Sanet Janse van VuurenNorth-West University | NWU · Unit for Environmental Sciences and Management
Sanet Janse van Vuuren
PhD
Phycology - the study of algae
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86
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Introduction
I love all aspects of algae!
Publications
Publications (86)
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...
This study investigates the morphology and distribution of infraspecific taxa of P. subcoronulatum. Research identified taxonomic issues and discrepancies in prior literature concerning morphological similarities among infraspecific taxa. The consolidation of two closely related taxa into a single variety, P. subcoronulatum var. majus, is suggested...
Algal research in many African countries, particularly southern Africa, remains limited, with numerous species yet to be documented. The lack of phycologists conducting research in Africa contribute to this issue, leaving vast gaps in our understanding of algal biodiversity across the continent. The Okavango Delta, situated in Botswana, is renowned...
Two extremely rare and morphologically similar Gonatozygon species, namely G. dicranoaculeatum and G. chadefaudii, were previously recorded from only two geographical locations in the world. G. dicranoaculeatum was reported from Zambia and Australian billabongs, while G. chadefaudii was known from French Guiana and Australian billabongs. During Jun...
In this study, the authors report the discovery of a rare desmid species (Euastrum compereanum) in Mozambique and Namibia. The species was previously documented from only three African countries, namely Chad, Zambia, and Botswana. In a prior publication about desmids from Namibia a line drawing of this species was included, but the species was iden...
The history of Actinodontum lomaense has been marked by taxonomic revisions since its initial discovery in samples from Sierra Leone during 1984. The reassignment from the genus Docidium to the genus Actinodontum primarily resulted from pronounced morphological differences, including variations in cell
size and shape, ornamentations on the cell wal...
Cosmarium knopkirri Levanets & Janse van Vuuren sp. nov. (Desmidiaceae, Zygnematophyceae) is a newly discovered desmid species collected from an inland wetland system near Palma, Cabo Delgado Province, northern Mozambique. The diagnostic features distinguishing it from other species in the genus include semicells decorated with four concentric, alt...
Prescottiella sudanensis is a rare, asymmetrical desmid currently known from only a few countries in equatorial Africa. During the present study, P. sudanensis cells were found in water samples from Vogel Pan located in the far north-eastern side of Namibia, thereby expanding the known geographical distribution of the species. The location of the s...
During 2012, aerial photographs of the Vaal River, South Africa, showed differences in water colour on either side
of the Lethabo Weir. Water upstream of the weir was muddy brown, while water downstream was olive-green.
Physical and chemical analyses indicated water quality differences upstream and downstream from the weir;
furthermore, microscopic...
Four species of the genus Mallomonas (M. alpina, M. annulata, M. caudata, and M. cratis), a unicellular silica-scaled chrysophyte, and one species of Synura (S. curtispina), a colonial silica-scaled chrysophyte, were found in the Mooi River, North West Province, South Africa. Entire Mallomonas cells, having intact scales and bristles, were photogra...
Blooms of Euglena sanguinea Ehrenberg were observed at two different locations in South Africa (Kruger National Park, Mpumalanga Province and Limpopo Province). Besides being responsible for a blood-red discolouration of the water, the species is also toxic, causing fish kills. Samples from South Africa were dominated by E. sanguinea and very low c...
Micrasterias foliacea (Desmidiales, Zygnematophyceae) is an interesting desmid species as its filamentous life form is quite different from all other species within the genus. Due to the large size of the filaments and cells, accurate species identification is easy. After its original description from Rhode Island (USA) it was recorded from five co...
Although Micrasterias apiculata is widely distributed and frequently found in samples throughout the world, its variety M. apiculata var. tjitjeroekensis, has a very limited geographical distribution. It was previously found in only three locations in the world. The variety was originally described in 1908 from Java, Indonesia (southeast Asia) and...
As a part of our study of South African algal diversity we present new records of four rare/endemical and interesting green algae discovered in the Cape Metropolitan and provide a detailed review of their distribution, with illustrations.
Hydrodictyon africanum Yamanouchi (Chlorophyta, Sphaeropleales) was described by Shigeo Yamanouchi from culture...
Exploration of desmid (Charophyta, Zygnematophyceae, Desmidiales) flora in Mozambique started in 1898 when Wilhelm Schmidle discovered 15 genera (89 species, 93 varieties and 97 forms) of Desmidiales. Among them 13 Cosmarium taxa (C. abruptum Lund. var. supergranulatum, C. decachondrum Roy et Biss. var. striatum, C. ellipsoideum Elfg. var. borgei,...
A unique opportunity arose to study algae in samples from northern Mozambique, near the Tanzanian border. One of these included cells of the genus Triplastrum Iyengar & Ramanathan 1942, which represents the first record of its presence in Mozambique. Triplastrum cells are elongated (mostly up to 85 µm long) and cylindrical, nearly rectangular, with...
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...
