Relationships Among Trophic Niche Width, Morphological Variation, and Genetic Diversity of Hemiculter leucisculus in China

Wenjing Li,Wenxuan Cao,Huanzhang Liu,Xin Gao,Chunling Wang,Dongdong Zhai

doi:10.3389/fevo.2021.691218

Abstract

According to the niche variation hypothesis (NVH), the populations with wider niches are phenotypically more variable than those with narrow niches. Giller expanded the NVH, suggesting that the niche width, morphological variation, and genetic diversity are all positively correlated. However, the hypothesis has been a subject of debate and discussion. In the present study, the NVH was tested by analyzing the relationships among trophic niche width, morphological variation, and genetic diversity of Hemiculter leucisculus, a widespread cyprinid fish. The fish samples were collected from six sites across Haihe, the Yellow, and the Yangtze River basins in China. The relationships among trophic niche width, morphological variation, and genetic diversity were analyzed using Pearson correlation at the inter-population level. Our analysis indicated that trophic niche width is significantly positively correlated with morphological variation, which corroborates the NVH. Morphological variation was significantly correlated to genetic diversity. However, no relationship was observed between trophic niche width and genetic diversity. We inferred that the dietary niche of H. leucisculus might change due to the plastic response toward environmental changes rather than due to the genetic variation. We also suggest that the effects of environment and heredity on the niche of the freshwater fish should be quantified separately in further studies.

Highlights

Niche is an important concept in ecology that helps in understanding species interactions and community structures (Syväranta et al, 2013)
principal component analysis (PCA) produced five factors; only the first three principal components (PC) were used in this study because they accounted for nearly 80% of the total variance (Table 2)
The PC scores varied among the local populations (Table 3)

Summary

Introduction

Niche is an important concept in ecology that helps in understanding species interactions and community structures (Syväranta et al, 2013). Previous studies on the niche width have contributed toward understanding the causes of species diversity (Roughgarden, 1974; Giller, 1984; Maldonado et al, 2017) and the response of species to environmental variation (Bolnick et al, 2010; Clavel et al, 2011; Bison et al, 2015). Van Valen (1965) found that the bird populations on the islands had more morphological variance than those on the mainland and concluded that the birds on the islands evolved to different morphological traits to using more diverse resources and avoid competition (Snowberg et al, 2015). Niche width variation at the population level can mainly result from the increased variation at the between-individual level (Bolnick et al, 2007), which is accompanied by greater morphological variation (Snowberg et al, 2015)

Methods

Results

Conclusion