Mallomonas rutabuliformis E. S. Gusev, Safronova, Podunay & Martynenko 2026, sp. nov.

Mallomonas rutabuliformis E. S. Gusev, Safronova, Podunay & Martynenko sp. nov. Figs 1 A, B, 2 Description. Cells oval or ovate, 8.3–15.9 × 6.6–11.2 μm, covered by scales with bristles. Scales oval or elongated oval, 3.2–4.1 × 1.8–2.2 μm, with a dome. Shield with regularly arranged papillae and minute base plate pores (approx. 0.01–0.03 μm). The dome is shallow, broadly oval or rounded, recessed from the anterior margin, and is covered with papillae. In some cases, the dome is perforated with pores. The anterior flange is slightly raised above the shield, with two or three rows of papillae and few minute base plate pores. The V-rib is prominent and rounded, with arms of unequal length. The posterior rim is narrow, encircles approximately one-third of the scale perimeter. The posterior flange is narrow, with few base plate pores. Bristles are 2.3–6.2 μm long, slightly curved, with a hook-shaped flattened foot, turned at an angle from 45 to 90 degrees relative to the shaft. The margins of the bristles are rolled to form an open U-shaped groove, the distal tip is bifurcated, with spines of unequal length. Cysts were not observed. Holotype. (here designated): Portion of a single gathering of cells on SEM stub, deposited at the Herbarium, Komarov Botanical Institute RAS (LE), Saint Petersburg, Russia (LE A 0007759). Material from a stream in the forest in Lam Dong Province, Vietnam, leg. N. A. Martynenko, 8 June 2019. Fig. 2 A is a representative scale from the specimen. Type locality. Vietnam, Lam Dong Province, stream in the forest. Latitude / longitude: 12°10.540'N, 108°41.996'E. Reference culture. Culture VNG 2139: Representative living and fixed culture VNG 2139 and DNA sample deposited at the Collection of the A. N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences. Genbank accession number for reference culture (VNG 2139): PX 698596 (nuclear SSU + ITS rDNA) and PX 703662 (rbc L cpDNA). Etymology. The epithet is named based on the morphological character of the bristles, which are bent in the distal part, reminiscent of a poker shape. Distribution. Species was found only in the type locality. Observations. Mallomonas rutabuliformis was found at pH 7.7, a specific conductance of 18 μS cm - 1 and temperature 19 ° C (Table 1). Description of Mallomonas multisetigera culture In our studies, we found morphotype of Mallomonas multisetigera, similar in ultrastructure to originally described form South Chile (Dürrschmidt 1982). Here, we provide a description of our cultures based on LM, SEM, and TEM studies and complement them with molecular studies.