Adlafia belyakovae Chudaev & Levkov, 2023

Chudaev, Dmitry & Levkov, Zlatko, 2023, A new species of the genus Adlafia (Anomoeoneidaceae, Bacillariophyta) from Moscow Region (Russia) and North Macedonia, Phytotaxa 629 (3), pp. 266-274 : 267-268

Adlafia belyakovae Chudaev & Levkov sp. nov.

Description: —LM( Figs 1–27 , 32–46 ):Valves lanceolate to linear-lanceolate with narrowly rounded to barely protracted ends, length 8.0–10.0 µm, width 2.5–3.2 µm, length to width ratio 2.7–3.7 (n=30, type material) 1. Valve structure invisible in LM, except the median raphe sternum with barely distinguishable straight central raphe endings.

SEM, external valve surface ( Figs 28–29 , 47–51 ): Valve surface flat, without ridges or furrows. Striae and areolae barely visible due to external position of hymenes, lying at the same level as valve surface. Axial area narrow, linear; central area almost absent to slightly expressed and wider than axial area. Raphe branches almost straight or slightly undulated with slightly expanded central ends and unilaterally gently curved terminal fissures, sloping down to the mantle.

1 Population from the North Macedonia has following values of metric characters: length 8.0–9.5 µm, width 2.3–3.4 µm, length to width ratio 2.5–3.8 (n=72).

SEM, internal valve surface( Figs 30–31 ):Striae radiate in valve centre, becoming subparallel or slightly convergent towards apices; in central region shortened marginal striae present between the longer ones. Striae density 41–50 in 10 µm. Areolae openings square to circular, 59–72 in 10 µm. Single rows of areolae surround valve apices. Raphesternum linear, thickened. Raphe straight, with unilaterally deflected proximal endings, at the apices terminates in well-developed straight helictoglossae. Small knob-like round thickening presents between proximal raphe endings.

Type: — RUSSIA: Moscow Region, Lytkarino , small temporary spring puddle in deciduous forest, washing from plant debris, 55.57276° N 37.93421° E, D.A. Chudaev, 27 April 2022 (Holotype: MW-D! slide # 979s1 = Fig. 1 , isotype: LE A0004241 ).

Etymology: —The species is thankfully dedicated to Dr. Galina Alekseevna Belyakova, the author of many Russian phycological textbooks and the first phycology teacher of D.A. Chudaev.

Distribution and ecology: —The species has been observed in its type locality and also a population was found in North Macedonia. The type population originates from a shallow temporary waterbody with slightly alkaline water (pH 7.8) and medium electrolyte content (370 µS/cm). Accompanying diatom flora is represented by Nitzschia acidoclinata Lange-Bertalot (1976: 277) , Nitzschia palea var. debilis ( Kützing 1844: 65) Grunow (in Cleve & Grunow 1880: 96), Pinnularia marchica I.Schönfelder (in Krammer 2000: 218), Pinnularia sinistra Krammer (1992: 175) , Sellaphora nigri (De Notaris in De Notaris & Baglietto 1872: num. 632) Wetzel & Ector (in Wetzel et al. 2015: 221), Sellaphora subseminulum (Hustedt in Brendemühl 1949: 441) Wetzel (in Wetzel et al. 2015: 218). Besides diatoms the slide contains a lot of chrysophycean cysts. The population from North Macedonia was found in a small temporary wetland near the cave Krasna, Mountain Jakupica. Diatom flora is represented by Navicula cryptocephala Kützing (1844: 95) , Gomphonema varioreduncum Jüttner, Ector, Reichardt, Van de Vijver & Cox (in Jüttner et al. 2013: 306), Nitzschia palea var. debilis , Nitzschia alpina Hustedt (1943: 232) , Planothidium lanceolatum (Brébisson ex Kützing 1846: 247) Lange-Bertalot (1999: 287) , Meridion circulare ( Greville 1822: 213) Agardh (1831: 40) and Fragilaria Lyngbye (1819: 182) sp.

Figures

FIGURES 1–31. Adlafia belyakovae sp. nov., type material from the Moscow Region. 1–27. LM, slide MW-D 979s1, Fig. 1 represents the holotype. 28–29. SEM, external valve surface. 30–31. SEM, internal valve surface. Scale bars = 10 µm (1–27), 2 µm (28–31).

FIGURES 32–51. Adlafia belyakovae sp. nov., population from the North Macedonia. 32–46. LM, slide MKNDC 004431. 47–51. SEM, external valve surface. 47–48. Whole valve. 49. Half-valve with centre and apex. 50. Central part of the valve from Fig. 47 at higher magnification. 51. Valve apex. Scale bars = 10 µm (32–46), 2 µm (47, 48), 1 µm (49–51).