Consensus tree showing relationships between Onchidium individuals based on concatenated nuclear ITS2 and 28S sequences. Numbers by the nodes are the bootstrap values (Maximum Parsimony analysis); only significant numbers (> 50%) are indicated. All other sequences serve as outgroups. Information on specimens can be found in the lists of material examined and Table 1. The colors used for each Onchidium species are the same as those used in Figs 1, 3, and 4.