Impact of mating strategies on life-history traits in the alien land snail Rumina decollata

Climate change and global transport are driving species introductions worldwide, leading to economic and ecological consequences. Hermaphroditic organisms are able to reproduce with any conspecific, and some can self-fertilize, enhancing their potential for population establishment despite low initial densities in colonization events. This study examines how mating strategies influence the life history traits of the alien land snail Rumina decollata by comparing individuals subjected to facultative cross-fertilization or enforced self-fertilization over two laboratory-reared generations. Key life history traits -including size and age at first reproduction, fecundity, hatching time, and juvenile survival-were measured, alongside individual growth and shell morphometry. Self-fertilizing individuals exhibited higher body weight at first clutch but lower fecundity and delayed reproduction compared to cross-fertilizers. Selfing offspring (F2) took longer to hatch and had lower survival rates, indicating significant inbreeding depression. Selfed snails of F1 grew faster than outcrossers, but experienced a decline in growth in F2, consistent with inbreeding depression. Conversely, shell shape remained similar between mating treatments. Although selfing imposed fitness costs, 32% of self-fertilizing individuals produced viable offspring, highlighting their ability to establish in new environments. This study improves our understanding of how R. decollata's reproductive strategies shape life history traits under environmental constraints.