Human health risk assessment for silver catfish Schilbe intermedius Rüppell, 1832, from two impoundments in the Olifants River, Limpopo, South Africa

As rural populations grow and rural poverty increases, consumption of fish from contaminated river systems will increase to supplement dietary protein requirements. The concentrations of metals in fish muscle tissue at two impoundments of the Olifants River (Flag Boshielo Dam and the Phalaborwa Barrage) were measured, and a human health risk assessment following Heath et al. (2004) conducted to investigate whether consumption of Schilbe intermedius from these impoundments posed a risk to human health. The results confirmed that metals are accumulating in the muscle tissue of S. intermedius. No patterns were observed in the ratios of the metals bio-accumulated at each impoundment. The human health risk assessment identified that all fish analysed exceeded the recommended levels for safe consumption for lead and chromium and about 50% exceeded the recommended level for antimony at Flag Boshielo Dam. Almost all fish analysed exceeded the recommended level for lead and more than 50% exceeded the recommended level for arsenic at the Phalaborwa Barrage. We conclude that weekly consumption of S. intermedius from these impoundments may pose an unacceptable risk to the health of rural communities.Keywords: risk assessment, human health, Schilbe intermedius, lead, chromium, antimon

Acanthocephalans, including the description of a new species of Mediorhynchus (Gigantorhynchidae) and a redescription of Centrorhynchus clitorideus (Centrorhynchidae) from vertebrate hosts from South Africa

Warner, LR ORCiD: 0000-0002-1587-8129Forty-seven individuals comprising 4 species of birds, Tockus leucomelas, Crecopsis egregia, Turdus smithi, and Bubo africanus; 4 species of mammals, Otolemur crassicaudatus, Gerbilliscus leucogaster, Mus minutoides, and Mus sp.; and 1 species of reptile, Varanus albigularis, all from South Africa were examined for acanthocephalans. Centrorhynchus clitorideus, Mediorhynchus mokgalongi n. sp., Masticophis taeniatus, Moniliformis acomysi, Moniliformis sp., Plagiorhynchus (Prosthorhynchus) cylindraceus, and a putative new genus of the Oligacanthorhynchidae were found. Additional characters of C. clitorideus were described. The new species of Mediorhynchus differs from all congeners by a suite of characters, including a proboscis armature of 125-156 hooks arranged in 24-26 longitudinal rows of 24-26 hooks and 30 rows of 5-6 spines. The putative new genus has a total of 24 hooks arranged in 12 longitudinal rows of 2 hooks. All are new host and locality records. © 2018 The Helminthological Society of Washington

Flow patterns and chemical loads in the middle Olifants River, Limpopo River System, South Africa

Historical data (July 1998 – June 2018) for the middle Olifants River, Limpopo River system, were compiled to evaluate the dynamics of selected water physico-chemical parameters with river discharge. The concentration of most water quality parameters increased over time. However, these concentrations are rapidly decreased, or reset, by the rapid filling, or spilling, of Loskop and/or Flag Boshielo Dams during a high-flow event. The flow-duration curves for stations below impoundments in the middle catchment on the Olifants River are typical of highly regulated rivers, although releases from Flag Boshielo Dam were more consistent through the 20 years. No outflow from Loskop Dam was recorded for 5.4% of the 20 years. The load-duration curves for gauging weirs on the Olifants and Elands rivers immediately upstream of Flag Boshielo Dam showed that the ‘tolerable’ concentrations were exceeded for total dissolved solids at the 60th and 20th percentiles of the flow, respectively. In addition, records for electrical conductivity, sodium, chloride, and alkalinity frequently exceeded the ‘tolerable’ concentrations at these sites. The results for Loskop and Flag Boshielo dams are generally lower than the tolerable concentrations for the parameters evaluated. Management of the flow regulation of the Olifants River should be aimed at meeting the water quality stipulations for all users in the agricultural, domestic, industrial, and recreational sectors

Microcystin-LR equivalent concentrations in fish tissue during a postbloomMicrocystisexposure in Loskop Dam, South Africa

National audienceVéritable guide pour accompagner le parcours des enseignants spécialisés à leur entrée dans le métier et tout au long de leur carrière, cet ouvrage met au jour les grands enjeux de l’école inclusive, et propose une présentation du renouveau de la formation professionnelle spécialisée et une réflexion sur les adaptations des pratiques professionnelles qui en découlent. Ces contenus intègrent : une lecture des textes institutionnels afférents à la formation professionnelle spécialisée, une analyse des travaux scientifiques les plus récents sur le handicap et la grande difficulté scolaire, une étude de cas concrets issus des expériences relatées par les différents acteurs du terrain scolaire

