Comparative analysis of diet in syntopic geophilomorph species (Chilopoda, Geophilomorpha) using a DNA-based approach

Abstract

Trophic niche partitioning between potentially competing species within the same coenosis has been little explored for most of the major groups of arthropod soil predators, among which are the geophilomorph centipedes. We performed a comparative study in nature on the diet of three species of Geophilomorpha living in the same site in Southern Europe. Through PCR-based molecular gut content analysis, we estimated trophic niche width and overlap with respect to three common prey groups: lumbricids, collembolans and dipteran larvae. Results show that apparently similar geophilomorph species differ significantly in prey spectrum, with quite different niche widths. Estimates of predator diet overlap gave moderate values, non-significantly different from null expectations. Within-species diet composition does not vary significantly with sex. This work, while providing the first evidence of trophic niche partitioning among coexisting geophilomorph species, contributes to recent progresses in the understanding of intra-guild interactions between predators in the soil food webs.