1 Meiofauna Marina, Vol. 17, pp. 1-34, 16 tabs., March 2009 © 2009 by Verlag Dr. Friedrich Pfeil, München, Germany – ISSN 1611-7557 Meiofauna of the Koster-area, results from a workshop at the Sven Lovén Centre for Marine Sciences (Tjärnö, Sweden) W. R. Willems 1, 2, *, M. Curini-Galletti3, T. J. Ferrero 4, D. Fontaneto 5, I. Heiner 6, R. Huys 4, V. N. Ivanenko7, R. M. Kristensen6, T. Kånneby 1, M. O. MacNaughton6, P. Martínez Arbizu 8, M. A. Todaro 9, W. Sterrer 10 and U. Jondelius 1 Abstract During a two-week workshop held at the Sven Lovén Centre for Marine Sciences on Tjärnö, an island on the Swedish west-coast, meiofauna was studied in a large variety of habitats using a wide range of sampling tech- niques. Almost 100 samples coming from littoral beaches, rock pools and different types of sublittoral sand- and mudflats yielded a total of 430 species, a conservative estimate. The main focus was on acoels, proseriate and rhabdocoel flatworms, rotifers, nematodes, gastrotrichs, copepods and some smaller taxa, like nemertodermatids, gnathostomulids, cycliophorans, dorvilleid polychaetes, priapulids, kinorhynchs, tardigrades and some other flatworms. As this is a preliminary report, some species still have to be positively identified and/or described, as 157 species were new for the Swedish fauna and 27 are possibly new to science. Each taxon is discussed separately and accompanied by a detailed species list. Keywords: biodiversity, species list, biogeography, faunistics 1 Department of Invertebrate Zoology, Swedish Museum of Natural History, Box 50007, SE-104 05, Sweden; e-mail:
[email protected],
[email protected] 2 Research Group Biodiversity, Phylogeny and Population Studies, Centre for Environmental Sciences, Hasselt University, Campus Diepenbeek, Agoralaan, Building D, B-3590 Diepenbeek, Belgium; e-mail:
[email protected] 3 Department of Zoology and Evolutionary Genetics, University of Sassari, Via F.