Spongia (Heterofibria) smaragdus, 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 : 70-72

Spongia (Heterofibria) smaragdus sp. nov.

( Fig. 32 A–F)

Material examined. Holotype. SAMC–A24792 (cross-reference TS 868 & Saf 03-Sod 93), Seven Mile reef, Sodwana Bay (27.4581°S, 32.7141°E), South Africa, 0 7 November 2003, collected by T. Samaai, depth 16 m.

Paratypes. SAMC–A24793 (cross-reference TS 878 & Saf 03-Sod 73), Deep-sponge reef, Sodwana Bay (27.5167°S, 32.6835°E), South Africa, 0 6 November 2003, collected by T. Samaai, depth 30 m. SAMC–A24794 (cross-reference TS 876 & Saf 03-Sod 49), Gotham reef, Sodwana Bay (27.4916°S, 32.7022°E), South Africa, 0 5 November 2003, collected by T. Samaai, depth 34 m.

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

Description. Massive, amorphous to thickly encrusting sponge, 110 × 80 × 65 mm diameter, with few retractable papillae, ± 20 mm high ( Fig. 32 A–C). Surface pinacoderm lost upon preservation. Surface conulose and honeycomb-like, with exposed fibres. Large, raised oscules visible in live specimen, 2–5 mm in diameter, not visible in preserved specimen. Texture firm, but soft, rubbery to the touch, compressible. Colour in life yellowgreen to emerald; in preservative, chocolate-brown.

Skeleton ( Fig. 32 D–F). Choanosomal skeleton consists of homogenous primary and secondary fibres. Primary fibres simple, irregularly cored with foreign material and extend into the choanosome and towards the surface. Secondary fibres uncored, more prevalent near the ectosome. Secondary fibre meshes rectangular; forming networks and interconnect with adjacent secondary fibres. Primary fibres, 40 (32–45) µm in diameter, secondary fibres, 20 (16–26) µm in diameter. Fibres are light brown to yellow. Collagen deposits present within the mesohyl, but only minor deposits at the surface.

Substratum, depth range and ecology. This sponge is found on shaded walls, under overhangs, in moderate to exposed locations between a depth range 16– 34 m.

Geographical distribution. Sodwana Bay, East coast of South Africa.

Etymology. Named for the emerald green colour of the sponge ( smaragdus meaning emerald, L.).

Remarks. This species is similar to Spongia (Heterofibria) cooki sp. nov. but there are marked dissimilarities. The surface features of S. (H) smaragdus sp. nov. differ from S. (H) cooki sp. nov. in the massive, amorphous shape, the presence of fistules, and yellow-green colouration. Spongia (H) cooki possesses larger primary (55–89 µm) and varying secondary (12–37 µm) than S. (H) smaragdus sp. nov. The primary fibres are simple in S. (H) smaragdus sp. nov. compared to primary fibres rising from coalescing secondary fibres in S. (H) cooki sp. nov.. The meshes in S. (H) smaragdus sp. nov. are more rectangular compared to a more irregular polygonal mesh in S. (H) cooki sp. nov. The dermal collagen band found in S. (H) cooki sp. nov. is absent in S. (H) smaragdus sp. nov. Spongia (Heterofibria) mokohinau ( Cook & Bergquist, 2001) has similar primary (29–78 µm), secondary (13–29 µm) and pseudo–tertiary (3–10 µm) fibre dimensions as Spongia (H) smaragdus sp. nov. but there are differences between these two species. Spongia (H) mokohinau Cook and Bergquist (2001) possesses an external morphology of distinct conical turrets rising from a solid base and fully cored primary fibres that are formed by coalescing secondary fibres.

Key diagnostic characters.

• Sponge thickly encrusting.

• Surface conulose and honeycomb-like, with exposed fibres.

• Secondary fibres uncored, more prevalent near the ectosome. Collagen deposits present within the mesohyl, but only minor deposits at the surface.

• Emerald green colouration.

Figures

FIGURE 32. Spongia (Heterofibria) smaragdus sp. nov. A-C. In situ; D-F. Skeletal architecture (D, x5; E, x10; F, x40)