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We evaluated craniometric sexual dimorphism and ontogenetic (age) variation in invasive Rattus norvegicus and R. rattus from urban and peri-urban areas of Gauteng Province, South Africa, using univariate and multivariate analyses. Two-way analysis of variance (ANOVA), percent contribution of the sum of squares (%SSQs) of each source of variation, principal components analysis (PCA) and unweighted pair-group method with arithmetic averages (UPGMA) cluster analysis showed no sexual dimorphism in both species, however in both species, significant age variation between five age classes based on maxillary molar toothrow cusp eruption and wear was found and the age classes were pooled into juveniles (i.e., individuals of tooth-wear class I), sub-adults (II–III), and adults (IV–V). Few variables showed statistically significant sex-age interaction. The largest %SSQs to the total variance were due to error (i.e., residual), suggesting that apart from sex, age, and their interaction, there were other components that are responsible for the variation. Our approach may be useful for partitioning the effect of sexual dimorphism and ontogenetic variation in other studies, such as our stable isotope analysis-based trophic ecological studies of Rattus species from urban and peri-urban areas of Gauteng Province, South Africa. [ABSTRACT FROM AUTHOR]

• A core DNA barcode reference database of commonly traded macrophyte taxa is assembled and tested. • The database is successfully used to identify macrophytes collected during a survey of aquarium and pond plant retailers in and around Johannesburg, South Africa. • It is revealed that multiple NEM:BA listed invasive taxa are still being traded within the local aquarium and pond plant industry. • Traded potentially invasive macrophytes that are not on the NEM:BA lists are identified and discussed. South Africa's water bodies have been invaded multiple times by various alien macrophytes in the last 200 years and this trend is set to continue – posing a significant threat to the already fragile indigenous aquatic ecosystems and the services they provide. The aquarium and ornamental pond plant industry has been found to serve as a primary pathway for the continued introduction of high-risk taxa. Although regulations like the National Environmental Management: Biodiversity Act (NEM:BA) 10 of 2004 together with some national programmes are currently in place to ensure compliance by the different industry role players, adequate enforcement is hampered by challenges inherent to definitive species identification. In this study, the utility of a DNA barcoding approach to aid in addressing these issues was assessed. An extensive macrophyte core barcode (matK and rbcLa) reference library was compiled and tested to: (i) establish if a "barcode gap" was present, ii) determine the optimised threshold for species delimitation and (iii) assess identification efficiency using different distance based metrices. This reference library was subsequently used to identify plants collected during a survey of ten macrophyte retailer shops in and around the Johannesburg metropolitan area for which DNA barcodes could be generated. Results obtained indicate the presence of considerable interspecific and curbed intraspecific distance between the marker combinations tested and demonstrate high species identification rates. Additionally, multiple alien aquatic plants currently in trade under the following NEM:BA categories were recovered: 1a (invasive species), 1b (invasive species controlled by program) and species prohibited in terms of section 67(1). A surprisingly large number of first-time invasive alien macrophytes not currently on the NEM:BA lists were also identified. The dataset and findings presented in this study have important implications for informing pre-emptive invasive macrophyte management in South Africa e.g. tracking the country's commitments towards achieving the Convention on Biological Diversity's (CBD) Aichi Biodiversity Target 9 (as well as its inheritor post-2020) and providing recommendations for updates to the NEM:BA alien and invasive species lists. The library also presents opportunities for exploring the utility of spin-off applications that rely on robust molecular datasets (e.g. eDNA monitoring). [ABSTRACT FROM AUTHOR]

