Cliona grandis, 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 : 12-13

Cliona grandis sp. nov.

( Fig. 3 A–G)

Material examined. Holotype SAMC–A24722 (cross-reference TS 840 & Saf 3-Sod51), Quarter Mile reef, Sodwana Bay, South Africa (27.5330°S, 32.6808°E), 0 5 November 2003, collected by T. Samaai, depth 8 m.

Comparative material examined. SAM-H4889 (TS 203), South Paw, Oudekraal (33.9333°S, 17.0166°E), depth 17–20 m, collected by P. Coetzee, April 1996.

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

Description. Massive mount-like sponge, 1100 × 700 × 180 mm diameter, apical ridge visible, with numerous oscules ( Fig. 3A, B ). Surface bumpy and undulating, but smooth, with polygonal pattern formed by numerous indented oscules and retractable inhalant papillae, 5–10 mm diameter. Oscules found along the ridge of the sponge and evenly distributed. Inhalant poral structure (ostia) raised 1 mm, 2 mm diameter, covered with membrane. Texture firm, leathery to the touch, barely compressible. Colour in life orange-yellow, interior dirty orange; in preservative dark brown.

Skeleton ( Fig. 3 C, D ). Choanosomal skeleton is a confused irregular reticulation of tylostyles with a complex mix of sponge tissue and sand debris haphazardly distributed through the tissue. The ectosomal skeleton consists of a distinct compact mass of tylostyles, 100 0–2000 µm wide, orientated perpendicular to the surface. The ectosome is not readily distinguishable from underlying choanosome. Spicules. Megascleres ( Fig. 3 E–G). Tylostyles smooth, straight or curved with prominent tylote heads, distal end fusiform, in one size category: 320 (176–370) × 8 (8) µm, n = 10. Tylostyle head variable. Microscleres. Absent.

Substratum, depth range and ecology. The new species is common on shallow rocky reef areas with sandy patches at a depth range 5– 25m. This sponge has been observed the southwestern cape biozone in the southern Benguala ecoregion and off the Agulhas & Natal bioregions where inshore upwelling occur.

Etymology. Named for the large, mount-like morphology of this species ( grandis , L.).

Remarks. This sponge is conspicuous and would be difficult to mistake for any other Cliona species occurring in the WIO. Unfortunately, Cliona species are challenging to identify (e.g. Rosell 1994; Bavestrello et al. 1996; Schönberg 2002; Schönberg & Beuck 2007); key features for differentiating Cliona species are growth forms (alpha: endolithic-papillate, beta: endolithic-encrusting, gamma: free-living massive), papillar characters, and the size and morphology of spicules and excavation patterns (e.g. Pang 1973; Rosell 1994; Rosell & Uriz 1997; Schönberg 2002; Rützler 2002; Schönberg et al. 2006). This massive-lobose species is placed in the genus Cliona due to the presence of tylostyles as principal megascleres, the skeleton showing no differentiation into ectosomal and internal architecture, the presence of tuberculate retractable inhalent papillae and raphyrus (gamma) growth stage.

The genus Cliona consists of approximately 79 valid species (Van Soest et al. 2017), many described from tropical-subtropical seas, i.e. Northwest Indo-Pacific (2 species), Central Indo-Pacific (12 species) and the Tropical Atlantic (33 species) (see Van Soest et al. 2017) considered a hot spot for Cliona diversity ( Schönberg et al. 2006). Four Cliona species are recorded from the WIO (Van Soest et al. 2017) and two from the west and south coast of South Africa (see Day 1974; Samaai & Gibbons 2005). The new species is well differentiated from the Western/ Central Indo-Pacific and Tropical Atlantic Cliona in being massive mound-shaped, having oscula organized in a line and lacking the microscleres compliment (raphides or spirasters).

