Dynamics in gut microbiota diversity, composition, and assembly reveal the adaptability of invasive snail Pomacea canaliculata during hibernation in rice fields

Abstract

The gut microbiota plays a crucial role in host immunity and metabolism and may facilitate the adaptation of invasive species to new environments. During hibernation, gut microbial communities undergo compositional shifts to help hosts cope with low temperatures and food scarcity. However, the dynamics of gut microbiota during hibernation in invasive animals remain poorly understood. Here, we conducted an in situ hibernation experiment on the invasive freshwater snail Pomacea canaliculata to investigate changes in its gut microbiota over the course of hibernation. Gut samples were collected at pre-hibernation (day 0) and on the 15th, 30th, 60th, 90th, and 120th days of hibernation, followed by 16S rRNA gene sequencing. Results showed that the survival rate of snails reached 85.7% after 120 days. The Shannon diversity index of gut microbiota increased with the duration of hibernation. Although species richness remained relatively stable, increased evenness led to higher alpha diversity. After 60 days of hibernation, the structure of gut microbial community changed. The dominant phylum shifted from Firmicutes to Bacteroidota (formerly Bacteroidetes) as hibernation progressed. Short chain fatty acids (SCFAs) producing genera such as Acetobacteroides, Bacteroides, Macellibacteroides, and Cetobacterium increased in abundance during hibernation, likely providing an energy source for both the gut and host. Gut microbiota changes appeared to be driven largely by stochastic assembly processes. Additionally, anaerobic bacteria and potential pathogens increased in abundance during hibernation. These adaptive shifts in gut microbiota may help maintain host metabolic and immune functions during hibernation and potentially contribute to the invasiveness of P. canaliculata.

Keywords: Pomacea canaliculata; community assembly; gut microbiota; hibernation; invasive alien species.

Figure 1

(a) Schematic diagram of P. canaliculata snails in situ hibernation experiment. (b) Survival rate of the snails during hibernation. (c) Soil temperature (right) and water content (left) during hibernation.

Figure 2

Alpha diversity indices (a–f) of gut microbiota in P. canaliculata snails during 0–120 days of hibernation.

Figure 3

(a,b) Gut bacterial community composition of P. canaliculata snails during hibernation. (c) Key phyla of microorganisms in the snails gut during hibernation. (d) Key genera of microorganisms.

Figure 4

Gut microbial community structure (a–f) of P. canaliculata snails during hibernation. NMDS: Non-metric multidimensional scaling.

Figure 5

(a) Petal diagrams of OTU levels in gut microbes of P. canaliculata snails during hibernation. (b,c) LEfSe analysis of the snail gut microbes during hibernation (|LDA| > 4, p < 0.05). c, class; g, genus; f, family; o, order; p, phylum.

Figure 6

Ecological processes (a–f) of gut bacterial community assembly in P. canaliculata snails during hibernation. (g) Dispersal limitation. (h) Drift (and others). HoS, Homogeneous selection; HeS, Heterogeneous selection; HD, Homogenizing dispersal; DL, Dispersal limitation; DR, Drift (and others). *Represents significant difference in ecological process between post-hibernation and pre-hibernation. One-side significance based on bootstrapping test was expressed as *p < 0.1, **p < 0.05, ***p < 0.01.

Figure 7

Phenotypic properties (a–f) of P. canaliculata gut microbes during hibernation predicted by BugBase. Y-axis represents the relative abundance of different phenotypic bacteria.

Figure 8

Schematic diagram revealing changes in gut microbiota of P. canaliculata snails during hibernation based on the obtained results. DL, Dispersal limitation; DR, Drift (and others). “↗” and “↘” represent positive and negative correlation with time, respectively. “↑” and “↓” represent increases and decreases, respectively.