The constitutional right to privacy is enshrined in section 14 of the Constitution of the Republic of South Africa, 1996. It is premised on the notion that all persons should be protected from intrusions on their privacy by any person or institution. The Constitutional Court has also, on numerous occasions, held that the right to privacy is bolstered by its connection with the right to human dignity. It is undeniable that every person's right to privacy should be protected. However, a person's right to privacy is violated when police officials conduct warrantless search and seizure operations. Generally section 22 of the Criminal Procedure Act provides for warrantless search and seizure operations when a police official has a reasonable suspicion that a search warrant will be issued to him and that a delay in obtaining such a warrant would defeat the object of the search. Warrantless searches are important for the prevention of crime, but recent case law has suggested that there has been a progressive shift towards protecting the right to privacy of the individual subjected to warrantless searches, since there are a number of laws besides section 22 that regulate warrantless searches and which have been declared to be constitutionally invalid. This article seeks to demonstrate that the current regulatory framework for warrantless searches should be reviewed in order to protect the legitimacy of the police as well as the dignity and privacy of the citizens of South Africa. [ABSTRACT FROM AUTHOR]

Tamarix species are major terrestrial riparian invaders in South Africa. The biocontrol agent, Diorhabda carinulata (Coleoptera: Chrysomelidae), was tested as the initial candidate agent in South Africa due to its success against invasive Tamarix in North America. The ability of Tamarix to grow across a broad soil salinity gradient may affect its suitability as a host for D. carinulata, and influence its invasive capability. Therefore, the effect of increased soil salinity was considered a potential influential factor on the host preference of D. carinulata and the suitability of the host plant for the beetle. Choice tests were conducted by exposing beetles to salt-treated and untreated plants of both the invasive alien T. chinensis x T. ramosissima hybrid and indigenous T. usneoides. Leaf chlorophyll content and relative water content were used as a proxy to measure how increased soil salinity affected the health of the Tamarix taxa. Adult host selection and oviposition, and subsequent larval survival and development of D. carinulata on salt-treated and untreated plants were not different on either the invasive hybrid or T. usneoides. Under salt stress, T. usneoides exhibited a greater reduction only in chlorophyll content compared to the invasive hybrid. Increased soil salinity thus does not alter the host preference of D. carinulata, or the suitability of the Tamarix taxa as host plants. The invasive alien Tamarix taxa may be less susceptible to salt-induced stress than T. usneoides, which could be contributing to its invasiveness in South Africa. [ABSTRACT FROM AUTHOR]

Background: Tithonia diversifolia and T. rotundifolia belong to the Asteraceae family and are native to Mexico and Central America. These plants have become invasive in parts of tropical Africa and Asia where they have become an ecological, agricultural and economic burden. Tithonia diversifolia is exploited by locals in its native and most parts of its invasive range as a source of medicines; however, T. rotundifolia is only used for medicinal purposes in one country in the native range (Venezuela) and none in the invasive range. Although T. diversifolia has been studied for different biological activities, little or no attention has been given to T. rotundifolia. This study compared the antimicrobial activity, phytochemistry, identification of bioactive compound(s) and toxicity levels of different leaf extracts and fractions of T. diversifolia and T. rotundifolia. Methods: Antimicrobial activity was evaluated against seven pathogenic bacteria, four non-pathogenic Mycobacterium species and three fungal species using serial microdilution assays. Phytochemical contents were determined through standard methods of analysis. UPLC/MS was used to analyse the fractions to identify possible bioactive compounds that may be responsible for bioactivity, while toxicity tests were carried out using the colorimetric MTT assay and the Ames test. Results: Both species had a range of antimicrobial activity against bacterial, mycobacterial and fungal species. However, T. rotundifolia displayed better activity against most of the strains tested with minimum inhibitory concentration values ranging between 0.01 and 0.07 mg/ml. Both species were rich in phenolics, flavonoids and tannins. Tagitinin A was identified as the main compound present in both species, and this compound may be responsible for the antimicrobial activity displayed. Toxicity tests showed that T. diversifolia was cytotoxic at concentrations used in this study, while T. rotundifolia was not. Both species did not show any mutagenic/genotoxic effects. Conclusion: The above results suggest that both species may be further developed as a source of antimicrobials for the treatment of infections caused by opportunistic pathogens. They may also serve as alternatives to highly exploited plant species with the same medicinal properties. However, T. diversifolia should be used with caution as it may be toxic. [ABSTRACT FROM AUTHOR]

