemeral wetlands of the lower Luapula River floodplain (upper Congo drainage: DR Congo). Ichthyological Exploration of Freshwaters, IEF-1203. [taxonomy as Nothobranchius poppi, distribution, ecology, phylogeny]

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