BertolinoMarcoCerranoCarloBavestrelloGiorgioCarellaMircoPansiniMaurizioCalcinaiBarbaraDiversity of Porifera in the Mediterranean coralligenous accretions, with description of a new speciesZookeys2792013201333613710.3897/zookeys.336.5139 Forcepia (Leptolabis) brunnea http://species-id.net/wiki/Forcepia_brunnea (Topsent, 1904)Figs 10A–FLeptolabis forcipula var. brunnea Topsent, 1904: 182.Leptolabis brunnea Topsent, 1928: 278.Material examined.

Specimen PdF-NE-BL2A-sp15-sciaf.; alcohol preserved, Portofino Promontory (Punta del Faro, station 4) 44°17'55.61"N, 9°13'07.95"E, 40 m depth, collected on 27-08-2009; specimen IG-S-BL3-sp13-sciaf.; alcohol preserved, Gallinara Island (station 3, Sciusciaù) 44°01'34"N, 8°13'45" E, depth 30 m, collected on 17-06-2009; specimen PdF-BL8-sp50-sciaf.; alcohol preserved, Portofino Promontory (Punta del Faro, station 4) 44°17'55.61"N, 9°13'07.95"E, 30 m depth, collected on 25-01-2013.

Description.

Thin, smallencrusting sponges (up to 0.5 cm2) on the surface of coralligenous blocks. Colour in life yellow-orange.

Skeleton. Basal acanthostyles erect on the substrate in a hymedesmioid arrangement. Other spicule types not detectable from the skeleton.

Spicules. Megascleres: anisotylotes straight or faintly curved, with slightly different extremities and a few malformations along the shaft (Fig. 10A), 127.5 (157.7) 280.5 × 1.25 (2.3) 2.5 μm; acanthostyles straight, conical with discrete but not swollen heads. Spines evenly distributed, slightly stouter on the spicule head (Fig. 10B), 61.2 (92.2) 142.8 × 5.2 (7.5) 10.4 μm. Microscleres: acanthose symmetric forceps with straight legs, ending in small, button-like swellings with toothed margin (Fig. 10C). They measure 12.5 (15.8) 17.5 × 2.5 μm in length, the distance between the legs being 5.2 (7.2) 7.5 μm. Acanthose asymmetric forceps, very thin, have unequal legs (Fig. 10D), the longer of which is straight or curved inward, 20.4 (22.3) 25 × 1.5 μm. Sigmas in two size categories: the larger ones, “C" shaped (Fig. 10E) or more rarely “S" shaped, 40.8 (64.3) 80 × 2.5 μm are very abundant, the smaller, 17.5–25.5 μm are rare. Palmate isochelae (Fig. 10F), 18 (20) 20.8 μm long.

Forcepia (Leptolabis) brunnea. A Anisotylotes B Acanthostyles C Symmetric forceps D Asymmetric forceps E Large and small sigmas F Isochelae.

Distribution and discussion.

Topsent (1904) describes three species of Leptolabis from the Azores: Leptolabis forcipula var. brunnea, Leptolabis arcuata and Leptolabis assimilis. The same author in 1928 states that the former three species actually belong to a single species: Leptolabis brunnea which showsa high variability in the large forceps shape.

Leptolabis brunnea was afterwards recorded from the Far-Oer Islands, the Azores, Spain (NW coast, Strait of Gibaltar, Castellón, Girona), France (Marseille, Monaco), Italy (Gulf of Naples), between 4 and 1360 m depth. It lives in caves, detritic bottoms, coralligenous concretions and epibiotic on other organisms (Topsent 1904, 1928, Sarà 1960, Pouliquen 1972, Carballo 1994, Cristobo 1996). This is the second finding for the Italian seas and a new finding for the Ligurian Sea.

TopsentE (1904) Spongiaires des Açores. Résultats des campagnes scientifiques accomplies par le Prince Albert I.Monaco25: 1-280.TopsentE (1928) Spongiaires de l’Atlantique et de la Méditerranée provenant des croisières du Prince Albert ler de Monaco. Résultats des campagnes scientifiques accomplies par le Prince Albert I.Monaco74: 1-376.SaràM (1960) Poriferi del litorale dell’isola d’Ischia e loro ripartizione per ambienti.Pubblicazioni della Stazione Zoologica di Napoli31: 421-472.PouliquenL (1972) Les spongiaires des grottes sous-marines de la région de Marseille: Ecologie et systématique.Téthys3(4): 717-758.CarballoJL (1994) Taxonomía, zoogeografía y autoecología delos Poríferos del Estrecho de Gibraltar.Universidad de Sevilla, PhD Thesis: 1331.CristoboFJ (1996) Esponjas del order Poecilosclerida (Porifera, Demospongiae) de la Ria del Ferrol (NW. de España).Universidade de Santiago de Compostela. PhD Thesis: 1571.