Gut microbiota is associated with host health and its environmental adaption, influenced by seasonal variation. Pomacea canaliculata is one of the world's 100 worst invasive alien species. Here, we used high‐throughput sequencing of the 16S rRNA gene to analyze the seasonal variation of gut microbiota of P. canaliculata. The results suggested that the predominant gut microbial phyla of P. canaliculata included Firmicutes and Proteobacteria, which helped digest plant food and accumulate energy. The gut microbiota of P. canaliculata in summer group showed the highest diversity, whereas the winter group possessed the lowest, probably due to the shortage of food resources of P. canaliculata in winter. Principal coordinate analysis analysis based on unweighted unifrac and weighted unifrac indicated that the composition of gut microbiota of P. canaliculata significantly varied across seasons. Bacteroidetes tended to be enriched in summer by linear discriminant analysis effect size analysis. Actinobacteria and Cyanobacteria were extremely abundant in autumn, while Fusobacteria and Cetobacterium enriched in winter. In conclusion, the structure of the gut microbiota of P. canaliculata was significantly different among seasons, which was beneficial to the environment adaptation and the digestion and metabolism of food during different periods.

The gut microbiome is vital to the physiological and biochemical functions of the host, and changes in the composition of these microbial communities may affect growth and adaptability to the environment. Pomacea canaliculata is an invasive freshwater snail which has become a serious agricultural pest. Temperature adaptation is considered an important reason for the widespread distribution of this species. To date, the contribution of the gut microbes to host fitness of P. canaliculata during long-term temperature stress is not well understood. In this study, the morphological changes and intestinal microbiome of P. canaliculata under long-term stress at low temperature (15°C) and high temperature (35°C) were investigated with laboratory experiments. Compared with control group (25°C), the alpha diversity increased and pathogenic bacteria enriched changed under high and low temperature stress. The effect of high temperature stress on the intestinal microbiome of P. canaliculata was more significant than that of low temperature stress. A sustained high temperature environment led to an increase in the abundance of pathogenic bacteria, such as Aeromonas and Enterobacter, and a decrease in the abundance of immune-related bacteria such as Bacteroidetes, Firmicutes, and Lactococcus. These intestine microbiome changes can increase the risk of diseases like intestinal inflammation, and lead to more deaths at high temperature environments. In addition, with the extension of stress time from 14 to 28 days, the beneficial bacteria such as Bacteroidetes, Firmicutes, and Lactococcus were significantly enriched, while potential pathogenic bacteria such as Pseudomonas, Acinetobacter, Shivalella, and Flavobacterium decreased, suggesting that intestinal microbiota may play an important role in host response to heat stress. These results are consistent with previously reported results that the survival rate of both male and female P. canaliculata no longer significantly reduced after 21 days of high temperature stress, suggesting that the surviving P. canaliculata had gradually adapted to high temperature environments under long-term high temperature stress.

The mitochondrial genome of Pomacea canaliculata (Gastropoda: Ampullariidae) is the first complete mtDNA sequence reported in the genus Pomacea. The total length of mtDNA is 15,707 bp, which containing 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a 359 bp non-coding region. The A + T content of the overall base composition of H-strand is 71.7% (T: 41%, C: 12.7%, A: 30.7%, G: 15.6%). ATP6, ATP8, CO1, CO2, ND1-3, ND5, ND6, ND4L and Cyt b genes begin with ATG as start codon, CO3 and ND4 begin with ATA. ATP8, CO2-3, ND4L, ND2-6 and Cyt b genes are terminated with TAA as stop codon, ATP6, ND1, and CO1 end with TAG. A long non-coding region is found and a 23 bp repeat unit repeat 11 times in this region.

Background: Tolerance of low temperature has a significant impact on survival and expansion of invasive snail Pomacea canalicuata. Cold acclimation can enhance cold tolerance of Pomacea canalicuata. To elucidate the molecular mechanism of P. canaliculata’s responses to cold acclimation and cold stress, a high-throughput transcriptome analysis of P. canaliculata was performed, and gene expression following artificial cold acclimation and then cold stress at 0 °C for 24 h was compared using RNA sequencing. Results: Using the Illumina platform, we obtained 151.59 G subreads. A total of 5,416 novel lncRNAs were identified, and 3166 differentially expressed mRNAs and 211 differentially expressed lncRNAs were screened with stringent thresholds. The potential antisense, cis and trans targets of lncRNAs were predicted. Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that many target genes were involved in proteasome, linoleic acid metabolism and retinol metabolism under cold acclimation. The lncRNA of P. canaliculata could participate in cold acclimation by regulating the expression of E3 ubiquitin protein ligase, 26S proteasome non-ATPase dependent regulation subunit, glutathione S-transferase, sodium/glucose cotransporter and cytochrome P450. Conclusions: These results broaden our understanding of cold acclimation and cold stress associated lncRNAs and mRNAs, and provide new insights into lncRNA mediated regulation of P. canaliculata cold acclimation and cold stress response.

We report the characterization of 16 polymorphic microsatellite markers in the golden apple snail, Pomacea canaliculata, a pest registered in the list of “100 of the world’s worst invasive alien species”. The fast isolation by AFLP (Amplified Fragment Length Polymorphism) of sequences containing repeats (FIASCO) method was used to isolate microsatellite loci, and polymorphism was explored with 29 individuals collected in an invasive region from China. These primers showed a number of alleles per locus ranging from three to 13. The ranges of observed and expected heterozygosity were 0.310–0.966 and 0.523–0.898, respectively. These microsatellite markers described here will be useful for population genetic studies of P. canaliculata.