taxonID	type	description	language	source
03EE87F9FFCEFFB1FF3393C35FB6F94C.taxon	description	Scanning electron microscopy (SEM): (19 – 35). Externally, striae composed of small open poroids, 20 – 23 in 10 µm, becoming denser towards apices, 30 – 35 in 10 µm. Areolae proximal in striae distinct, enlarged, slit-like in the center, rounded at poles, forming a row surrounding the sternum (Figs 20 – 23). Virgae wide. Striae uniseriate, areolae on the surface of canals biseriate return to being uniseriate on the deep mantle (Figs 20, 22). Apical valve areas smooth and non-porous (Figs 22, 23). Proximal raphe endings simple, drop-shaped, lay in grooves (Figs 20, 21). Distal fissures widely curved unilaterally, do not extend on the mantle (Figs 22, 23). Cingulum of at least two bands (Figs 25, 26). Internally, each stria consists of transversely elongated alveoli interrupted by a narrow hyaline area, continuing as offset rows of shorter alveoli (Figs 27 – 33). Alveoli covered with porous hymens (Figs 28, 31). Paired slit-like foramina at alveolus margins form two rows along the valve (Fig. 32). External pores are visible in a partially damaged valve through alveoli lacking hymens (Figs 34, 35). Proximal raphe endings terminate on an elevated, apically oblong central nodule, resembling a double helictoglossa, distal fissures end in small helictoglossae (Figs 28, 29, 31).	en	Rodionova, Yelena V., Pomazkina, Galina V., Sherbakova, Tatyana A. (2025): Neidiopsis baicalensis sp. nov. (Bacillariophyta) - the first recorded occurrence of the genus in Lake Baikal. Phytotaxa 708 (2): 227-235, DOI: 10.11646/phytotaxa.708.2.9, URL: https://doi.org/10.11646/phytotaxa.708.2.9
03EE87F9FFCEFFB1FF3393C35FB6F94C.taxon	materials_examined	Type: RUSSIA. Lake Baikal: Southern basin, near the settlement Mangutie, sand sample collected by a diver at 2 m depth at station 41 (51.6069 ° N, 103.91028 ° E) on June 22 1998 (holotype: NS 1000203 housed at the Central Siberian Botanical Garden, Novosibirsk, Russia, Herbarium of Vascular Plants. Holotype specimen is illustrated in Fig. 6. Isotypes: slides 0140 – ВК, 0145 – ВК Limnological Institute SB RAS, Irkutsk, Russia, station 40 near the city of Baikalsk). Habitat and distribution: yet found in Lake Baikal in the type locality.	en	Rodionova, Yelena V., Pomazkina, Galina V., Sherbakova, Tatyana A. (2025): Neidiopsis baicalensis sp. nov. (Bacillariophyta) - the first recorded occurrence of the genus in Lake Baikal. Phytotaxa 708 (2): 227-235, DOI: 10.11646/phytotaxa.708.2.9, URL: https://doi.org/10.11646/phytotaxa.708.2.9
03EE87F9FFCEFFB1FF3393C35FB6F94C.taxon	etymology	Etymology: The epithet baicalensis refers to the name of the type locality.	en	Rodionova, Yelena V., Pomazkina, Galina V., Sherbakova, Tatyana A. (2025): Neidiopsis baicalensis sp. nov. (Bacillariophyta) - the first recorded occurrence of the genus in Lake Baikal. Phytotaxa 708 (2): 227-235, DOI: 10.11646/phytotaxa.708.2.9, URL: https://doi.org/10.11646/phytotaxa.708.2.9
03EE87F9FFCEFFB1FF3393C35FB6F94C.taxon	biology_ecology	Ecology and associated diatom taxa: Neidiopsis baicalensis inhabits oligotrophic, slightly alkaline waters (pH 7.6 – 8.4) with low mineral content (less than 100 mg / l), typically found on silty – sand substrates at depths of 2 – 20 m. Water temperatures range from 4 ° C to 7 ° C, with upper layers warming to 14 ° C – 16 ° C during the summer season (Votintsev 1961, Blinov et al. 2017, Podlesnaya et al. 2021). At the type locality in the southern basin of Lake Baikal, Neidiopsis baicalensis was uncommon but formed a noticeable part of the benthic diatom assemblage, with less than 3 % abundance. The dominant species (each with over 5 % abundance) included widely distributed taxa such as Amphora pediculus (Kützing) Grunow in Schmidt (1875: fig. 26: 99), Navicula radiosa Kützing (1844: 91, fig. 4: 23), Sellaphora bacillum (Ehrenberg) D. G. Mann in Reichardt (2018: 210), and Cocconeis placentula Ehrenberg (1838: 194), as well as endemic species such as Aneumastus perodon Kulikovskiy, Metzeltin & Lange-Bertalot (2012: 48), Aneumastus odon Kulikovskiy, Metzeltin & Lange-Bertalot (2012: 47), Sellaphora baicalobacillum Metzeltin, Kulikovskiy & Lange-Bertalot in Kulikovskiy et al. (2012: 244), Skabitschewskia oestrupii (A. Cleve) Kulikovskiy & Lange-Bertalot in Kulikovskiy et al. (2015: 85), Amphora crispans Pomazkina & Rodionova (2014: 126), and Amphora baicalopseudoeximia Pomazkina & Rodionova (2014: 124). Other taxa, each with less than 1 % abundance, were rare species with exclusively Baikalian distribution, including Lacustriella rombea Rodionova, Pomazkina & Sherbakova (2022: 174), L. solita Rodionova, Pomazkina & Sherbakova (2022: 175 – 178), Neidium spirale Pomazkina & Sherbakova in Pomazkina et al. (2021: 93 – 94), N. levii Sherbakova in Pomazkina et al. (2021: 65 – 66), Diploneis pumicosus Sherbakova, Pomazkina & Rodionova in Rodionova et al. (2019: 99), and D. implicatus Pomazkina, Rodionova & Sherbakova in Rodionova et al. (2019: 96).	en	Rodionova, Yelena V., Pomazkina, Galina V., Sherbakova, Tatyana A. (2025): Neidiopsis baicalensis sp. nov. (Bacillariophyta) - the first recorded occurrence of the genus in Lake Baikal. Phytotaxa 708 (2): 227-235, DOI: 10.11646/phytotaxa.708.2.9, URL: https://doi.org/10.11646/phytotaxa.708.2.9
