First record of Peridinium gatunense and the reappearance of Peridinium bipes in South African waters.

• First record of the presence of P. gatunense in South Africa. • Reappearance of P. bipes , last reported from South Africa during the 1930s. • Both are potential bloom-forming associated with several problems. • The morphology, taxonomy geographical distribution and limited ecology are discussed. The common freshwater dinoflagellate genus Peridinium includes the species P. gatunense and P. bipes , which are found globally. Despite forming a significant portion of algal communities, research on dinoflagellates in Africa is limited. This paper reports the first record of the presence of P. gatunense in South Africa, as well as the reappearance of P. bipes , which was last reported from South Africa during the 1930s. Light and scanning electron microscopy were used for species identification. Knowledge about the presence of these species is crucial because both are potential bloom-forming and associated with several problems having ecological impacts. The presence of both these species has potential in inhibiting the growth of the problematic cyanobacterium Microcystis aeruginosa , as demonstrated by previous studies. It may present a natural and effective solution for the remediation of water bodies subjected to harmful cyanobacterial blooms. These insights are crucial for proactive management of freshwater ecosystems in the country. This paper discusses the morphology, taxonomy, geographical distribution, and some ecological aspects of P. gatunense and P. bipes. [ABSTRACT FROM AUTHOR]