Tsitsikamma (Clavicaulis subgen. nov.) madiba Samaai, Kelly, Payne and Ngwakum sp. nov.

Samaai, Toufiek, Kelly, Michelle, Ngwakum, Benedicta, Payne, Robyn, Teske, Peter R., Janson, Liesl, Kerwath, Sven, Parker, Denham & Gibbons, Mark J., 2020, New Latrunculiidae (Demospongiae, Poecilosclerida) from the Agulhas ecoregion of temperate southern Africa, Zootaxa 4896 (3), pp. 409-442 : 429-431

Tsitsikamma (Clavicaulis subgen. nov.) madiba Samaai, Kelly, Payne and Ngwakum sp. nov.

( Fig. 12 , Table 4)

Material examined. Holotype SAMC-A090883, Amathole region Stn 3813, East London , Eastern Cape, 32.681° S, 28.458° E, 52–54 m, RV Ellen Khuzwayo, collected by R. Payne, dredge, 26 Aug 2016 . Paratypes. SAMC-A 090882 , Thunderbolt reef, Cape Recife, Port Elizabeth , 34.052° S, 25.689° E, 38–40 m, collected by Patrick L. Colin , CRRF, 30 Mar 2000 ; SAMC-A090884, SAMC-A090885, SAMC-A090886, SAMC-A090889, Amathole region Stn 3893, East London , Eastern Cape, 33.163° S, 27.774° E, 36 m, RV Ellen Khuzwayo, collected by R. Payne, dredge, 03 Sep 2016 ; SAMC-A090887, Amathole region Stn 3832, East London , Eastern Cape, 32.759° S, 28.410° E, 45 m, RV Ellen Khuzwayo, collected by R. Payne, dredge, 27 Aug 2016 ; SAMC-A090888, Amathole, Stn 3872, East London , Eastern Cape, 32.950° S, 28.066° E, 40.5 m, RV Ellen Khuzwayo, collected by R. Payne, dredge, 31 Aug 2016 .

Type locality. Amathole , Eastern Cape Province, South Africa .

Distribution. Algoa Bay, Port Elizabeth and Amathole region off East London.

Description. Sponge wrinkled and purse-like, not stalked, but ovate, attached to a narrow base, 20 mm wide by 45 mm length by 36.5 mm bulb diameter ( Fig. 12A, B ). A very tough leathery purse surrounds a much softer choanosome that pulls away from the outer case upon collection. Surface undulating but smooth, crowded with small, button-shaped oscules, 1–2 mm diameter, 2 mm high and cauliform areolate porefields, 2–3 mm diameter, 6 mm high ( Fig. 12A ).. In preserved specimens the oscules are not visible ( Fig. 12B ). Texture rubbery, leathery and tough. Moderately compressible, breaks easily. No spicules visible. Colour in life is dark green to dark green brown; in preservative, the ectosome is brown, the choanosome is dark brown ( Fig. 12A ). Green/brown exudate present.

Skeleton. The overall architecture is purse-like, consisting of a thick ‘purse’ of tangential megascleres surrounding a much softer choanosome containing an irregular reticulation of wispy tracts of anisostyles. No honeycomb chambers present as in the Tsitsikamma subgenus. The choanosome detaches and falls away from the ectosomal purse in preservative. The choanosomal tracts range in width from 60–100 μm thick and form meshes that are elliptical in cross section and 350 μm wide. Microscleres are abundant throughout the choanosome and form an irregular palisade of oblique or erect microscleres, below which is a dense feltwork of tangential and paratangential styles approximately 560–960 μm deep ( Fig. 12G, H ).

Spicules ( Tables 1, 4; Fig. 12 C-F). Megascleres anisostyles, in two size categories: (1) Large, thick, straight or slightly sinuous, thickened centrally, hastate, 737 (681–758) × 19 (19) μm, sometime strongylote modification present; (2) straight or slightly sinuous, thickened centrally, hastate: 612 (576–672) × 19 (19) μm ( Tables 1, 4). Microscleres are small isochiadiscorhabds ( Fig. 12 C-F) with two whorls of cylindrical, conical tubercles, medium whorl absent, the apex of each tubercular projection is acanthose. Some isochiadiscorhabds (15%) shows signs of a small developing rudimentary spine centrally ( Fig. 12F ): 32 (28–36) × 5 (5) μm ( Table 4).

Substratum, depth range and ecology. Rocky reef with 1 m relief rocky bottom with areas of sand, 38–40 m depth.

DNA sequence data. We sequenced partial COI of collected material from different localities; GenBank accession numbers: COI MK153272 – MK153275 ; MK016477 .