This research provides the first detailed assessment of Cistus ladanifer , a woody, perennial shrub native to the Mediterranean, as an invasive species in South Africa. Three small naturalising populations (all less than 0.1 ha) of this species were discovered in 2012 in native heathland vegetation (“Fynbos”) of the Western Cape Province of South Africa. Prior to this discovery, C. ladanifer had not previously been recorded or recognised as an invasive species in South Africa. It poses a significant threat to the local endemic vegetation, largely due to its pre-adaptation to similar environmental conditions, and, if left unmanaged, it has the potential to invade further. However, given the small size of currently known populations and its ease of management, we propose that eradication of C. ladanifer is feasible in South Africa. Here we provide insights into options for the management of C. ladanifer , in particular its eradication from South Africa. Based on the weed risk assessment presented here, we recommend that C. ladanifer be listed as an invasive species under national legislation, thus requiring compulsory management. The results of this study provide detailed information on the extent of the invasion by C. ladanifer and the aspects of its biology pertinent to management (e.g. its reproductive ability, soil-stored seed banks). We show that complete removal of C. ladanifer populations is feasible and results in a steady decline in population size over time. Local extirpation of populations of C. ladanifer can be enhanced through fire-stimulation of the seed bank, but this may not be feasible in an urban setting. Our study emphasises the importance of scientific research in the development and evaluation of species-based management plans for invasive species. [ABSTRACT FROM AUTHOR]

The presence of Brevipalpus lewisi (Trombidiformes: Tenuipalpidae) is reported from South Africa for the first time. Previously this mite was a listed phytosanitary pest to South Africa, and entry of infested goods was prohibited. During a country-wide survey, B. lewisi was found on grapevine in the Western Cape and Northern Cape provinces. It has not been found in other provinces or on other crops, most notably on citrus, on which it is considered a pest in other countries. Brevipalpus lewisi was regularly collected together with several other mite species, including predatory species. Other Brevipalpus species collected were B. californicus and B. obovatus on grapevine and citrus and B. yothersi on grapevine. [ABSTRACT FROM AUTHOR]

* Background and Aims The ability to fix atmospheric nitrogen is thought to play an important role in the invasion success of legumes. Interactions between legumes and nitrogen-fixing bacteria (rhizobia) span a continuum of specialization, and promiscuous legumes are thought to have higher chances of forming effective symbioses in novel ranges. Using Australian Acacia species in South Africa, it was hypothesized that widespread and highly invasive species will be more generalist in their rhizobial symbiotic requirements and more effective in fixing atmospheric nitrogen compared with localized and less invasive species. * Methods To test these hypotheses, eight localized and 11 widespread acacias were examined using next- generation sequencing data for the nodulation gene, nodC, to compare the identity, species richness, diversity and compositional similarity of rhizobia associated with these acacias. Stable isotope analysis was also used to determine levels of nitrogen obtained from the atmosphere via symbiotic nitrogen fixation. * Key Results No differences were found in richness, diversity and community composition between localized and widespread acacias. Similarly, widespread and localized acacias did not differ in their ability to fix atmospheric nitrogen. However, for some species by site comparisons, significant differences in d15N isotopic signatures were found, indicating differential symbiotic effectiveness between these species at specific localities. * Conclusions Overall, the results support recent findings that root nodule rhizobial diversity and community composition do not differ between acacias that vary in their invasiveness. Differential invasiveness of acacias in South Africa is probably linked to attributes such as differences in propagule pressure, reasons for (e.g. forestry vs. ornamental) and extent of, plantings in the country. [ABSTRACT FROM AUTHOR]

