Gracilariaceae (Rhodophyta) from the Gulf of Taranto (Italy).

According to recent check-lists for the Mediterranean marine algae, the family Gracilariaceae is represented in the Gulf of Taranto by six species: Gracilaria armata (C. Agardh) Greville, Gracilaria bursa-pastoris (S.G. Gmelin) P.C. Silva, Gracilaria dura (C. Agardh) J. Agardh, Gracilaria longa Gargiulo, De Masi et Tripodi, Gracilaria multipartita (Clemente) Harvey and Gracilariopsis longissima (S.G. Gmelin) Steentoft, L.M. Irvine et Farnham. However, species discrimination within Gracilariaceae is problematic, despite the great amount of studies on this group, because of the high morphological plasticity and the difficulty in observing fertile structures in the field. Modern researches on this family are based on nucleotide sequence analyses in accordance with more traditional features. Mediterranean reports wait for re-examination after these systematic revisions. Particularly, reports of Gracilariopsis longissima are frequently referred to vegetative populations of Gracilaria verrucosa (Hudson) Papenfuss nom. rej., hardly discriminated from morphologically similar taxa, and they result from mere nomenclature revisions rather than from actual verifications of specimens. Moreover, foliose specimens need to be accurately investigated, because various entities were reported in the past years but they were often considered as misidentifications by subsequent taxonomic re-examinations. Molecular markers might be a fast and accurate tool for species identification. Our project intends to verify the specific attribution of the Gracilariaceae currently reported for the Gulf of Taranto, using both nucleotide sequences of the plastid encoded rbcL gene and comparative reproductive structures analyses. We present data on some of these entities, excluding the presence of some ambiguous taxa and adding new taxa to previously listed.