Spring marine vegetation on rocky substrata of Pantelleria Island (the Straits of Sicily, Italy)

Spring aspect of the benthic marine communities on rocky substrata from midlittoral to lower infralittoral zones of Pantelleria Island (the Straits of Sicily) is described. In the midlittoral zone the following three communities were found: that with Nemalion helminthoides; that with Polysiphonia elongata and that with Osmundea pelagiensis and Laurencia spp. In the infralittoral fringe the most widespread community is that with Cystoseira amentacea var. stricta. In the upper infralittoral zone the most widespread communities are that with Cystoseira sedoides, that with Cystoseira brachycarpa and that with Dictyotaceae and Stypocaulon scoparium; in the middle infralittoral zone the most widespread communities are that with Dictyopteris polypodioides and that with Dictyotaceae and Sphacelariaceae; in the lower infralittoral zone the community with Flabellia petiolata and Halimeda tuna dominates. As the present vegetation is considerably different from what has been described in the literature, some hypotheses on these changes are tentatively proposed.