Tsitsikamma favus Samaai & Kelly, 2002

Parker-Nance, Shirley, Hilliar, Storm, Waterworth, Samantha, Walmsley, Tara & Dorrington, Rosemary, 2019, New species in the sponge genus Tsitsikamma (Poecilosclerida, Latrunculiidae) from South Africa, ZooKeys 874, pp. 101-126 : 104-106

Tsitsikamma favus Samaai & Kelly, 2002 Figure 1 a–p

Tsitsikamma favus Samaai & Kelly, 2002: 718, fig. 6 A–G. Samaai, Gibbons, Kelly & Davies-Coleman, 2003: 19.

Type locality.

Western Cape Province, Garden Route National Park, Tsitsikamma , Rheeders Reef, South Africa.

Type material.

Holotype. - NHMUK 1997.7.3.2: Rheeders Reef; Tsitsikamma MPA, Eastern Cape Province, Garden Route National Park, -34.166667, 23.90000, 22 m, collector Philip Coetzee, 1995 ( Samaai and Kelly 2002).

Material examined.

SAIAB 141112: The Knoll, Tsitsikamma MPA, Garden Route National Park, Eastern Cape Province, -34.02555, 23.90708, 18 m depth, collected by Colin Buxton, 2 May 1993, three specimens; SAIAB 207166, SAIAB 207167: Rheeders Reef, Tsitsikamma MPA, Garden Route National Park, Western Cape Province, -33.84548, 25.81663, 25-30 m depth, 25 May 1994, collected by John Allen and Steve Brower, nine specimens; SAIAB 141356: Rheeders Reef, Tsitsikamma MPA, Garden Route National Park, Eastern Cape Province, 22 m depth, 18 March 1995 collected by Rob Palmer, Brad Carté and Philip Coetzee, two specimens (material collected at same locality and time as type material); SAIAB 207168: Rheeders Reef, Tsitsikamma MPA, Garden Route National Park, Eastern Cape Province, 30 m depth, 25 May 1994, collected by John Allen and Steve Brower; SAIAB 207172 and SAIAB 207174: RIY Bank, Algoa Bay, Eastern Cape Province, 28 m depth, 23 February 1999, collected by Coral Reef Research Foundation, Koror, Palau (CRRF); SAIAB 207175: Whitesands Reef, Algoa Bay, Eastern Cape Province, 20 m depth, 18 May 2001; SAIAB 103531: Whitesands Reef, Algoa Bay, Eastern Cape Province, -33.99980, 25.70842, 15 m depth, 20 March 2002, collected by Scripps; SAIAB 207176, SAIAB 207221, SAIAB 207222, SAIAB 207223, SAIAB 207224, SAIAB 207225, SAIAB 207226, and SAIAB 207227: Evans Peak, Algoa Bay, Eastern Cape Province, -33.84297, 25.81647, 25-30 m depth, 15 May 2009; SAIAB 207177: Evans Peak, Algoa Bay, Eastern Cape Province, -33.84548, 25.81663, 30 m depth, May 2009; SAIAB 207217 and SAIAB 207218: Evans Peak, Algoa Bay, Eastern Cape Province, -33.84548, 25.31663, 25-33 m depth, 10 October 2010; SAIAB 207179, SAIAB 207180, SAIAB 207184, SAIAB 207185, SAIAB 207186, SAIAB 207187, and SAIAB 207188: RIY Banks, Algoa Bay, Eastern Cape Province, -33.98868, 25.86553, 25-30 m depth, 14 December 2012; SAIAB 207189: Evans Peak, Algoa Bay, Eastern Cape Province, -33.84548, 25.316633, August 2014, 22-30 m depth, 10 specimens; SAIAB 207190 and SAIAB 207228: Evans Peak, Algoa Bay, Eastern Cape Province, -33.84548, 25.31663, 30 m depth, 6 September 2015; SAIAB 207192: Evans Peak, Algoa Bay, Eastern Cape Province, -33.84548, 25.3166315, 20 m depth, 2 June 2016, collected by Thomas Bornman, Shaun Deyzel, and Shirley Parker-Nance, several specimens; SAIAB 207193: Shark Alley, Bell Buoy Reef, Algoa Bay, Eastern Cape Province, -33.98248, 25.69430, 9-10 m depth, 5 June 2016.

Additional material.

CASIZ 300636: White Sands Reef, Algoa Bay, Eastern Cape Province, -33.99537, 25.70790, 14 m, 14 February 1999, collected by Coral Reef Research Foundation, Koror, Palau CRRF, identified by Michelle Kelly, National Institute of Water and Atmosphere, Auckland (NIWA); CASIZ 300535: Table Top Reef, Algoa Bay, Eastern Cape Province, -33.98067, 25.69367, 16 m, 4 October 1998, collected by CRRF, identified by Michelle Kelly, NIWA; CASIZ 301054: Grootbank Reef, Plettenberg Bay, Western Cape Province, -34.00765, 23.49647, 10-13 m, 22 March 2000, collected by CRRF, identified by Michelle Kelly, NIWA.

Diagnosis (emended from Samaai and Kelly 2002). Large, firm, dark brown hemi-spherical to thick encrusting sponges, up to 15 cm high and 20 cm in diameter, sessile with a large area of attachment. Surface smooth and firm although undulant presenting a folded or bumpy appearance in some specimens ( Fig. 1 a–c ), only slightly to moderately compressible, resilient and leathery. Surface with large single to multichambered cylindrical lance-shaped oscula, and pedunculate cauliform areolate porefields, colour in life is light to dark brown or liver brown.

