Latrunculia microacanthoxea Samaai, Gibbons, Kelly & Davies-Coleman, 2003, sp. nov.
Creators: name: Samaai, Toufiek
name: Gibbons, Mark J.
name: Kelly, Michelle
name: Davies-Coleman, Mike
Publisher: name: Zenodo
Year: 2003
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Demospongiae
Poecilosclerida
Latrunculiidae
Latrunculia
Latrunculia microacanthoxea

description: Latrunculia microacanthoxea sp. nov. (Figs. 3 B, 4C, H, 5C)
Holotype material. BMNH 1996.7.3.1: Rheeders Bay, Tsitsikamma National Park, South Africa, 34º 10'S; 23º 54'E, collected by P. Coetzee, University of Port Elizabeth, 15 February 1995, 28 m.
Paratype material. SAM H­ 4962: Rheeders Bay, Tsitsikamma National Park, South Africa, 34º 10'S; 23º 54'E, 28 m, collected by P. Coetzee, University of Port Elizabeth, 10 April 1995.
Description. Semispherical sponge, 5 x 5 x 6 cm (length x width x height) (Fig. 3 B). Surface smooth with numerous regularly spaced, low, cylindrical oscules, 0.1 mm high and 1–4 mm wide. Numerous short, thick lipped crater­like areolate porefields, 2–6 mm wide, 0.1 mm high, with a distinct net­like poral membrane. Texture firm, resilient and leathery. Colour in life is olive green, mottled with brown patches, dark chocolate brown in preservative. Contains biologically active pyrroloquilonine alkaloids, discorhabdins A & H (Hooper et al., 1996; Beukes, 2000; Samaai, 2002; Antunes et al., unpublished data­ a).
Spicules. Megascleres— Styles: smooth with slight irregular inflations on shaft, centrally thickened, hastate and slightly sinuous, 397 (374–422) x 9.6 (9.6) m. Microscleres — Anisodiscorhabds (Fig. 4C): Manubrium base is bulky and irregularly spinose, basal shaft 11 m long, 8 m wide, median whorl 27 m diameter, apical whorl with spines slanted upwards, apex a small, regular crown­like tuft of spines. All whorls are notched along rim and divided into four segments, each segment with denticulate margins. Median and subsidiary whorls with secondary spines; 55 (50–60) x 7 (7.2–9.6) m. Microacanthoxeas (Fig. 4H): straight, thin, slightly blunt on both ends; 52 (50–55) x 3.4 m.
Skeleton. The choanosomal architecture is a dense well developed irregular polygonal­meshed reticulation formed by wispy tracts of styles (Fig. 5 C). The tracts range in width from 120–150 m in thickness, and form meshes that are 220 m wide. Towards the surface the tracts become dense, more regular, 136–140 m wide, plumose, and 280–300 m wide. Numerous megascleres and microscleres are scattered interstitially. Microacanthoxeas lines the tracts of the choanosome. The ectosome is clearly visible between microscleres in the surface palisade. Beneath the ectosome is a thick, paratengential layer of megascleres, approximately 300 m deep.
Ecology. Found on horizontal rocky substrata or under rocky overhangs, together with coral, bryozoa and other sponges at about 28 m.
Etymology. Named for the characteristic microacanthoxeas found in this species.
Remarks. Latrunculia microacanthoxea sp. nov. is morphologically very similar to L. lunaviridis sp. nov. and is not easily differentiated from it on field characteristics; both species are olive green and have similar surface structures. The colouration in preservative is different, however; L. lunaviridis sp. nov. is lighter and greener. Apart from some very minor differences in the morphology of the microsclere, the primary criteria for separation of this species from L. lunaviridis sp. nov. is the presence of microacanthoxeas, apparent restriction to the Eastern Cape coastline at Tsitsikamma National Park, and the lack of 3­ dihydrodiscorhabdins, found in L. lunaviridis sp. nov (see Table 2). An unusual and quite consistent histological feature is the sparseness of the ectosomal palisade in L. microacanthoxea sp. nov ..
description: Published as part of Samaai, Toufiek, Gibbons, Mark J., Kelly, Michelle & Davies-Coleman, Mike, 2003, South African Latrunculiidae (Porifera: Demospongiae: Poecilosclerida): descriptions of new species of Latrunculia du Bocage, Strongylodesma Lévi, and Tsitsikamma Samaai & Kelly, pp. 1-26 in Zootaxa 371 on pages 13-14, DOI: 10.5281/zenodo.156901