scholarly journals Nematode parasites of Clarias gariepinus (Burchell, 1822) from the Rietvlei Dam, South Africa

Author(s):  
M. Barson ◽  
A. Avenant-Oldewage

Catfish, Clarias gariepinus, from the Rietvlei Dam near Pretoria, South Africa were examined for nem atode parasites. Two species, Procamallanus laeviconchus in the stomach and Contracaecum spp. larvae in the abdominal cavity, were found. The morphology of these species, based on light and scanning electron microscopy, and how they compare with previously described specimens are discussed. Infection rates were mild compared to previous surveys although Contracaecum spp. had a high prevalence of 86 %.

1988 ◽  
Vol 62 (2) ◽  
pp. 141-147 ◽  
Author(s):  
F. J. Kruger ◽  
V. L. Hamilton-Attwell

ABSTRACTSchistosoma haematobium miracidia were collected from a locality with a high prevalence of human infection with the animal parasite, S. mattheei, which hybridizes with S. haematobium, and from 2 localities with negligible infection rates. The terebratoria of the miracidia from these localities were compared with each other, with laboratory maintained S. haematobium and with four populations of S. mattheei by means of scanning electron microscopy. It was found that the terebratorial membrane of certain of the S. haematobium miracidia from the locality with a high S. mattheei prevalence in humans, resembled the more intricate membrane of S. mattheei. This suggests introgressive hybridization between S. haematobium and S. haematobium x S. mattheei.


Author(s):  
M. Barson ◽  
A. Avenant-Oldewage

Sharptooth catfish, Clarias gariepinus, from the Rietvlei Dam near Pretoria, South Africa were examined for internal platyhelminth parasites. Two adult cestodes, Polyonchobothrium clarias (stomach) (prev alence 71 %, mean intensity = 5, n = 7) and Proteocephalus glanduliger (anterior intestine) (prevalence 14 %, mean intensity = 2, n = 7), were found in the gut while metacercariae of one larval digenean, Ornithodiplostomum sp. (prevalence 14 %, mean intensity = 140, n = 7), were found encysted in the muscles. The morphology of these species, based on light and scanning electron microscopy as well as histological analysis, and how they differ from previously described specimens, are discussed. Ornithodiplostomum is a new record in southern Africa. Infection levels of the host fish were mild compared to records from previous surveys.


Crustaceana ◽  
1996 ◽  
Vol 69 (4) ◽  
pp. 509-523 ◽  
Author(s):  
A. Avenant-Oldewage ◽  
Hazel M. Marx

AbstractThe morphology of the gill parasite Lamproglena clariae Fryer, 1956, from the Olifants River, Kruger National Park, South Africa, was studied with the aid of light and scanning electron microscopy. Ultrastructural details of all appendages are given as well as a table and map with information on the occurrence and distribution of L. clariae in Africa. Important morphological findings include: the observation of only one claw on the maxilla; first time findings and descriptions of the nuchal organ, upper and lower lips, the fifth pair of legs and circular openings on all appendages.


Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 97 ◽  
Author(s):  
Xiang Li ◽  
Kai Tang ◽  
Merete Tangstad

The reduction and liquidus behaviour of manganese slag with different basicities were studied in non-isothermal experiments in the temperature range of 1400–1500 °C. Certain amounts of quartz were added to Assmang ore (South Africa), and lime was added to Comilog ore (Gabon), to adjust the charge basicity to 0.5, 0.8 and 1.2. The extent of manganese ore reduction as a function temperature were determined by thermo-gravimetric (TG) balance. Morphology of ores and its change in the course of reduction was examined by scanning electron microscopy (SEM). The results show that the reduction rate of Assmang slag decreases with decreasing basicity, as the liquidus temperature of slag decreases. When spherical MnO phase is present, the activity of MnO is high, and the reduction rate is rapid. Comilog slags show a much higher reduction rate than Assmang slags. The activation energies of MnO reduction between 1400 to 1500 °C are estimated in this study and found to be 230 kJ/mol for Assmang charges and 470 kJ/mol for Comilog charges. The dissolution behaviours of Assmang and Comilog slags were also studied by FactSage simulation and verified by experiments.


2018 ◽  
Vol 23 (7) ◽  
pp. 1290 ◽  
Author(s):  
Philipp Chetverikov ◽  
Charnie Craemer ◽  
Stefan Neser ◽  
Sarah Zukoff

A new phytoptid genus and two new species, Solenocristus karooensis n. g. & n. sp. and S. searsius n. sp. (Phytoptidae, Sierraphytoptinae, Sierraphytoptini), were collected in the Eastern and Western Cape provinces of South Africa, from southern African endemic dicotyledonous trees Schotia afra (Fabaceae) and Searsia lucida (Anacardiaceae) respectively. They are described and illustrated with the aid of conventional light microscopy and low temperature scanning electron microscopy. Females of both new species possess a distinct pregenital plate divided into two parts by a subcuticular medial ridge. Additionally, in S. karooensis n. sp. the movable digit of the male chelicerae varies in length: among six observed males, three males had a movable digit (md) twice shorter than the fixed digit (fd), in one male it was slightly shorter than fd and in the remaining two males md and fd were of the same length. An updated key to the world genera of the tribe Sierraphytoptini is given. The key incorporates data on seven sierraphytoptine genera including three genera (Neoprothrix Reis & Navia, Solenoplatilobus Chetverikov & Craemer and Solenocristus n. g.) which were described since the last generic key of Eriophyoidea by Amrine et al. (2003) was published.


