Tsitsikamma scurra Samaai, Gibbons, Kelly & Davies-Coleman, 2003

Parker-Nance, Shirley, Hilliar, Storm, Waterworth, Samantha, Walmsley, Tara & Dorrington, Rosemary, 2019, New species in the sponge genus Tsitsikamma (Poecilosclerida, Latrunculiidae) from South Africa, ZooKeys 874, pp. 101-126 : 109

Tsitsikamma scurra Samaai, Gibbons, Kelly & Davies-Coleman, 2003 Figure 3 a–k

Tsitsikamma scurra Samaai, Gibbons, Kelly and Davies-Coleman, 2003: 20.

Type locality.

Holotype. - NHMUK 2003.1.10.3 (CASIZ 301103): Hout Bay. Western Cape Province, -34.03600, 18.30567, 28 m depth, 31 March 2000, near the wreck of British "The Maori", collected by P.L. Colin; Paratype - SAM H-4971: Hout Bay. Western Cape Province, -34.03600, 18.30567, 28 m depth, 25 January 2003, near the wreck of British "The Maori, collected by Lynden West of the Scripps Institute of Oceanography (after Samaai et al. 2003).

Material examined.

SAIAB 207201, SAIAB 207229: west of Hout Bay Western Cape Province, -34.03600, 18.30567, 28 m depth, 25 January 2003, near the wreck of British "The Maori, collected by Lynden West of the Scripps Institute of Oceanography.

Diagnosis

(emended from Samaai et al. 2003). Sponge massive, semispherical to thick encrusting and lime green in life, compressible with a tough sandpapery ectosome. Samaai et al. (2003) noted the surface crowded with large hollow strap-like oscula with the apex slightly expanded and fungiform areolate porefields, with the overall skeleton dominated by an ectosomal envelope of tangential megascleres, extending up into the large oscular tubes ( Fig. 3a, b ). In the preserved specimen small pear-shaped oscula (2-5.5 mm high and 1-1.5 mm in diameter) and long narrow stalked areolate porefields (7-9 mm high, 2.5-5 mm in diameter) are distributed over the folded surface ( Fig. 3 a–d ).

Skeleton. The ectosome is thin with a fine sandpapery feel that seems to continue and fold within the interior of large specimens to form smaller subunits or internal chambers (Table 3 , Fig. 3 c–e ). The choanosome is soft and may contain varying amounts of sand, shell and other foreign material ( Fig. 3d ).

Spicules. Megascleres consist of slightly curved styles, conspicuously thickened centrally sometimes bend basally and thinner styles, slightly curved centrally (Table 3 , Fig. 3 f–h ). Microscleres. Isochiadiscorhabds with three whorls of conico-cylindrical tubercles, the apex of each is acanthose. The median whorl is polar and situated closer to the apex whorl than to the slightly larger manubrium (Table 3 ), this polarity may be less pronounced in larger microscleres ( Fig. 3i ). The acanthose tubercles arranged in pairs in the apex whorl and manubrium ( Fig. 3 i–k ). Microscleres are abundant throughout the choanosome (after Samaai et al. 2003).

Distribution.

West of Hout Bay, a local area known as Maori Bay along the Western Cape Province coast.

Remarks.

The specimens examined compared well with the description given by Samaai et al. (2003) except that the colour in life of the type specimen was described as lime green and colour photographs of the freshly collected specimen indicate a brownish colouration ( Fig. 3a ). Preserved specimens are a medium to dark brown colour in ethanol ( Fig. 3c, d ). Tsitsikamma scurra differs from all other known Tsitsikamma species in the folded globular thick encrusting growth structure ( Fig. 3d ) with thin sandpaper-like ectosome (Table 3 ). Epifauna may be present on the sponge surface and the interior may contain a substantial amount of sand particles and shell fragments.

We obtained 28S rRNA gene sequences for only one T. scurra specimen. The interspecific diversity of the 28S rRNA gene sequence for T. scurra and other Tsitsikamma did not support clear genetic identity, with between 0.16-0.32 % at 28S for T. favus and 0.32 % for T. pedunculata .

Figures

Figure 3. Tsitsikamma scurra a, b freshly collected CASIZ 301103 and SAIAB 207201 c preserved specimens SAIAB 207229 d preserved specimens SAIAB 207201 e section of ectosome with underlying choanosome SAIAB 207201 f, g robust centrally thickened sinuous style SAIAB 207201 h thin slightly centrally thickened sinuous style SAIAB 207201 i, j light microscope image of chiadiscorhabds SAIAB 207201 k light microscope image of chiadiscorhabds SAIAB 207229. Scale bars 2.5 cm (c); 5 cm (d); 1 mm (e); 100 µm (f-h); 20 µm (i-k).