Tedania (Tedaniopsis) charcoti Topsent, 1907

(Figure 20)

Synonomy: Tedania charcoti Topsent, 1907 .

Specimens. BELUM. Mc 2015.560 , BELUM. Mc 2015.564 , BELUM. Mc 2015.572 Port Lockroy (64°49.572’S, 63° 29.390’W), depth 12–17 m, 14/02/2015 ; BELUM. Mc 2015.577 , BELUM. Mc 2015.579 , BELUM. Mc 2015.580 , BELUM. Mc 2015.588 , BELUM. Mc 2015.589 , BELUM. Mc 2015.593 Port Circumcision, Pieterman Island (65°10.471’S, 64° 08.070’W), depth 5–9 m, 15/02/2015 ; BELUM. Mc 2015.786 Under Spiggot Peak, Orne Harbour (64°37.755’S, 62° 33.018’W), depth 5–21 m, 25/02/2015 ; BELUM. Mc 2015.837 Diomedea Island (62°12.185’S, 58° 56.760’W), depth 10–18 m, 01/03/2015 .

Comparative material examined. Tedania charcoti Topsent, 1907 . MNHN DT678, ‘Porquoi-pas’ specimen no. 259, (tissue section on microscope slide) and DT679, ‘Pourquoi-pas’ specimen no. 530 (spicule preparation on microscope slide). These are not the type specimen but were collected on the same expedition.

External morphology. In situ appearance Figure 20A): Yellow-orange thickly encrusting sponge which often has small mounds or folds on its surface. Soft texture.

Preserved appearance. Firm beige sponge with very smooth surface. The preserving alcohol is coloured mustard yellow.

Skeleton (Figure 20B): Anastomosing ascending columns of up to 20 styles joined by thinner columns of styles. Dense pallisade of tornotes at the surface. Onychaetes present throughout the tissue.

Spicules: Measurements and images from BELUM.Mc2015.589. Skeleton image from BELUM.Mc2015.580.

Styles (Figure 20C): 377(433)491 by 10(14) 16 µm. Slightly curved with an abrupt point.

Tornotes (Figure 20D, E): 304(328)366 by 7(9) 12 µm. Often with one end slightly mucronate.

Onychaetes: Two size categories 87(111) 158 µm (Figure 20F) and 181(239) 275 µm (Figure 20G, H).

Remarks. Topsent (1907) describes the form of this species as mammiform with large oscules on top of conical mounds. We cannot find a reference to the live colour in the literature, but Rios (2006) reports specimens are light orange externally and yellow in the choanosome when living, and that they dye ethanol yellow-orange. Topsent (1907) also reports the alcohol being lightly stained yellow. The size range found in our specimens is very similar to the type specimen; Topsent (1907) reports styles (420–450 by 13 µm; tornotes 305–340 by 10 µm, onychaetes of two size categories, 90–120 by 2 µm, with one inflated end, and 250–265 by 2 µm.

Distribution. The type locality is Port Charcot, Booth Island from 0–40 m, it was reported as common at this location. It has also been recorded from East Antarctic Wilkes Land, the Ross Sea, (Koltun, 1964); Falkland Islands and South Georgia (Topsent 1913; Burton 1932, 1934); the South Orkney Islands (Burton 1940); the South Shetland Islands (Rios et al. 2004), the Patagonian shelf (Bertolino et al. 2007), and the Chilean Coast (Tierra de Fuego) (Desqueyroux 1989). We found it to be particularly abundant on the shallow rock wall, between 5 and 9 m, of Port Circumcision Harbour, Pieterman Island (Site 12), where it was one of the dominant sponge species. This site is very close to Booth Island, Interestingly, although we sampled the type location (Site 10) we did not collect any specimens from there.