A “living hotel” in the Taranto seas (NW Ionian Sea): preliminary data on associated macrofauna of the Mediterranean alien Paraleucilla magna (Porifera, Calcarea)

The present study investigated macrofauna associated with Paraleucilla magna, an alien and invasive calcareous sponge in the Mediterranean Sea, in a partially confined basin along the Apulian coast (Mar Grande of Taranto, NW Ionian Sea) comparing specimens sampled in Autumn and Spring. Richness and abundance of associated taxa were recorded, and values of frequency, density, diversity (H’) and evenness (J’) were calculated. On the whole, the phylum Arthropoda showed the highest values of species richness and abundance, in accordance with data referred to P. magna from Brazilian coasts. The phyla Cnidaria, Echinodermata and Mollusca were well represented as well. Surprisingly, no Polychaeta’s species were found, while the same taxon was the second most rich in the Brazilian specimens. Macrofauna associated with P. magna in the Mar Grande of Taranto showed a different taxa composition between Autumn and Spring. This result suggests the necessity for monthly, year-round sampling in order to better define how the macrofaunal assemblages change with changing environmental parameters.