Acanthocephalans, including the description of a new species of Mediorhynchus (Gigantorhynchidae) and a redescription of Centrorhynchus clitorideus (Centrorhynchidae) from vertebrate hosts from South Africa

Forty-seven individuals comprising 4 species of birds, Tockus leucomelas, Crecopsis egregia, Turdus smithi, and Bubo africanus; 4 species of mammals, Otolemur crassicaudatus, Gerbilliscus leucogaster, Mus minutoides, and Mus sp.; and 1 species of reptile, Varanus albigularis, all from South Africa were examined for acanthocephalans. Centrorhynchus clitorideus, Mediorhynchus mokgalongi n. sp., Masticophis taeniatus, Moniliformis acomysi, Moniliformis sp., Plagiorhynchus (Prosthorhynchus) cylindraceus, and a putative new genus of the Oligacanthorhynchidae were found. Additional characters of C. clitorideus were described. The new species of Mediorhynchus differs from all congeners by a suite of characters, including a proboscis armature of 125-156 hooks arranged in 24-26 longitudinal rows of 24-26 hooks and 30 rows of 5-6 spines. The putative new genus has a total of 24 hooks arranged in 12 longitudinal rows of 2 hooks. All are new host and locality records. © 2018 The Helminthological Society of Washington

A new species of Centrorhynchus Lühe, 1911 (Acanthocephala: Centrorhynchidae) from the lizard buzzard Kaupifalco monogrammicus (Temminck) (Aves: Accipitridae) in South Africa

© 2017, Springer Science+Business Media Dordrecht. Centrorhynchus sarehae n. sp. is described from the lizard buzzard Kaupifalco monogrammicus (Temminik) in Louis Trichardt City, Limpopo Province, South Africa. The new species can be distinguished from all other species of Centrorhynchus Lühe, 1911 except C. gendrei (Golvan, 1957) and C. mariauxi Smales, 2011 in having a dilated region in the posterior trunk of the female. Centrorhynchus sarehae differs from both these species in the characters of the proboscis armature, particularly the number of hooks per row and the lengths of the longest hooks. This is the first record of a fully identified species of Centrorhynchus in South Africa

Bioaccumulation of selected metals in the gill, liver and muscle tissue of rednose labeo <i>Labeo rosae</i> from two impoundments on the Olifants River, Limpopo river system, South Africa

<p>Metal concentrations in the gill, muscle and liver tissues of <i>Labeo rosae</i> from two impoundments, Loskop and Flag Boshielo dams on the Olifants River, were evaluated in 2011 to detect patterns in metal associations between tissues and impoundments. Elevated concentrations of Ba, Zn, B, Al, Si and Fe, relative to a pristine site in the catchment, were found in the muscle, liver and gill tissues at both impoundments. Molybdenum concentrations were exceptionally high in all tissues at Loskop Dam and in liver at Flag Boshielo Dam. No definite pattern in the ratio metal concentrations within, or between, fish tissues was identified. The expected trend, liver > gills > muscle, was found at both impoundments, but was less prominent at Loskop Dam. Metal concentrations in muscle of Loskop Dam fish were significantly higher than in those at Flag Boshielo Dam. The inverse was true for liver. The long-term impact of elevated metal concentrations on fish health at both impoundments raises concern.</p

Human health risks of metals and metalloids in muscle tissue of <i>Synodontis zambezensis</i> Peters, 1852 from Flag Boshielo Dam, South Africa

<p>Muscle tissue from 63 <i>Synodontis zambezensis</i> collected bimonthly in 2013 at Flag Boshielo Dam were analysed for metals and metalloids in a desktop human health risk assessment. The Hazard Quotient, based on a weekly meal of 67 g of fish muscle, exceeded the maximum acceptable level of one for lead, cobalt, cadmium, mercury, arsenic and selenium. The concentrations of these elements were higher in 2013 than those recorded in 2009 and 2012 in other fish species from Flag Boshielo Dam and these may pose a long-term health risk if consumed regularly by impoverished rural communities reliant on fish as a source of protein.</p

Checklist of acanthocephalan parasites of South Africa

Twenty-one species of acanthocephalans, representative of thirteen genera from ten families of seven orders and three classes, are included in this updated checklist of acanthocephalans in South Africa. Although South Africa appears to have a less diverse acanthocephalan fauna compared to some other countries such as Iran in Asia, or Brazil in South America, this is probably an artefact of fewer parasitological surveys. © Ali Halajian et al