Dysidea incrustans (Schmidt, 1862) Fig. 10

Spongelia incrustans Schmidt, 1862: 29.

Description.

Growth form encrusting (3-8 mm thick). Consistency fragile. Colour light grey to pale violet. Surface reticulate, conulose showing the internal aquiferous system in transparency. Conules 1-3 mm high, 3-5 mm apart. Oscules (5-7 mm) scattered, with a transparent collar. Skeletal network irregular with meshes (200-600 µm in diameter) formed by ascending primary fibres (70-90 µm in diameter) cored of foreign material, and secondary fibres (5-30 µm in diameter) generally lacking inclusions.

Habitat.

Cave, rocky bottom, artificial reefs, Posidonia oceanica meadow, lagoon, also. Frequently as encrusting patches also on other sponges or epibiotic on Pinna nobilis . Bathymetric range 1-100 m.

Mediterranean Caves.

Galatea* Cave (Sardinian Sea); Lerici Cave (Ligurian Sea); Mago, Mitigliano caves (Central Tyrrhenian Sea); Taccio Vecchio 1 Cave-Lampedusa* (Sicily Channel); Gamberi*, Gymnasium* caves (Ionian Sea) (Pulitzer-Finali and Pronzato 1976, 1980; Pansini et al. 1977; Pulitzer-Finali 1977; Pansini and Pronzato 1982; Pronzato and Manconi 2011; Cadeddu 2012).