THE NOTHOBRANCHIUS SITE

SAIAB 200550, holotype, male, 39.3 mm SL; Namibia: Sakamanduna Pan, Gunkwe district, eastern Zambezi Region; two shallow seasonal pools on opposite sides of road, about 16 km directly south of Katima Mulilo (23 km by road) on the road to Linyanti via Gunkwe, 17°38.65' S, 24°17.66' E; J. Ippel & J. Bornman, 18 Dec 2001, [field code: NA 01-1].

SAIAB 200551 (2), SAIAB 200552 (8), MRAC B5-01-P-7-9 (4)

​Males of Nothobranchius capriviensis can be distinguished from its closest known relative, N. kafuensis, by the paler shade of blue than the blue phenotype, the lack of orange-red scale margins and the orange-red color on the head of the latter species, a more prominent and consistent barring on the body of the former, a deeper body, a longer head and a more posterior position of the anal fin (after Watters et al., 2014).

Males have a light blue body with irregular red-brown to maroon, chevron crossbars on the trunk to caudal fin base; the caudal and anal fins have a light blue to white subdistal band and a narrow black distal margin. Females have narrow, faint grey crossbars on the posteroventral parts of the trunk.

Subgenus: Zononothobranchius

Species group: N. brieni group

Nothobranchius capriviensis was established as a species by Watters, Wildekamp & Shidlovskiy in 2015, and that status has been accorded by all authors since. The year for the journal issue in which the description appeared is 2014 but that issue of the journal was printed in August 2015, thereby representing the year in which the species description became available.

Namibia: Sakamanduna Pan, Gunkwe district, eastern Zambezi Region; two shallow seasonal pools on opposite sides of road, about 16 km directly south of Katima Mulilo (23 km by road) on the road to Linyanti via Gunkwe; (17°38.65’ S, 24°17.66’ E).

This species is endemic to freshwater habitats in the Zambezi Region of Namibia. It is known from temporary pools and swamps confined to the eastern part of the Zambezi Region (formerly the Caprivi Strip) of Namibia, and situated between the Zambezi River to the north and the Chobe River to the south.

Upper Zambezi floodplains (556)

572–588 m

Water parameters (Watters et al., 2014):

Water temperature: 19.0–31.0 °C

pH: 6.6–7.6

TDS: 70–160 ppm

Conductivity: 140–320 µS

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: 49.7 mm SL (SAIAB 200552, paratype, male)

Diploid chromosome number 2n = 36, NF = 58, karyotype structure 4m+18sm+14st/a (Krysanov & Demidova, 2018).

Karyotype structure shared with other species in the subgenus Zononothobranchius.

The specific name represents a toponym after the Caprivi Strip, the historical name for the narrow extension of northeastern Namibia, where this species occurs. This part of Namibia was originally named after the German statesman Count Leo von Caprivi.

Endangered B1ab(iii,iv,v)+2ab(iii,iv,v) (Watters & Nagy, 2019);

Previous assessments:

Recommended as Endangered (Tweddle et al., 2014; Watters et al., 2014);

Least Concerns (Tweddle, 2007, considered as a population of N. kafuensis);

Endangered (IUCN Red List, 1996).

    Van der Waal, B.C.W. 1976. ’n Visekologiese studie van die Liambezi meer in die Oos-Caprivi met verwijsing na visontginning deur die Bantoe bevolking. Unpublished D.Sc. Thesis, Rand Afrikaans University, Johannesburg, South Africa: 192 pp. [collecting as Nothobranchius brieni]

    Watters, B. R., R. H. Wildekamp & K. M. Shidlovskiy. 2014. Description and biogeography of Nothobranchius capriviensis, a new species of annual killifish from the Zambezi Region of Namibia (Cyprinodontiformes: Nothobranchiidae). Journal of the American Killifish Association, 47 (4–6): 97–133. [taxonomy as Nothobranchius capriviensis]

    Tweddle, D., B. C. W. van der Waal & R. A. Peel. 2014. Distribution and migration of the Caprivi killifish, Nothobranchius capriviensis Watters, Wildekamp & Shidlovskiy 2015, with an assessment of its conservation status. Journal of the American Killifish Association, 47 (4–6): 134–151. [ecology, distribution, conservation]

    Watters, B. R. & B. Nagy. 2019. Nothobranchius capriviensis. The IUCN Red List of Threatened Species: e.T131470504A131470521. [conservation]

    Nagy, B. & B. R. Watters. 2020. Threatened - the world is a dangerous place for seasonal fishes. Journal of the American Killifish Association, 53 (4): 141–156. [conservation]

    Nagy, B. & B. R. Watters, 2021. A review of the conservation status of seasonal Nothobranchius fishes (Teleostei: Cyprinodontiformes), a genus with a high level of threat, inhabiting ephemeral wetland habitats in Africa. Aquatic Conservation: Marine and Freshwater Ecosystems, 1–18. [conservation]