Guides to the Freshwater Invertebrates of Southern Africa. Volume 6: Arachnida and Mollusca

June 2002, Water Research Commission, Pretoria, South Africa

Ring-bound, soft cover, 141 pages

WRC Report No. TT 182/02; ISBN 978–1-86845875–2; price R100.00 (South Africa), US$50.00 (International)

Obtainable from the Water Research Commission, Private Bag X03, Gezina, Pretoria 0031, South Africa. or orders@wrc.org.za     

Systemwide Initiative on Malaria and Agriculture: AnInnovative Framework for Research and Capacity Building

The Systemwide Initiative on Malaria and Agriculture (SIMA) is an initiative of international agricultural research centers to promote research and capacity building on the links between malaria and agriculture and to validate innovative interventions that would strengthen and complement existing malaria-control strategies in clearly defined settings. Knowledge regarding the nature and dynamics of agroecosystems is particularly needed for the purpose of developing appropriate farmer-managed preventive measures against malaria. SIMA research aims to make use of new and existing information on biomedical and socioeconomic determinants of malaria risks in formulating and evaluating the feasibility of integrated strategies. The initiative is especially interested and proactive in promoting and facilitating transdisciplinary and participatory research in relation to malaria. The convening institute for SIMA is the International Water Management Institute at its Africa Regional Office in Pretoria, South Africa. This article outlines SIMAs objectives and scope of activities and also highlights achievements, challenges, and opportunities for future collaboration.     

Lightning density and burning frequency in South African vegetation

This study investigates lightning density in relation to burning frequency in five South African biomes. Data from automatic lightning flash counters distributed throughout South Africa are used to estimate the range and mean values of annual lightning ground-strike density in each biome. The lowest average lightning frequencies were recorded in the karoo and fynbos biomes, while the highest values were obtained in the sour and inland mountain divisions of the grassland biome, with intermediate values computed for the savanna-woodland and forest biomes. These results were compared with published findings on the effects of different burning frequencies on plant communities in each biome. In general, plant communities occurring in areas experiencing the highest annual lightning densities (e.g., sour and mixed grassland, and moist savanna-woodland) tolerate and require more frequent burning than those typical of areas subject to lower lightning densities (e.g., fynbos, forest, sweet grassland, and arid savanna-woodland). These findings suggest that the constituent plant populations in each biome have adapted to burning frequency according to the local probability of ignition by lightning in the areas they inhabit, and that present day responses of plant communities to burning reflect their ancestral exposure to fire in the course of their evolutionary development under pre-existing, natural fire regimes.Research sponsered by the South African Council for Scientific and Industrial Research. We thank the Director, National Electrical Engineering Research Institute (NEERI), Pretoria, South Africa, and H. Kröninger, Lightning Research Division, NEERI, for providing data on lightning ground-strike densities and coordinates and elevations for counters in South Africa. We thank Drs J. H. Bock and M. T. Mentis for commenting on an early draft of this paper.     

Ploidy differences in Cryptococcus albidus

Presumed haploid and diploid cultures ofCryptococcus albidus were analysed for their DNA content per cell. A ratio of approximately 1:2 was obtained by relating the DNA content per cell of the two phases to ploidy. As the diplophase formed neither longitudinally septated cells nor ballistoconidia, the earlier suggestions thatCryptococcus is closely related toTremella seems less likely. On the assumption that the metabasidia ofCryptococcus are gastromycetoid, a closer relationship between this genus and the tulasnelloid fungi appears more probable.Microbiology Research Group, South African Council for Scientific and Industrial Research, Pretoria, South Africa.     