Main priorities in algal systematic research are to develop a checklist of all known species in South Africa, database associated information, make this information accessible online, and to stimulate research projects addressing taxonomic problems (Bolton 2018). As an initial step in realizing of this aim we started preparation of taxonomic checkl...
A unique opportunity to study the sexual reproduction of Chlamydomonas proboscigera was presented when this species reached high densities in the Vaal River, South Africa during 2019. A peculiar and unique way of sexual reproduction in C. proboscigera was revealed for the first time and differs from earlier knowledge on the sexual reproduction of t...
Cyanoprokaryotes (or cyanobacteria), the most ancient photoautotrophs on Earth, and eukaryotic algae are present nearly in all biomes across the globe. Besides their key role in the production of most of the global net oxygen, they also play multiple pivotal ecological roles in the environments they colonize. Most cyanoprokaryotes and algal species...
In this paper we celebrate this milestone by giving an overview of the history of the Department at this campus, including its recent establishment and expansion on the NWU Mahikeng Campus (formerly the University of NorthWest). A brief overview is presented of the advances in teaching and research over the years, and the development and relevance...
Chlamydomonas proboscigera is a unicellular, ellipsoidal-to-spherical chlorophyte distinguished by a flattened papilla, a large spherical pyrenoid and a disc-shaped stigma located anterior in a cup-shaped chloroplast. The species is common in eutrophic water, but also occurs in terrestrial environments, such as soils. Previously, Chlamydomonas prob...
Effluents from agricultural activities, metal and peat mining, urban and industrial areas, informal settlements and wastewater treatment plants all influence tributaries feeding the Mooi River. All these land uses ultimately result in a deterioration of water quality in the Mooi River.
The main objective was to relate the effects of inflowing tribu...
Background: Effluents from agricultural activities, metal and peat mining, urban and industrial areas, informal settlements and wastewater treatment plants all influence tributaries feeding the Mooi River. All these land uses ultimately result in a deterioration of water quality in the Mooi River.Objectives: The main objective was to relate the eff...
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 ver...
There is a lack of knowledge on cyanobacteria and algae living in caves in the southern hemisphere. As a result, a pioneer study was undertaken to investigate cyanobacterial and algal community composition in two morphologically and geologically distinct caves in South Africa. Skilpad Cave is characterized by a large sinkhole entrance in a dolomiti...
Cyanobacteria and algal genera belonging to 5 major phyla were identified in dense biofilms growing in shaded parts of moist rocks against cave overhangs in South Africa. Amongst the cyanobacteria filaments of Petalonema alatum were found. Intensive literature searches revealed that P. alatum has a relatively narrow geographical distribution. It ha...
Cyanobacteria and algal genera belonging to 5 major phyla were identified in dense biofilms growing in shaded parts of moist rocks against cave overhangs in South Africa. Amongst the cyanobacteria filaments of Petalonema alatum were found. Intensive literature searches revealed that P. alatum has a relatively narrow geographical distribution. It ha...
Background: Botryococcus braunii is well known from all continents, but it has been sparsely recorded from Africa compared to other continents. The alga recently formed a rusty orange-red bloom in the Tilda Viljoen Dam, situated near Gobabis in Namibia. Blooms of this species are known to produce allelopathic substances that inhibit the growth and...
Petalonema alatum (Borzì ex Bornet & Flahault) Correns is a nitrogen fixing, subaerial cyanobacterium characterized by a blue-green trichome surrounded by a very broad, lamellated mucous sheath. It typically grows on dripping limestone rocks in temperate regions, but it has also been observed in some calcareous lakes and limestone springs. Although...
Petalonema alatum (Borzì ex Bornet & Flahault) Correns is a nitrogen fixing, subaerial cyanobacterium characterized
by a blue-green trichome surrounded by a very broad, lamellated mucous sheath. It typically grows on dripping
limestone rocks in temperate regions, but it has also been observed in some calcareous lakes and limestone springs.
Although...
Phytoplankton synthesize biomolecules through the process of photosynthesis, and the decomposition of these molecules causes odors in water. While the freshwater dinoflagellate Ceratium hirundinella is well known for causing a variety of odors in water, the organic acid profile of this specimen has not been studied, and the compounds causing the od...
Spiral colonies of the diatom Aulacoseira ambigua were assigned the rank of forma (Aulacoseira ambigua f. japonica). This spiral-shaped, colonial, centric diatom has limited geographical distribution and is currently reported to occur in only a few countries in the world. In Africa this species was described for the first time from the Vaal River,...
The freshwater dinoflagellate, Ceratium hirundinella (C. hirundinella) with its complex morphology and robust thecal plate cell covering, is responsible for extensive problems during drinking water production. To have a better understanding of these problems, knowledge of what happens to the integrity of the cells after each step of the conventiona...
Water quality and algal populations in the Vaal River Barrage Reservoir have been monitored extensively for many decades, because of its importance as a water source for the most densely populated area in South Africa. Although Aulacoseira granulata (Ehrenberg) Simonsen is frequently found and at it times dominates algal assemblages in the Barrage,...