Dispersal and observed genetic structure of sessile marine invertebrates such as the alien polydorid polychaete, Polydora hoplura , which is associated with cultured molluscs, may be influenced by biogeographic barriers and human-mediated dispersal. To test this hypothesis, we compared the population genetic structure of P. hoplura to that of Boccardia polybranchia since both species have similar larval developmental modes (and consequently natural dispersal potential) and distribution ranges in southern Africa. However, since B. polybranchia is not a pest, its population structure should reflect the effects of only biogeographic barriers on natural dispersal. Boccardia polybranchia was collected from five wild sites along the South African coast, and P. hoplura from seven wild sites and four oyster farms; two each were on-shore and off-shore. Analyses of mtDNA Cyt b sequence data indicate two distinct lineages for B. polybranchia , supporting Cape Point as a biogeographic barrier to the dispersal of larvae. In contrast, no distinct geographic lineages were identified for P. hoplura occurring in the wild, and haplotype sharing suggest possible cross infestation between farm and nearby wild sites. At farms the genetic diversity of P. hoplura is lower but also more structured, suggesting separate anthropogenic introductions at each site possibly from genetically distinct source populations. Furthermore, more limited genetic sharing was detected between worms from on-shore and nearby wild sites, whereas the opposite was observed for off-shore farms and associated wild sites. This suggests that populations in on-shore farms are more contained with most of the individuals carrying parasites corresponding to the source of introduction while those on off-shore farms display much more genetic exchange with wild populations. Thus oysters in off-shore facilities are probably more vulnerable to infestation by polydorid pests than are those in on-shore facilities. Statement of relevance Movement of oysters spreads associated pests [ABSTRACT FROM AUTHOR]

African sharptooth catfish Clarias gariepinus is native to most of Africa and small parts of Asia, but has been introduced to 37 countries mainly for aquaculture. This review of introductions, establishment, spread and impact of C. gariepinus in Brazil and outside of its native range in South Africa provides evidence that the species has been able to overcome all barriers to invasion in both countries. Following initial introductions across geographical barriers, containment seems to have been impossible and escape from aquaculture facilities and spread by illegal introductions is an invasion pathway in both countries. There is evidence of individuals dispersing rapidly following escape, and surviving and reproducing at multiple sites in a wide spectrum of habitats in both countries. There is a severe paucity of research on impacts, many of which are inferred from field and laboratory observations, but have not been demonstrated at population or community level. Such impact studies are urgently required to better understand the consequences of these invasions and to develop appropriate strategies to mitigate impacts and spread. [ABSTRACT FROM AUTHOR]

Biological control of Azolla filiculoides in South Africa with the Azolla specialist Stenopelmus rufinasus has been highly successful. However, field surveys showed that the agent utilized another Azolla species, thought to be the native Azolla pinnata subsp. africana , which contradicted host specificity trials. It is notoriously difficult to determine Azolla species based on morphology so genetic analyses were required to confirm the identity of the Azolla used by the agent. Extensive sampling was conducted and samples were sequenced at the trnL-trnF and trnG-trnR chloroplastic regions and the nuclear ITS1 region. Current literature reported A. filiculoides as the only Section Azolla species in southern Africa but 24 samples were identified as Azolla cristata , an introduced species within Section Azolla that was not used during host specificity trials. A. pinnata subsp. africana was only located at one site in southern Africa, while the alien A. pinnata subsp. asiatica was located at three. What was thought to be A. pinnata subsp. africana was in fact A. cristata , a closer relative of A. filiculoides and a suitable host according to specificity trials. This study confirms that S. rufinasus is a proficient Azolla taxonomist but also supports the use of molecular techniques for resolving taxonomic conundrums. [ABSTRACT FROM AUTHOR]

