The introduced seaweed Grateloupia turuturu (Rhodophyta, Halymeniales) in two Mediterranean transitional water systems

Abstract

Lagoon environments are particularly subject to the introduction,
\neither accidental or voluntary, of alien species that
\nmay cause biological pollution. On the basis of morphological
\ndata and molecular analyses (rbcL and mitochondrial
\ncox2-cox3 spacer sequences) we confirmed the taxonomic
\nidentity (previously only hypothesised) of Grateloupia turuturu
\nin both the Lagoon of Venice and the Mar Piccolo basin
\nof Taranto, where it was most probably introduced by shellfish
\ntransfers. A detailed morphological description of vegetative
\nand reproductive thalli is given, focusing particularly
\non the encrusting bases. The bases act as resting structures
\nthat are able to survive during unfavourable environmental
\nconditions. In both the Lagoon of Venice and the Mar Piccolo
\nof Taranto, G. turuturu does not yet exhibit invasive
\nbehaviour.