Completing the conservation puzzle of Pomacea scalaris: pieces that do not fully fit

Abstract

Three species of apple snails of the genus Pomacea have been transported from southern South America and introduced to other continents, where they have established in different types of freshwater habitats. Pomacea canaliculata and P. maculata spread rapidly and soon became important pests of rice and promoters of ecological changes in wetlands. The process began in 1980, when P. canaliculata was brought from Argentina to Taiwan for commercial aquaculture, and Pomacea scalaris was unintentionally introduced along with it; both apple snail species subsequently spread into various natural water bodies, becoming part of Taiwan’s freshwater ecosystems. Over time, P. canaliculata expanded its range far beyond Taiwan, invading many countries across East Asia, the Americas and Africa, and is currently listed among 100 of the world’s worst invasive species . In contrast, P. scalaris has shown a much more limited expansion, remaining restricted to localised areas in southern and central Taiwan. In the previous issue of Tentacle, our project to provide evidence on the conservation status of this apple snail was presented in the article “The apple snail Pomacea scalaris: a puzzle with many missing pieces” which is part of the doctoral theses of Rocío P. Amondarain and Valentina Asgrizze at the Universidad Nacional del Sur (Argentina). The overarching goals of these theses regarding P. scalaris are to determine its geographic distribution, model its ecological niche and predict its future potential distribution, thereby contributing to the assessment of its conservation status. In addition, they aim to assess its tolerance to environmental stressors and its ecological niche amplitude in comparison with P. canaliculata, in order better to understand their contrasting invasive capacities and vulnerabilities.