Cliona grandis sp. nov. contains only tylostyles, whereas the WIO Cliona have spirasters. Schönberg et al. (2006) list 15 Cliona possessing only tylostyles (see table 2 in Schönberg et al. 2006). Comparison with the 15 species that contain only tylostyles [ C. celata Grant, 1826 , C. minuscula Schönberg, Grass & Heiermann, 2006 , C. arenosa (Schmidt, 1870) , C. californiana? ( de Laubenfels, 1932) , C. delitrix Pang, 1973 , C. caesia ( Schönberg, 2000) , C. dissimilis Ridley & Dendy, 1886 , C. ecaudis Topsent, 1932 , C. insidiosa Hancock, 1849 , C. janitrix Topsent, 1932 , C. kempi Annandale, 1915 , C. laticavicola Pang, 1973 , C. macgeachi Holmes, 2000 , C. millepunctata Hancock, 1849 and C. peponaca Pang, 1973 ] showed that the new species has not previously been described. The form and dimensions of the megascleres of C. grandis sp. nov. indicates that it is distinct from all species with tylostyles. For example, C. ecaudis , C. janitrix , C. kempi and C. macgeachii has tylostyles that are shorter and often wider than in C. grandis sp. nov. These species are also encrusting and have erosion chambers. Cliona arenosa , C. californiana , C. delitrix , C. dissimilis and C. laticavicola are yellow to orange and have similar tylostyles dimensions to C. grandis sp. nov., but the spicule shapes differ. Furthermore, these species are encrusting and has only been found in the Caribbean, Atlantic, and in the Western Pacific, which reduces the chance of conspecifity with C. grandis sp. nov. Cosmopolitism within sponges is questionable due to the inability of larvae to travel long distances (Maldonado & Bergquist 2002).

The only known records of Cliona species recorded from South Africa are by Day (1974) and Samaai & Gibbons (2005). The record by Day (1974) of an unidentified Cliona sp. from an unknown location is brief and vague. The species had an excavating habit (2 mm diameter) and possessed spirasters as microscleres. No length measurements were provided for the undescribed species. The specimens described by Samaai and Gibbons (2005) as C. cf. celata from the west coast of South Africa (and Namibia) lack spirasters and had similar tylostyle dimensions [320 (182–373) × 8 (8) µm as found in C. grandis sp. nov. [320 (176–370) × 8 (8) µm]. Other similarities between the west coast specimens and C. grandis sp. nov. are: they are massive mounded sponges, with a huge apical ridge, along which numerous oscules are situated. The inhalant poral structures are delicate and covered by a fine membrane marking the surface in a polygonal pattern. Colour in situ yellow, orange to orangeyellow with the interior dirty orange. The tylostyles exhibit noticeable plasticity in head shape and placement of the head along the shaft. It is considered that the west coast specimens were wrongly identified by Samaai and Gibbons (2005) as C. cf celata and considered here to be conspecific to C. grandis sp. nov. based on the morphological similarities.

Cliona celata Grant, 1826 is originally described as an endolithic, greenish-yellow sponge growing on oyster shells in a Scottish estuary. In its gamma stage the sponge is free, massive and looks like a pumpkin. The tylostyles are long and slim with dimension between 200–400 µm long and 3–12 µm thick. Apart from these, C. celata also possess rhaphides [100–150 × <1 µm] and spirasters have been found mainly in the papillae of young specimens [20–25 × 2–3 µm] (see Rützler 2002). Cliona grandis sp. nov. differs from C. celata in its spicule length and width of the tylostyles [320 (176–370) × 8 (8) µm vs. 200–400 µm × 3–12 µm],, It is highly unlikely that C. celata would be spread across the entire Northern and Southern Hemispheres. Cliona celata is considered a dustbin assemblage and in need of taxonomic revision ( Rützler 2002; Rosell & Uriz 2002, Schönberg et al. 2006) as it may contain a series of cryptic undetected species, as noted for the C. viridis species complex (Leal et al. 2015; Zea and López- Victoria 2016). Rosell & Uriz (2002) indicated that specimens with and without raphides often belong to different species.

Key diagnostic characters.

• Sponge massive, mount-like.

• Surface has numerous indented oscules and retractable inhalant papillae forming a polygonal pattern.

• Absence of rhaphides and spirasters.

• Presence of sand debris distributed haphazardly through the tissue.

• Presence of a distinct ectosomal layer.

• Huge apical ridge where oscules are found.

Figures

FIGURE 3. Cliona grandis sp. nov. A & B. In situ; C & D. Skeletal archtecture (C, x5; D, x 10); E. Tylostyles; F & G. close up of the tylostyle heads.