Gomphosinica chongbayongcuoensis 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 : 109-110

Gomphosinica chongbayongcuoensis Y.-L. Li sp. nov. (LM: 23–34 SEM: 35–42)

LM: ( Figs 23–34 ): Valves are elliptical-clavate, distinctly asymmetrical to the transapical axis. Headpole is constricted, subcapitate or capitate. The footpole is protracted, rostrate-subcapitate. Length 19.5–26.0 μm, width 6.0–7.0 μm. Axial area is narrow and straight. Central area is round to irregularly-rounded and has alternating long and short striae on either side. A single stigma is positioned at the end of a central stria. The raphe is filiform and straight. Striae are radiate more strongly towards the central area, and number 19–22/10 μm.

SEM: Valve exterior ( Figs 35–38 ): The areolae are small and round, occurring mostly in 3 rows, sometimes 2 rows near the footpole. The raphe is slightly undulate. The proximal raphe ends are slightly dilated. The distal raphe ends are nearly straight, terminating on the valve face without apical pore field at the headpole, while bisecting the apical pore field at the footpole. Porelli are round, morphologically similar to the individual areolae. The single stigma opening is prominent and round.

Valve interior ( Figs 39–42 ): The central nodule is irregular, located in the center of the valve. Proximal raphe ends are recurved towards the same direction The distal raphe ends terminate in helictoglossae and slightly bent. The stigma opening is covered by a hooded structure, which has around it and on it several perforations.

Type: CHINA. Xizang: Chumba Yumco , Kangma County, 28°14′52.48′′ N, 89°38′53.89′′ E, 28 July 2021. Stone scraping samples collected by Yan-Ling Li (Holotype CY 2020032802 in Coll. Yan-Ling Li, Yunnan University, Kunming, China = Fig. 26 ; Isotype YUNGL20220511 , Harbin Normal University, Harbin, China) .

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

Ecology:— Gomphosinica kangmaensis sp. nov. and G. chongbayongcuoensi s sp. nov. has been observed from epilithic samples from Lake Chumba Yumco. G. kangmaensis sp. nov. comprises 20 % and G. chongbayongcuoensis sp. nov. comprises 24.6 % of the community, together accounting for 44.6 % of the total. They were mainly associated with Cymbella pusilla Grunow (15.7 %), Gomphosinica sp. (11.2 %), Navicula crypytotenella Lange-Bertalot (1985: 62–64) (9.7 %), Nitzschia dissipata (Kützing) Rabenhorst (1860: 968) (4.3 %), and Gomphonema sp. (3.2 %).

Figures

FIGURES 23–34. Gomphosinica chongbayongcuoensis sp. nov., LM, DIC. Valve views, showing the valve variability of the holotype population. Scale bar = 10 μm (Figs 23–34).

FIGURES 35–38. Gomphosinica chongbayongcuoensis sp. nov., SEM, external view. Fig. 35: External view of the entire valve. Fig. 36: Headpole of the valve, showing 3 rows round areolae and nearly straight proximal raphe end. Figs 37: Footpole of the valve, showing 2 rows round areolae and nearly straight distal raphe end. Fig. 38: External view of valve center, showing the opening of the stigma, bordered by 2–4 shortened striae. Scale bars = 2 μm (Figs 35–38).

FIGURES 39–42. Gomphosinica chongbayongcuoensis sp. nov., SEM, internal view. Fig 39: The entire valve; Fig.40: Headpole of the valve, showing the helictoglossa and the pseudoseptum; Fig. 41: Footpole of the valve, showing the pseudoseptum; Fig. 42: Internal view of the entire valve, showing the opening of the stigma and proximal raphe ends. Scale bars = 2 μm (Figs 39–42).