Cliona burtoni Topsent 1932

Boring sponge in alpha growth form, occupying a surface of 1 cm2 in a section of conglomerate. Colour beige in dry state. Skeleton. Not observed. Spicules. Macroscleres: tylostyles to subtylostyles straight or slightly curved, 132 (225) 287 × 5 (6) 7.5 μm. Heads with a rounded or oval tyle, sometimes in terminal position but more often shifted along the shaft (Figs 4A, B, C). Microscleres: spirasters of various shape and thickness, straight or curved, 10 (26.5) 45 × 1.25 (10) 17.5 μm. The most abundant have scattered conical spines (Figs 4D, E, F, G, H, I, J, K) and numerous are amphiaster-like (Figs 4H, I, K). The smaller ones are microspinated (Fig. 4J, L).

This is a Mediterranean endemic species (Pansini and Longo 2008) originally described from Corsica (Strait of Bonifacio), where it is known to bore into calcareous rocks and mollusc shells (Topsent 1932). This is a new record for the Ligurian Sea (Gallinara Island) and the coralligenous assemblage and the first finding after the original description.