THE NOTHOBRANCHIUS SITE

MSNG 58043, holotype, male, 40.1 mm SL; Tanzania: temporary ditch associated with an unnamed affluent of the Mhwala River, Wembere River drainage, Lake Eyasi basin (05°53.09’ S, 34°17.12’ E); Andrey Nikiforov & Sergey Torgashev, 21 April 2014, [field code: TNT 2014-04].

MSNG 58044 (9)

The colour pattern of Nothobranchius torgashevi males is comparable to that of other N. ugandensis group members, comprising light blue scales and a broad, irregular reticulated pattern on the body, vivid orange or red oblique bars on the head and dorsum, a yellow or blue anal fin, and large vivid red spots on the dorsal and anal fins. Other shared characters include: head rounded with a slightly concave to nearly straight dorsal profile; predorsal region convex between the nape and posterior extremity of the dorsal fin base; cephalic squamation variable. N. torgashevi can be distinguished from all other species in the N. ugandensis group by the following combination of characters: flank scales with red margins; caudal fin plain red; pectoral fin hyaline with a few proximal red dots; anal fin light blue with red dots proximally, yellow or creamy white distally; dorsal and anal fins with red margin; 16-17 dorsal fin rays; 17-18 anal fin rays; 31-33 scales in the median lateral series; 11-12 transverse scale rows; 16 circumpeduncular scales (Valdesalici, 2015).

Subgenus: Zononothobranchius

Species group: N. ugandensis group

Nothobranchius torgashevi was established as a species by Valdesalici in 2015.

Tanzania: temporary ditch associated with an unnamed affluent of the Mhwala River, Wembere River drainage, Lake Eyasi basin (05°53.09’ S, 34°17.12’ E).

This species is endemic to seasonal freshwater habitats in central Tanzania. It is currently known only from the area of the type locality, from a seasonal ditch along a road, in the Wembere River drainage in the endorheic Lake Eyasi basin in central Tanzania.

Southern Eastern Rift (566)

1259–1378 m

Water parameters at type locality: temperature of 25–30°C; pH of 8.3; and turbid (Valdesalici, 2015).

N. taeniopygus - 60%

N. neumanni - 20%

This species has an annual life cycle.

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

Maximum size reported: 44.1 mm SL (MSNG 58044, 3 males).

Diploid chromosome number 2n = 36 (Valdesalici, 2015), NF = 68, karyotype structure 6m+4sm+26st/a (Krysanov & Demidova, 2018).

Karyotype structure and fundamental number unique in the species group.

The specific name is given in honour of aquarist and collector Sergey Torgashev from Elektrostal, Moscow Oblast, Russia, who discovered the species.

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

    Valdesalici, S. 2015. Nothobranchius torgashevi (Cyprinodontiformes: Nothobranchiidae), a new species of annual killifish with two male colour morphs from the Lake Eyasi basin, central Tanzania. Killi-Data Series, 2015: 17–30. [taxonomy as Nothobranchius torgashevi]

    Nagy, B. & B. R. Watters. 2019. Nothobranchius torgashevi. The IUCN Red List of Threatened Species: e.T131472058A131472095. [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]