Demospongiae of ANT XXIV / 2 (SYSTCO I) Expedition — Antarctic Eastern Weddell Sea Author Göcke, Christian Author Janussen, Dorte text Zootaxa 2013 3692 1 28 101 journal article 10.11646/zootaxa.3692.1.5 ddffc7b3-2654-49ec-b046-f32bc78af2d6 1175-5326 249019 136660B8-7DCC-490E-AB79-46546CC18E40 Pseudosuberites hyalinus (Ridley & Dendy, 1886) (compare Fig. 5 B) Pseudosuberites hyalinus (Ridley & Dendy, 1886) : Topsent 1896: 127, 1900: 170. Kirkpatrick 1908: 21, pl. 26, fig. 7. Hentschel 1914: 52–53. Burton, 1930: 674. Van Soest 2002d: 238–239, fig. 9. Synonymy: Hymeniacidon ? hyalina Ridley and Dendy 1887: 168, pl. 45 fig. 6; Material. 1 specimen from station 048-1 (SMF 11769), 602.1 m , 70° 23.94' S , 8° 19.14' W , 12.01.2008 , growing on the holotype of Cornulum antarcticum sp. nov (SMF 11770). Material examined for comparison: BMNH 1908.2.5.121c, National Antarctic Expedition HMS “Discovery”, stn. 10 hole, 130 fms, described in Kirkpatrick (1908), slide; BMNH 1910.1.1.750, Canon Norman’s Collection of British Sponges, stn. 32, wet specimen; BMNH 1926.10.26.63, Terra Nova Collection 1910–1913 , Antarctic , stn. 3, dry specimen; BMNH 1949.10.19.54, “Manihine” Collections, English Channel 1949, stn. 66, 30 fms., 21.08.1949 , 10th Cruise, Identification no. M’hine 105f, slide; BMNH 1982.9.6.38a, stn. 13, Vaagegrund, North of Litla Sotra, 60° 24’ 24” N , 5°7’ 6” E , 120 to 80 m , Norwegian Collection, Bergen, det. van Soest, Tendal, de Weerdt and Stone, spirit and slide specimens. Description. A small sponge growing on the holotype of Cornulum antarcticum sp. nov. (see below), thickly encrusting with a distinct central apex. Elongate rounded, wrapped around the tube-shaped substrate. Spicules tylostyles of a considerable size variation, about 250 to 950 µm in length and about 15 to 30 µm in diameter. Remarks. This species shows an extremely wide, almost global distribution (van Soest 2002d). This is probably due to the wide variance in characters and the relatively ambiguous species description by Ridley and Dendy (1886; 1887). The variance of characters in Antarctic specimens was furthermore extended by Kirkpatrick (1908) and later by Hentschel (1914), who described his specimens as a subspecies Pseudosuberites hyalinus var. compactus Hentschel, 1914 . According to van Soest (2002d), not all records of the species are undoubtedly valid. Most likely, P. hyalinus , as it is currently defined, is a polymorphic construct, comprising several cryptic species. Thus, a detailed revision of the species is needed, including molecular analysis, comparing specimens from all known populations. Until this is done, sponges with characters like in our specimen can rightfully be considered as P. hyalinus . Furthermore, since the type was sampled off SW Patagonia (Ridley & Dendy 1887) it seems likely that a distinct relation exists between Antarctic specimens and the holotype . Unfortunately, apart from the holotype , no further specimens have been found at the type locality (van Soest 2002d).