Gomphosinica lugunsis Liu, Kociolek, You & Fan, 2018

Cheng, Yu, Liu, Yan, Kociolek, John Patrick, You, Qingmin & Fan, Yawen, 2018, A new species of Gomphosinica (Bacillariophyta) from Lugu Lake, Yunnan Province, SW China, Phytotaxa 348 (2), pp. 118-124 : 119

Gomphosinica lugunsis Liu, Kociolek, You & Fan sp. nov. ( Figs 1–30 )

Light microscopy ( Figs 1–18 ): Valves narrowly linear-clavate, asymmetrical to the transpical axis. Headpole slightly protracted to not protracted, rounded; valve narrows towards the rounded footpole. Length 10–16 μm, breadth 2.4– 3.7μm (25 specimens were measured based on the LM and SEM observations). Axial area linear, narrow, central area small, irregular in shape. Striae radiate in the middle of the valve and alternating in length, becoming convergent near the apices, 13–16/10μm. Stigma indistinct, positioned at the end of a central stria.

SEM: The exterior valve face has broad, biseriate striae ( Figs 19, 20 ). Striae are composed of 2 rows of small and round areolae ( Fig. 21 ). The raphe is straight and the proximal raphe ends are slightly dilated, round ( Fig. 22 ). Distal raphe ends nearly straight at both poles ( Figs 21, 24 ). At the headpole, the raphe end is present only on the valve face and it terminates well before the apex ( Fig. 21 ). At the footpole, distal raphe ends extend slightly from the valve face onto the valve mantle, but does not bisect the apical pore field (APF) into two parts ( Fig 24 ). The APF extends across the valve mantle, barely extending to the valve face. The valve mantle at the footpole is more heavily silicified, giving the impression that the porelli of the APF are larger than the areolae ( Fig. 23 ). A stigma located at one side of the central area, has a round opening ( Fig. 22 ). Internally, interstriae are thickened and raised ( Fig. 28 ). Areolar openings are small and round ( Fig. 30 ). Proximal raphe ends recurved to the same direction ( Fig. 29 ). Opening of the stigma is covered by a hooded structure, with several small perforations ( Fig. 29 ). Helictoglossae and pseudosepta are evident at the poles ( Fig. 27 ). The helictoglossae at the headpole are positioned a distance from the terminus of the valve. Septa and pseudosepta present at the apices ( Figs 27, 28 ).

Type:— CHINA. Yunnan Province: Lugu Lake. Filamentous algae, Coll. Y. Liu August 2014 (holotype: HANU! Individual in slide THHN 2014469, here illustrated as Fig. 2 , isotype: COLO! JPK material No. 11748, slide No. 613003)

Etymology: — This species is named for the lake in which it resides.

Figures

FIGURES 1–18. Gomphosinica lugunsis Liu, Kociolek,You & Fan sp. nov. Figs 1–17: LM pictures.Valve views showing size diminution series. Figure 2 is of the holotype. Fig. 18: Girdle view. Scale bar=10 μm.

FIGURES 19–24. Gomphosinica lugunsis Liu, Kociolek, You & Fan sp. nov. SEM pictures, externally view. Figs 19–20: The whole valve; Fig. 21: Headpole of the valve, showing the distal raphe end (white arrow), and the two rows of areolae (black arrow); Fig 22: Central area of the valve, showing the opening of the stigma (white arrow), and the central pore (black arrow); Figs 23–24: Footpole of the valve, Fig. 27: showing the apical pore field, Fig. 28: showing the distal raphe end.

FIGURES 25–30. Gomphosinica lugunsis Liu, Kociolek, You & Fan sp. nov. SEM pictures, internally view. Figs 25–26: The whole valve; Fig.27: Headpole of the valve, showing the helictoglossa (white arrow) and the septa (black arrow); Fig. 28: Footpole of the valve, showing the pseudosepta; Fig. 29: Central area, showing the opening of the stigma (white arrow) and proximal raphe ends (black arrow); Fig. 30: Magnification of the striae, showing the internal opening of the areolae.