The "Minor Water Bodies" and Their Malacofauna: Are Freshwater Gastropod Communities Usable for Habitat Classification?

The typology of inland water bodies remains a topical issue in limnology. Numerous classifications of freshwater habitats have been proposed, but none of them has gained the universal acceptance. Current global changes and the increasing human impact on freshwater ecosystems make it important to understand the ecological relationships between freshwater animals and their environment. In this study, we tested a typology of the so-called "minor water bodies" proposed in the 1960s by the Polish ecologist Klimowicz. The term "minor water bodies" refers to a group of semi- or impermanent habitats that are prone to periodical or occasional desiccation. The division of habitat categories within this typology was based on qualitative features, and the validity of this classification has never been tested statistically. Here, we used the data on occurrences of 18 species of freshwater and semiaquatic gastropods observed in 86 minor water bodies of the Bolshoy Yugan River basin (Western Siberia, Russia) to test the hypothesis that each type of minor water body, in accordance with the aforementioned classification, maintains its own unique set of species. The statistical analysis confirmed the significant differences between the three habitat types on the basis of their gastropod communities, whereas one type (groundwater springs) appeared to be indistinguishable from the others. Our results show that freshwater gastropod communities are a suitable tool for habitat classification, and, at the same time, they highlight the need to apply statistical methods to a priori classifications based on the qualitative approach to the division of habitat types. [ABSTRACT FROM AUTHOR]