We acknowledge for partial funding support ASSEMBLE grant agreement no. 227799 for specimens sampled in Roscoff. Valentina Delogu skillfully sectioned the specimens used in this study. This research is part of the PhD thesis of Fabio Scarpa.
Received: 23 April 2015
Revised and accepted: 22 September 2015
Published online: 21 March 2016
Editor: R. Sluys