THE NOTHOBRANCHIUS SITE

MRAC 50016, lectotype, male, 46.3 mm SL; DR Congo: Lualaba drainage: Bukama, approx. 09°11' S, 25°51' E; P. Brien, May 1937.

MRAC 50017-27 (11), MRAC 50028-39 (12), CAS-SU 17484 (2)

​Cette espèce se distingue de N. orthonotus par un nombre plus élevé de rayons à l’anale et des ventrales plus courtes, de N. melanospilus par la hauteur du corps nettement plus grande, de N. guentheri par un nombre moins élevé de rayons à la dorsale et de N. taeniopygus par un nombre de rayons moins élevé à la dorsale et la hauteur du corps plus grande. Elle se distingue de toutes par une coloration typique bien différente (after Poll, 1938).

Males are light blue to blue-green, with distinct dark grey-brown scale margins; the anal fin is spotted proximally, and has a yellow-orange subdistal band and a dark brown distal margin; the caudal fin is completely spotted and has a distinct light blue distal margin. Females have a dark grey reticulation on the dorsal and posteroventral parts of the flanks.

Subgenus: Zononothobranchius

Species group: N. brieni group

Nothobranchius brieni was established as a species by Poll in 1938, and that status has since been accepted by all authors. It was the first Nothobranchius species described from the Congo and upper Zambezi river drainages. Despite the good impression of the specific colour pattern provided in the original description, the species name was also attributed to other Nothobranchius species collected in the Congo and upper Zambezi drainages, until Wildekamp published a redescription of N. brieni in 1978, together with the description of other species from the region, thereby clarifying the situation.

"Bukama, fl. Lualaba, mares reliées au fleuve par des chenaux" (Poll, 1938).

[Democratic Republic of Congo: ​Lualaba drainage: Bukama, swamps connected to the river by channels, 09°11' S, 25°51' E.]

This species is endemic to south-eastern Democratic Republic of Congo. It is known from temporary pools and swamps near Bukama and Lake Upemba, in upper Lualaba River drainage, Haut-Lomami province in Democratic Republic of Congo.

Upper Lualaba (545)

572–588 m

Personal observation at collecting sites (4 locations):

Water temperature: 25.6–28.5 °C

pH: 6.54–6.90

TDS:  35–340 ppm

Conductivity: 70–680 µS

None

This species has an annual life cycle.​

Embryonic development under captive conditions in peat moss is about four months at room temperature.

Maximum size reported: 46.3 mm SL (MRAC 50016, lectotype, male)

Diploid chromosome number 2n = 49 for males and 2n = 50 for females. NF = 50/50. The female karyotype consists of 25 pairs of acrocentric chromosomes. The male karyotype consists of 23 pairs of acrocentric chromosomes and one bi-armed pair and two unpaired acrocentric chromosomes; karyotype structure ♀ = 50st/a, ♂ = 1m+48st/a (Krysanov et al., 2016; Krysanov & Demidova, 2018).

Karyotype structure unique in the genus.

The specific name is given in honour of Professor Paul Brien, Belgian zoologist and collector of this species.

​

"To our knowledge this is the first Nothobranchius species discovered in the Congo Basin. As such, it is one of the most interesting species of Brien’s collection and it is for us a great pleasure to dedicate it to its collector" (Poll, 1938).

Vulnerable B1ab(iii,iv) (Nagy & Watters, 2019);

Previous assessment: Least Concern (Moelants, 2010)

​    Poll, M. 1938. Poissons du Katanga (bassin du Congo), récoltés par le professeur Paul Brien. Revue de Zoologie et de Botanique Africaines, 30 (4): 389–423. [taxonomy as Nothobranchius brieni]   

    Wildekamp, R. H. 1978. Redescription of Nothobranchius brieni Poll, 1938 and the description of three new Nothobranchius species (Pisces, Cyprinodontidae) from the province of Shaba, Zaire. Revue de Zoologie Africaine, 92 (2): 341–354. [systematics]

    Nagy, B. 2014. Adventures in the Rediscovery of the Legendary Nothobranchius brieni. Tropical Fish Hobbyist, #694, January 2014: 62–66. [collecting]

    Nagy, B. 2014. Nothobranchius chochamandai, a new species of annual killifish from the Luapula drainage, Democratic Republic of Congo (Cyprinodontiformes: Nothobranchiidae). Ichthyological Exploration of Freshwaters, 25 (2): 167–183. [systematics in N. brieni species group]

    Nagy, B. 2014. Nothobranchius flagrans, a new species of annual killifish from the Lufira drainage, Democratic Republic of Congo (Cyprinodontiformes: Nothobranchiidae). Ichthyological Exploration of Freshwaters, 25 (3): 259–276. [morphology]

    Krysanov, E., T. Demidova & B. Nagy. 2016. Divergent karyotypes of the annual killifish genus Nothobranchius (Cyprinodontiformes; Nothobranchiidae). Comparative Cytogenetics, 10 (3): 439–445. [chromosomes]

    Nagy, B., F. P. D. Cotterill & D. U. Bellstedt. 2016. Nothobranchius sainthousei, a new species of annual killifish from the Luapula River drainage in northern Zambia (Teleostei: Cyprinodontiformes). Ichthyological Exploration of Freshwaters, 27 (3): 233–254. [phylogeny]

    Nagy, B. & B. R. Watters. 2019. Nothobranchius brieni. The IUCN Red List of Threatened Species: e.T182281A58329824. [conservation]