Tsitsikamma 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 : 103-104

Genus Tsitsikamma Samaai & Kelly, 2002

Tsitsikamma favus Samaai & Kelly, 2002

Tsitsikamma pedunculata Samaai, Gibbons, Kelly & Davies-Coleman, 2003

Tsitsikamma scurra Gibbons, Kelly & Davies-Coleman, 2003

Tsitsikamma michaeli Parker-Nance, sp. nov.

Tsitsikamma nguni Parker-Nance, sp. nov.

Diagnosis.

Hemispherical, thick encrusting or pedunculate Latrunculiidae with a smooth, in some species generously folded, surface with cylindrical or volcano-shaped oscula and prominent areolate porefields. The ectosome is resident and leathery, the colour varies between species from pinkish to dark liver brown, dark turquoise or green in life. Megascleres are anisostyles with isochiadiscorhabd microscleres. The microscleres are present in an irregular palisade layer on the surface ectosome and line the internal tracts (from Samaai and Kelly 2002, Samaai et al. 2003).

Type species.

Tsitsikamma favus Samaai & Kelly, 2002

Remarks.

The diagnostic character that unites species of Tsitsikamma is the possession of isochiadiscorhabd microscleres. Isochiadiscorhabd or isochia(acantho)dis corhabds have a short straight smooth shaft bearing an apex whorl and manubrium and when present median whorls. These whorls consist of singular or grouped conico-cylindrical tubercles, radiating from the shaft, with the distal end acanthose. These differ from microscleres present in other Latrunculiidae such as the acanthose isospinodiscorhabds with stout straight shaft, with similar terminal whorls and discrete conical spines unevenly distributed along it in Cyclacanthia ; microscleres with disk-like whorls of spines that are different in shape and size, such as the anisodiscorhabds found in Latrunculia ; or isoconicodiscorhabds or ‘sceptres’ with stout straight shaft and undifferentiated terminal whorls found in Sceptrella ( Samaai and Kelly 2002, Samaai et al. 2006, Kelly et al. 2016). The ontogeny of the microscleres further set the genera within this family apart, as the protorhabd projections develop simultaneously in Tsitsikamma , Cyclacanthia , and Sceptrella but not so in Latrunculia ( Samaai and Kelly 2002, Samaai et al. 2004).

Interestingly, Tsitsikamma species occur in two very different growth forms. In two of the species, T. favus and T. scurra , the interior of the sponge is partitioned by reinforced dense spiculose tracks through the delicate choanosome. The third species, T. pedunculata , has a spicule dense stalk that supports a spherical pouch without the characteristic spicule tracts penetrating into the choanosome. The description of an additional two Tsitsikamma species, presented in this work, support this separation further as one has internal tracts and the other is purse-shaped.