The pseudoindigenous bryozoan Zoobotryon verticillatum along the Mediterranean and Atlantic European coasts.

The ctenostome bryozoan Zoobotryon verticillatum (Delle Chiaje, 1822) has recently been recognized as a non-indigenous species (NIS) in the Mediterranean Sea. Here the updated distribution of Z. verticillatum along the Mediterranean and European Atlantic coasts is presented. We discuss the potential role of this habitat-forming bryozoan in facilitating further introductions and spread of other NIS.