1. Marine Biological Section, University of Copenhagen, Strandpromenaden 5, DK-3000, Helsingør, Denmark
2. Zoological Institute, Christian-Albrechts-University, Am botanischen Garten 1–9, G-24116 Kiel, Germany
3. Section for Biomolecular Science, University of Copenhagen, Ole Maaløes Vej 5, DK-2200, København N, Denmark