Spheciospongia ndabazithe, Samaai & Pillay & Janson, 2019

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 : 19-21

Spheciospongia ndabazithe sp. nov.

( Fig. 6 A–G)

Material examined. Holotype. SAMC–A24731 (cross-reference TS 888 & Saf 03-Sod 05), Ramsay reef, Sodwana Bay (27,4466°S; 32,7152°E), South Africa, 0 3 October 2003, collected by T. Samaai, depth 18 m.

Type locality. Ramsay reef, Sodwana Bay, east coast of South Africa .

Description. Vase-shaped sponge, 150 × 180 × 40 mm in diameter ( Fig. 5A ). Surface smooth with oscules, 2 mm in diameter, scattered randomly on the inner side of the vase. Texture tough, firm and rubbery to the touch, barely compressible. Lip area of vase, thick with vein-like appearance. Surface membrane visible in preserved specimen. Colour in life dirty yellow with dark brown interior; in preservative, exterior grey, interior dark grey to brown.

Skeleton ( Fig. 5 B–D). Choanosomal skeleton consists of a dense, irregular reticulation of bundles of tylostyles and styles. Spirasters scattered randomly throughout the choanosome. Subdermal cavities present filled with sand and lined with a confused reticulation of tylostyles. The ectosomal skeleton is composed of a dense, confused paratangential reticulation of tylostyles and a few spirasters. Tylostyles occasionally protrude through the ectosome.

Spicules. Megascleres ( Fig. 5E, F ).Tylostyles, smooth, slightly sinuous with variable proximal head shape, distal end hastate to fusiform: 428 (398–499) × 6 (6) µm, n = 10. Styles, smooth, slightly sinuous with distal end fusiform: 388 (326–432) × 7 (7) µm, n = 10. Microscleres ( Fig. 5G ). Spirasters, C-shaped with spines on the outer curve: 18 (17–19) µm, n = 10.

Substratum, depth range and ecology. The sponge is found on exposed rocky/sandy area at a depth of 18 m.

Etymology. Named in honour of David Smith, who rescued the author TS’s son from drowning while he was out collecting sponges in Sodwana Bay. Ndabazithe is David’s Zulu name which means ‘respect’.

Remarks. This sponge has a skeletal arrangement typical of the genus Spheciospongia , and its surface is lined with pore sieves. The spicules are clearly those of the family Clionaidae . The genus Spheciospongia is well defined ( Rützler 2002) with currently seven species described from the WIO [( S. vagabunda ( Ridley 1884) , S. excentrica ( Burton 1931) , S. florida ( Lendenfeld 1897) , S. inconstans ( Dendy 1887) , S. globularis ( Dendy 1922) , S. poterionides ( Vacelet & Vasseur 1971) , S. mastoidea ( Keller 1891) ], two of which also occur in South African waters: S. excentrica and S. vagabunda . A third species, S. capensis , was described by Carter (1882) from Port Elizabeth on the south coast of South Africa.

Spheciospongia excentrica ( Burton, 1931) is a non-stipitate cup-shaped sponge possessing centrotylote oxeas and tylotes and no spirasters, whereas S. ndabazithe sp. nov. is massive, vase-shaped with numerous spirasters but no centrotylote oxeas present. Spheciospongia excentrica has smaller tylostyles (320 µm) oppose to those found in S. ndabazithe sp. nov. Pulitzer-Finali’s (1993) description of S. excentrica from Mombasa differs from Burton’s (1931) type in being stipitate, have spirasters (although only two recorded) and smaller tylostyles, (260–460 µm). Whether Pulitzer-Finali’s species from Mombasa is S. exentrica is questionable.

Spheciospongia florida described from Zanzibar and widely distributed within the WIO, is columnar in shape and differs in spiculation and spicule dimensions to S. ndabazithe sp. nov. and S. vagabunda ( S. florida holotype 200–650 µm & spirasters 5–15 µm; S. vagabunda holotype tylostyles 600 x 20 µm & spirasters 32 µm; S. ndabazithe sp. nov. tylostyles, 398–499 µm & spirasters 17–19 µm).

Spheciospongia capensis differs from S. ndabazithe sp. nov. in being semicircular, flat and having contorted spirasters with four bends as oppose to being c-shaped as in the new species.

Spheciospongia ndabazithe sp. nov. has long thin c-shaped spirasters with spines only on the outer curve, sinuous tylostyles and styles, and the tylostyles project through the ectosome. The presence of subdermal cavities within the choanosome, a paratangential reticulation of tylostyles and a confused reticulation of tylostyles in the choanosome have not been observed in S. excentrica , S. florida and S. globularis . This may be a diagnostic feature of S. ndabazithe sp. nov.

Key diagnostic characters.

• Sponge vase-shaped.

• Oscules found on the on the inner side of the vase.

• C-shaped with spines on the outer curve.

• Subdermal cavities filled with sand

Figures

FIGURE 5. Spheciospongia excentrica (Burton, 1931). A-D. In situ; E & F. Skeletal architecture (E, x5; F, x10); G. Tylostyles of two classes.

FIGURE 6. Spheciospongia ndabazithe sp. nov. A. In situ; B, C & D. Skeletal architecture (B, x5; C, x10; D, x40); E. Primary tylostyles; F. Auxiliary styles; G. Spirasters.