Iophon unicorne Topsent, 1907

Schejter, Laura, Cristobo, Javier & Ríos, Pilar, 2024, New records of demosponges (Porifera) from the South Orkney Islands (Antarctica) with a checklist for the region, Zootaxa 5403 (4), pp. 401-430 : 407

Iophon unicorne Topsent, 1907

( Fig. 2f–j )

Restricted synonymy: Iophon spatulatum Kirkpatrick, 1907 , Iophon spatulatus Kirkpatrick, 1907 ; Iophon unicornis Topsent, 1907 .

Material examined: eight specimens collected at stations 1 ( SOI; 60°28'S, 46°29'W; 139 m; 19/2/2014; MACNIn 44372; IEO-CSIC Col.), 2 ( SOI; 60°53'S, 44°33'W; 218 m; 20/2/2014; MACN-In 44373), 3 ( SOI; 61°31'S, 45°39'W; 308 m; 28/2/2014; MACN-In 44374; IEO-CSIC Col.), 4 ( SOI; 60°55'S, 44°04'W; 256 m; 2/3/2014; MACN-In 44375), 7 ( SOI; 61°00'S, 46°44'W; 609 m; 3/3/2014; IEO-CSIC Col.), 17 ( SOI; 60°42,260'S, 46°01,18'W; 86 m; 8/3/2012; MACN-In 44376; IEO-CSIC Col.) and 18 ( SOI; 60°47,561'S, 45°36,854'W; 96 m; 10/3/2012; MACN-In 44377; IEO-CSIC Col.) .

Description: Massive to slightly flabellate or digitiform specimens, sometimes with evident oscula, brown colour ( Figure 2f ). Spicules are oxeas of 400–630 µm by 20–30 µm; acanthotylotes of 270–350 µm/ 10 µm, usually mucronate at one end, rare anisochelae 17.5 µm and abundant bipocilli in many specimens, measuring 10–12.5 µm ( Figure 2g –j ).

Remarks: This is a common Antarctic species, well known from several locations and previously recorded by Koltun (1964), Ríos (2006), Campos et al. (2007), Göcke & Janussen (2013), Fernández et al. (2021), among others. It may be epibiotic on bryozoans, algae or ophiuroids. It was previously recorded at the SOI by Topsent (1913).

Figures

FIGURE 2. a–e Iophon gaussi. a. general morphology, scale: 4 cm; b. oxeote, scale: 100 µm; c. tylote, scale: 60 mm; d. anisochelae, scale: 20 µm; e. bipocilli, scale: 5 µm, taken from Ríos (2006). f–j. Iophon unicorne, f. general morphology, scale: 4 cm; g. oxeote. Scale: 100 µm; h. tylote, scale: 50 µm; i. anisochelae, scale: 8 µm; j. bipocilli, scale: 10 µm.