THE NOTHOBRANCHIUS SITE

​MRAC 2019.016.P.0048, holotype, male, 44.2 mm SL; Tanzania: Lake Victoria basin: Grumeti system: pools on both sides of road at a culvert, 56 km west of Ikoma Gate in the direction of Bunda, 7 km west of Nata, 02°00'41" S, 34°23'47" E; B. Watters, I. Sainthouse & M. Agnew, 12 May 1993, [field code: Nata TAN 93-4].

MRAC 2019.016.P.0049–0056 (5), MRAC 2019.016.P.0057 (1), MRAC 2019.016.P.0058 (1)

Nothobranchius attenboroughi belongs to the N. ugandensis species group presenting the following combination of characters in males: body coloration light blue with red or red-brown scale margins; frontal part of head red-brown, throat light blue or red; caudal fin uniform red; and anal fin light blue or yellow with red-brown spotted pattern. Nothobranchius attenboroughi differs from all other members of the N. ugandensis species group by a light blue anal fin with red-brown dots proximally and medially; becoming yellow distally with red-brown narrow stripes parallel to fin rays; and caudal peduncle length 122–129 % of its depth (vs. 96–121 or 130–157). Furthermore, it differs from N. moameensis, by a smaller body depth (25.7–31.0 % SL vs. 31.6–33.2); a smaller head depth (80.1–86.2 % HL vs. 87.1–94.3); and a dorsal fin that is positioned posterior to anal fin (preanal length mean 59.8 % SL and predorsal length mean 60.6 % SL vs. anteriorly positioned with mean values of 62.2 % SL and 60.9 % SL, respectively, in N. moameensis).

Subgenus: Zononothobranchius

Species group: N. ugandensis group

​Populations of this species were regarded as part of a diverse complex generally lumped into Nothobranchius species ‘Lake Victoria’, from the basin of that lake in central and western Tanzania and south-western Kenya, together with populations from drainage systems in central Tanzania. Combined morphometric and molecular analyses have revealed that populations from the Grumeti and other lesser systems east of Lake Victoria in northern Tanzania represent a different species, which was described as Nothobranchius attenboroughi by Nagy, Watters & Bellstedt in Nagy et al. (2020).

Tanzania: Lake Victoria basin: Grumeti system: pools on both sides of road at a culvert, 56 km west of Ikoma Gate in the direction of Bunda, 7 km west of Nata, 02°00'41" S, 34°23'47" E.

Nothobranchius attenboroughi is endemic to seasonal freshwater habitats in northern Tanzania. It is currently known from ephemeral pools and marshes associated with the Grumeti and other small systems draining into Lake Victoria at the east side of the lake, which ecological integrity is maintained by the congruence of its catchments largely within the Serengeti-Mara ecosystem.

Lake Victoria basin (521)

1142–1327 m

Water parameters based on seven observations, measured by Watters and Nagy between 1993 and 2019, were as follows: temperature of 22–27 °C; pH of 6.7–8.0; conductivity of 100–740 μS; and typically turbid (Nagy et al., 2020).

​The distribution area of N. attenboroughi overlaps with those of N. sagittae and N. serengetiensis, both belonging to the N. neumanni species group, but syntopic occurrences are rare (Nagy et al., 2020).

This species has an annual life cycle.

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

Maximum size reported: 44.2 mm SL; MRAC 2019.016.P.0048, holotype, male (Nagy et al., 2020)

Diploid chromosome number 2n = 36, NF = 58, karyotype structure 8m+14sm+14st/a (Krysanov et al., 2023).

The specific name is given in honour of Sir David F. Attenborough, in recognition of his dedicated efforts to promote biophilia: raising awareness of the wonders and beauties of nature for so many people worldwide, promoting awareness of the importance of biodiversity conservation, and above all, inspiring so many researchers in the field of natural history, including the authors of this paper. A noun in genitive case.

Vulnerable B1ab(iii)+2ab(iii) (Nagy & Watters, 2021)

    Rosenstock, J. 1989. Nothos I have known. Journal of the American Killifish Association, 22: 85–92. [discovery and collecting as N. sp. Mugeta] 

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

    Nagy, B. 2020. An Expedition Around Lake Victoria. Tropical Fish Hobbyist, #744, Sep/Oct 2020, 69 (1): 44–50. [collecting]

    Nagy, B. 2020. Lands of the unknown Nothobranchius. Practical Fishkeeping, 2020 (12): 24–31. [collecting]

    Nagy, B. & B. R. Watters. 2020. Threatened - the world is a dangerous place for seasonal fishes. Journal of the American Killifish Association, 53 (4): 141–156. [conservation]

    Nagy, B. & B. R. Watters. 2021. Nothobranchius attenboroughi. The IUCN Red List of Threatened Species 2021: e.T175184840A175184849. [conservation]

    Krysanov, E. Y., B. Nagy, B. R. Watters, A. Sember & S. A. Simanovsky. 2023. Karyotype differentiation in the Nothobranchius ugandensis species group (Teleostei, Cyprinodontiformes), seasonal fishes from the east African inland plateau, in the context of phylogeny and biogeography. Comparative Cytogenetics, 17 (1): 13–29. [chromosomes]