Trophic niche partitioning in communities of African annual fish: evidence from stable isotopes
- 604 Downloads
Annual killifish of the genus Nothobranchius often co-occur in temporary savannah pools. Their space- and time-limited environment does not allow for any substantial habitat or temporal segregation. Coexisting species are therefore predicted to have well separated trophic niches to avoid intense food competition. Although in a previous “snapshot” study using stomach content analysis (SCA), the trophic niches of three sympatric species (N. furzeri, N. orthonotus, and N. pienaari) were found to vary among species, the difference was relatively weak and inconsistent across different sites. Here, we used the time-integrative capacity of stable isotope analysis to test whether the trophic niches of sympatric Mozambican Nothobranchius are more distinct over a long-term period. Analysis of carbon and nitrogen stable isotopes separated the trophic niche and trophic position of N. pienaari but failed to find any difference between N. furzeri/N. kadleci and N. orthonotus. No segregation was found at the sites with low prey diversity. In contrast, SCA identified N. orthonotus as the species with the most distinct trophic niche. We discuss the effect of prey diversity and different sensitivities of stomach content and stable isotope analysis in general and conclude that the trophic niches of the three sympatric Nothobranchius species are well separated.
KeywordsNothobranchius Coexistence Niche separation Sympatric Extreme environment Africa
Funding came from the Czech Science Foundation, Project P505/11/P646 to M. P. The authors would like to thank three anonymous referees whose comments greatly improved the paper.
- Allan, D. G., M. T. Seaman & M. Kaletja, 1995. Endorheic pans of South Africa. In Cowan, G. I. (ed.), Wetlands of South Africa. Department of Environmental Affairs and Tourism, Pretoria: 75–101.Google Scholar
- Anderson, M. J., 2001. A new method for non-parametric multivariate analysis of variance. Austral Ecology 26: 32–46.Google Scholar
- Anderson, M. J., R. N. Gorley & K. R. Clarke, 2004. Permanova+ for Primer: Guide to Software and Statistical Methods. PRIMER-R, Plymouth, UK.Google Scholar
- Curry-Lindahl, K., 1956. On the ecology, feeding behaviour and territoriality of the African lungfish, Protopterus aethiopicus Heckel. Arkiv für Zoologi 9: 479–497.Google Scholar
- Davis, A. M., M. L. Blanchette, B. J. Pusey, T. D. Jardine & R. G. Pearson, 2012. Gut content and stable isotope analyses provide complementary understanding of ontogenetic dietary shifts and trophic relationships among fishes in a tropical river. Freshwater Biology 57: 2156–2172.CrossRefGoogle Scholar
- Dorn, A., E. Ng’oma, K. Janko, K. Reichwald, M. Polačik, M. Platzer, A. Cellerino & M. Reichard, 2011. Phylogeny, genetic variability and colour polymorphism of an emerging animal model: the short-lived annual Nothobranchius fishes from southern Mozambique. Molecular Phylogenetics and Evolution 61: 739–749.PubMedCrossRefGoogle Scholar
- Reichard, M., 2010. Nothobranchius kadleci (Cyprinodontiformes: Nothobranchiidae), a new species of annual killifish from central Mozambique. Zootaxa 2332: 49–60.Google Scholar
- Watters, B. R., 2009. The ecology and distribution of Nothobranchius fishes. Journal of the American Killifish Association 42: 37–76.Google Scholar
- Wildekamp, R. H., 2004. A World of Killies: Atlas of the Oviparous Cyprinodontiform Fishes of the World. American Killifish Association, Elyria.Google Scholar