Mallomonas kicherica, Bessudova & Firsova & Tomberg & Bayramova & Hilkhanova & Bedoshvili & Bashenkhaeva & Zakharova & Likhoshway, 2023

Bessudova, Anna, Firsova, Alena D., Tomberg, Irina V., Bayramova, Elvira, Hilkhanova, Diana, Bedoshvili, Yekaterina D., Bashenkhaeva, Maria, Zakharova, Lyubov I. Kopyrina Yulia R. & Likhoshway, Yelena V., 2023, Two new species of silica-scaled chrysophytes (Chrysophyceae, Synurales) Mallomonas kicherica and M. sibirica water bodies of Eastern Siberia, Russia, Phytotaxa 620 (1), pp. 59-69 : 62-63

Mallomonas kicherica sp. nov. Bessudova ( Figs. 2–4 ).

Description: Scales are 3.4–4.5 × 1.8–2.4 μm, oval with lateral incurvings. The dome is subcircular with labyrinth-like reticulation. Small ribs extending to the first transverse rib extend from the dome towards the shield. The shield is patterned with of 8–11 regularly spaced transverse ribs. The transverse ribs, except for the area between the first and second (closest to the dome), are connected in random order by short ribs-jumpers ( Figs. 2–4 ). The anterior flanges with 8–11 closely spaced struts on each side ( Figs. 2–4 ). The anterior submarginal ribs are well-developed. The V-rib on the scales is acutely angled, hooded. The posterior rim is wide and smooth. The posterior flange contains approximately 20–23 struts ( Figs. 2–4 ). Bristles are 6.5–9.2 μm in length, slightly curved ( Fig. 2 ). The tip of the bristle is bifurcated with unequal diverging branches. One branch is short and sharp, whereas the other is wide with an acute tip and flat dorsal side. Cysts were not observed.

Holotype (here designated): Portion of a single gathering of cells on SEM stub No. 18422 deposited at the herbarium of the Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk ( LIN). Material from the Angara-Kichera estuary , a tributary of the northern part of Lake Baikal , was collected in June 2022. Figures 2–4 illustrates the characteristic scales from the holotype.

Type locality: Mouth of the Kichera River , a tributary of the northern part of Lake Baikal , Republic of Buryatia, Russia. Latitude/Longitude: 55°43′55′′N, 109°32′24′′E.

Etymology: The new species name is derived from the type locality, the Kichera River.

Distribution: Up-to-date, M. kicherica has been only observed in its type locality. At the time of collection, pH = 8.04, T = 16.9°C, and EC = 112 μS̛ сm−1 (see Table 1 ).

Figures

FIGURES 2–4. Mallomonas kicherica sp. nov. Figure 2. Tips of bristles with teeth and bristle’s foot. Figures 3–4, scales with labyrinthlike reticulation on the dome and transverse ribs, except for the area between the first and second, are connected in random order by short ribs-jumpers. SEM Scale bars: 2 μm.