Olifantiella gondwanensis M.Rybak, A.Witkowski & C.Riaux-Gobin, 2023

Rybak, Mateusz, Arsad, Sulastri, Riaux-Gobin, Catherine, Luthfi, Oktiyas Muzaky, Hallegraeff, Gustaaf, Cias, Renata, Kierzek, Agnieszka & Witkowski, Andrzej, 2023, Distribution and morphology of the diatom genus Olifantiella Riaux-Gobin & Compere in Indonesian and Australian waters, including the description of O. gondwanensis sp. nov., PhytoKeys 236, pp. 197-213 : 197

Olifantiella gondwanensis M.Rybak, A.Witkowski & C.Riaux-Gobin sp. nov.

Fig. 2A-X

LM.

Valves small, elliptic to linear-lanceolate with broadly rounded apices, 6.3-13.7 μm long and 2.7-3.4 μm in width. Striae barely resolvable with LM, 26-31 in 10 μm, an isolated pore (buciniportula) visible near the central area.

SEM.

Striae composed of macroareolae, equidistant, with finely perforated hymen. At the junction of the valve face and the mantle, a ridge runs over the striae and opens to the exterior by round to oblong fenestrae, bordered by long thin spines - pili. Near the buciniportula, 1-2 shortened striae are present. Buciniportula located on opposite side of valves. Macroareolae on mantle the same as on valve and possessing long thin spines. Apical slits are few and small-sized without spines in their lumen. External raphe slits are straight and filiform. External proximal raphe endings slightly bent towards buciniportula bearing side, terminal raphe endings strongly hooked to the same side. Buciniportula opening sunken in the valve face connected with central raphe endings by small grooves. Small silica warts present externally along the raphe slits. Girdle bands numerous without ornamentation. Internally proximal raphe endings simple, terminal raphe endings forming small helictoglossae. Small siliceous warts present near the proximal raphe endings. Internally double buciniportula, slightly raised and closed. Longitudinal channels visible internally along the valve margin.

Type locality.

Fitzroy Island, the Great Barrier Reef, Queensland, NE Australia, 16°55′38′′S, 149°59′24′′E (Fig. 1 ).

Type material.

Holotype: Slide SZCZ 28526 and unmounted material with the same number in the collection of Andrzej Witkowski at the University of Szczecin. Holotype population is depicted in Fig. 2A-X .

Isotype: Slide number 2022/64 at the Diatom Collection at the University of Rzeszów.

Etymology.

The species epithet is derived from Gondwana, a super continent of which Australia was part of during the Paleozoic and Mesozoic Era.

Distribution.

So far observed only from the Australian type locality.

Figures

Figure 1. Locality of the sampling sites 1 Bangka Island 2 Bawean Island 3 Poso Pesisir, Sulawesi Island 3 a, b view of the sampling site, photo. S. Arsad 4 type locality of Olifantiella gondwanensis sp. nov. in Fitzroy Island, Queensland, Australia 4 a view of the type locality 4 b green algae Chlorodesmis sp. from which sample was taken, photo. A. Witkowski.

Figure 2. Holotype population of Olifantiella gondwanensis sp. nov. from Fitzroy Island A-P valves in size diminution series viewed by light microscopy Q-X SEM micrographs Q, R external view of the valve, white arrowhead indicates the girdle band S opened frustule T details of valve central part in external view U detail of valve apex in internal view V internal view of valve W details of valve central part in internal view X detail of valve apex in internal view. = indicates a valves of the same specimen. Scale bars: 10 µm (A-P); 5 µm (Q, R); 4 µm (S); 3 µm (V); 1 µm (T, U, W, X).