Effect of temperature and light on the toxicity and growth of the blue-green alga Microcystis aeruginosa (UV-006)

The toxicity and growth of Microcystis aeruginosa (UV-006) from the Hartbeespoort Dam, South Africa were investigated at different temperatures and photon fluence rates under laboratory conditions. Cells harvested in late logarithmic growth phase were most toxic when grown at 20°C (LD₅₀) median lethal dose [IP, mouse]=25.4 mg kg^-1). Toxicity was markedly reduced at growth temperatures above 28° C. Fluence rate had a smaller effect on the toxicity of the cells, but toxicity tended to be less at the very low and high light fluences. Optimal conditions for growth did not coincide with those for toxin production. Well-aerated cultures of this isolate kept at pH 9.5 by CO₂ addition, a temperature of 20–24° C, a fluence rate of 145 mol photons m^-2 s^-1 and harvested in the late logarithmic growth phase yielded the maximum quantity of toxin.Abbreviation LD₅₀ median lethal dose An abstract of this work, presented as a poster at the IUBS symposium on toxins and lectins, held at the CSIR, Pretoria, South Africa during 1982 was published in S. Afr. J. Sci. 78, 375 (1982)     

Molecular phylogenetic analysis of <Emphasis Type="Italic">Eugenia</Emphasis> L. (Myrtaceae), with emphasis on southern African taxa

With approximately 1000 species, Eugenia s.str. (excluding Syzygium) is one of the largest genera in the Myrtaceae. Morphological and anatomical studies concluded that two supraspecific groups (X and Y) exist in African members of Eugenia. A multigene approach was used to investigate phylogenetic/molecular relationships within southern African Eugenia, as well as representatives from elsewhere in the world. The cpDNA rpl16 intron data supported the distinctness of species groups X and Y. Little sequence divergence was found within the rpl16 intron of Eugenia. Nuclear sequence data were more variable than cpDNA and also supported the two groups. Combined data enhanced the resolution of closely related species. Species group X is related to Eugenia of the New World whereas the affinity of species group Y lies with Eugenia of the Old World. It is hypothesised that the origin of Eugenia in southern Africa is twofold. The presence of cryptic dioecy (structural androdioecy) in both groups of Eugenia in Africa is probably due to convergence. The suggestion that E. incerta is not native to Africa is supported by molecular evidence. The genus Monimiastrum is embedded within a clade with Mauritian Eugenia.We thank Danielle Florens, J. C. Sevathian and G. dArgent of the Mauritius Herbarium, Reduit, for the collection of all the material from Mauritius; Ed Biffin, CSIRO, Australia, for supplying DNA of E. reinwardtiana and Rhodamnia argentea; A. Salywon, Arizona State Univeristy, Tempe, USA for material from Florida; Timothy Lowrey, University of New Mexico, Albuquerque, USA, for material from Madagascar; and A. Urban, Stefan Neser (ARC, Pretoria) and J. H. Pedrosa-Macedo (Forest Research Foundation, Federal University of Parana, Curitiba, Brazil) for the material from Brazil. The authors are indebted to the National Research Foundation (South Africa) and the University of Pretoria for financial assistance.     

The Sexual Risk Context among the FEM-PrEP Study Population in Bondo,Kenya and Pretoria,South Africa

Background

Incidence rates in the FEM-PrEP and VOICE trials demonstrate that women from diverse sub-Saharan African communities continue to be at substantial HIV risk.

Objective

To describe and compare the sexual risk context of the study population from two FEM-PrEP trial sites–Bondo, Kenya, and Pretoria, South Africa.

Methods

At baseline we collected information about demographics, sexual behaviors, and partnership beliefs through quantitative questionnaires with all participants (Bondo, n = 720; Pretoria, n = 750). To explore the sexual risk context, we also conducted qualitative, semi-structured interviews with HIV-negative participants randomly selected at several time points (Bondo, n = 111; Pretoria, n = 69).

Results

Demographics, sexual behavior, and partnership beliefs varied significantly between the sites. Bondo participants were generally older, had fewer years of schooling, and were more likely to be employed and married compared to Pretoria participants. Bondo participants were more likely to report multiple partners and not knowing whether their partner had HIV than Pretoria participants. A significantly higher percentage of Bondo participants reported engaging in sex without a condom with their primary and other partners compared to Pretoria participants. We found a borderline association between participants who reported not using condoms in the 4 weeks prior to baseline and lower risk of HIV infection, and no association between having more than one sexual partner at baseline and HIV infection.

