Niche Differentiation of Three Terrestrial Isopod Species Based on DNA Metabarcoding

Abstract

Species coexistence is a hot topic in ecology, with niche differentiation playing a key role in reducing interspecific competition. This study investigates the dietary habits and niche differentiation of three terrestrial isopod species ( Armadillidium vulgare , Sphaeroma raffaelei , and Trachelipus semiproiectus ) using DNA metabarcoding technology. By analyzing plant food composition, we identified significant differences in dietary preferences and niche widths among the species, with niche width (B) values of 13.3987 for T. semiproiectus , 10.0396 for S. raffaelei , and 6.0363 for A. vulgare . Trachelipus semiproiectus exhibited the broadest trophic niche, consuming a diverse range of plant taxa, including Bryopsida and Polypodiopsida, while A. vulgare and S. raffaelei showed more specialized diets dominated by Sapindales and Rosales, respectively. Dietary overlap indices ( O jk ) revealed moderate overlap between T. semiproiectus and A. vulgare (0.48) and S. raffaelei (0.39), whereas A. vulgare and S. raffaelei showed the lowest overlap (0.29). The results highlight the importance of dietary specialization and resource partitioning in facilitating species coexistence. This study provides new insights into the feeding ecology of terrestrial isopods and contributes to understanding soil invertebrate community dynamics, offering a foundation for biodiversity conservation and ecosystem management.