Ngoma, E., S. Valdesalici, K. Reichwald & A. Cellerino. 2013. Genetic and morphological Studies of Nothobranchius (Cyprinodontiformes) from Malawi with Description of Nothobranchius wattersi sp. nov. J. Fish Biol., 82 (1): 178, Figs. 5c, 5d, 5e, 5f. Abstract Molecular and morphological data were used to explore evolutionary differentiation among populations of Nothobranchius in the Lake Malawi-upper Shire River and the Lakes Chilwa-Chiuta drainage systems in Malawi. The aim of the study was to test the hypothesis that Nothobranchius of the Malawi-Shire system constitute a separate evolutionary group from Nothobranchius kirki. Mitochondrial and nuclear sequence data show a strongly supported phylogenetic split into two monophyletic groups separating the Lake Malawi basin fish from N. kirki. Unlike N. kirki, Lake Malawi-Shire fish do not deviate from neutrality and express an excess of rare haplotypes and mutations in terminal branches, characteristic of recently expanded populations. Further, the two groups significantly differ in morphology. Two body characters (dorsal-fin base length and pre-pelvic-pre-anal distance) are significantly different between the two species in both sexes. Several other characters are significantly different in either male or female comparisons with respect to both standard and head lengths, and robust morphological differentiation is detected by multivariate analysis. The two groups are readily distinguished on the basis of male colouration, especially in scale centres and the caudal fin. On the basis of this differentiation at the molecular and morphological levels, in addition to colouration, the Lake Malawi- Shire fish are hereby formally recognized as constituting a new species, Nothobranchius wattersi. This distinction is in agreement with the geomorphologic and recent climatic history in the region. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.
Genus: Nothobranchius Subgenus: Adiniops Group:
Geographical Distribution Maps
Malawi Type locality:19-11 km East-North-East Salima on road S29, Salima District, (eastern) Malawi. 13°46' S, 34°33' E Others places: - 12 km S. bridge over Chia Lake, near Wabango, Malawi [13.217 S : 34.301 E] Watters, 1991 | Ngoma et al., 2013 - near Salima, along Lake shore Rd, Malawi [13.750 S : 34.483 E] Grant, 1972 | Grant, 1973 - Ngwimbi, 2.5km E. M5 road, Malawi [14.347 S : 34.591 E] Ngoma, 2009 | Ngoma et al., 2013 - 4.5 km N.N.E. Golomoti, on road D81, Malawi [14.383 S : 34.617 E] Watters, 1988 | Ngoma et al., 2013 - D221 road, 4 km E. Liwonde, Malawi [15.067 S : 35.251 E] Watters, 1988 | Ngoma et al., 2013 Extension:Relatively wide
Salima (MW 88-1) Abrahamu MW 88-2 Benga MW 92-2 Chia MW 92-4 Hoba (MZMW 96) Chipoka MWH 2005-01 Hoba MZMW 09-6
Status specie: unanimously confirmed Difficult to distinguish morphologically from N.kirki. In captivity it presents some differences in its maintenance such as its tolerance to a higher salt concentration than most Nothobranchius species and higher GH values. It also requires a somewhat higher temperature than standard maintenance species.
Related: Vermaak, J. 1984. Collecting Nothobranchius in Malawi. British Killifish Association (B.K.A.), Killi News, 226: 154-160. [wattersi N.: Coll/Eco/as sp. aff. kirki] Watters, B.R. 1991a,b,c,d. The Nothobranchius of Malawi. Parts I, II, III & IV (Nothobranchius Habitats in Malawi). Journal of the American Killifish Association (J. Amer. Killifish Assoc., JAKA), 24 (4-6): 126-201, figs. [wattersi N.: Eco/Coll/Dis/Sys/Mis kirki] Grégoir, A.F., Philippe, C., Pinceel, T., Reniers, J., Thoré, E.S.J., Vanschoenwinkel, B. and Brendonck, L. (2017), Life stage dependent responses to desiccation risk in the annual killifish Nothobranchius wattersi. J Fish Biol, 91: 880-895. Abstract: To assess whether the annual killifish Nothobranchius wattersi responds plastically to a desiccation risk and whether this response is life stage dependent, life-history traits such as maturation time, fecundity and life span were experimentally measured in N. wattersi that were subjected to a drop in water level either as juveniles, as adults or both as juveniles and adults. Fish that were exposed to simulated pool drying as juveniles did not show changes in reproductive output or life span. Adults reacted by doubling short term egg deposition at the cost of a shorter lifespan. Overall, these results suggest that annual fish species can use phenotypic plasticity to maximize their reproductive output when faced with early pond drying, but this response appears to be life-stage specific. In addition to frogs and aquatic insects, phenotypic plasticity induced by forthcoming drought is now also confirmed in annual fishes and could well be a common feature of the limited number of fish taxa that manage to survive in this extreme environment.
Ng'oma, Valdesalici, Reichwald & Cellerino, 2013
Nothobranchius wattersi Nothobranchius wattersi Nothobranchius wattersi Nothobranchius wattersi
N. wattersi Hoba MZMW 09-06 N. wattersi Hoba MZMW 09-06 (C) Attila Remenyi N. watersi chipoka Malowa MW 24-1 PLR