THE NOTHOBRANCHIUS SITE

​MRAC 2018.015.P.0007, male, 39.5 mm SL; Tanzania: upper Ruaha drainage: extensive, shallow pools on both sides of the road at a culvert, 1 km southwest of the railroad at Itigi, 05°41.9' S, 34°28.8' E; B. Watters, B. Cooper & W. Bishopp, 20 May 2003 [field code: Itigi TAN 03-8].

​MRAC 2018.015.P.0007-11 (5), MRAC 2018.015.P.0013 (1), MRAC B2.039.P.0011 (1), MRAC 79.07.P.142-3 (2), MRAC 2018.015.P.0012 (1)

Nothobranchius angelae is distinguished from all other species of the genus by the following combination of characters in males: body coloration light blue to blue-green with red-brown or dark grey scale margins; anal fin light blue-grey to yellow-grey with irregular brown spots, with narrow brown submedial band, slender white to pale cream medial band and broad black distal band; caudal fin light brown-grey with irregular dark brown spots proximally, followed by a narrow dark brown medial band, a slender white subdistal band and a slender to broad black distal band; pelvic fins light blue-grey to blue-green, with broad white to cream medial band and narrow black distal band. Furthermore, it differs from the other members of the N. taeniopygus species group in central and western Tanzania by a postorbital length 55-63 % HL (vs. 43-54); and caudal peduncle length 132-137 in % of its depth (vs. 119-130 and 140-169) (Watters et al., 2019).

​Subgenus: Zononothobranchius

Species group: N. taeniopygus group

​Following its early discovery in 1893 and more recent collections since 1978, populations of this species were referred to N. taeniopygus, based on general similarities of colour pattern with that species. The differences described by Wildekamp (1990) in colour pattern and morphology were attributed at the time to interpopulation variation; so specimens of this species were included in the redescription as representatives of N. taeniopygus. However, more recent morphometric and molecular analyses on a broader range of specimens confirmed the distinction from N. taeniopygus and the species was described as N. angelae by Watters, Nagy & Bellstedt in Watters et al. in 2019.

​Tanzania: upper Ruaha drainage: extensive, shallow pools on both sides of the road at a culvert, 1 km southwest of the railroad at Itigi, 05°41.9' S, 34°28.8' E.

This species is endemic to north-central Tanzania. It is known from seasonal pools and marshes associated with the Bahi Swamp and associated drainage systems, including the Bubu River system. The easternmost known site, near Itigi, immediately west of the Bahi Swamp region, is associated with marshy terrain drained by the Mlumbi and Kisigo streams in the extreme north-western headwaters of the Ruaha River system.

Southern Eastern Rift (566)

823–1307 m

Water parameters are as follows: temperature of 24–28°C; pH of 7.3–9.1; conductivity of 360–840 µS; and typically turbid (Watters, personal data in Nagy & Watters, 2020).

N. neumanni - 47%

N. itigiensis - 26%

This species has an annual life cycle.

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

Maximum size reported: 43.5 mm SL; MRAC 2018.015.P.0013, paratype, male (Watters et al., 2019)

Karyotype structure unique in the genus (Krysanov, pers. comm.)

​The specific name is given in honour of Angela Watters, wife of the first author, in recognition of her unwavering support for his many field trips to Africa to study fishes of the genus Nothobranchius, during which she also very capably maintained the fishes in the tanks of his large fish room. A noun in genitive.

Vulnerable B1ab(iii)+2ab(iii) (Nagy & Watters, 2020)

    Wildekamp, R. H. 1990. Redescription of two lesser known Nothobranchius from central Tanzania, N. taeniopygus and N. neumanni (Cyprinodontiformes: Aplocheilidae). Ichthyological Exploration of Freshwaters, 1 (3): 193–206. [taxonomy, systematics, distribution, ecology]

    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. [taxonomy as Nothobranchius angelae, distribution, ecology, phylogeny, systematics]

    Nagy, B. & B. R. Watters. 2020. Nothobranchius angelae. The IUCN Red List of Threatened Species: e.T156302218A156302224. [conservation]