Chondropsis isimangaliso, 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 : 35-38

Chondropsis isimangaliso sp. nov.

( Fig. 14 A–I)

Material examined. Holotype . SAMC–A24750 (cross-reference TS 884 & Saf 03-Sod 60), Two Mile reef, Sodwana Bay (27.5167°S; 32.6834°E), South Africa, 0 3 November 2005, collected by T Samaai, depth 12 m.

Paratypes. SAMC–A24751 (cross-reference TS 873 & Saf 03- Sod 100), Seven Mile reef, Sodwana Bay (27.4580°S, 32.7141°E), South Africa, 0 7 November 2003, collected by T Samaai, depth 20 m ; SAMC–A24752 (cross-reference TS 882 & Saf 03– Sod 12), Ramsay reef, Sodwana Bay (27.4466°S, 32.7152°E), South Africa, 0 3 November 2003, collected by T Samaai, depth 18 m ; SAMC–A24753 (cross-reference TS 885 & Saf 03- Sod 81), Deep-sponge reef, Sodwana Bay (27.5167°S, 32.6835°E), South Africa, 0 3 November 2003, collected by T Samaai, depth 30 m ; SAMC–A24754 (cross-reference TS 916 & Saf 03- Sod 78), Deep sponge reef, Sodwana Bay (27.5167°S, 32.6835°E), South Africa, 0 3 November 2003, collected by T Samaai, depth 30 m ; SAMC–A24755 (cross-reference TS 904 & Saf 03- Sod 04), Ramsay reef, Sodwana Bay (27.4466°S, 32.7152°E), South Africa, 0 3 November 2003, collected by T Samaai, depth 18 m ; SAMC–A24756 (cross-reference TS 914 & Saf 03- Sod 54), Quarter Mile, Sodwana Bay (27.5330°S, 32.680°E), South Africa, 0 5 November 2003, collected by T Samaai, depth 8 m.

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

Description. Large, thickly encrusting sponge, 130 x 100 x 80 mm diameter, divided into tall, erect ridges, 10– 20 mm thick ( Fig. 14 A–E). Surface conulose with honeycombed appearance, oscules, 2–3 mm in diameter, randomly scattered on the surface of the sponge. Texture firm, hard, but brittle, not compressible, breaks easily. Colour in life orange-brown; in preservative, dull brown.

Skeleton ( Fig. 14F & G ). Choanosomal skeleton consists of a reticulation of coarse sand tracts held together by spongin. Interspersed in the sand tracts are bundles of thin flexuous strongyles. These bundles of thin strongyles occur infrequently. Mesh size range from 600–950 µm and thickness of tracts range from 260–420 µm near the periphery. No strongyles observed at the ectosomal surface. Foreign spicules are sometimes found in the subectosomal region.

Spicules. Megascleres ( Fig. 14H ). Strongyles, smooth, straight, often thin and flexuous, 129 (119–138) × 2 (2) µm, n = 10. Microscleres ( Fig. 14I ). C-Sigmas, large, smooth, with ends sharply pointed, 52 (43–59) µm, n = 10,

Substratum, depth range and ecology. Rocky ledges on coral reefs; growing in sandy areas at a depth range 12– 30 m. This sponge has been observed in the Delagoa ecoregion (WIO) and off the Agulhas & Natal bioregions where inshore upwelling occur.

Etymology. Named for the occurrence of the species in the iSimangaliso wetland park, Sodwana Bay, Western Indian Ocean.

Remarks. The majority of 12 Chondropsis known species occur around Australia and the East Pacific ( Van Soest 2002), although one, Chondropsis lamella ( Lendenfeld, 1888) has been recorded by Vacelet et al. (1976) from western and northern Madagascar. Chondropsis lamella is described and recorded above for the first time from the east coast of South Africa.

Chondropsis isimangaliso sp. nov. provides the second record of the genus in South African waters. Chondropsis isimangaliso sp. nov. differs from C. lamella in having a red colouration, smaller strongyles (119–138 × 2 µm) and one class of larger C–shaped sigmas (43–59 µm). Chondropsis arenifera ( Carter, 1886) has a similar honeycomb appearance and colouration to C. isimangaliso sp. nov. in addition to possessing bundles of strongyles in the sand tracts. However, C. arenifer has larger strongyles (160–190 × 1–2 µm) and no sigmas. Chondropsis australis differs from to C. isimangaliso sp. nov. in possessing larger sand tracts (up to 900 µm in diameter), larger strongyles (160–193 × 2–3 µm), reduced isochelae and smaller sigmas (20–30 µm).

Key diagnostic characters.

• Sponge thickly encrusting with a honeycombed appearance.

• Large C-shape sigmas with sharply pointed ends.

• Small strongyles.

Figures

FIGURE 14. Chondropsis isimangaliso sp. nov. A-E. In situ; F & G. Skeletal architecture (F, x5; G, x 10); H-I. Spicule compliment of strongyles and sigmas.