Scale dependent niche conservatism found in a lake fish community
Tingyue Yang1,2, Lan Zhu1,2, Dan Yu1, Chunling Wang1, Qinghua Cai1, Huanzhang Liu1*
1 The Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
2 University of Chinese Academy of Sciences, Beijing, China
*Correspondence: Huanzhang Liu, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China. E-mail: hzliu@ihb.ac.cn
AUTHORSHIP STATEMENT: HL conceived this study. HL and TY wrote the first draft of the manuscript with contributions from DY. TY carried out the experiment with the help of CW. TY, LZ and QC contributed to data analyses. All authors approved the manuscript for submission.
Abstract: Investigations to niche evolution have received controversial results in recent times, leading to some confusions in ecological studies: competitive exclusion principle (CEP) predicts that closely related species should be adequately divergent; while niche conservatism (NC) predicts that closely related species should be ecologically most similar. In the present study, by using stable isotope to signify trophic niche, we analyzed niche divergences of 57 fishes from a lake (Poyang Lake, central China) at the phylogenetic scale, as well as niche divergences and overlaps of 7 fishes (same subfamliy) at 5 sites of this lake, and comprehensively investigated the concepts of NC and competitive exclusion principle (CEP). The results showed that, NC exists on a large scale (trophic differences showing positive relationships with genetic distances), but not at the local scale (sister species showing larger differences than closely related species, and almost no trophic overlap), where the CEP works better. Besides, trophic convergence was also found between some very distantly related species, leading to the possible limited divergence. We believe these findings will contribute to future theoretical and empirical niche explorations.