2004 ◽  
Vol 71 (2) ◽  
Author(s):  
R. Watermeyer ◽  
J. Boomker ◽  
J.F. Putterill

Mönnig (1933) described Setaria thwaitei from a sable antelope, Hippotragus niger, the type host, as well as from roan antelope, Hippotragus equinus, and waterbuck, Kobus ellipsiprymnus. Yeh (1959) considered Setaria thwaitei to be synonym of Setaria hornbyi. Material collected from roan antelopes, sable antelopes and gemsbuck, Oryx gazella, from several localities in the north and south of South Africa, together with Mönnig's (1933) material, were re-examined. Measurements of the adult worms obtained in this study were compared with those in the original description of the species. Scanning electron microscopy of the anterior and posterior regions of the female worms confirmed S. thwaitei as a valid species.


2015 ◽  
Vol 24 (1) ◽  
pp. 72-77 ◽  
Author(s):  
Gabrielle Fontenelle ◽  
Marcelo Knoff ◽  
Nilza Nunes Felizardo ◽  
Eduardo José Lopes Torres ◽  
Leila Maria da Silva Lopes ◽  
...  

Between February and August, 2012, thirty specimens of Atlantic moonfish, Selene setapinnis, were purchased in local markets in Niterói, State of Rio de Janeiro, Brazil, with the aim of analyzing the presence of anisakid nematodes, establishing their rates of parasitism and infection sites, due to importance in the sanitary inspection. A total of sixty nematode larvae, belonging to at least two species were found: nine larvae of Terranova sp., Anisakidae, with prevalence (P) of 13.3%, mean intensity (MI) of 2.25, mean abundance (MA) of 0.30 and range of infection intensity (RI) from 1 to 6; and 51 larvae of Hysterothylaciumfortalezae, Raphidascarididae, with P = 26.7%, MI = 6.40, MA = 1.70, and RI = 1-17. The infection sites for Terranova sp. were the mesentery and liver serosa; and for H. fortalezae, the infection sites were the mesentery, abdominal cavity and liver serosa. New morphological data from scanning electron microscopy, on the external structures of H. fortalezae (mainly at the posterior end), are presented. This is the first report of H. fortalezae parasitizing S. setapinnis.


Phytotaxa ◽  
2013 ◽  
Vol 87 (1) ◽  
pp. 11 ◽  
Author(s):  
YVONNE NĚMCOVÁ ◽  
JANA KREIDLOVÁ

This paper describes two new species of Mallomonas. Mallomonas temonis was identified in the Table Mountain Plateau, South Africa; Mallomonas divida was identified in Aquitaine, France. The descriptions are based on silica-scale morphology studied by means of transmission and scanning electron microscopy. Mallomonas temonis belongs to the section Heterospinae. A scale is surrounded by a submarginal rib connected at lateral parts by a strong, more or less transversal rib. Mallomonas divida belongs to the section Torquatae. The shield of scales is covered by regularly arranged, delicate papillae and marked by one or several rows of more distinctive papillae.


Nematology ◽  
2008 ◽  
Vol 10 (6) ◽  
pp. 835-844 ◽  
Author(s):  
Oleksandr Holovachov ◽  
Manuel Mundo-Ocampo ◽  
Irma Tandingan De Ley ◽  
Paul De Ley

AbstractAn unusual new ceramonematid, Ceramonema nasobema sp. n., is described using light and scanning electron microscopy. It is particularly characterised by the presence of a perioral tube projecting 5.5-7.0 μm anterior to the lips, moderately long body (0.86-1.09 mm), relatively small number of body annules (121-134), weakly developed zygapophyses, absence of intracuticular vacuoles, pronounced sexual dimorphism in amphid shape with the male ventral amphidial branch extending as far posterior as the 55-80th annule (no extension in females), barrel-shaped stoma, sigmoid and anteriorly inclined vagina without sclerotisations, gubernaculum with dorsal apophyses and relatively uniform cloacal annules. The new species differs from all other known species of Ceramonema especially by the shape of the amphid in males, the strongly projecting perioral tube and the inclined, sigmoid, vagina. Additional data on morphology of Ceramonema algoensis (from Natal Bay, South Africa) are also provided as this species has the most prominent perioral tube among previously described members of the genus.


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