Haliclona (Soestella) crowtheri, Goodwin & Brickle, 2012

Goodwin, Claire & Brickle, Paul, 2012, Sponge biodiversity of South Georgia island with descriptions of fifteen new species, Zootaxa 3542, pp. 1-48 : 33-36

Haliclona (Soestella) crowtheri sp. nov.

( Figure 19)

Type material: Holotype: Sample in 95% ethanol, tissue section and spicule preparation on slides. BELUM Mc 7579. Prion Island Site 1, South Georgia (54°001.590’S, 37°15.178’W); depth 17.6m; collected by C. Goodwin, D. Poncet, and P. Brewin, 19 th November 2010.

Paratypes: Sample in 95% ethanol, tissue section and spicule preparation on slides . BELUM Mc 7587 and BELUM Mc 7594. Prion Island Site 2, South Georgia (54°001.862’S, 37° 15.032’W); depth 18m; collected by C. Goodwin, D. Poncet, and P. Brewin, 19 th November 2010 . BELUM Mc 7612. Rosita Harbour Site 2, South Georgia (54°00.649’S, 37° 25.618’W); depth 11.5m; collected by C. Goodwin, J. Brown, and S. Brown, 20 th November 2010 . BELUM Mc 7623. Right Whale Bay, South Georgia (54°00.173’S, 37° 40.856’W); depth 18m; collected by C. Goodwin, J. Brown and S. Brown, 21 st November 2010 . BELUM Mc 7633. Bird Sound Site 1, South Georgia (54°02.058’S, 38° 00.242’W); depth 18m; collected by C. Goodwin, S. Cartwright and P. Brickle, 22 nd November 2010 .

Etymology: Named for the former Head of the Department of Natural Sciences National Museums Northern Ireland, Dr Peter Crowther, who retired this year after many years of service to the museum; in recognition of his support of this work when in post.

External morphology: In situ appearance: Thickly encrusting white sponge (up to 15mm thick) forming large patches (up to 20cm in diameter) on bedrock. Smooth surface bearing numerous large oscules (up to 1cm in diameter) ( Fig. 19a).

Preserved appearance: Thick crust with very hard texture. Choanosome brick red in Mc7612 but white in some specimens and patchily red in others. The ectosome is a white, easily detachable, smooth layer.

Skeleton: Confused choanosomal skeleton with primary columns of 4–7 spicules joined by unispicular secondary lines. Some rounded meshes present ( Fig. 19b). Detachable white ectosome formed of hexagonal meshes of oxea, each side composed of single bundle of oxea 2–3 spicules thick ( Fig. 19c).

Spicules: Measurements from Mc7579.

Oxea: 266(299)321 by 11(17)20µm—occasional very thin (<1µm oxea) of a similar length are also present ( Fig. 19d).

Remarks: This species is assigned to Haliclona as it is a Chalindae with unispicular secondary lines (de Weerdt 2002). The presence of a specialised ectosomal skeleton with rounded meshes assigns it to the subgenus Haliclona (Soestella) (de Weerdt 2002) .

Two other species of Haliclona (Soestella) have been recorded from this region: H. auletta ( Thiele, 1905) from Calbuco, Chile and H. chilensis ( Thiele, 1905) . However, these both possess much smaller oxeas (150 and 130–200µm respectively).

The taxonomy of this genus is still confused so species from other sub-genera were considered. Although descriptions of other species from different genera in the family occurring in the region have been examined none can be found in which such a distinctive ectosomal skeleton is described.