Etymology. Named in honour of the great South African president Nelson Rolihlahla Mandela, also known by his clan name “Madiba”, liberation struggle hero and Nobel Peace Prize laureate, who passed away on 5 December 2013 at the age of 95.

Remarks. The anisodiscorhabds of Tsitsikamma (C.) madiba subgen. et sp. nov. and T. (C. subgen. nov.) pedunculata have two whorls of cylindrical conical spines, the median and subsidiary conical spines are absent. In about 20% of isochiadiscorhabds in all specimens of T. (C.) madiba subgen. et sp. nov., there is a small medium rudimentary conical-cylindrical spine protruding from the shaft ( Fig. 12F ). This character is absent in the isochiadiscorhabds of T. (C. subgen. nov.) pedunculata , which are stouter, shorter and have a wide manubrium. The shaft length in T. (C.) madiba subgen. et sp. nov. is longer than in T. (C. subgen. nov.) pedunculata . Tsitsikamma (C.) madiba subgen. et sp. nov. has larger, thicker anisostyles [thick 737 (681–758) × 19 (19) μm; thin 612 (576–672) × 19 (19) μm] than T. (C. subgen. nov.) pedunculata (thick 684 (591–728) × 16 μm; thin 536 (500–555) µm), but the isochiadiscorhabds are smaller than those found in T. (C. subgen. nov.) pedunculata [29 (27–30) × 7 µm]; T. (C.) Madiba subgen. et sp. nov. [32 (28–36) × 5 (5) μm] (see Table 1, 4).

Tsitsikamma (C. subgen. nov.) michaeli differs from T. (C.) madiba subgen. et sp. nov. in the following characteristics: 1) Tsitsikamma (C. subgen. nov.) michaeli is a small light olive-green sponge with a short stalk and surface dominated by small short tube-shaped oscula and large stalked cauliform porefields, while T. (C.) madiba subgen. et sp. nov. is dark green, oval shaped with small button-like oscules and large cauliform porefields (see Table 1); 2) Tsitsikamma (C. subgen. nov.) michaeli have smaller isochiadiscorhabd ( Table 4), and large anisostyles similar in average size to that found in T. (C. subgen. nov.) madiba sp. nov.; 3) The isochiadiscorhabds of T. (C. subgen. nov.) michaeli differ in the number of the conical-cylindrical tubercles having four or more groups, as opposed to two to three per group in T. (C.) madiba subgen. et sp. nov.; 4) the anisodiscorhabds of T. (C.) madiba subgen. et sp. nov. have two whorls of cylindrical-conical spines, the median and subsidiary conical spines are absent, as opposed to T. (C. subgen. nov.) michaeli having three to four whorls of cylindrical conical spines ( Fig. 5 ; Table 1).

Tsitsikamma (C.) madiba subgen. et sp. nov. is distinguishable from other Tsitsikamma species in the form of the sponge, being wrinkled and purse-like, no stalk, oval shaped, but attached to a narrow base, and in the microornamentation and structure of the isochiadiscorhabd. The Tsitsikamma (C.) madiba subgen. et sp. nov. is also encrusted by a grey/white encrusting didemnid ascidian ( Fig. 12A ).

There was no intraspecific genetic diversity for the COI gene sequences for specimens of T. (C. subgen. nov.) michaeli and no interspecific genetic diversity for T. (C. subgen. nov.) michaeli and the other specimens.

Figures

FIGURE 5. Microsclere morphology in Tsitsikamma (Tsitsikamma) and T. (Clavicaulis subgen. nov.) species (not to scale): A. T. (T.) favus Samaai & Kelly, 2002; B. T. (T.) scurra Samaai & Kelly 2003; C. T. (T.) amatholensis sp. nov.; D. T. (T.) nguni Parker-Nance, 2019; E. T. (Clavicaulis) pedunculata Samaai & Kelly, 2003; F. T. (C.) madiba subgen. et sp. nov.; G. T. (C.) michaeli Parker-Nance, 2019; H. T. (C.) beukesi subgen. et sp. nov.

FIGURE 12. Tsitsikamma (C.) madiba sp. nov.: A. In-situ image of paratype SAMC-A090882; B. Preserved holotype SAMC- A090883; C, D. Isochiadiscorhabds from paratype; E, F. Isochiadiscorhabds from holotype; G. Skeletal architecture of paratype showing thick ectosome (choanosome very fragile and breaks easily); H. Skeletal architecture of holotype, showing thick ectosome and ill-formed choanosomal spicule tracts.