Aplysilla cf. lacunosa Keller, 1889

Samaai, Toufiek, Pillay, Ruwen & Janson, Liesl, 2019, Shallow-water Demospongiae (Porifera) from Sodwana Bay, iSimangaliso Wetland Park, South Africa, Zootaxa 4587 (1), pp. 1-85 : 74-75

Aplysilla cf. lacunosa Keller, 1889

( Fig. 34 A–C)

Material examined. SAMC–A24797 (cross-reference TS 927 & Saf 03-sod111), Ribbon reef, Sodwana Bay (27.4880°S, 32.6977°E), South Africa, 0 3 November 2007, collected by T. Samaai, depth 20 m.

Description. Thinly encrusting sponge, 10 × 80 × 60 mm diameter ( Fig. 34A ). Surface smooth but conulose, with fibres protruding through the surface giving the sponge a prickly appearance. Oscules evenly distributed over the surface of the sponge, 1 mm in diameter. Texture soft, compressible not easily torn. Colour in life bright-yellow, turns purple out of water; in preservative dark purple-black.

Skeleton ( Fig. 34B, C ). Choanosomal skeleton dendritic, made up of fibres 100 µm wide, with a distinct medulla and only slightly narrower apically. Fibres may branch, but are usually simple and do not coalesce to form a network.

Substratum, depth range and ecology. This sponge is found on a rocky ledge at a depth of 20 m.

Geographic distribution. WIO

Remarks. No species of Aplysilla has been described from the WIO, except A. lacunosa from the red sea and A. cf. rosea recorded from South Africa. Bergquist and Warne (1980) and Bergquist and Cook (2002) indicated that colour is a stable specific character in Aplysilla and that variation in colour within a species does not occur ( Samaai & Gibbons 2005). The position adopted here follows that of Bergquist and Cook (2002), is that colour is consistent and that A. lacunosa is a valid species.

The sponge described here agrees well with the description of P. lacunosa provided by Keller (1889) from the Red Sea. Aplysilla lacunosa is thinly encrusting, surface conulose and slimy, being intensely butter yellow in situ. The conuli are pointed elevations on the surface 3–4 mm high. This is similar to the sponge described here. Classifying this sponge fully as A. lacunosa is difficult due to its distribution in South Africa. No other Aplysilla species are described here or in the WIO. Due to its similarity to A. lacunosa , this sponge is regarded as A. cf. lacunosa .

Key diagnostic characters.

• Sponge thinly encrusting with fibres protruding through the surface giving the sponge a prickly appearance.

• Thin dendritic choanosomal skeleton.

• Butter-yellow colouration

Figures

FIGURE 34. Aplysilla cf. lacunosa Keller, 1889. A. In situ; B & C. Skeletal architecture (B, x5; C, x10)