THE NOTHOBRANCHIUS SITE

MSNG 57812, holotype, male, 51.2 mm SL; Tanzania: Malagarasi River basin, Ugalla River drainage: temporary pool in Nkululu River (06°40'52" S, 33°41'00" E); S. Torgashev & A. Nikiforov, 22 Apr 2014, [field code: TNT 2014-07].

MSNG 57654 (1), MSNG 57655 (6)

Nothobranchius streltsovi males are similar to other members of the N. ugandensis species group in possessing light blue scales with a broad, irregular, reticulated pattern on the body, oblique red or orange bars on the head and dorsum, yellow or blue anal fin, large vivid red spots on the dorsal and anal fins, rounded head with slightly concave to nearly straight dorsal profile, convex predorsal profile from nape to posterior extremity of dorsal-fin base, and variable cephalic squamation. Males can be distinguished from all other species of this species group by the following combination of characters: scale margins orange; caudal fin orange, spotted proximally; pectoral fin spotted proximally; anal and pelvic fins with a pattern of red dots, light blue proximally, yellow or creamy white distally; seven branchiostegal rays; 31-34 longitudinal scales; 14-16 transverse scales; 15-16 circumpeduncular scales; supraorbital neuromast formula 2 + 3 + 4 (Valdesalici, 2016).

​Subgenus: Zononothobranchius

Species group: N. ugandensis group

A first population of this species was collected by Seegers in 1994 and referred to as Nothobranchius sp. Limba Limba (Seegers, 1997). In 2010, 2012 and 2014, specimens apparently corresponding to N. sp. Limba Limba were collected from small pools associated with the Nkululu river in central Tanzania, close to the Limba Limba river, which were described as Nothobranchius streltsovi by Valdesalici in 2016.

Tanzania: Malagarasi River basin, Ugalla River drainage: temporary pool in Nkululu River (06°40'52" S, 33°41'00" E).

This species is endemic to seasonal freshwater habitats in central Tanzania. It is known from a single locality associated with the Nkululu River, a tributary of the Ugalla River of the Malagarasi River basin, central Tanzania.

Malagarasi–Moyowosi (543)

1300–1312 m

The type locality in April 2014 comprised an ephemeral pool located near a culvert measuring approximately 6 × 6 m, less than 50 cm deep, and without aquatic vegetation. The water was light grey due to suspended clay particles and slightly turbid with low conductivity (approximately 150 μS), pH of 7.9 and a temperature of approximately 26 °C (Valdesalici, 2012).

N. seegersi - 60%

This species has an annual life cycle.

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

Maximum size reported: 51.2 mm SL (MSNG 57812, holotype, male)

Diploid chromosome number 2n = 36, NF = 48, karyotype structure 6m+6sm+24st/a (Krysanov & Demidova, 2018).

Karyotype structure unique in the genus, whereas fundamental number unique in the species group.

The specific name is given in honour of Sergey Streltsov (Russia), who collected the type specimens.

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

    Valdesalici, S. 2016. Nothobranchius streltsovi, a new species of annual killifish with two male colour morphs from the Malagarasi drainage, central Tanzania (Teleostei: Cyprinodontiformes: Nothobranchiidae). Ichthyological Exploration of Freshwaters, 27 (2): 153–161. [taxonomy as Nothobranchius streltsovi]

    Nagy, B. & B. R. Watters. 2019. Nothobranchius streltsovi. The IUCN Red List of Threatened Species: e.T131471945A131471960. [conservation]

    Nagy, B., B. R. Watters, P. D. W. van der Merwe, F. P. D. Cotterill & D. U. Bellstedt. 2020. Review of the Nothobranchius ugandensis species group from the inland plateau of eastern Africa with descriptions of six new species (Teleostei: Nothobranchiidae). Ichthyological Exploration of Freshwaters, 30 (1): 21–73. [phylogeny]