Background: Although the colonial flagellate alga Anthophysa vegetans is well known in Europe, it has only been recorded from Africa (Nigeria) once. It was recently found in the Mooi River, South Africa – making this a first record of the presence of A. vegetans in southern Africa.
Objectives: The objective of this study is to record a new geograp...
A first survey was done on algae present in the Sundays River from its source to its confluence with the sea. Species found in the upstream sections of the river included indicators of good water quality, but the quality deteriorated downstream with peaks in algal abundance being ascribed to peaks in nutrient concentrations. Cyanobacteria and eugle...
Prokaryotes are primitive cells lacking both a membrane enclosing the nucleus, and
organelles such as chloroplasts and mitochondria. Prokaryotic organisms fall into two domains, the Archaea and the Bacteria. The Archaea, ancient bacteria-like life forms that live in extreme environments, are not dealt with here. The Bacteria include the photosynthe...
Protista form a large group of diverse organisms that includes photosynthetic algae and heterotrophic (animal-like) protozoans. The relationships between these groups are not well understood and the term ‘protist’ is thus best used only as a common name. Protists are eukaryotic, meaning that their DNA is enclosed in a nucleus within the cell, and m...
The dinoflagellate, Ceratium hirundinella (C. hirundinella) cells are known to cause many problems when source water due for purification contains relatively high concentrations. The objective of this study was to investigate strategies for the effective and simultaneous removal of turbidity and C. hirundinella cells using turbidity and total photo...
The water purification plants at Virginia and Bothaville, South Africa, experience problems with cyanobacteria and other algae. Their algal assemblages were studied during 2010 and 2011 to determine the dominant species that may pose problems in purification. Cyanobacteria, diatoms and green algae were the dominant phytoplankton taxa and constantly...
An ecologically healthy Mooi River system is important for maintaining the quality of potable water of Potchefstroom and surrounding areas. However, this system is under constant threat from anthropogenic pollution arising from both agricultural and mining activities in its catchment. A survey of planktonic algal and cyanoprokaryote assemblages in...
Die Vaalrivier is, met verloop van tyd, tot so ’n mate verryk deur voedingstowwe dat algopbloeie tans probleme skep. ’n Unieke geleentheid om te bepaal of daar veranderinge in die waterchemie en algsamestelling in die Vaalrivier voorgekom het, het hom voorgedoen nadat oligomesotrofe Katsedamwater (Lesotho) ingevoer is om in die toenemende wateraanv...
We studied the diversity of algae (desmids and diatoms) and cyanoprokaryota in freshwater and aerophytic biotopes in the Drakensberg (South Africa and Kingdom of Lesotho). Diversity, species composition and distribution of the taxa, their ecological characteristics, level of endemism and perspectives of taxonomical studies are being discussed. Spec...
Cylindrospermopsis raciborskii, a problem-causing cyanobacterium capable of releasing potent toxins, has become increasingly prevalent in South African freshwaters, especially in the lower reaches of the Orange River. This organism was first detected during the summer (January to March) of 2000 in the lower reaches of the Orange River. During this...
Whereas limited knowledge exists on the ecology and algae present in Lesotho’s high-altitude Katse Dam, nothing is published
about these aspects in the linked Mohale Dam, completed in 2003. This study investigated the changes in algal composition and
associated environmental variables since the construction of the Mohale Dam until the present. Mont...
Chemical monitoring of water resources is time-consuming and comparatively expensive and may not always provide a composite reflection of actual water quality. Biotic indices using faunal elements, such as macroinvertebrates and fish, are already in place in South Africa as part of the National Biomonitoring Programme for Aquatic Ecosystems (NBPAE)...
Links between spatial differences in phytoplankton composition and changes in environmental variables in the Vaal River, South Africa, were investigated. Multivariate analysis showed that the most important environmental variables influencing algal abundance were turbidity, conductivity, nutrient concentrations and temperature. Of these variables c...
The highly eutrophic Vaal River system is subjected to algal blooms that cause problems ranging from aesthetically unacceptable conditions to the release of toxins. In order to understand how environmental variables influence one another and to determine the key environmental variables that affect phytoplankton composition, multivariate analyses we...
Oscillatoria simplicissima is a blue-green alga that was first observed in the Vaal River during 1984. It replaced Microcystis aeruginosa as the dominant blue-green algal species and became dominant after an increase in the organic phosphorus supply in the Loch Vaal catchment area to form algal blooms of great intensity. Although this blue-green al...
Verhandeling (MSc (Plantkunde))--PU vir CHO, 1996. Includes bibliographical references (blaaie 140-164)
Word processed copy. Thesis (Ph. D.)--Potchefstroom University for Christian Higher Education, 2001. Includes bibliographical references (leaves 309-373).
Questions
Question (1)
If you have any published information about its geographical distribution references thereof will also be highly appreciated.