Introduction of a New Potential Invader into the Mediterranean Sea: The Indo-Pacific Avrainvillea amadelpha (Montagne) A. Gepp & E.S. Gepp (Dichotomosiphonaceae, Ulvophyceae)

The Indo-Pacific species Avrainvillea amadelpha (Montagne) A. Gepp & E.S. Gepp is reported for the first time from the Mediterranean Sea (Kerkennah Islands, Tunisia). The species is considered as introduced and invasive in the Hawaiian Archipelago. The Mediterranean specimens are studied and the reproductive structures are described and illustrated here for the first time. The possible origins and vectors of this introduction and the risk of propagation of the species in the Mediterranean Sea are discussed.