New records of demosponges (Porifera) from the South Orkney Islands (Antarctica) with a checklist for the region Author Schejter, Laura Author Cristobo, Javier Author Ríos, Pilar text Zootaxa 2024 2024-01-23 5403 4 401 430 http://dx.doi.org/10.11646/zootaxa.5403.4.1 journal article 10.11646/zootaxa.5403.4.1 1175-5326 10562154 C2EAB19C-07CB-4013-9C93-D25259EA2673 Tedania (Tedaniopsis) oxeata Topsent, 1916 ( Figure 8g –j ) Restricted synonymy: Tedania oxeata Topsent, 1916 . Material examined: 2 specimens collected at station 4 ( SOI ; 60°55' S , 44°04'W ; 256 m ; 2/3/2014 ; MACN-In 44400; IEO-CSIC Col.) . Description: massive sponge, cavernous, soft, porous, beige in colour. Ectosome only evident in some parts of the specimens as a thin layer composed of a palisade of tornotes. Spicules are oxeas 480–720 µm by 20–35 µm, tornotes 480–550 µm by 10–20 µm and two categories of raphides 400–500 µm and 75–85 µm ( Figure 8 g-j). Remarks: This is an unusual Tedania species , having oxeas as the main megascleres, instead of styles. It has been recorded from several Antarctic regions (e.g. Koltun 1964 ; Burton 1929 , 1932 ; Desqueyroux 1975 ; Ríos 2006 ), but this finding represents the first record for the SOI.