Taxonomic composition of zoopsammon in fresh and brackish waters of Estonia, a Baltic province ecoregion of Europe

摘要

Zoopsammon communities, i.e. fauna dwelling in the interstitial sandy habitat at the water’s edge, are largely understudied. The aim of the present study was to provide an overview of the taxonomic structure of zoopsammon in Estonian waters. The study is based on samples collected from four lakes across Estonia and from three sandy beaches on the Estonian coast of the Gulf of Finland, Baltic Sea, in 2008–2014. Animals from 12 phyla were found, of which the majority of rotifers and testate amoebae were identified to species level. A total of 156 taxa were determined, including 84 rotifer species and 39 testate amoebae species. In addition to the 46 new taxa for the Estonian fauna already registered in our previous works, the present study reports further 11 new rotifer, 19 testate amoebae, and 6 nematode taxa. The psammic communities in lake beaches had higher species richness than in coastal beaches, and the communities were more similar in coastal beaches than in lake beaches. The mesotrophic Lake Saadj?rv had the highest taxon richness with 80 taxa from 10 phyla. Similarly, the number of testate amoebae species was higher in lake beaches than in coastal beaches. The number of taxa, especially the number of rotifer species, was lower in sampling sites with an elevated trophic state and/or human population density. The number of testate amoebae species was the highest in the hypertrophic Lake Verevi. As compared to testate amoebae, rotifer communities had a higher taxonomic richness at landscape scale characterized by variable communities both in time and space.