Gomphosinica kangmaensis Y.-L. Li, 2025

Xie, Shi-Yi, Huang, Ji-Min, Zheng, Kun, Guo, Ji-Shu, Kociolek, John Patrick & Li, Yan-Ling, 2025, Two new diatoms of the genus Gomphosinica from Chumba Yumco, Xizang, China, Phytotaxa 684 (1), pp. 105-116 : 106-107

Gomphosinica kangmaensis Y.-L. Li sp. nov. (LM: Figs 1–14 SEM: Figs 15–22 )

LM: ( Figs 1–14 ): Valves narrow linear-clavate, asymmetrical to the transapical axis, headpole rounded, footpole protracted, slightly rostrate to narrowly-rounded. Length 26.0–33.0 μm, width 4.5–5.5 μm. Raphe straight. Axial area narrow and linear. Central area expanded to form a round to bow-tie-shaped, bordered by 3–4 shortened central striae.

Striae radiate more strongly towards the central area, density 12–15/10 μm. Single stigma positioned at the end of a central stria.

SEM: Valve exterior ( Figs 15–18 ): Areolae are small and round, arranged in mostly 2 rows. The raphe is straight to slightly undulate with the proximal raphe ends being dilated slightly. Distal raphe ends are expanded on the valve mantle and bisect the pore field at the footpole. Condensed striae present at the foot pole on the mantle, being morphologically similar to the areolae, organized into double rows ( Figs 15, 17, 18 ). The external stigma opening is prominent and round. At the headpole, porelli are parallel around the valve mantle.

Valve interior ( Figs 19–22 ): There is a distinct irregular central nodule in the center of the valve. Proximal raphe ends are recurved to the same direction. Distal raphe ends are bent slightly and terminate in small, knob-like helictoglossae. Pseudosepta are evident at the poles. The stigma opening is covered by a hooded-like structure, which has around it and on it several perforations. Apical pore field partly evident at foot pole ( Figs 19, 21 ).

Type: CHINA. Xizang: Kangma County, Chumba Yumco , 28°14′52.48′′ N, 89°38′53.89′′ E, 28th July 2021, stone scraping samples collected by Yan-Ling Li (Holotype CY 2020032801 in Coll. Yan-Ling Li, Yunnan University, Kunming, China = Fig. 4 ; Isotype YUNGL20220510 , Harbin Normal University, Harbin, China) .

Etymology: The specific epithet ‘kangmaensis’ refers to the locality from which the new species was described.

Figures

FIGURES 1–14. Gomphosinica kangmaensis sp. nov., LM, DIC. Valve views, showing the valve variability of the holotype population. Scale bar = 10 μm (Figs 1–14).

FIGURES 15–18. Gomphosinica kangmaensis sp. nov., SEM, external view. Fig. 15: External view of the entire valve. Fig. 16: External view of valve center, showing the opening of the stigma, the white arrows in the figure indicate partly 1 row near the central area; Fig. 17: Headpole of the valve, showing condensed striae that appear as a possible apical pore field. Figs 18: Footpole of the valve, showing partly apical pore field on mantle. Scale bars = 2 μm (Figs 15–18).

FIGURES 19–22. Gomphosinica kangmaensis sp. nov., SEM, internal view. Fig 19: The entire valve; Fig. 20: Headpole of the valve, showing the helictoglossa and the pseudoseptum; Fig. 21: Footpole of the valve, showing the weak pseudoseptum; Fig. 22: Central area, showing the opening of the stigma and proximal raphe ends. Scale bars = 2 μm (Figs 19–22).