Parasites in cockles and periwinkles

Large-scale distributions of marine parasites in coastal ecosystems such as the Wadden Sea can be studied best in hosts with a broad geographical distribution. As they widely occur along the European coast, common cockles (Cerastoderma edule) and periwinkles (Littorina spp.) are thus ideally suited to study distributional patterns of their parasite fauna. In addition, these host species harbour a rich diversity of parasites, allowing to study a broad range of parasite species.

To study general macroecological patterns in marine parasitism and the genetic population structures of parasites, we use literature-based data sets and field collections of cockles and periwinkles throughout Europe, including the Wadden Sea. In addition to unveiling distributional patterns, we try to identify the underlying drivers of parasite distributions and population structures. For example, the type of definitive host used by parasites with complex life cycles (such as the group of trematodes) has a strong effect on their distribution and genetic population structure. Parasite using highly vagile birds tend to have wider distributions and more homogenous population structure compared to parasites using fish.