Research Interests:
Research Interests: Urine and Trace Metal
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Ornithonyssus bacoti (Hirst) is an important parasite of rodents. The characteristic shape of the dorsal and sternal shields and gnathosoma used as taxonomic characteristics was confirmed by scanning electron microscopy. The anal plate is... more
Ornithonyssus bacoti (Hirst) is an important parasite of rodents. The characteristic shape of the dorsal and sternal shields and gnathosoma used as taxonomic characteristics was confirmed by scanning electron microscopy. The anal plate is distinctly pear-shaped with a pair of adanal setae lateral to the anal valves, a single postanal seta and a distinct dentate cribrum formed by peg-like projections. In the adult mites a peritreme extends anteriorly to the 1st coxa from the spiracle situated laterally between the 3rd and 4th coxa. The peritreme is an open canal protected by an overhanging dorsal ridge and lined with short peg-like aciculae. The gnathosoma includes a pair of pedipalps, a pair of protrusile chelicerae retracted into the hypostoma, and a serrate tritosternum ventrally. A unique feature to the normal setae of the pedipalps is a golf club-shaped seta which is found medially on the palp genu. A distinctive double-bladed 'palpal claw' or apotele is directed medially from the palp tibia. The pincer-like chela consists of a spear-like prong forming the moveable digit and a curved stylus-like fixed digit used to pierce the skin. Each leg ends with a pair of hooked tarsal claws and a pair of lateral comblike pretarsal appendages adjacent to the pulvillus. The pulvillus may be retracted, allowing the pretarsal operculum to function as a 'clasping organ' that enables the mite to clasp the hairs of the host during feeding.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The occurrence of the copepod Lamproglena cleopatra Humes, 1957, parasitising freshwater fishes in the Limpopo River System is presented, along with new morphological data. This crustacean was originally described parasitising a cyprinid... more
The occurrence of the copepod Lamproglena cleopatra Humes, 1957, parasitising freshwater fishes in the Limpopo River System is presented, along with new morphological data. This crustacean was originally described parasitising a cyprinid (Labeo forskalii Rüppell) from the River Nile, Egypt. During 2014-2015 crustacean samples were collected from the gills of three cyprinid fish species, Labeo rosae Steindachner from Flag Boshielo Dam, Labeo molybdinus Du Plessis from Nwanedi-Luphephe Dam in South Africa, and Labeo ruddi Boulenger from the River Bubye in Zimbabwe. The specimens from the present study were morphologically similar regardless of the host, but exhibited some morphometric intraspecific differences in comparison with the type-specimen from Egypt. A description of L. cleopatra copepodid III stage and a taxonomic key to Lamproglena spp. is provided.
Research Interests:
The redclaw crayfish, Cherax quadricarinatus (Decapoda: Parastacidae), is native to Australia but has been introduced to South Africa as a warm-water aquaculture species. In a South African natural waterbody, examined crayfish had high... more
The redclaw crayfish, Cherax quadricarinatus (Decapoda: Parastacidae), is native to Australia but has been introduced to South Africa as a warm-water aquaculture species. In a South African natural waterbody, examined crayfish had high intensity infections of 3 temnocephalan species on their body surfaces and within the branchial chambers. Temnocephalans were characterized using light and scanning electron microscopy and identified as Craspedella pedum, Diceratocephala boschmai and Didymorchis sp. This is the first report of the introduction of Australian temnocephalans, C. pedum and Didymorchis sp., to Africa and expands the known distribution of these species beyond their presumptive native range. The present study also documents a naturalized population of C. quadricarinatus from a natural waterbody in South Africa, comprising a new geographical locality record.
Research Interests:
As Cimex lectularius is an important blood sucking parasite not only of man but also infesting poultry['*41, it was considered important to investigate the micromorphology of the taxonomic characteristics of the bedbug so that these... more
As Cimex lectularius is an important blood sucking parasite not only of man but also infesting poultry['*41, it was considered important to investigate the micromorphology of the taxonomic characteristics of the bedbug so that these parasites may be identified more accurately. Previous electron microscopic studies of the bedbug included the antenna1 receptors[31 and the comparative morphology of the legs of two Cimex specie$] The bedbugs from poultry houses were collected and fixed in 70% ethanol. The specimens were routinely processed for scanning electron microscopy and viewed in a Leica Stereoscan 420 at 5 to 7 kV. The head, thorax and abdomen are extremely dorso-ventrally flattened, an adaptation to fitting into narrow crevices . I41 The hinged rostrum that includes the stylet-like mouthparts, folded ventrally under the flattened head which also bears a pair of laterally protruding compound eyes (Fig.lA). The pronotum was similarly flattened with rounded wing-like extensions...
