Paradiplozoon vaalense n. sp. (Monogenea: Diplozoidae) from the gills of moggel, Labeo umbratus (Smith, 1841), in the Vaal River System, South Africa

2013 ◽  
Vol 89 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Q.M. Dos Santos ◽  
B. Jansen van Vuuren ◽  
A. Avenant-Oldewage
Keyword(s):  
South Africa ◽  
Sequence Data ◽  
Light And Electron Microscopy ◽  
River System ◽  
Ribosomal Gene ◽  
Its2 Region ◽  
Genetic Characteristics ◽  
Vaal River ◽  
Vaal Dam ◽  
Second Internal Transcribed Spacer

AbstractAn unidentified monogenean diplozoid species was collected from the gills of moggel in the Vaal River and Vaal Dam, South Africa. Specimens were removed from gills of the hosts and observed using light and electron microscopy to compare these diplozoids with known species. The second internal transcribed spacer (ITS2) of the ribosomal gene was amplified, sequenced and compared to that of other diplozoid taxa. Morphological species delimitation was used to determine the identity of these diplozoids, but they did not match the description of any diplozoid taxa. This species is recognized by the specific size of the hooks, number of plicae in posterior and trapezoid anterior projection of the median sclerite connecting to the clamp jaws via a single sclerite, occasionally with two small additional sclerites. Genetic characteristics based on sequence data from the ITS2 region also distinguish this taxon from all other diplozoid taxa. This South African diplozoid grouped in the same clade as Paradiplozoon ichthyoxanthon Avenant-Oldewage, 2013. Data clearly indicate that diplozoids collected from moggel represent a new, distinct taxon of Paradiplozoon Akhmerov, 1974 and are described here as Paradiplozoon vaalense n. sp.

Paradiplozoon ichthyoxanthon n. sp. (Monogenea: Diplozoidae) from Labeobarbus aeneus (Cyprinidae) in the Vaal River, South Africa

2013 ◽  
Vol 88 (2) ◽  
pp. 166-172 ◽  
Author(s):  
A. Avenant-Oldewage ◽  
L.E. le Roux ◽  
S.N. Mashego ◽  
B. Jansen van Vuuren
Keyword(s):  
South Africa ◽  
New Species ◽  
South African ◽  
Internal Transcribed Spacer ◽  
Morphological Characteristics ◽  
Reproductive Organs ◽  
Ribosomal Gene ◽  
Vaal River ◽  
Vaal Dam ◽  
A New Species

AbstractA new species, Paradiplozoon ichthyoxanthon (Monogenea: Diplozoidae) is described from the gills of Labeobarbus aeneus (Cyprinidae) in the Vaal Dam and Vaal River Barrage in the Vaal River, South Africa. This species is the first in this genus from southern Africa; Paradiplozoon aegtyptense and Paradiplozoon ghanense have been described from northern Africa. The new species differs from all other Paradiplozoon species on the basis of the combination of morphological characteristics, namely disk-like haptor, eggs without filaments, clamp and central hook morphology and size of specimens. The species description is accompanied by a description of the reproductive organs. The internal transcribed spacer of the ribosomal gene (ITS2) was studied and the South African individuals formed a distinct clade, supporting the establishment of a new species.

scholarly journals Aspects of the Ecology of Lamproglena Clariae (Copepoda: Lernaeidae) from the Vaal River System, South Africa

2004 ◽  
Vol 24 (4) ◽  
pp. 529-536 ◽  
Author(s):  
A. M. Tsotetsi ◽  
S. N. Mashego ◽  
A. Avenant-Oldewage
Keyword(s):  
South Africa ◽  
River System ◽  
Vaal River

scholarly journals Notes on the occurrence of Trypanosoma sp. (Kinetoplastida: Trypanosomatidae) in freshwater fishes from South Africa

2013 ◽  
Vol 80 (1) ◽  
Author(s):  
Maryke L. Ferreira ◽  
Annemariè Avenant-Oldewage
Keyword(s):  
South Africa ◽  
Nature Reserve ◽  
Clarias Gariepinus ◽  
Host Record ◽  
New Host ◽  
New Host Record ◽  
Infection Pattern ◽  
Vaal River ◽  
Vaal Dam ◽  
Seasonal Infection

A total of 257 fishes from four families, Clariidae, Cichlidae, Cyprinidae and Schilbeidae were collected from three localities: the Sand River Dam, Swaziland; the Nylsvlei Nature Reserve, South Africa and the Vaal Dam and Vaal River Barrage, South Africa. Only fishes (n= 154) from Clariidae and Cichlidae were found to be infected with trypanosomes. A total of 221 Clarias gariepinus (Burchell 1822) were collected from the Vaal Dam and Vaal Barrage area, South Africa. Of these, 74%(89/121) were infected with trypanosomes from the Vaal Dam and 63%(63/100) from the Vaal River Barrage, with no seasonal infection pattern. A prevalence of 25%(1/4) was found in C. gariepinus from the Sand River Dam, Swaziland, and a 50% (1/2) prevalence was found in Tilapia sparrmanii from the Nylsvlei Nature Reserve, South Africa. Standard measurements conformed closely to the morphometric and morphological descriptions of Trypanosoma mukasai. This article provides new locality records for T. mukasai from the Vaal Dam, Vaal River Barrage and Nylsvlei Nature Reserve (South Africa) and the Sand River Dam (Swaziland). Tilapia sparrmanii collected in the Sand River Dam in Swaziland is also noted as a new host record.

