Revealing potential mechanisms of native and non-native snail coexistence through fecal microbiomes and dietary compositions.

Abstract

Understanding how animals coexist within an ecosystem is essential for the conservation of biodiversity. In China, large populations of a non-native snail Rumina decollata (a highly invasive species reported by various other countries) coexist with two native snail species (Acusta ravida and Euphaedusa aculus). However, the potential mechanisms that facilitate this non-native and native snail coexistence remain uncertain. Here, we analyzed the fecal microbiomes and dietary compositions of R. decollata, A. ravida, and E. aculus to elucidate the mechanisms that drive the cohabitation of non-native and native species in Nanjing, China. It was found that the composition of the E. aculus fecal microbiome was similar to that of R. decollata, while it was significantly different from that of A. ravida. Furthermore, R. decollata preyed on E. aculus and had similar plant food compositions like A. ravida. These results indicated that the fecal microbiomes of snails may be adaptable to variable environmental conditions, while being minimally influenced by host genetics. R. decollata integrated a portion of the fecal microbes of E. aculus by preying on them. Our findings highlighted that the coexistence of R. decollata with native snails may have been due to abundant environmental resources, which negated the emergence of strong competition. However, the specific dietary changes of R. decollata and their propagation still need to be continuously monitored to better understand the long-term effects of R. decollata on ecosystems. This research provides a new understanding toward the prevention of invasive species and biodiversity conservation.