Marine and Brackish Bryozoans from the Southern Bight of the North Sea

In 2009, Hans published a Dutch identification guide for marine and brackish water Bryozoans ("moss animals") of the Southern Bight of the North Sea, illustrated with drawings, scanning-electron and light microscope images. It is a reliable reference for professional bryozoologists and keen amateur naturalists studying northern European bryozoans. This virtually complete inventory of a group of animals that have been the object of very few studies so far, but that encompasses a surprisingly large variety of species. The sandy substrate that is predominant in this area is usually poor in moss animal species. The fact that such a large number of species are described in this work is the result of an in-depth study of recent observations (tidemark material, specimens collected on the hard substrate of breakwaters and port structures, shells and stones near sandbanks) and the review of historical collections. As many as 179 species were discussed in the Dutch book, the present English update treats 201 species, describing 9 species as new to science. The area bounded to the south by Cap Gris Nez (Northern France) covers the Belgian and Dutch coast and is now extended to the German North Sea coast. This update includes more native and non-indigenous species, new distribution data, new taxonomic insights, additional references, and additional or better illustrations. What is especially remarkable is that each species has been illustrated using both stereomicroscope showing natural coloration and colony shape, and scanning electron microscope showing small details of zooidal morphology. Thanks to the different identification keys in the book and a 20-30x magnifying glass, it is possible to recognize most of the moss animals in the study area. We hope that this work will contribute to a better understanding of this colony-forming, undervalued group of animals.