Gomphonema shanghaiensis W. Zhang & Kociolek, SEM. External 2016, sp. nov.
Creators: name: Zhang, Wei
name: Xu, Xiao-Ying
name: Kociolek, J. Patrick
name: Wang, Li-Qing
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Chromista
Ochrophyta
Bacillariophyceae
Cymbellales
Gomphonemataceae
Gomphonema
Gomphonema shanghaiensis

description: Gomphonema shanghaiensis W. Zhang & Kociolek, sp. nov. (Figs 1–30)   
Light microscopy: valves narrowly-lanceolate to rhombic-lanceolate, slightly asymmetrical to the apical axis, with a gibbous central portion. Footpole rounded and headpole slightly rostrate to narrowly-rounded (Figs 1–8). Valve length 45.9–74.8 μm, breadth 9.8– 12.5 μm, length/breadth ratio 4.6–5.9 (n=37). Raphe straight, filiform for most of its length, slightly lateral near the central area. Axial area narrow, linear. Center area small, irregularly rectangular in shape, unilaterally widened, formed by one short stria being slightly more distant from others. 1–5 rounded external stigmal openings present in or around the central area (Figs 1–8). Striae slightly radiate at the center and towards the headpole, radiate towards the footpole. Striae number 14–16/10 μm (mostly 14–15/10 μm) in the middle of the valve, becoming up to 17–19/10 μm towards the ends. Areolae not discernible in LM. Prominent bilobed apical pore field (APF) at the footpole separated from the striae by a smooth area (Figs 1, 2, 4). Small septa and pseudosepta at head and footpole. Scanning electron microscopy: valve exterior has a linear, straight axial area, a straight and mostly filiform raphe (Figs 9–11). External proximal raphe endings slightly expanded and dilated. Distal raphe ends deflected in the same direction onto the valve mantle (Fig. 11). Striae uniseriate, occasionally biseriate near the headpole (Figs 15–21), with C-shaped, curved, irregularly S- or 3-shaped areolae. 1–5 round external stigmal openings present at the end of individual striae in the central area (Figs 15–20). At the footpole the distal raphe end bisects the porelli of the APF. The APF is composed of round, unoccluded porelli and extends from the valve face across the mantle (Fig. 22). Porelli, of differing sizes, are physically separate and morphological differentiated from the valve face areolae (Fig. 22). Porelli number 60–70/10 μm. Internally, the central nodule is rounded and a distinct helictoglossa is present at each pole (Figs 12–14). The helictoglossae are offset to one side of the axial area and appears elevated on a ridge of silica (Figs 29, 30). Internal proximal raphe ends bend at a slightly acute angle and deflected in opposite directions (Figs 23–28). 1–5 slitlike or elliptical stigmal openings are present on the primary or secondary sides of the center area (Figs 23–28). A pseudoseptum is present at each pole (Figs 29, 30).  
 Type:— CHINA. Shujiawan River, Baoshan District, Shanghai, 31° 29’ 6.2” N, 121° 19’ 15.8” E, X. Y. Xu, 12 January 2016 (holotype: Laboratory of Aquatic Ecology and Environmental Restoration, Department of Hydrobiology, College of Fisheries and Life Science, Shanghai Ocean University, slide Shujia 01, illustrated in Fig. 1. Isotype COLO, slide deposited in the J.P. Kociolek Collection).   
 Etymology:— Gomphonema shanghaiensis is named after the type locality.
description: Published as part of Zhang, Wei, Xu, Xiao-Ying, Kociolek, J. Patrick & Wang, Li-Qing, 2016, Gomphonema shanghaiensis sp. nov., a new diatom species (Bacillariophyta) from a river in Shanghai, China, pp. 29-38 in Phytotaxa 278 (1) on pages 31-32, DOI: 10.11646/phytotaxa.278.1.3, http://zenodo.org/record/13651181