Reproductive strategies, genetic diversity, and invasive ability in Lymnaeidae

Abstract

The family Lymnaeidae is a worldwide-distributed group that originated and diversified 200 Myr ago, which now inhabits freshwater areas from all continents (except for Antarctica) ranging from tropical and to arctic regions and from sea level to very high altitudes. Researchers have studied genetic diversity, life-history traits and reproductive strategies to better understand their ecological and evolutionary history, and how they are related to the current distribution of the family. Yet, compared to other zoological groups (e.g., insects, vertebrates), relatively few studies have been conducted on this group and they have focused mainly on a handful of species. In this chapter, we review the life-history traits associated with lymnaeid survival and invasion by focusing on evolutionary and ecological studies performed in this family. We also call upon studies performed in other animal groups, and sometimes in plants, in an attempt to understand lymnaeid ecological and evolutionary success. We review the morphological, behavioral and physiological traits involved in lymnaeid reproduction. We also discuss the factors that can affect lymnaeid mating systems, and how lymnaeids have expanded their geographical range by natural, as well as human-mediated ways. Finally, we explain why we believe that lymnaeids are suitable model organisms for studying mechanisms and processes involved in the ecology and evolution of mating systems and biological invasions. In the whole chapter, we draw heavily on results obtained in the most studied species––that is, the great pond snail Lymnaea stagnalis and the Galba genus, putting emphasis on the mating system (selfing vs. outcrossing).