Callyspongia (Callyspongia) fadwae, 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 : 59-61

Callyspongia (Callyspongia) fadwae sp. nov.

( Fig. 25 A–E)

Material examined. Holotype. SAMC–A24779 (cross-reference TS 874 & Saf 03-Sod 62), Two Mile reef, Sodwana Bay (27.5167°S, 32.6834°E), South Africa, 0 5 November 2005, collected by T Samaai, depth 12 m.

Paratype. SAMC–A24780 (cross-reference TS 862 & Saf 03-Sod63), Two Mile reef, Sodwana Bay (27.5167°S, 32.6834°E), South Africa, 0 5 November 2003, collected by T Samaai, depth 12 m.

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

Description. Laminate, thin ridge sponge with fibrous projections 150 × 100 × 35 mm in diameter ( Fig. 25A, B ). Surface finely hispid with numerous sunken oscules, 2–7 mm in diameter, inside the sponge. Texture firm but soft, velvety to the touch, compressible, difficult to tear. Colour in life, mauve; in preservative, beige.

Skeleton ( Fig. 25C, D ). Choanosomal skeleton is a regular network of rectangular to circular meshes, 470–643 µm in diameter, formed by primary unispicular fibres (1 spicule in central row), 38–48 µm, thick which are connected perpendicularly by smaller unispicular secondary fibres, 28 µm thick and showing fasciculation. Spongin is sparsely scattered in the choanosome. The ectosomal skeleton is a tangential network of rectangular meshes, formed around the apex of primary longitudinal fibres, 38 µm thick. Mesh diameter formed by primary fibres, 124 µm; finer secondary fibres, and tertiary fibres 38 µm and 5 µm in diameter respectively. Secondary and tertiary fibres are also unispicular.

Spicules. Megascleres ( Fig. 25E ). Oxeas, smooth, curved, sharply pointed, often tornote, in one size class, 80 (74–91) × 5 (5) µm, n = 10.

Substratum, depth range and ecology. Coral/rocky reef habitat growing on and between Porites coral at a depth of 12 m.

Etymology. Named after Fadwa Samaai, for her consistent support to the author TS.

Remarks. Currently, 16 species of Callyspongia is recorded from the WIO and South Africa respectively (Van Soest 2017). Callyspongia (C) tubulosa (Esper, 1798), C. (Cladohalina) foliacea (Esper, 1797) and C. hospitalis ( Stephens, 1915) are described from the west coast of South Africa, while C. mammillata ( Burton, 1933) and C. (Toxochalina) dendyi ( Burton, 1931) are described from Natal on the east coast of South Africa. Callyspongia (Callyspongia) fadwae sp. nov. differs from C. (C) tubulosa (Esper, 1798) and C. hospitalis ( Stephens, 1915) by location, its gross morphology, distinct spicule geometries (fusiform and thin), and its wide meshed reticulated skeleton of well-developed multispicular fibres. Callyspongia mammillata ( Burton, 1933) differs from C. (C) fadwae sp. nov. in spicule size (140 × 6 µm), being encrusting with numerous mammillate processes on surface, ash-grey colouration in dried state, having numerous sand grains present.

Dendy (1905 & 1922) described C. (C) reticutis and C. (C) differentiata from the Seychelles, while Pulitzer- Finali (1993) described C. abnormis , C. contorta , C. hirta , C. perforata , C. subtilis and C. violacea from Kenya on the east African coast. No described Callyspongia species to date (Esper 1798; Dendy 1905, 1922; Stephens 1915; Burton 1931, 1933; Pulitzer-Finali 1993; Samaai & Gibbons 2005), being laminate, fibrous and mauve in colouration, from the WIO or South Africa are even remotely similar in gross morphology or choanosomal architecture to C. (C) fadwae sp. nov. as evident in the literature. Callyspongia (C) fadwae sp. nov. is distinguished from other species of Callyspongia by morphology; no genera are known to have such a consistently laminate, thin ridge and soft form.

Callyspongia perforata Pulitzer-Finali, 1993 is a subcylindrical bifurcating sponge and differs from the new species in having a grey colouration, being elastic and rough and having oxeas as megascleres. Comparison of spicules dimensions indicates that C. perforata has similar smaller oxeas (90–95 × 2.5 µm) and a skeleton of spicule fibres with a reticulation of rectangular multispicular meshes. Callyspongia reticulata ( Keller, 1889) is claviform and has strongyles as spicules, whereas Callyspongia hirta Pulitzer-Finali, 1993 is erect and colouration in life varies from light brown to light orange. This species also has strongyles as megascleres as oppose to oxeas found in the new species. Callyspongia violacea Pulitzer-Finali, 1993 is erect, branching with a violet colouration and the oxeas are larger and thinner (100–110 × 2.5 µm) than what is found in the new species. Callyspongia (Callyspongia) confoederata (sensu Ridley, 1884) is erect, subcylindrical and hollow and have a hard consistency. Callyspongia (C) fadwae sp. nov. have similar spicule complement and dimensions to C. abnormis Pulitzer-Finali, 1993 , C. contorta Pulitzer-Finali, 1993 and C. subtilis (Schmidt, 1870) but vary in gross morphology and colouration. Based on the morphological differences between all these species, and the limited distribution potential of sponges, Callyspongia (C) fadwae sp. nov. is considered a new species in of Callyspongia .

Key diagnostic characters.

• Sponge laminate and thin ridged.

• Soft with velvety texture and mauve colouration.

• Small oxeas.

Figures

FIGURE 25. Callyspongia (Callyspongia) fadwae sp. nov. A. In situ; C & D. Skeletal architecture (C, x5; D, x10); E. Oxeas.