Callyspongia (Cladochalina) diffusa ( Ridley, 1884 )

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 : 61

Callyspongia (Cladochalina) diffusa ( Ridley, 1884)

( Fig. 26 A–D)

Material examined. SAMC–A24778 (cross-reference TS 861 & Saf 03-Sod77), Deep-sponge reef, Sodwana Bay (27.5167°S, 32.6835°E), South Africa, 0 6 November 2003, collected by T. Samaai, depth 30 m.

Description. Branching sponge with coalescent tubes, rising from a common base ( Fig. 26A ). Surface smooth, finely hispid with numerous oscules, 1 mm in diameter, evenly scattered on the surface of the sponge. Texture firm but spongy, velvety to the touch, compressible. Colour in life pale pink-white; in preservative, white.

Skeleton ( Fig. 26B, C ). Choanosomal skeleton is a regular network of rectangular meshes, 240–345 µm in diameter, formed by primary multispicular fibres, 123 (67–96) µm thick, which are connected perpendicularly by multispicular secondary fibres and showing no fasciculation. Spongin is sparsely scattered in the choanosome, but the multispicular fibres are covered with sponging sheath. The ectosomal skeleton is a plumoreticulation of protruding spicules and is an extension of the primary spiculation formed within the choanosome.

Spicules. Megascleres ( Fig. 26D ). Oxeas, smooth, curved and sharply pointed, 107 (101–113) × 5 (5–7) µm, n = 10.

Substratum, depth range and ecology. Found growing on coral spp. at a depth of 30 m.

Geographic distribution. Sodwana Bay, east coast of South Africa

Remarks. Callyspongia (Cladochalina) diffusa ( Ridley, 1884) is a widely distributed Indo-Pacific species and has been recorded from the Gulf of Manaar ( Dendy 1889), East African Coral coast ( Burton 1959) and from Mozambique ( Thomas 1979). This sponge is easily identified by its unique morphology. Our specimen agrees well with the original published description of Callyspongia (Cladochalina) diffusa from Singapore and the subsequent description of material from Mozambique ( Thomas 1979).

Key diagnostic characters.

• Sponge branching with pale pink-white colouration.

• Soft with velvety texture and mauve colouration.

• Large oxeas.

Figures

FIGURE 26. Callyspongia (Cladochalina) diffusa (Ridley, 1884). A. In situ; B & C. Skeletal architecture (B, x5; C, x10); D. Oxeas.