Tsitsikamma michaeli Parker-Nance

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 : 109-112

Tsitsikamma michaeli Parker-Nance sp. nov. Figure 4 a–n

Type material.

Holotype. - SAIAB 207202 Evans Peak, Algoa Bay, Eastern Cape Province, -33.84548, 25.81663, 30-34 m depth, 12 November 2015.

Paratype. - TIC2009-009, Evans Peak, Algoa Bay, Eastern Cape Province, -33.84297, 25.81647, 25-30 m depth, 15 May 2009.

Material examined.

SAIAB 207204, SAIAB 207205: Evans Peak, Algoa Bay, Eastern Cape Province, -33.84548, 25.31663, 25-33 m depth, 10 October 2010; SAIAB 207206, SAIAB 207207, SAIAB 207208, SAIAB 207209: Evans Peak, Algoa Bay, Eastern Cape Province, -33.84418, 25.81522, 30-34 m depth, 30 October 2015; SAIAB 207210: Evans Peak, Algoa Bay, Eastern Cape Province, -33.84548, 25.31663, 30 m depth, April 2011; SAIAB 207211: Algoa Bay, Eastern Cape Province, 5 November 2002.

Description.

Small olive-green, purse shaped sponge up to 5 cm high (2 cm stalk and 3 cm rounded head) or sessile, 5-10 cm in diameter. In some cases, the large sponge may be loosely subdivided into sections ( Fig. 4 a–c ). Small short tube-shaped oscula, 2.5-4 mm high and 1.8-5.5 mm wide at the base narrows to a point and may be laterally flattened in preserved material. The particularly large stalked cauliform porefields are 3-7 mm high and 3-6.5 mm wide, with the porefields spilling over the supporting stalk ( Fig. 4d ). The freshly collected sponge is a dark to olive green colour with light cream tipped oscula and darker brown green areolate porefields ( Fig. 4d ). The interior choanosome is bright green. Preserved specimens are olive to tan in colour.

Skeleton. The soft delicate, bright green, interior choanosome is encapsulated by a protected firm resilient green ectosome 1000 (200-1500) µm thick ( Fig. 4d, e ). The attachment area or short stalk is represented by a thickening of the ectosome. No reinforced tracts are present through the interior.

Spicules. Megascleres consists of acerate, hastate or blunt styles that are prominently centrally thickened prominently; (i) 713 (537-935) x 21 (12-30) µm and (ii) long slender styles 622 (439-769) x 9 (4-13) µm, with occasionally short thick anisostrongyles ( Fig. 4 f–h ). Microscleres. Isochiadiscorhabds are 38 (34-44) µm in length with three or four whorls. The shaft is 30 (19-37) x 6 (4-8) µm. The terminal whorls consist of a clearly larger manubrium 19 (14-23) µm and apical whorls 16 (13-21) µm in diameter (Table 4 ). The acanthose tubercles are arranged in sets of two to four, radiating from the terminal ends ( Fig. 4 i–n ). The sponge is often encrusted by a yellow Mycale (Mycale) sponge species also found on the surface of T. pedunculata .

Etymology.

Tsitsikamma michaeli sp. nov. is named after Professor Michael T Davies-Coleman, Dean of Science, Department of Medical BioScience, University of the Western Cape in recognition of his outstanding contributions to our knowledge of the diversity of South African marine fauna and their production of bioactive secondary metabolites.

Distribution.

Algoa Bay

Substrate, depth range, and ecology.

Tsitsikamma michaeli sp. nov. is a small species found on similar reef habitat as to T. pedunculata in Algoa Bay, sometimes in close proximity, at depths between 33-38 m. It shares the same epibiont Mycale (Mycale) species, which grow on the sponge surface between the oscula and porefields.

Remarks.

The absence of reinforcing spicule-dense tracts through the interior choanosome differentiates this new species from T. favus and T. scurra . The sac- or purse-like shape of the T. michaeli sp. nov. and the well-spaced oscula and porefields resemble those of T. pedunculata but the species differs in colour, bright to olive-green compared to the purplish pink to brown of T. pedunculata . It does not have a stalk, although the basal attachment area of T. michaeli sp. nov. is reinforced by a thickening of the ectosome ( Fig. 4d ). The resistant ectosome is of similar thickness for the two species (Table 4 ). The category (i) megascleres are shorter and thinner in T michaeli sp. nov. while the category (ii) styles are longer and more robust than that of T. pedunculata (Table 4 ). The microscleres of these two species have a similarly structured manubrium with tubercle in groups of four or more, but the tubercles are arranged in groups of three in T. pedunculata and in pairs in the apex whorl of T. michaeli sp. nov. Tsitsikamma pedunculata lack the median whorl and the spicule is shorter (Table 4 ), while T. michaeli sp. nov. may have up to two whorls between the apical whorls and manubrium.

There was no intraspecific genetic diversity for the 28S rRNA gene region for T. michaeli and no interspecific genetic diversity for T. michaeli and T. pedunculata was observed in this work (Suppl. material 1: Table S1). There was, however, interspecific genetic diversity of between 0.48-0.65 % between T. michaeli and T. favus and 0.32 % between T. michaeli and T. scurra .

Figures

Figure 4. Tsitsikamma michaeli sp. nov. a-c in situ d collected specimens with yellow encrusting Mycale (Mycale) sp. short stalk visible SAIAB 207204 e section through the ectosome with underlying choanosome SAIAB 207220 f robust centrally thickened sinuous style SAIAB 207202 g thin slightly ventrally thickened sinuous style SAIAB 207208 h short slightly sinuous strongyles i-l SEM images of chiadiscorhabds SAIAB 207204 m-n light microscope images of chiadiscorhabds SAIAB 207204 and SAIAB 207220. Scale bars 6 cm (distance between laser points) (a-c); 5 cm (d); 1 mm (e); 100 µm (f-h); 20 µm (i-n).