Spongia lamella (Schulze, 1879) Fig. 26

Euspongia officinalis lamella Schulze, 1879a: 617.

Description.

Growth form vase- or fan-shaped, large (up to over 1 m). Surface finely conulose, inhalant and exhalant openings of the aquiferous system on the outer and inner sides, respectively, of the vase, or on the opposite sides of the fan. Wall 5-10 mm thick. Inhalant apertures large and irregular. Oscules small with a diameter ca. 1.5 mm and grouped in clubs regularly scattered. Colour in vivo from grey to brown. Surface conulose . Ectosomal skeleton covered by a dermal membrane rich of sand, as a network of secondary fibres (15-20 µm in diameter) connected to the apices of primaries. Choanosomal skeleton as an irregular network of secondaries (20-40 µm in diameter) with evident tracts of primary fibres (50-80 µm in diameter) extended between inner and outer surfaces. Primary fibres cored by mineral inclusions.

Habitat.

Cave, rocky/muddy/detritic bottom. Bathymetric range from shallow water to 22-300 m.

Mediterranean caves.

Galatea*, Falco*, Bisbe* caves (Sardinian Sea); Trèmies Cave (Gulf of Lions); Bergeggi Cave (Ligurian Sea) (Pouliquen 1972; Bianchi and Morri 1994; Manconi et al. 2011; Pronzato and Manconi 2011; Cadeddu 2012).