Diploneis krammeri Lange-Bertalot & Reichardt 2000
Creators: name: Jovanovska, Elena
name: Levkov, Zlatko
name: Edlund, Mark B.
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Chromista
Ochrophyta
Bacillariophyceae
Naviculales
Diploneidaceae
Diploneis
Diploneis krammeri

description: Diploneis krammeri Lange-Bertalot & Reichardt (Figs 113–134)   
Valves are elliptical-lanceolate with convex margins and round ends (Figs 113–124). The valve length is 23.0–34.0 μm, and the valve breadth is 13.0–17.0 μm. The axial area is linear to lanceolate, expanding toward the round to slightly elongate central area. Internally a thick silica plate covers the longitudinal canal throughout (Fig. 125). Externally the central area is elongate, 2.5–3.5 μm wide. From outside the longitudinal canal is linear to lanceolate, expanded in the middle of the valve with one to two rows of areolae. The external openings of the canal areolae are covered with cribra similar to those on the striae, from which the canal areolae are separated with a thick hyaline area (Figs 129, 130, 133). From inside, the longitudinal canal is covered with thick silica forming a “depression” where the raphe is placed (Figs 125, 156). Externally, the raphe is straight with expanded proximal ends slightly bent to the same side of the valve and positioned within a small depression (Figs 129, 130, 133). From outside the distal raphe endings finish with short terminal fissures bent to the same side of the valve (Figs 129, 131, 132, 134). Internally, the raphe is straight and simple, placed in the “depression” formed by the longitudinal canal (Fig. 125). The proximal raphe endings are the only raphe section reaching the height of the longitudinal canal in contrast to the only slightly elevated distal ends (Figs 125–127). The striae are radiate, 11(12) in 10 μm, with round areolae covered with cribra (Fig. 128), 13–15 in 10 μm. The external areolar openings increase in size and become more complex in structure, or are biseriate toward the valve margins (Figs 129, 131, 132, 134). Internally the alveoli open via a single continuous and elongate opening covered with a fine silica layer (Figs 125, 126).  
 Observations: —In the original description of D. krammeri the longitudinal canal is composed of one row of areolae throughout the whole length (Lange-Bertalot & Reichardt 2000: pl. 4, figs 1–10, 12). However, on the SEM illustrations the external openings of the longitudinal canal are composed of two rows of areolae in the middle of the valve narrowing into one at the valve apices (Lange-Bertalot & Reichardt 2000: pl. 5, figs 1–5). The longitudinal canal in Lake Hövsgöl populations are composed of one row of areolae throughout, which unambiguously fits the LM illustrations given by Lange-Bertalot & Reichardt (2000).   
 Ecology and Distribution: —M063A; M248A; M273A; M274A; M280A; M329A: distributed in shallow to deep benthic habitats throughout Lake Hövsgöl in the sediments and marl.
description: Published as part of Jovanovska, Elena, Levkov, Zlatko & Edlund, Mark B., 2015, The genus Diploneis Ehrenberg ex Cleve (Bacillariophyta) from Lake Hövsgöl, Mongolia, pp. 201-248 in Phytotaxa 217 (3) on page 227, DOI: 10.11646/phytotaxa.217.3.1, http://zenodo.org/record/13634131