Mass developments of Euglena sanguinea Ehrenberg in South Africa

Blooms of Euglena sanguinea Ehrenberg were observed at two different locations in South Africa, Mpumalanga province during 2016 and Limpopo province during 2020. Besides being responsible for a blood-red discolouration of the water, the species is also toxic, causing fish mortalities. Samples from South Africa were dominated by E. sanguinea and very low concentrations and diversity of other algal species were present. Microscopic studies revealed that the size ranges and the morphology of the cells corresponded to descriptions of the species in literature. High quality micrographs, illustrating the general cell structure and most features used for accurate identification, are provided. Intensive literature searches allowed mapping of the worldwide geographical distribution of the species, which revealed that it was sparsely distributed throughout Africa, because it was reported from only seven countries. Only one previous record of its presence in experimental ponds in South Africa exists, rendering this study a second record for its presence in the country.

Automated summary

Blooms of Euglena sanguinea were observed in South Africa in 2016 and 2020, leading to blood-red water and fish mortalities. Samples from South Africa were dominated by E. sanguinea with low concentrations and diversity of other algal species. Microscopic studies confirmed the size ranges and morphology of the species as described in literature. Intensive literature searches revealed the sparse global distribution of the species with only one previous record of its presence in South Africa.