Discussion

Despite significantly different demographics, sexual behaviors, and partnership beliefs, many women in the FEM-PrEP trial were at risk of acquiring HIV as demonstrated by the sites’ high HIV incidence. Though gender dynamics differed between the populations, they appear to play a critical role in women’s sexual practices. The findings highlight different ways women from diverse contexts may be at-risk for HIV and the importance of providing HIV prevention options that are both effective and feasible given personal and social circumstances.     

MANAGEMENT,CONSERVATION AND RESEARCH OF INTERNATIONALLY SHARED WATERCOURSES IN SOUTIIERN AFRICA—NAMIBIAN EXPERIENCE WITH THE OKAVANGO RIVER AND RIVERS OF THE EASTERN CAPRIVI

Summary

Although the emphasis of the recent National Rivers Research Initiative (now the Research Programme for the Management of Rivers) in South Africa was on river research in that country, the reality is that in southern Africa many watercourses are shared by more than one country. Therefore a central issue in integrated river basin management and development should be the recognition of the principle of international joint planning, conservation, monitoring and research.

Co-operation and a better understanding of shared waters would prevent deleterious impacts, not only in the country where they occur, but also in those downstream. With this in mind, since the early 1980s Namibia has worked on joint cross-border projects in efforts to manage and conserve her shared water bodies. These include joint river gauging exercises, biological control of Saivinia molesta in the eastern Caprivi region and, more recently, the application of a biological monitoring technique, the South African Scoring System version 4, to north-eastern perennial rivers.

The formation of the Joint Permanent Water Commission between Botswana and Namibia enabled the Departments of Water Affairs of both countries to work together on their shared rivers. The establishment of the Permanent Okavango River Basin Water Commission between Angola, Botswana and Namibia in 1994 improved this co-operation even further. Namibia and its' counterparts are thus committed to sharing information, co-ordinating research and monitoring activities and to undertaking detailed studies to improve their knowledge of these shared systems.

Such cross-border co-operation is vital for the survival of shared river systems not only as ecological entities in their own right, but also as sources of water, power and the other resources they provide, both directly and indirectly, to the human and wildlife populations that they support.     

Thornbush invasion in a savanna ecosystem in eastern Botswana

The paper describes the thornbush invasion (bush encroachment) found in the savanna at Olifants Drift in eastern Botswana. Overgrazing by cattle is responsible for the opening up of the grass sward and has enabled woody species to establish. A quantification of this process between 1950 and 1975 in an area of ca. 100 km² is given in terms of plant density as well as aboveground biomass. The loss of herbaceous biomass which generally accompanies bush encroachment and the possibilities for pasture restoration are mentioned.Species nomenclature follows the Flora of Southern Africa and the system in use at the herbarium of the Botanical Research Institute at Pretoria, South Africa.     

TIMING OF LAYING BY GREATER KESTRELS FALCO RUPZCOLOZDES NEAR PRETORIA,SOUTH AFRICA

Kemp, A. C. 1991. Timing of laying by Greater Kestrels Fulco rupicoloides near Pretoria, South Africa. Ostrich 62: 35–39.

Laying dates for a population of individually marked Greater Kestrels Falco rupicoloides, on grass- and croplands near Pretoria, South Africa, were determined for 89 nesting attempts during 1975–1988. Laying occurred in the austral spring between 23 July and 11 November. Timing of laying was negatively correlated with rainfall of the previous summer and positively correlated with rainfall of the winter and spring preceding laying. Success in fledging young was significantly higher for clutches laid before the median laying date of 1 September and for clutches laid after seasons of above average rainfall.     

ASPECTS OF THE BREEDING BIOLOGY AND BEHAVIOUR OF THE SECRETARYBIRD SAGITTARIUS SERPENTARIUS NEAR PRETORIA,SOUTH AFRICA

Kemp, A. C. 1995. Aspects of the breeding biology and behaviour of the Secretarybird Sagittarius serpentarius near Pretoria, South Africa. Ostrich 66: 61–68.

