New records of one cryptogenic and two questionable alien species of polychaetes (Annelida) in Italian waters

We report new records for three potentially non-indigenous polychaetes in Italian waters. The Nereididae Leonnates aylaoberi & Ccedil;inar & Da & gbreve;li, 2013 is reported for the first time in the Tyrrhenian, Ionian and Adriatic Sea; this species has type locality in the Mediterranean Sea, but the genus Leonnates has Indo-Pacific affinity, and its distinctive characters suggest that it is a recent newcomer to this area. We here suggest that L. aylaoberi should be considered cryptogenic in the Mediterranean Sea. Moreover, we report the first records of Paucibranchia cf. adenensis Gravier, 1900 for the Italian coastline, in the Ionian and Tyrrhenian Sea, and the first records of Isolda cf. pulchella M & uuml;ller, 1858 in the Tyrrhenian Sea. The meaning of the differences identified between the Mediterranean material and the available descriptions of these species is briefly discussed. Juvenile individuals of L. aylaoberi and P. cf. adenensis are also described for the first time.