Abstract
Lagoon environments are particularly subject to the introduction, either accidental or voluntary, of alien species that may cause biological pollution. On the basis of morphological data and molecular analyses (rbcL and mitochondrial cox2-cox3 spacer sequences) we confirmed the taxonomic identity (previously only hypothesised) of Grateloupia turuturu in both the Lagoon of Venice and the Mar Piccolo basin of Taranto, where it was most probably introduced by shellfish transfers. A detailed morphological description of vegetative and reproductive thalli is given, focusing particularly on the encrusting bases. The bases act as resting structures that are able to survive during unfavourable environmental conditions. In both the Lagoon of Venice and the Mar Piccolo of Taranto, G. turuturu does not yet exhibit invasive behaviour.
©2011 by Walter de Gruyter Berlin New York
