THE NOTHOBRANCHIUS SITE

Pe0155, holotype, male, 38.1 mm SL; Malawi: Salima District: temporary roadside pools 9–11km ENE of Salima, on road S29, (approx. 13°46' S, 34°33' E); collected by B. R. Watters, 19 Mar 1988, [field code: Salima MW 88-1].

Pe0156 (12)

Nothobranchius wattersi males similar to N. kirki and differing from all other species of the genus by the following combination of characters: red colouration on caudal fin and part of caudal peduncle, anal fin red with a blue-green proximal portion, dorsal fin with light blue margin; pectoral, caudal and anal fins with black margin. Nothobranchius wattersi is readily distinguished from N. kirki by light blue colouration in scale centres (v. blue-green), plain deep red colouration on caudal and distal portion of anal fin (v. orange hue on distal portion), vermiculated blue pattern on anal fin (v. less irregular and limited at fin base), dorsal fin blue-green (v. bright light blue), anal fin more rounded (v. slightly wedge shaped in N. kirki), dorsal-fin base shorter, pre-pelvic to pre-anal distance longer and head longer, with a more flattened to slightly concave shape on the upper head surface relative to N. kirki (Ng'oma et al. 2013).

Nothobranchius wattersi was established as a species by Ng'oma, Valdesalici, Reichwald and Cellerino in 2013, and that status has been accepted by all authors since.

Populations that are currently identified as N. wattersi, were previously referred to as N. kirki or N. aff. kirki (Seegers 1997, Wildekamp 2004).

Malawi: Salima District: temporary roadside pools 9–11km ENE of Salima, on road S29, (approx. 13°46' S, 34°33' E)

This species is endemic to freshwater habitats in Malawi. It is known from the floodplains of rivers associated with the central and southern sections of Lake Malawi, and from areas around Lake Malombe and the Upper Shire River region in Malawi (Watters 1991a, Ng'oma et al. 2013). The distribution of N. wattersi coincides with the distribution of vertisol type soils that typically develop in alluvium (Watters 1991b, 2009).

Lake Malawi (559)

480–544 m

Water parameters from Watters (1991) are: water temperature 26–35 °C, pH 6.5–8.1, and total dissolved solids 30–280 ppm.

None

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: 53.4 mm SL (Ng'oma et al, 2013).

Diploid chromosome number 2n = 36 (Scheel, 1990 [as N. cf. kirki Salima]), NF = 40, karyotype structure 4m+32st/a (Krysanov & Demidova, 2018).

Karyotype structure shared with some members of the subgenus Adiniops.

The specific name is given in honour of Brian R. Watters, who has studied Malawi Nothobranchius and their biotopes extensively, and has also made significant contributions to the further understanding of the ecology of Nothobranchius fishes.

Near Threatened (Nagy, Watters & Tweddle, 2018)

    Watters, B. R. 1991. The Nothobranchius of Malawi. Part II - Collections during 1988. Journal of the American Killifish Association, 24 (4-6): 138–185.​ [collecting as Nothobranchius sp.]

    Watters, B.R. 1991. The Nothobranchius of Malawi. Part III - Distribution and Classification. Journal of the American Killifish Association, 24 (4-6): 186–193. [distribution, ecology as Nothobranchius sp.]

    Ng'oma, E., S. Valdesalici, K. Reichwald & A. Cellerino, 2013. Genetic and morphological studies of Nothobranchius (Cyprinodontiformes) from Malawi with description of Nothobranchius wattersi sp. nov. Journal of Fish Biology, 82: 165–188. [taxonomy as Nothobranchius wattersi]

    Nagy, B., B. R. Watters & D. Tweddle. 2018. Nothobranchius wattersi. The IUCN Red List of Threatened Species: e.T53904610A58340399. [conservation]

    Watters, B. R., B. Nagy, P. D. W. van der Merwe, F. P. D. Cotterill & D. U. Bellstedt. 2020. Redescription of the seasonal killifish species  Nothobranchius ocellatus and description of a related new species  Nothobranchius matanduensis, from eastern Tanzania (Teleostei: Nothobranchiidae). Ichthyological Exploration of Freshwaters, 30 (2): 151–178. [phylogeny]