Community assembly in Lake Tanganyika cichlid fish: Quantifying the contributions of both niche-based and neutral processes

Thijs Janzen*, Adriana Alzate Vallejo, Moritz Muschick, Martine E Maan, Fons van der Plas, Rampal S Etienne

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

7 Citaten (Scopus)
289 Downloads (Pure)


The cichlid family features some of the most spectacular examples of adaptive radiation. Evolutionary studies have highlighted the importance of both trophic adaptation and sexual selection in cichlid speciation. However, it is poorly understood what processes drive the composition and diversity of local cichlid species assemblages on relatively short, ecological timescales. Here, we investigate the relative importance of niche-based and neutral processes in determining the composition and diversity of cichlid communities inhabiting various environmental conditions in the littoral zone of Lake Tanganyika, Zambia. We collected data on cichlid abundance, morphometrics, and local environments. We analyzed relationships between mean trait values, community composition, and environmental variation, and used a recently developed modeling technique (STEPCAM) to estimate the contributions of niche-based and neutral processes to community assembly. Contrary to our expectations, our results show that stochastic processes, and not niche-based processes, were responsible for the majority of cichlid community assembly. We also found that the relative importance of niche-based and neutral processes was constant across environments. However, we found significant relationships between environmental variation, community trait means, and community composition. These relationships were caused by niche-based processes, as they disappeared in simulated, purely neutrally assembled communities. Importantly, these results can potentially reconcile seemingly contrasting findings in the literature about the importance of either niche-based or neutral-based processes in community assembly, as we show that significant trait relationships can already be found in nearly (but not completely) neutrally assembled communities; that is, even a small deviation from neutrality can have major effects on community patterns.

Originele taal-2English
Pagina's (van-tot)1057-1067
Aantal pagina's11
TijdschriftEcology and Evolution
Nummer van het tijdschrift4
StatusPublished - feb-2017

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