New Gomphoneis Cleve (Bacillariophyceae: Gomphonemataceae) species from Xinjiang Province, China
Author
You, Qingmin
College of Life and Environment Science, Shanghai Normal University, Shanghai 200234, China
Author
Kociolek, John Patrick
Museum of Natural History and Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309 USA * Corresponding author (wangqx @ shnu. edu. cn)
Author
Wang, Quanxi
College of Life and Environment Science, Shanghai Normal University, Shanghai 200234, China
text
Phytotaxa
2013
2013-05-28
103
1
1
24
http://dx.doi.org/10.11646/phytotaxa.103.1.1
journal article
10.11646/phytotaxa.103.1.1
1179-3163
5077594
Gomphoneis distorta
Q. You & Kociolek
,
sp. nov.
(
Figs 97
–108; figure 98 is
holotype
)
Type:—
CHINA
.
Little Kalakule Lake
,
Kunlun Mountains
(
SHTU
, slide XJ-071015!
holotype
illustrated in figure 98)
.
In LM, valves linear-clavate straight or with only a slight tumid swelling at the center, headpole narrowly rounded and footpole rounded. Length 30.0–
45.2 µm
, breadth
5.5–7.5 µm
. Axial area narrow, expanded to form a small, round to elliptical, to sometimes nearly rectangular central area, stigmoids wanting. Raphe straight, lateral, with external proximal ends dilated slightly and external distal raphe ends extending straight to the terminus. Internal distal raphe ends are indistinct. Costate striae 10–14/
10 µm
, arched and strongly radiate around the center, with 1–2 shortened striae on either side of the central area. Striae towards the headpole become parallel and nearly convergent towards the terminus. Towards the footpole striae are radiate to parallel. Septa and pseudosepta indistinct. Apical pore fields bisected, distinct at the footpole.
PLATE 16, FIGURES 97–101.
Gomphoneis distorta
, LM.
Valve views showing size diminution series. Figure 98 is the holotype. Scale bars = 10 µm for all figures.
In the SEM, the exterior of the valve is dominated with striae composed of two rows of areolae (
Figs 103–
105). The headpole has striae that extend onto the mantle, and the distal raphe end is deflected slightly before reaching the apex and extending onto the mantle (
Fig. 103
). The central area has dilated proximal raphe ends and striae that are biseriate near the margins but taper to uniseriate striae towards the axial area and central area (
Fig. 104
). The apical pore fields have porelli in distinct rows and extend all over the mantle (
Fig. 105
).
Internally, the valve interior has prominent helictoglossae and pseudosepta at the poles (Figs 102, 106, 108). The central part of the valve has a slightly raised central nodule, where deflected proximal raphe ends occur. Striae become uniseriate near the axial area, and in this region strong thickenings are evident (Fig. 107).
Etymology:—
The species is named for its slightly distorted valve outline.
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
).
Observations:—
This species is differentiated from
G. stoermeri
in being more linear in outline, without the distinct tumid middle section of the valves.