Concerns on research history overview, distribution patterns, and potentially neglected ecological consequences of the invasive apple snail (Pomacea sp.): A review

Invasive species pose a threat to global ecosystems and biodiversity, with the apple snail standing out as one kind of the worst invasive species due to its exclusive expansion. In order to draw a conceptual framework of its invasion pattern from an overview, we endeavor to conduct a bibliometric analysis and systematic review to explore the existing knowledge on research history and subjective categorization of Pomacea canaliculata and P. maculata, and to uncover emerging trends of distribution and possible neglected impact on food webs. The research history reveals that the first international research publication was documented in 1958. However, a substantial increase in international publications occurred only after 2000. The adoption and effective implementation of a universally agreed upon management strategy may greatly enhance the progress of research on apple snail invasion. Notably, co-word analysis revealed that the content of each thematic cluster has a shift from basic biology to the monitoring of occurrences and environmental adaptation. Currently, the global distribution of apple snails has expanded to 39 countries primarily as a result of anthropogenic translocation. All infested countries, with the exception of Israel and Singapore, are major paddy rice producers. The northernmost distribution limit is Tyumen in Russia, while the southernmost limit is the Buenos Aires Province in Argentina. Biological control has emerged as a prominent technology for the prevention of apple snail infestations, leading to the identification of 98 non-target enemy species as potential control agents. A taxonomic diversity analysis revealed that these species encompassed a wide range of phylogenetic classifications, including 6 Phyla, 12 Classes, 33 Orders, 55 Families, and 82 Genera. This observation suggests that there is a substantial pool of animals from diverse phylogenetic levels that can prey upon apple snails. Given the high population density and extensive distribution of apple snails, there is a pressing need for further research to explore their potential ecological ramifications. The current understanding of the upward ecological impacts of apple snails remains inadequate. These findings provide valuable insights for future research endeavors and contribute to the effective management of invasive apple snail populations.