Review of the Nothobranchius ugandensis group from eastern Africa

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, IEF-1129, pp. 1-53

Abstract

The Nothobranchius ugandensis species group from the inland plateau of Kenya, Tanzania and Uganda is reviewed. Members of this group are characterized in males by the combination of characters of a light blue body coloration with red to red-brown scale margins; a frontal part of head red-brown; throat light blue or red; a uniform red or yellow caudal fin; and a light blue or yellow anal fin with red-brown spotted pattern. Six new species are identified, to raise total species richness to eleven.

Nothobranchius albertinensis, Nagy, Watters & Bellstedt, new species, from the Albert Nile drainage in western and north-western Uganda, is characterized by a yellow dorsal fin with stripes in medial part parallel to fin rays; yellow anal fin without markings; and anal fin positioned anterior to dorsal fin.

Nothobranchius attenboroughi Nagy, Watters & Bellstedt, new species, from the Grumeti and other lesser systems east of Lake Victoria in northern Tanzania, is characterized by a light blue anal fin with red-brown dots proximally and medially, and becoming yellow distally with narrow red-brown stripes parallel to fin rays.

Nothobranchius hoermanni Nagy, Watters & Bellstedt, new species, from the upper Wembere drainage in central Tanzania, is characterized by a red throat; light blue anal fin with red-brown spots and stripes proximally and medially, and with a broad light blue distal zone without markings; pectoral fin hyaline with red-brown stripes parallel to fin rays; and exposed branchiostegal membrane red-brown, with cream distal margin.

Nothobranchius itigiensis Nagy, Watters & Bellstedt, new species, from the uppermost Ruaha drainage and the Bahi Swamp area in central Tanzania, is characterized by a yellow anal fin with red-brown spots proximally, that merge medially to a pattern parallel to fin rays and are fused distally to form a marginal band.

Nothobranchius moameensis Nagy, Watters & Bellstedt, new species, from the Moame system south of Lake Victoria in northern Tanzania, is characterized by a light blue anal fin with red-brown dots proximally and medially, and with light blue or yellow distal zone without markings.

Nothobranchius venustus Nagy, Watters & Bellstedt, new species, from lesser systems in south-western Lake Victoria basin in north-western Tanzania, is characterized by a dorsal fin with a narrow light blue subdistal band and a narrow red-brown to black distal band; a light blue anal fin with irregular red-brown stripes perpendicular to fin rays proximally and medially, and orange with red-brown stripes parallel to fin rays in distal zone.

The species group on the inland plateau in eastern Africa also includes N. derhami, N. kardashevi, N. streltsovi, N. torgashevi and N. ugandensis; furthermore N. nubaensis from southern Sudan and western Ethiopia is also included.

Phylogenetic analysis of the sequences of their mitochondrial ND2 and COI, and nuclear Glyt, MyH6 and SNX33 gene sequences supports the genetic distinction of the six new species and confirms their position, together with all known members in the N. ugandensis species group.