Zandsuppleties op Texel en de gevolgen voor de malacoloog

After finding, for the first time, a valve of the small bivalve, Tellina pygmaea, on the island Texel, the Netherlands, near the tide line I took one litre of shell grit for examination at home. The results are incorporated in a species list. It is not clear where this material comes from. Laban (1996) mentions that the supplementary sand comes from a depth of 20 m about 20 km off Texel. The presence of Paphia aurea senescens proves that in spite of the small difference in depth (the sand is taken down to a depth of 2 m [Eemien]). The shell grit contains recent and fossil species, both transported by the sand sucker. Although the number of species which can be found are increased there are local differences due the place where the sand sucker does its work.