BertolinoMarcoCerranoCarloBavestrelloGiorgioCarellaMircoPansiniMaurizioCalcinaiBarbaraDiversity of Porifera in the Mediterranean coralligenous accretions, with description of a new speciesZookeys2792013201333613710.3897/zookeys.336.5139 Clathria (Microciona) armata http://species-id.net/wiki/Clathria_armata (Bowerbank, 1862)Figs 6A–FMicrociona armata Bowerbank, 1862; 1866: 129.Material examined.

Specimen IG-F-BL4-sp2-fot.; alcohol preserved, Gallinara Island (station 2, Falconara) 44°01'22"N, 8°13'34"E, depth 35 m, collected 31-7-2009.

Description. Thickly encrusting sponge (3-5 mm thick) covering a surface of 1.5 cm2 on a coralligenous block (Fig. 6A). Surface irregular, smooth. Consistency soft. The red-orange colour of the living specimen slightly fades when alcohol preserved.

Clathria (Microciona) armata. A Specimen on the surface of the coralligenous block B Large acanthostyle heads C Small acanthostyle D Subtylostyle with spined head E Palmate isochelae F Toxas of variable size, with smooth extremities.

Skeleton. Not observed.

Spicules. Macroscleres: acanthostyles in two size categories: I) large acanthostyles slightly curved, with obtuse spines concentrated on the head (Fig. 6B), 220 (484.5) 830 × 3.75 (8.5) 12 μm; II) small acanthostyles, with scattered spines, but more concentrated on the head (Fig. 6C), 100 (110) 122.5 × 3.75 (5) 6 μm; subtylostyles straight, often with slightly spined head (Fig. 6D), 440 (503.7) 550 × 2.5 (2.9) 3.8 μm. Microscleres: palmate isochelae (Fig. 6E), 10 (12.5) 13.5 μm long. Toxas of variable size, with more or less wide central curvature and slightly reflexed smooth points (Fig. 6F), 80 (114.5) 210 μm long.

Distribution and discussion.

This species has been recorded on rocky walls and on mollusc shells from 10 to 180 m depth (Bowerbank 1866, Arndt 1934, Pulitzer-Finali 1983, van Soest and Stone 1986). It is widely distributed in the Mediterranean Sea (Northern Adriatic Sea, Alboran Sea and Ionian Sea (Pansini and Longo 2003, 2008) and along the Atlantic coast of Europe: Arctic, Sweden, Ireland, United Kingdom, France (van Soest et al. 2013).

This specimen, like that described by van Soest and Stone (1986), differs from the type material in the toxa dimensions. Actually Bowerbank measured small toxas 50 µm long and large toxas 130 µm long dividing them in two size categories. Van Soest and Stone (1986) confirm the large variability of spicule size. The species is a new finding for the coralligenous community and the Ligurian Sea.

BowerbankJS (1866) A Monograph of the British Spongiadae.Ray Society, London, 2(i-xx): 1388.Pulitzer-FinaliG (1983) A collection of Mediterranean Demospongiae (Porifera) with, in appendix, a list of the Demospongiae hitherto recorded from the Mediterranean Sea.Annali del Museo civico di storia naturale Giacomo Doria84: 445-621.Van SoestRWMStoneSM (1986) Antho brattegardi sp. n. (Porifera: Poecilosclerida), with remarks on and a key to the clathriids of Norwegian waters.Sarsia71(1): 41-48.PansiniMLongoC (2003) A review of the Mediterranean Sea sponge biogeography with, in appendix, a list of the demosponges hitherto recorded from this sea.Biogeographia, Marine biogeography of the Mediterranea Sea: patterns and dynamics of biodiversity24: 59-90.PansiniMLongoC (2008) Porifera. In: ReliniG (Ed) Checklist della flora e della fauna dei mari italiani.Ministero dell’Ambiente e tutela del territorio, Roma.Biologia Marina Mediterranea15(1): 42-66.Van SoestRWMBoury-EsnaultNHooperJNARützlerKVoogdNJ deGlasbyB Alvarez deHajduEPiseraABManconiRSchoenbergCJanussenDTabachnickKRKlautauMPictonBKellyMVaceletJ (2013) World Porifera Database. http://www.marinespecies.org/porifera