Seasonal dietary shifts in an invasive snail <i>Pomacea canaliculata</i> revealed by 18S rRNA metabarcoding

Abstract Pomacea canaliculata, an invasive species, has caused severe damage to ecosystems due to its omnivorous diet and strong invasive capabilities. However, information about how its diet changes across seasons is limited. In the present study, 18S rRNA metabarcoding was used to analyze the seasonal variation in diet of P. canaliculata from 3 habitats (pond, river, and ditch). The results indicated that the dietary diversity of P. canaliculata in the ditch significantly decreased in summer, while dietary richness diminished in winter, likely reflecting seasonal differences in temperature and the availability of edible resources. P. canaliculata exhibited a preference for Streptophyta during summer, Chlorophyta in river and ditch during autumn, and Arthropoda during winter. Additionally, P. canaliculata in the pond and ditch consumed more molluscs, which may negatively impact the density and diversity of native molluscs. Female and male P. canaliculata exhibited differences in dietary diversity in summer and autumn, which may be related to meeting reproductive demands and increasing cold hardiness, respectively. The flexible diet of P. canaliculata across different seasons and habitats enables its survival in a broader range of environments. This study reveals the feeding strategies of P. canaliculata in different seasons, helping us understand the adaptation mechanisms of invasive P. canaliculata to environmental alteration.