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Issue: Vol. 730 No. 3: 21 Nov. 2025
Type: Article
Published: 2025-11-21
DOI: 10.11646/phytotaxa.730.3.5
Page range: 277-284
Abstract views: 56
PDF downloaded: 3

Two new species from the Mallomonas favosa species complex (Synurales, Chrysophyceae) from acidified water bodies in Vietnam

Institute for Cellular and Intracellular Symbiosis, Orenburg Federal Research Center, Ural Branch, Russian Academy of Sciences, Pionerskaya Street, 11, 460000, Orenburg, Russia; Coastal Branch of Joint Viet Nam-Russia Tropical Science and Technology Research Center, 30 Nguyen Thien Thuat, Nha Trang 650000, Vietnam
Coastal Branch of Joint Viet Nam-Russia Tropical Science and Technology Research Center, 30 Nguyen Thien Thuat, Nha Trang 650000, Vietnam
Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninsky Prospect 33, Moscow, 119071, Russia
Mallomonas new species scale ultrastructure section Torquatae Vietnam Algae

Abstract

Two new species of the genus Mallomonas, M. ridens and M. multilobata, are described from acidified water bodies in Vietnam based on silica-scale morphology studied by transmission and scanning electron microscopy. Based on scale ultrastructure, the new species are assigned to the Mallomonas favosa species complex within the section Torquatae. The primary distinguishing feature of both new species is the presence of rounded pits on the shield surface. In M. ridens, the pits are fused into linearly arranged groups of 2–3, exhibiting expansions and constrictions, and are predominantly located along the shield periphery, adjacent to the posterior submarginal rib and the anterior flange. In M. multilobata, the shield possesses numerous rounded pits that are grouped into rosettes of 2–5, with thin partitions separating individual pits. Both species are rare, found in only a few localities.

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How to Cite

Ignatenko, M.E., Huan, P.T. & Gusev, E.S. (2025) Two new species from the Mallomonas favosa species complex (Synurales, Chrysophyceae) from acidified water bodies in Vietnam. Phytotaxa 730 (3): 277–284. https://doi.org/10.11646/phytotaxa.730.3.5