Ornithonyssus bacoti (Hirst) is an important parasite of rodents. The characteristic shape of the dorsal and sternal shields and gnathosoma used as taxonomic characteristics was confirmed by scanning electron microscopy. The anal plate is... more
Ornithonyssus bacoti (Hirst) is an important parasite of rodents. The characteristic shape of the dorsal and sternal shields and gnathosoma used as taxonomic characteristics was confirmed by scanning electron microscopy. The anal plate is distinctly pear-shaped with a pair of adanal setae lateral to the anal valves, a single postanal seta and a distinct dentate cribrum formed by peg-like projections. In the adult mites a peritreme extends anteriorly to the 1st coxa from the spiracle situated laterally between the 3rd and 4th coxa. The peritreme is an open canal protected by an overhanging dorsal ridge and lined with short peg-like aciculae. The gnathosoma includes a pair of pedipalps, a pair of protrusile chelicerae retracted into the hypostoma, and a serrate tritosternum ventrally. A unique feature to the normal setae of the pedipalps is a golf club-shaped seta which is found medially on the palp genu. A distinctive double-bladed 'palpal claw' or apotele is directed mediall...
Research Interests:
The microstructure of the omasum of the African goat was investigated macroscopically, as well as by scanning electron microscopy to determine how the omasum is anatomically specialised to enable the goat to graze and browse so... more
The microstructure of the omasum of the African goat was investigated macroscopically, as well as by scanning electron microscopy to determine how the omasum is anatomically specialised to enable the goat to graze and browse so successfully in the harsh environments of Africa. The omasum of the African goat was found to be more simple in structure than that of other domesticated ruminants. The omasal laminae were arranged in only 3 orders with the number of laminae varying between 27 and 33, considerably fewer than previously described for other goats, sheep or cattle. The large conical and unguiculiform papillae surrounding the reticulo-omasal orifice, as well as the hooked papillae present on the laminae, were more similar to those of wild ruminants that browsed than domestic grazing species. The papillae on the laminae were also found to be directionally orientated towards the orifices, which may suggest a "sieve mechanism' at the reticulo-omasal orifice and interlaminar...
Research Interests:
Freshwater snails are known to serve as first intermediate hosts for various parasitic diseases such as schistosomosis and fasciolosis. Snails were collected on several occasions in the proximity of Pretoria, South Africa and their... more
Freshwater snails are known to serve as first intermediate hosts for various parasitic diseases such as schistosomosis and fasciolosis. Snails were collected on several occasions in the proximity of Pretoria, South Africa and their cercarial sheddings were studied. This article describes three different types of cercariae shed by the freshwater snail, Lymnaea natalensis, viz. a fork-tailed cercaria of a Trichobilharzia sp., an avian parasite belonging to the family Schistosomatidae, an echinostomatid cercaria of the family Echinostomatidae, also avian parasites and a xiphidiocercaria of the family Plagiorchiidae which parasitise avians and amphibians. The morphology of these cercariae was studied by light and scanning electron microscopy.
Research Interests:
The metacercarial (larval) stages of diplostomid digeneans are known to inhabit freshwater fish, causing tissue damage in the process. Due to their widespread diversity, little is known about their life cycle. The classification of these... more
The metacercarial (larval) stages of diplostomid digeneans are known to inhabit freshwater fish, causing tissue damage in the process. Due to their widespread diversity, little is known about their life cycle. The classification of these parasitic stages to the species level using only the morphology is very challenging due to the lack of genitalia; they are regarded to be the most important structures in the identification of these organisms. In this study, additional morphological information through light and scanning electron microscopy is given for two different diplostomids found in the cranial cavity of Clarias gariepinus and the vitreous chambers of Tilapia sparrmanii and Pseudocrenilabrus philander. The diplostomid metacercaria inhabiting the cranial cavity of Clarias gariepinus was morphologically identified as Diplostomulum (Tylodelphys) mashonenseand an unknown metacercaria of the genus Diplostomumwas found in the vitreous chambers of Pseudocrenilabrus philander and Tila...
Research Interests:
Research Interests:
Research Interests:
Freshwater snails are known to serve as first intermediate hosts for various parasitic diseases such as schistosomosis, amphistomosis and fasciolosis. Two freshwater snail species, Lymnaea natalensis, Krauss 1848 and Bulinus tropicus,... more
Freshwater snails are known to serve as first intermediate hosts for various parasitic diseases such as schistosomosis, amphistomosis and fasciolosis. Two freshwater snail species, Lymnaea natalensis, Krauss 1848 and Bulinus tropicus, Krauss 1848 were sampled from five localities in Gauteng and one locality in the North West Province from 2007 to 2010. These snails were collected in order to study their cercarial sheddings. They were found to be infected with three different types of strigea cercariae, of which the morphology was studied using standard light and scanning electron microscopy techniques.