Gomphoneis xinjiangiana Q. You & Kociolek, 2013

You, Qingmin, Kociolek, John Patrick & Wang, Quanxi, 2013, New Gomphoneis Cleve (Bacillariophyceae: Gomphonemataceae) species from Xinjiang Province, China, Phytotaxa 103 (1), pp. 1-24 : 11

Gomphoneis xinjiangiana Q. You & Kociolek , sp. nov. ( Figs 39 –54; figure 42 is holotype)

Type:— CHINA. Little Kalakule Lake , Kunlun Mountains ( SHTU, slide XJ-071014! holotype illustrated in figure 42) .

In LM, valves lanceolate-clavate with headpole tapering and narrowly rounded and footpole tapering and slightly broader than headpole, rounded to squarish in shape. Length 22.4–32.7 µm, breadth 5.3–6.3 µm. Axial area narrow, straight, expanded at the center to form a bow-tie shaped central bordered on either side by 2–3 shortened striae on the margins. Stigmoids in the central area wanting. Raphe is weakly lateral and undulate, with external proximal ends dilated extending slightly into the central area, and external distal raphe ends extended straight to the valve terminus at both poles. Internal distal raphe ends (“terminal nodules”) are distinct, positioned well before the valve terminus. Costate striae number 14–16/ 10 µm, are arched about the center of the valve and radiate, becoming parallel towards the headpole and weakly radiate towards the footpole. Septa and pseudosepta are indistinct. Apical pore fields bilobed and present at the footpole.

In the SEM, the valve exterior has striae composed of double rows of small, round puncta that alternate (Figs 49–51). These striae terminate at double rows along the axial area (Figs 49, 51), except at the center where they taper and go from double to single rows of puncta (Fig. 50). Striae continue from the valve face to the mantle. The raphe is straight, with proximal ends dilated (Fig. 50) and distal ends deflected slightly and continue onto the mantle (Figs 49, 51). The apical pore fields are composed on of round porelli that are the same size or slightly larger than the puncta. Porelli are organized into double rows, but much more condensed than the puncta (Fig. 51).

Internally, the raphe is located in the axial area that becomes raised near the rounded central nodule (Fig. 48). The proximal raphe ends terminate on the edges of the central nodule (Fig. 53). Striae around the centeral area terminate as single rows of areolae (Fig. 53). Prominent pseudosepta and helictoglossae are evident at the ends of the valve (Figs 52, 54). The apical pore fields are seen to have divisions between rows of porelli, but the divisions are thinner than interstriae (Fig. 54).

Etymology:— The species is named for Xinjiang Province, in which it was found.

Distribution and ecology:— Little Kalakule Lake, Kunlun Mountains, Xinjiang, China, altitude 3300m, pH 9.0, collected in the wetland near the lake (summarized in Table 1).

Figures

PLATE 8, FIGURES 39–47. Gomphoneis xinjiangiana, LM. Valve views showing size diminution series. Figure 42 is the holotype. Scale bar = 10 µm for all figures.