Gomphoneis fourtanierae Kociolek & Kulikovskiy, 2013

Kociolek, John P., Kulikovskiy, Maxim S. & Solak, Cüneyt N., 2013, The diatom genus Gomphoneis Cleve (Bacillariophyceae) from Lake Baikal, Russia, Phytotaxa 154 (1), pp. 1-37 : 18

Gomphoneis fourtanierae Kociolek & Kulikovskiy , sp. nov. ( Figs 287–306 402–404 )

Valves clavate with headople protracted and rostrate, footpole rounded. Length 19–55 µm, breadth 5–11 µm. Axial area very narrow, straight, broadening to form a rectangular to bow-tie shaped central area, bordered on each side by 1–2 shortened striae which area more coarsely arranged than other striae. Stigmoids in the central area wanting. Raphe barely lateral, straight, with external proximal raphe ends dilated slightly. Striae costate, radiate near the central area, becoming parallel to slightly convergent towards both poles. Striae 15–18/ 10 µm. Apical pore fields not visible on the valve face. Small septa and pseudosepta present at the poles.

In the SEM, this species is shown to have small pseudosepta at the apices ( Figs 402–404), with the pore field having thin ribs ( Fig. 404). Proximal raphe ends are recurved in the same direction, being located on irregularly-shaped central nodule. Helictoglossae are also present near the poles ( Figs 402–404).

Type:— RUSSIA: Lake Baikal , Cape Khoboj, stones and algae, 1998, Darwin Initiative sample ( COLO, slide for Station 9, number 9, holotype designated here (= Fig. 288 ); IBIW slide no. Station 9, number 9m, isotype) .

Etymology:— Named in honor our friend and colleague, of Dr. Elisabeth Fourtanier, in honor of her outstanding contributions to diatom research.

Observations:— This species is proportionally more stout, and the apices less protracted, as compared to G. capitata .

Figures

PLATE 8: LM. Figs 283–286: Gomphoneis baicaliana sp. nov. Fig. 285 is of the holotype. Figs 287–304: G. fourtanierae sp. nov. Fig. 288 is of the holotype. Figs 305–315: G. potapovae sp. nov. Fig. 307 is of the holotype. Figs 316–327: G.strelnikovae sp. nov. Fig. 319 is of the holotype. Figs 328–334: G. minuscula sp. nov. Fig. 333 is of the holotype. Figs 335–352: G. capitata sp. nov. Fig. 336 is of the holotype. Scale bar = 10 µm for all figures.

PLATE 9: LM. Figs 353–359: Gomphoneis russica sp. nov. Fig. 353 is of the holotype. Figs 360–364: G. subrussica sp. nov. Fig. 364 is of the holotype. Figs 365–367: G. impressa sp. nov. Fig. 366 is of the holotype. Scale bar = 10 for all figures.

PLATE 10: SEM. Figs 368–371: Gomphoneis lata. External valve views. Fig. 368: Overall valve view showing robust interstriae, thickened central area, straight raphe and isolated stigmoids. Fig. 369: Headpole with raphe extending well onto valve mantle. Fig. 370: Central area with doubly punctate striae ending as single areolae and isolated stigmoids much larger than the areolae. Fig. 371: Footpole, with apical pore field bisected by distal raphe end curving onto mantle, porelli elongate and right next to the striae, and some striae composed of 2 or 3 rows of areolae.