WildNothos
THE NOTHOBRANCHIUS SITE
THE NOTHOBRANCHIUS TAENIOPYGUS COMPLEX
Members of the Nothobranchius taeniopygus species group in Tanzania are characterized by an anal fin with a slender to broad light medial band and broad black distal band in males.
Nothobranchius angelae Itigi TAN 03-8, wild-caught male - Copyright Brian Watters
Nothobranchius ivanovae Mpanda K 2011-25, male - Copyright Béla Nagy
Nothobranchius ottoschmidti Manonga River TAN 00-8, wild-caught male - Copyright Brian Watters
Nothobranchius rungwaensis Rungwa River TAN 03-6, wild-caught male - Copyright Brian Watters
Nothobranchius skeltoni Nyanguge TAN 93-15, wild-caught male - Copyright Brian Watters
Nothobranchius sonjae Tabora TZHK 2018-02, wild-caught male - Copyright Béla Nagy
Nothobranchius taeniopygus Kazi Kazi KTZ 85-9, wild-caught male - Copyright Ruud Wildekamp
Nothobranchius taeniopygus is characterized by an anal fin with a narrow yellow to white subdistal band; a caudal fin that is light yellow-grey with brown stripes proximally parallel to fin rays, followed by a narrow brown medial band and a narrow yellow to white subdistal band; and its distribution is restricted to the uppermost reaches of the Wembere River system.
Nothobranchius angelae from the Bubu River system and the Bahi Swamp, as well as the north-western part of the Ruaha River system, is characterized by an anal fin with a slender white medial band; a caudal fin with a narrow dark brown to black medial band, followed by a slender white subdistal band.
Nothobranchius ottoschmidti from the Wembere and Manonga river systems, the eastern and north-eastern parts of the Malagarasi system, and the southern Lake Victoria basin, is characterized by a caudal fin with small red-brown spots proximally, a slender semi-translucent grey subdistal band and a narrow irregular dark grey to black distal band.
Nothobranchius rungwaensis from the Rungwa River system, is characterized by an anal fin yellow proximally with a narrow red-brown submedial band, a broad yellow medial band with red to red-brown spots, and a broad black distal band.
Nothobranchius skeltoni from the Lake Victoria basin, is characterized by an anal fin that is grey to red-grey with irregular dark grey spots proximally, followed by a broad dark red to maroon medial band, a narrow light grey subdistal band.
Nothobranchius sonjae from the Malagarasi River drainage and the Moame River of the Lake Victoria basin, is characterized by a golden-brown to grey stripe on the dorsal scale row between nape and dorsal-fin origin.
Distribution of species in Tanzania belonging to the Nothobranchius taeniopygus complex:
N. angelae (blue-filled diamond),
N. ivanovae (red-filled pentagon),
N. ottoschmidti (yellow-filled triangle),
N. rungwaensis (green-filled square),
N. skeltoni (purple-filled star),
N. sonjae (orange-filled inverted triangle),
N. taeniopygus (black-filled circle),
and populations of uncertain affinity (red-filled plus symbol).
The letter “T” indicates type localities; the letter “M” represents sites from which specimens were subjected to molecular analysis.
Note that individual symbols may represent
multiple sites where such sites are in close proximity to one another.
Distribution map published in:
Watters, B. R., B. Nagy, P. D. W. van der Merwe, F. P. D. Cotterill & D. U. Bellstedt. 2019. Review of the Nothobranchius taeniopygus species group from central and western Tanzania with descriptions of five new species and redescription of Nothobranchius taeniopygus (Teleostei: Nothobranchiidae). Ichthyological Exploration of Freshwaters, 29 (3): 239–278.
Key to the species of Nothobranchius taeniopygus species group
Species of the genus Nothobranchius exhibit pronounced sexual dichromatism and dimorphism. Colour pattern elements and morphometric characters are based on mature males.
1a. Caudal fin with slender white subdistal band.
.............................................................................................................. 2
1b. Caudal fin with slender red or semi-translucent grey subdistal band or without subdistal band.
.............................................................................................................. 3
2a. Anal fin with slender cream to yellow medial band and narrow yellow to white subdistal band; postorbital length of 43–46 % HL (uppermost reaches of the Wembere system).
...................................................................... Nothobranchius taeniopygus
2b. Anal fin with slender white medial band and without subdistal band; postorbital length of 55–63 % HL (Bubu River system and the Bahi swamp, as well as the north-western part of the Ruaha system).
............................................................................ Nothobranchius angelae
3a. Distinct golden-brown to grey stripe on the dorsal scale row between nape and dorsal-fin origin; head length of 25.8–27.0 % SL (Malagarasi drainage).
.............................................................................. Nothobranchius sonjae
3b. Without distinct stripe on dorsal scale row; head length of 27.3–37.6.
.............................................................................................................. 4
4a. Caudal-fin base dusky red (Katuma system).
.......................................................................... Nothobranchius ivanovae
4b. Caudal-fin base light grey or brown.
.............................................................................................................. 4
5a. Anal fin cream, light brown or yellow medial band, and with red to red-brown spots; body depth at pelvic-fin origin 30.3–37.6.
.............................................................................................................. 6
5b. Anal fin with broad dark red to maroon medial band and without spots; body depth at pelvic-fin origin 26.3–30.0 % SL (minor seasonal systems flowing into Lake Victoria from south of the lake).
............................................................................ Nothobranchius skeltoni
6a. Caudal fin with small red-brown spots proximally, a slender semi-translucent grey subdistal band and a narrow irregular dark grey to black distal band; head width 67–73 % HL (Wembere and Manonga river systems).
..................................................................... Nothobranchius ottoschmidti
6b. Caudal fin without spots proximally, without subdistal band, and with slender semi-translucent dark grey distal band; pelvic fins light blue-grey, with broad yellow medial band with red-brown spots, and narrow black distal band; head width 54 % HL (Rungwa River system).
..................................................................... Nothobranchius rungwaensis
A dichotomous key allows to determine the identity of items in the natural world. Keys consist of a series of subsequent choices between two character states. 'Dichotomous' means 'divided into two parts'. Therefore, dichotomous keys always give two choices in each step.
The keys are written using pairs of contrasting characteristics, known as couplets, where the choice of one character state systematically leads to another couplet until the organism is identified.