Secretarybirds in three adjacent territories were monitored from 1977 to 1988 on grass- and croplands near Pretoria, South Africa. Most observations of breeding biology and behaviour confirmed or extended previous studies. There was no correlation between pairs in occupancy of territory, productivity or development periods of young: this confirms the flexible breeding abilities which are unusual for such a large bird. Some aspects of breeding biology (egg shape and texture, watering of chicks) and behaviour (Wings open and Up-down greeting displays) may be homologous with storks and important in understanding the phylogeny and evolution of the Sagitariidae and other diurnal raptors.     

Three new species of Crenitis Bedel, 1881 from South Africa,with a revised key to African species (Coleoptera: Hydrophilidae)

Three new species of Crenitis Bedel, 1881 are described from South Africa; C. castellus sp.n. and C. rupestris sp. n. from the KwaZulu-Natal Drakensberg, and C. quagga sp.n. from the Western Cape Province. All three new species were found in madicolous habitats, which appear to be characteristic for a number of species of the genus. A revised key to African species of Crenitis is included.

http://zoobank.org/urn:lsid:zoobank.org:pub:18BE876C-46CB-4AD5-9BB0-EA6F8D711F09     

A new species of entomopathogenic nematode Oscheius safricana n. sp. (Nematoda: Rhabditidae) from South Africa

In a recent entomopathogenic nematode (EPN) survey in the North West province of South Africa, Oscheius safricana was isolated from soil samples using the Galleria mellonella bait method. Morphological studies using light microscopy and scanning electron microscopy, molecular analysis of the internal transcribed spacer region (ITS), D2\D3 expansion segments of the large subunit rDNA gene (LSU) and concise small subunit rDNA gene (SSU), revealed that it was a new species, described herein as Oscheius safricana n. sp. Oscheius safricana n. sp. was characterised by unique ribosomal DNA sequences, amphidelphic reproduction, six separate lips each two bristle-like sensillae, narrow pharynx, valvated basal bulb, lateral field with four lines, leptoderan and closed bursa and fused spicules. This EPN belongs to the group Insectivorus and is morphologically closest to O. necromenus, O. chongmingensis and O. carolinensis. Oscheius safricana n. sp. is symbiotically associated with Serratia marcescens strain MCB.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:642E1B7E-B88F-4CE0-9D06-4FA9ECA48847     

Four new species of the genus Cheimacheramus Barnard, 1934 from Madagascar (Trichoptera: Sericostomatidae)

The genus Cheimacheramus Barnard, 1934 Barnard, K.H. (1934), ‘South African Caddis-Flies (Trichoptera)’, Transactions of the Royal Society of South Africa, 21, 291–394.[Taylor &; Francis Online] , [Google Scholar] included only three species, one from South Africa and two from Madagascar. Four new Malagasy species are described herein: Cheimacheramus akandi sp. n., Cheimacheramus barnardi sp. n. and Cheimacheramus anjojorobensis sp. n. from the Anjojorobe Forest, Cheimacheramus madecassus sp. n. from the Lakato Forest and the Marojejy National Park. Diagnostic characters of the genus and species are discussed and illustrated. In Madagascar, these discoveries confirm the localization of the genus within the eastern evergreen forests.

http://zoobank.org/urn:zoobank.org:pub:79472077-04E9-42FA-B55B-9EE291556E60     

Intergrading between members of the "regularis group" of toads in South Africa

The mating calls of three members of the " regularis group" of toads (Anura: Bufonidae) that are sympatric in part of South Africa are examined. A naturally occurring population of hybrid toads from Pretoria (South Africa) has previously been described as representing an intergrading between Bufo garmani Meek and Bufo rangeri Hewitt. Examination of the mating calls of these toads provides little evidence of intergrading between Bufo rangeri and Bufo garmani , and indicates the involvement of Bufo regularis Reuss in the hybridization. The mating calls of the hybrids are varied, and are structurally intermediate between those of the parental species. Mating call parameters are found to be useful in separating forms that are difficult to distinguish on morphological grounds alone. They are further found to be a sensitive non-morphological means of ascertaining the affinities of naturally occurring hybrid toads.     

