Clathria (Axosuberites) nidificata ( Kirkpatrick, 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 : 409

Clathria (Axosuberites) nidificata ( Kirkpatrick, 1907)

( Fig. 3k–n )

Restricted synonymy: Ophlitaspongia nidificata Kirkpatrick, 1907 ; Axociella nidificata ( Kirkpatrick, 1907) .

Material examined: 4 small specimens collected at station 11 ( SOI; 60°53'S, 42°35'W; 487 m; 10/3/2014; MACN-In 44362; IEO-CSIC Col.) .

Description: Small sponges shrub-like, 3 to 4 cm in height. The living specimens were light brown ( Figure 3k ). Spicules are two categories of styles and toxas. The skeleton of the branches is constituted of a central axis of styles II, echinated by styles I mostly ( Figure 3n ). The styles I are straight and measure 750–1510 / 10–50 μm ( Figure 3l ); styles II are also straight but thinner, 400–590 / 5–10 μm; toxas are numerous and measure 170–600 μm, usually with spined tips ( Figure 3l–n ).

Remarks: Some specimens were epibiotic on dead Caryophyllia corals ( Figure 3k ), that are common corals in the area ( Schejter et al. 2016a), and on pebbles. The specimens here studied were morphologically similar to Artemisima plumosa , but unlike this species, they lack chelae. Clathria (A.) nidificata is well known from Antarctic waters ( Campos et al. 2007; Ríos 2006, Koltun 1964, Fernández et al. 2021), sub-Antarctic regions such as South Georgias Islands ( Koltun 1964), Burdwood bank ( Schejter et al. 2017), and deep sea Argentinean waters ( Burton 1940). This represents the first record for the SOI.

Figures

FIGURE 3. a–e. Artemisina apollinis. a. general morphology, scale: 7 cm; b. thick style, scale: 120 µm; c. ectosomal style, 100 µm; d. toxa, scale: 350 µm; e. isochelae, 20 µm; f–j. Artemisina plumosa. f, general morphology, scale: 15 mm; g. principal style, scale 115 µm; h. ectosomal style, scale: 65 µm; i. toxa, scale: 50 µm; j. isochelae, 10 µm; k–n. Clathria (A.) nidificata, k. general morphology, scale: 3 cm; l. style, 200 µm; m. toxa, scale: 300 µm; n. detail of one dried branch, scale: 3 mm.