Abstract
The shallow-water reef building polychaete Sabellaria alveolata is recorded from a new locality in the southeastern corner of Sicily, off Portopalo di Capo Passero. Here, a particular habitat is formed on upper infralittoral rocky bottoms beaten by waves, with S. alveolata developing as veneer-like bioconstructions interspersed/covered with a dense macroalgal community including alien Caulerpa taxa and dominated by Ericaria giacconei. First insights about the development of this particular habitat, as well as observations on possible relationships between Sabellaria and the associated algae, are presented.