A capitosauroid from the Lower Triassic of South America (Sanga do Cabral Supersequence: Paraná Basin), its phylogenetic relationships and biostratigraphic implications

Surviving through the end-Permian mass extinction, stereospondyls reemerged reaching a widespread distribution during the Early Triassic. A well representative lineage of this clade, Capitosauroidea, became worldwide abundant from Early to Late Triassic, in which their first undoubtful representatives were recovered from Lower Triassic deposits. Here, we describe a new capitosauroid, Tomeia witecki gen. et sp. nov., from the Sanga do Cabral Supersequence (Paraná Basin). Although relatively incomplete, the material presents a particular combination of early and late-diverging capitosauroid characters. Supporting Tomeia witecki as a new capitosauroid, our phylogenetic analysis placed the taxon as part of a clade that comprises only Early Triassic capitosauroids, specifically as the sister-taxon of the madagascarian Edingerella madagascariensis and close to Watsonisuchus spp., from Australia, South Africa and Madagascar. The status of Tomeia witecki as a new capitosauroid from western Gondwana supports a continuous record of the Stereospondyl lineage, since their first appearance during the Middle Permian in this supercontinent. Additionally, the temporal range of the Sanga do Cabral Supersequence during the Early Triassic was specifically reinforced as Olenekian, mainly based on the overall faunal content previously reported to this unit, associated with the known temporal distribution from those taxa phylogenetically closer to Tomeia witecki.

http://zoobank.org/urn:lsid:zoobank.org:pub:7AA9F874-BED5-4A99-B098-B50656E706C1     

conservation in the bush: game breeding centres in South Africa

Approximately 5% of the Republic of South Africa is set aside for national parks, nature reserves, private game reserves or wilderness areas. Within these areas a large variety of animals and plant species is protected. Many of these species are indigenous to the Southern African subregion. Most of the zoological gardens in South Africa are owned privately or by a municipality. The zoo in Pretoria is the only one which has national status. In addition to facilities in Pretoria, the National Zoological Gardens owns two game breeding centres covering an area of more than 7000 ha. The game breeding centres act as important gene pool reservoirs and are used for the breeding of threatened species. They thus fulfill an important role in conserving threatened species and, in some cases, supplementing dwindling populations in protected areas.     

The Impact of Prior Information on Estimates of Disease Transmissibility Using Bayesian Tools

The basic reproductive number (R₀) and the distribution of the serial interval (SI) are often used to quantify transmission during an infectious disease outbreak. In this paper, we present estimates of R₀ and SI from the 2003 SARS outbreak in Hong Kong and Singapore, and the 2009 pandemic influenza A(H1N1) outbreak in South Africa using methods that expand upon an existing Bayesian framework. This expanded framework allows for the incorporation of additional information, such as contact tracing or household data, through prior distributions. The results for the R₀ and the SI from the influenza outbreak in South Africa were similar regardless of the prior information (R^0 = 1.36–1.46, μ^ = 2.0–2.7, μ^ = mean of the SI). The estimates of R₀ and μ for the SARS outbreak ranged from 2.0–4.4 and 7.4–11.3, respectively, and were shown to vary depending on the use of contact tracing data. The impact of the contact tracing data was likely due to the small number of SARS cases relative to the size of the contact tracing sample.     

Descriptions of Tachygonetria africana n. sp. and T. pretoriensis n. sp. and redescriptions of two other species of Tachygonetria Wedl, 1862 (Nematoda: Pharyngodonidae), all parasitic in Geochelone pardalis (Testudinidae) from South Africa

Two new species of Tachygonetria, T. africana n. sp. and T. pretoriensis n. sp. are described. Both are parasites of Geochelone pardalis (Bell) from South Africa. In addition, two subspecies, T. longicollis fitzsimmonsi Petter, 1966 and T. macrolaimus macrolaimus (Linstow, 1899), also parasites of Geochelone pardalis (from Pretoria Zoo, South Africa), are redescribed and new information on their morphology is presented. On the basis of their morphology, these subspecies are raised to full specific level.