Spongia nitens (Schmidt, 1862) Fig. 27

Ditela nitens Schmidt, 1862: 24, 1864.

Description.

Growth form irregularly lobate, rarely larger than 15-20 cm. Oscules (2 mm in diameter) on each lobe, with evident very long converging exhalant canals. Consistency soft and strong. Colour whitish to light brown. Conules small and regular . Primary fibres (40-60 µm in diameter) sometimes showing a fibrous opaque core, avoiding inclusion or with rare spicule fragments. Secondary fibres (20-35 µm in thickness) connecting primary ones in a regular network; a second superficial network is formed by thinner (4-10 µm) fibres. Skeleton extremely soft. The specific name refers to the silky sponge’s surface with an external membrane smooth and translucent.

Habitat.

Cave, coralligenous community. Bathymetric range 0-15 m.

Mediterranean caves.

Falco*, Bisbe* caves (Sardinian Sea); Endoume, Figuiers caves (Gulf of Lions); Leuca caves (Ionian Sea); Croatian caves (Northern Adriatic Sea); Farà, Agios Vasilios caves (Aegean Sea)( Sarà 1968; Pouliquen 1972; Pronzato and Manconi 2011; Bakran-Petricioli et al. 2012; Cadeddu 2012; Gerovasileiou and Voultsiadou 2012).