Gomphoneis skabitchevskii Kociolek, Kulikovskiy & Solak, 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 : 17

Gomphoneis skabitchevskii Kociolek, Kulikovskiy & Solak , sp. nov. ( Figs 251–260 , 410–411)

Valves elliptical-clavate, with headpole not protracted and rounded, footpole narrowly rounded. Length 7–19 µm, breadth 3–5 µm. Axial area narrow, expanded laterally to form a rectangular central area bordered by 1–2 shortened striae margin more coarsely arranged than other striae. 4 stigmoids occur around the central area, positioned at the ends of striae. Raphe is broadly lateral, undulate, with external proximal raphe ends rounded. External distal raphe ends extend straight onto the valve mantle at both apices. Costate striae radiate, except parallel at the headpole. Striae 17–21/ 10 µm. Apical pore field small. Septa and pseudosepta at poles, indistinct.

SEM shows the valve of G. skatichevskii to have 4 isolated stigmoids which are round in shape both internally (Fig. 410) and externally (Fig. 411). The valve interior has proximal raphe ends that are recurved in the same direction, and prominent helictoglossae at the poles (Fig. 410). Small pseudosepta are present at the apices. Externally, the striae are shown to have double rows of areolae that terminate near the axial area with one or two areolae. The proximal raphe ends are dilated, and the raphe is undulate. The apical pore field porelli are very similar to the areolae in shape and size (Fig. 411).

Type:— RUSSIA: Lake Baikal , Kapustinskaya Bay, N52 o 38.484, E107 o 23.218, 17.07.2011, leg. M. Kulikovskiy ( IBIW slide no. 18580m, holotype designated here (= Fig. 258 ); COLO slide no. 18580p, SZCZ slide no. 18580a, isotypes) .

Figures

PLATE 7: LM. Figs 169–174: Gomphoneis metzeltinii sp. nov. Fig. 169 is of the holotype. Figs 175–192: G. cf. subcapitata. Figs 193– 200: G. subcapitata sp. nov. Fig. 200 is of the holotype. Figs 201–214: G. inconspicua sp. nov. Fig. 201 is of the holotype. Figs 215– 222: G sp. cf. subcapitata. Figs 223–228: G. reichardtii sp. nov. Fig. 223 is of the holotype. Figs 229–237: G. sp. cf. skabitchevskii. Figs 238–250: G.sp. cf. skabitchevskii. Figs 251–260: G. skabitchevskii sp. nov. Fig. 258 is of the holotype. Figs 261–282: G.sp. cf. reichardtii. Scale bar = 10 µm for all figures.