scholarly journals Assessing the Genetic Diversity of Alternaria Bataticola in South Africa using Molecular Markers

2017 ◽  
Vol 5 (2) ◽  
Author(s):  
J. Chalwe ◽  
P. Adebola ◽  
M. Pillay
Keyword(s):  
South Africa ◽  
Genetic Diversity ◽  
Ipomoea Batatas ◽  
Cultural Practices ◽  
Sequence Data ◽  
Control Measure ◽  
Secondary Structures ◽  
Its2 Sequence ◽  
Its2 Region ◽  
Alternaria Blight

Sweetpotato (Ipomoea batatas) an economically important food crop is affected by viral and fungal diseases. The most important fungal disease is Alternaria blight caused by Alternaria bataticola. Alternaria blight can be controlled using fungicides and cultural practices in the short-term. A sustainable control measure is the development of resistant sweetpotato cultivars. A prerequisite to this approach is the knowledge of the genetic diversity of this fungal pathogen. This study assessed the genetic diversity of A. bataticola in South Africa using RAPD analysis, DNA sequencing and secondary structures of the ITS2 region. Samples were collected from 25 different localities and the pathogen was identified in the laboratory. Both RAPD and ITS2 sequence data showed that there is high levels of genetic diversity among the isolates of A. bataticola. Although the dendrograms generated from the RAPD and ITS2 sequences clustered some isolates according to their place of origin, the majority of isolates did not group according to their geographic origins. The predicted ITS2 secondary structure models were variable ranging from simple to complex. The unique secondary structures of each isolate can be used to identify and distinguish each of the isolates used in this study.  

Monogenean parasites from fishes of the Vaal Dam, Gauteng Province, South Africa II. New locality records

2014 ◽  
Vol 59 (3) ◽  
Author(s):  
Dionne Crafford ◽  
Wilmien Luus-Powell ◽  
Annemariè Avenant-Oldewage
Keyword(s):  
South Africa ◽  
River System ◽  
Parasitic Infections ◽  
Site Preference ◽  
Locality Record ◽  
Monogenean Species ◽  
Vaal Dam ◽  
Baseline Information ◽  
Stereo Microscope ◽  
Proactive Measures

AbstractBaseline information on parasitic infections, including monogenean infections on wild fishes, may aid in implementation of proactive measures as opposed to reactive research aimed at crisis control with reference to future aquaculture applications. The aim of this project was to examine the freshwater monogenean fauna of the Vaal Dam, Vaal River system, South Africa. This short communication reports on infection statistics for monogenean species, some representing new locality records. Parasites were collected from host species other than Labeo spp. from the Vaal Dam, during a summer (January 2010) survey. Fish collected using gill nets of varying mesh sizes were weighed and measured. Mucous smears were prepared from the skin and fins with the aid of microscope slides. Fish were killed humanely by severing the spinal cord behind the head. Gills were carefully removed and divided into areas which were separately scraped to investigate potential parasite site preference. The areas examined were dorsal, median and ventral positions on both the anterior and posterior hemibranch. Both mucous smears and gill scrapings were examined with the aid of a stereo microscope. More parasites were collected from the first or second gill arches, the medial position on the gill, and the anterior hemibranch. Preference for either left or right gill set was inconclusive. Spatial distribution of parasites is thought to result from water flow over the gills during respiration. This paper reports a new locality record for the following monogenean species: Quadriacanthus aegypticus, Dactylogyrus extensus, Dactylogyrus minitus, Gyrodactylus kherulensis and Dactylogyrus lamellatus.

Effects of altered water quality and trace elements on the infection variables of Paradiplozoon ichthyoxanthon (Monogenea: Diplozoidae) from two sites in the Vaal River system, South Africa

2016 ◽  
Vol 61 (1) ◽  
Author(s):  
Beric Michael Gilbert ◽  
Annemariè Avenant-Oldewage
Keyword(s):  
South Africa ◽  
Water Quality ◽  
Trace Elements ◽  
Trace Element ◽  
Trace Element Analysis ◽  
River System ◽  
Element Analysis ◽  
Vaal River ◽  
Trace Element Levels ◽  
River Site

AbstractUsing parasites as sentinel organisms has received increased attention due to their responses toward environmental degradation. In some sections of the Vaal River, South Africa, water quality is altered and biota distribution affected. The aims of this study were to assess and compare infection variables of Paradipolozoon ichthyoxanthonAvenant-Oldewage, 2014 in Avenant- Oldewage et al. (2014) at two sites along the Vaal River and compare the water quality and trace element levels at the sites. Infection variables of the parasite, physico-chemical variables, and sediment and water samples for trace element analysis were collected at each site. Conductivity and trace element concentrations were higher at the Vaal River site than the Vaal Dam. Temporal variances in water quality and parasite prevalence, mean intensity and mean abundance, at intervals over a 14 year period occurred, P. ichthyoxanthon was absent at the Vaal River site though the host fish are present. Prevalence peaks in summer and winter. Comparison of infection data to water quality and trace elements indicated that conductivity and trace element levels negatively affected/correlated with the infection variables. Higher trace elements concentration and conductivity at the Vaal River site are thought to be driving factors responsible for absence of the parasite.

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