De Stompe grondwaterslak Avenionia roberti Boetters, 1967 in het Jekerdal met de begeleidende molluskenfauna

In 2015, for the first time after its discovery there in 1942, the groundwater snail Avenionia roberti Boetters, 1967 was re-claimed from the valley of the river Jeker, just south of Maastricht (province of Limburg, the Netherlands). In 2016 an analysis was made of the accompanying mollusc fauna which encompassed 21 species of land snails and 18 species of freshwater molluscs. At the site where Avenionia roberti was found fresh shells of other species may derive from a small marsh with chalk-rich seepage; old shells may be delivered by small sources from sediments in the underground. It was demonstrated that the lower situated sources provided fresh and living specimen of Avenionia roberti.