Ircinia oros (Schmidt, 1864) Fig. 16

Hircinia oros Schmidt, 1864: 29.

Description.

Growth form massive, lobate, with large size (20-30 cm in diameter and 10-15 in height). Each lobe usually bears a large oscule (30-60 mm in diameter), sometimes at the end of a short funnel (1 cm high). Colour medium to dark grey in vivo. Surface covered by a slim layer of very fine and regular mineral sediment engulfed in a slender regular network showing a lighter colour. Conules (1-2 mm in height) regularly distributed, 24 mm apart. Choanosomal skeleton rust coloured and rich in fibres and filaments. Skeleton network of cored primary fibres (200-250 µm in diameter) and free (or almost free) secondary fibres (100-200 µm). Filaments (9-13 µm) with an oval knob (15-22 µm).

Habitat .

Cave, detritic and rocky bottom, coralligenous community. Specimens of this species are frequently covered by large specimens of Haliclona (Reniera) cratera (Schmidt 1862). Bathymetric range 1-150 m.

Mediterranean caves.

Blava, La Catedral, J1, Blue, Misidacis caves (Balearic Sea); Galatea*, Falco*, Bisbe* caves (Sardinian Sea); Endoume, Figuiers caves (Gulf of Lions); Western-Zoagli Cave (Ligurian Sea); Lacco Ameno, Tuffo Tuffo caves (Central Tyrrhenian Sea); Monastir, Salakta caves (Sicily Channel); Mazzere* Cave (Ionian Sea); Croatian caves (Northern Adriatic Sea); Trypia Spilia, Ftelio, Farà, Madhes, Alikes caves (Aegean Sea) ( Sarà 1960a, 1964a; Rützler 1966; Pouliquen 1972; Bibiloni et al. 1989; Ben Mustapha et al. 2003; Martì et al. 2004; Turon et al. 2009; Pronzato and Manconi 2011; Bakran-Petricioli et al. 2012; Cadeddu 2012; Gerovasileiou and Voultsiadou 2012).