Skeleton.. The ectosome is composed of a thick dense feltwork of anisostyles with a single layer of erect isochiadiscorhabds arranged perpendicular to the underlying megascleres ( Fig. 1e ). The ectosome is generally thinner than the dense spiculose tracts that penetrate and divide the soft choanosome into honeycomb-like chambers (Table 1 , Fig. 1d, f ).

Spicules. Megascleres. Slightly sinuous anisostyles, hastate, mucronate or blunt, occasionally tylote form the main structural components with two categories pre sent; (i) long slightly curved and thickened centrally and (ii) shorter, thinner slightly curved centrally (Table 1 , Fig. 1 g–j ). Short thick anisostrongyles, may also be present ( Fig. 1k ). Microscleres. Isochiadiscorhabd, with three whorls of conico-cylindrical tubercles terminally acanthose ( Fig. 1p ), line the tracts and are found abundantly throughout the choanosome ( Fig. 1l ). In addition to the three whorled microscleres, as described by Samaai and Kelly (2002) for the type material, are chiadiscorhabds with up to five complete whorls as well as many intermediate forms ( Fig. 1 m–o ). Typically, the manubrium and the apical whorl differ slightly in diameter (Table 1 ) and tubercles projections arranged pairwise or in groups of three respectively ( Fig. 1 l–p ). Isochiadiscorhabds with the terminal tubercles arranged in such a way to give a flattened appearance are also present (basal whorl in Fig. 1o ). Oocytes were present in specimens (after Samaai and Kelly 2002).

Distribution.

Plettenberg Bay, Tsitsikamma Marine Protected Area and Algoa Bay.

Substrate, depth range, and ecology.

Collected from rocky benthic reef, 9-33 m deep, occurring singly or in clumps of two or three, in abundance on both shallow reef systems such as Bell Buoy on the top of medium profile reef and at Evans Peak on the sides of high steep profile reef. Note that for some of the older collections the GPS position of the collection site is not available or inaccurate; for clarity Rheeders Reef is an inshore reef system within the Tsitsikamma MPA situated east of Storms River Mouth and the Knoll between -34.025730, 23.906138 and -34.032780, 23.960138 inshore and -34.044530, 23.906138 and -34.04453, 23.96013 off shore.

Remarks.

Examined material compares well with the type description given by Samaai and Kelly (2002) including the shape of the oscula, distribution of the pedunculate cauliform areolate porefields, arrangement, and distribution and size of megascleres and microscleres (Table 1 ). The structure of the chiadiscorhabds corresponds with the type description Samaai and Kelly (2002); however, some sponges exhibited various ratios of typical microscleres with three whorls, as per the type description ( Samaai and Kelly 2002), to microscleres with tubercles not arranged in or missing from or present between complete whorls ( Fig. 1 m–o ). These variations were suggested but not discussed in the type description (see Samaai and Kelly 2002: fig. 6J, central two images; Samaai et al. 2004: fig. 2B, central image) which suggests that spicules of this nature were observed in the type specimen. It is interesting to note that T. favus specimens, even some collected no more than 10 cm apart and although clearly T. favus with respect to 28S rRNA sequence analysis (as shown by sequence identity or a maximum of one nucleotide difference), differ in the firmness or compressibility of the individual sponge. Closer inspection of the spicules showed an increased occurrence of misshaped or irregular microscleres and a distinct chromatographic profile in these T. favus sponges ( Kalinski et al. 2019).

Live or freshly collected specimens are dark brown, olive or dark green in colour and may be heavily encrusted with soft corals, hydroids, ascidians and other encrusting sponges with the oscula and porefields protruding through the surface epibionts. As freshly collected specimens are preserved, the extract dyes the preservative (70% ethanol) a deep brown colour which intensifies as the tissue lightens; long exposure to the stained preservative darkens the tissue again. Successive preservative changes (long-term curated specimens) remove the pigment and the specimens are beige in colour. Frozen material may be dark slate green to tan externally, and the tracks are prominently tan and the choanosome dark brown.

An estimation of divergence between sequences, intraspecific genetic diversity of T. favus included in this study, was found to be 0.16 % for the 28S rRNA gene sequence and 0-0.18 % for COI ( Walmsley et al. 2012; Walmsley 2013). Interspecific diversity between T. favus , T. nguni , and T. scurra at 28S was 0.16 % (Suppl. material 1: Table S1).

Examination of specimens collected from Tsitsikamma in 1993 showed that one sample contained two distinct species, the one clearly T. favus the other a new species included below (SAIAB 207216: The Knoll, Tsitsikamma MPA Garden Route National Park, Eastern Cape Province, 18 m, 2 May 1993, collected by Colin Buxton).

Figures

Figure 1. Tsitsikamma favus a in situ SAIAB 207193 b collected specimens SAIAB 207193 c collected SAF 1995 - 001 d section through preserved specimen SAIAB 141356 e isochiadiscorhabds arrangement on the surface of the ectosome f section of ectosome with underlying choanosome SAIAB 141356 g, h thin sinuous style i large sinuous centrally thickened style j occasionally tylote styles k rare short thick strongyles l-o isochiadiscorhabds SAIAB 207218 SEM p acanthose tubercles SAIAB 207217. Scale bars 5 cm (b, c); 1 cm (d); 1 mm (f); 100 µm (k); 20 µm (l-p).