Estivation Strategies of Invasive Snail Pomacea canaliculata in Paddy Fields: Roles of Gut Microbiota and Digestive Gland Metabolism

ABSTRACT

The agricultural pest Pomacea canaliculata burrows into soil for estivation after the summer rice harvest, and reemerges to damage crops once late rice irrigation begins, posing a major challenge to crop management. Understanding its strategies during estivation is therefore essential for developing effective control measures. In this study, a 60‐day in situ experiment was conducted during the summer fallow period in a rice field to investigate the survival dynamics, gut microbiota, and metabolic adaptations of estivating snails, aiming to elucidate their oversummering strategies. Our results showed that P. canaliculata maintained a high survival rate of up to 92% after 60 days of estivation, even when the maximum soil temperature reached 43°C. Among the 42 medium‐ and long‐chain fatty acids detected in the digestive gland (liver), 39 remained stable, while docosatetraenoic acid increased and caprylic acid and docosapentaenoic acid decreased. During estivation, the gut microbiota underwent pronounced structural shifts, with increased richness, evenness, and diversity. The relative abundance of the dominant phylum Firmicutes declined sharply, whereas Bacteroidota increased, with community assembly driven mainly by stochastic processes. Short‐chain fatty acid (SCFA)‐producing genera, including anaerobes such as Paludibacter , Bacteroides , and Acetobacteroides , were enriched during estivation. The remodeled gut microbiota may help maintain fatty acid metabolic homeostasis in the digestive gland via the gut‐liver axis. Our findings reveal the adaptive responses of P. canaliculata to high‐temperature and drought stress during estivation and highlight the urgency of implementing control measures during the fallow period. Future work should explore agronomic strategies for suppressing P. canaliculata populations during this vulnerable stage.