Morphology, phylogenetic position and distribution of Mallomonas mangofera and Mallomonas foveata comb. et stat. nov. (Synurales, Chrysophyceae)

Strains of Mallomonas mangofera var. mangofera and M. mangofera var. foveata from Russia and Vietnam were studied. Their phylogenetic position was revealed using the SSU rDNA + rbcL cpDNA dataset. The ultrastructure of scales and bristles was studied using transmission and scanning electron microscopy. Based on these studies, a new combination was proposed: Mallomonas foveata comb. et stat. nov. The problems associated with the identification of Mallomonas mangofera and determination of the scale morphotype belonging to this taxon are discussed, and a new emended formal description and holotype are proposed. Based on the literature data and metabarcoding results, the distribution of Mallomonas mangofera and Mallomonas foveata was revised. Mallomonas mangofera has been recorded mainly in the temperate zone of Eurasia, North America and Japan. Mallomonas foveata has a wider distribution and is more often observed in regions with a warm climate.