Abstract

A higher phenotypic plasticity has been reported for many invasive organisms when compared to native species, especially for those whose metabolism depends on environmental conditions. Climate change acts synergistically with biological invasions; therefore, it is important to study trade-offs between temperature and biological traits that could act in favour of invasive species. To study whether temperature can shift morphological changes, two species of tropical snails were used as a model: the native Pyrgophorus coronatus and the invasive Tarebia granifera. Individuals were bred until adulthood, at three different temperatures. The shells of each species were photographed, and 12 landmarks were digitalized using the software MorphoJ; the shape variations were analysed with canonical variate analysis. The results showed that the native species shows a high shell shape plasticity, especially at the lowest temperature, whereas the invasive species showed little shell shape variation. Therefore, high phenotypic plasticity is a trait not always attributable to invasive species. Given that the shell structure and shape of freshwater gastropods seems to have deep implications in thermoregulation, the lack of shell shape plasticity evidenced by some species seems to be related to a higher tolerance to temperature changes.