Morphology, ecology and geographic distribution of three Mallomonas (Phylum Ochrophyta) species from the Vaal River, South Africa

This paper reports on the presence of three Mallomonas species (Phylum Ochrophyta) in the Vaal River, South Africa. Scanning electron microscope observations of entire cells with intact scales and bristles allowed accurate identifications of M. corymbosa, M. kenyana and M. portae-ferreae. Descriptions and dimensions of each of the three species are given, their geographical distribution is discussed and physico-chemistry of the water at the time of their finding is presented. M. corymbosa was recorded for the first time in Africa, expanding its known geographical distribution to an additional continent. The climatic preferences of the tropical and subtropical species, M. kenyana were extended to temperate regions in South Africa. These species were present under eutrophic to hypertrophic conditions, a water temperature of 25.4 degrees C, neutral to slightly alkaline water (pH 7.25) and a conductivity value of 440 mu S/cm. (C) 2022 SAAB. Published by Elsevier B.V. All rights reserved.

Automated summary

This paper reports the presence of three Mallomonas species in the Vaal River, South Africa. The accurate identification of the species was achieved through scanning electron microscope observations and analysis of the water's physico-chemistry. The findings include the first record of M. corymbosa in Africa and the extension of the climatic preferences of M. kenyana to temperate regions in South Africa.