An overview of the Mediterranean cave-dwelling horny sponges (Porifera, Demospongiae) Author Manconi, Renata Author Cadeddu, Barbara Author Ledda, Fabio Author Pronzato, Roberto text ZooKeys 2013 281 1 68 http://dx.doi.org/10.3897/zookeys.281.4171 journal article http://dx.doi.org/10.3897/zookeys.281.4171 1313-2970-281-1 Spongia officinalis Linnaeus, 1759 Fig. 28 Spongia officinalis Linnaeus, 1759: 1348 (partim). Description. Growth form massive-lobate, surface finely conulose, single oscules scattered or at the apex of lobes, pre-oscular cavities well evident. Colour in vivo from light grey to black. Ectosomal skeleton as apices of primary fibres joining secondary fibres to form the conical reticulum which supports the conules. Choanosomal skeleton: network dense with irregular polygonal meshes of secondaries joining to form ascending primaries. Primary fibres (50-100 µm in diameter) typically twisted with ornamentations as parallel ridges along the main fibre axis mainly developed and evident towards the surface, cored with sand grains and spicules. Secondaries (20-35 µm in diameter) with ornamentations as parallel ridges along the main fibre axis, twisted and characterised by concentric layers of compact spongin surrounding the compact axial core without inclusions. Habitat. Cave, coralligenous community, rocky/detritic/muddy/sandy bottom, lagoon, coralligenous community, Posidonia oceanica meadow. Bathymetric range 1-70 m. Mediterranean caves. Meda Petita, Petita de la Vaca caves (Balearic Sea); Falco*, Bisbe* caves (Sardinian Sea); Endoume, Figuiers, Tremies , Niolon, Bagaud caves (Gulf of Lions); Bergeggi, Eastern-Bonassola, Zoagli-Chiavari caves (Ligurian Sea); Azzurra, Isolotto, Mago, Misteri, Tuffo Tuffo caves (Central Tyrrhenian Sea); Taccio Vecchio 1 Cave-Lampedusa*, Cani Islands Tunnel (Sicily Channel); Leuca caves (Ionian Sea); Croatian, Vrbnik-Krk caves (Northern Adriatic Sea); Pagliai, Regina caves (Southern Adriatic Sea) ( Laborel and Vacelet 1958 ; Sara 1959 , 1964a ; Vacelet 1959 ; Labate 1965 ; Ruetzler 1966 ; Pouliquen 1972 ; Pulitzer-Finali and Pronzato 1976 , 1980 ; Cinelli et al. 1977 ; Pansini et al. 1977 ; Pulitzer-Finali 1977 ; Bibiloni et al. 1984a , b ; Bianchi et al. 1986 ; Arko-Pjevac et al. 2001 ; Ben Mustapha et al. 2002 ; Harmelin et al. 2003 ; Manconi et al. 2011 ; Pronzato and Manconi 2011 ; Bakran-Petricioli et al. 2012 ; Cadeddu 2012 ). Figure 28 Spongia officinalis . a massive large living specimen (ca. 25 cm) showing a finely conulose surface with scattered small oscula b close up of the conulose surface covered by a thin uncellularized collagenous layer (SEM) c magnifications of an inhalant cribrose basal area (SEM) d conules at the spongin skeleton surface (SEM) e twisted surface of secondary fibres (SEM). b, c modified from Pronzato et al. (1998) d, e modified from Pronzato & Manconi (2008) b, d scale bars in mm.