Assessing the intrinsic correlates of extinction risk in European freshwater gastropods

Invertebrate biodiversity, especially in the freshwater realm, is severely underrepresented in conservation research and action, leading to an underestimation of current global extinction rates. Species differ in the biological traits that make them susceptible to extinction, and estimating extinction risk for freshwater species can aid conservation measures under limited available knowledge. Identifying traits as predictors of extinction risk may serve as a profile for each group of organisms and contribute to predicting which species will be at higher risk of extinction in the foreseeable future. Here we focus on European freshwater gastropods, a severely understudied taxon of high conservation priority due to many threatened species and high rates of species extinction. Our analyses showed that multiple factors such as body size, shell shape, breadth of habitat types, and even the type of habitat contribute to vulnerability to extinction. Species with smaller body size and narrower habitat breadths are facing greater extinction risk. Shell shape and habitat type may also play a role in extinction risk. Our analysis provides insight into why some gastropod species are more susceptible to extinction than others. This information can guide conservation assessment and action and help identify potentially threatened species lacking sufficient data for evaluation.