Molecular genetic techniques were used to determine the identity of two catfish individuals that could not be identified as indigenous Clarias gariepinus after phenotypic analysis. The unidentified catfish were compared to 126 reference samples, using sequences of the mitochondrial DNA control region. The reference dataset included African catfish from South Africa and Kenya, as well as GenBank records for this species and for three species of Southeast Asian catfish, including the potentially invasive walking catfish, C. batrachus. Visual inspection of sequences showed parallel polymorphisms in the unidentified catfish and C. batrachus that did not occur in C. gariepinus. A bioinformatics approach using the Basic Local Alignment Search Tool (BLAST) of the National Center for Biotechnology Information confirmed that the unidentified catfish show more similarity to catfish of Asian origin compared to C. gariepinus. Finally, a phylogenetic approach showed that the catfish analysed group according to continent of origin (Africa and Asia) with strong bootstrap support, and with the unidentified fish contained in the Asian cluster.We conclude that the unidentified catfish are most likely imported C. batrachus. [ABSTRACT FROM AUTHOR]

Abstract: Invasive species are a major threat to global biodiversity. Rose-ringed parakeets Psittacula krameri are widely established outside their native range and are successful invaders in many countries, including South Africa. Physiological and behavioral responses to environmental conditions are considered to be major factors that influence the abundance and distribution of birds. As rose-ringed parakeets are able to tolerate wide varieties of climatic conditions as invaders, it is important to understand their physiological responses to these. This study examined the effects of seasonal changes in ambient temperatures (T a ) on metabolic rate and body temperature (T b ) of captive-bred rose-ringed parakeets. Resting metabolic rate at various T a and basal metabolic rate were significantly lower in winter compared to summer, and the thermo-neutral zone was broader in winter than in summer. There was no significant difference in body mass (M b ) between seasons. These parakeets showed seasonal thermoregulatory responses that represented energy conservation as expected, rather than cold tolerance. They were relatively tolerant of low T a and showed no hypothermia at 5°C. Our results suggest that this species is physiologically and behaviorally equipped to cope with a range of climatic situations and this partly explains their global success as an invader species. [Copyright &y& Elsevier]

The whitefly Bemisia tabaci cryptic species complex contains some important agricultural pest and virus vectors. Members of the complex have become serious pests in South Africa (SA) because of their feeding habit and their ability to transmit begomovirus species. Despite their economic importance, studies on the biology and distribution of B. tabaci in SA are limited. To this end, a survey was made to investigate the diversity and distribution of B. tabaci cryptic species in eight geographical locations (provinces) in SA, between 2002 and 2009, using the mitochondrial cytochrome oxidase I (mtCOI) sequences. Phylogenetic analysis revealed the presence of members from two endemic sub-Saharan Africa (SSAF) subclades coexisting with two introduced putative species. The SSAF-1 subclade includes cassava host-adapted B. tabaci populations, whereas the whiteflies collected from cassava and non-cassava hosts formed a distinct subclade, referred to as SSAF-5, and represent a new subclade among previously recognized southern Africa clades. Two introduced cryptic species, belonging to the Mediterranean and Middle East-Asia minor 1 clades, were identified and include the B and Q types. The B type showed the widest distribution, being present in five of the eight provinces explored in SA, infesting several host plants and predominating over the indigenous haplotypes. This is the first report of the occurrence of the exotic Q type in SA alongside the more widely distributed B type. Furthermore, mtCOI PCR-RFLP was developed for the SA context to allow rapid discrimination between the B, Q and SSAF putative species. The capacity to manage pests and disease effectively relies on knowledge of the identity of the agents causing the damage. Therefore, this study contributes to the understanding of South African B. tabaci species diversity, information needed for the development of knowledge-based disease management practices. [ABSTRACT FROM AUTHOR]

Myosotella myosotis is shown to be a well-established alien species in South Africa. Discovered in Port Elizabeth more than 100 years ago, it was initially thought to be indigenous and was described under two different names, but subsequent taxonomic work has demonstrated that these are synonyms of the variable and widely introduced European M. myosotis. This information, published in a revision of western Atlantic Ellobiidae, has escaped the attention of the South African marine science community. There has been no recent mention of M. myosotis or its two pseudoindigenous synonyms in the literature pertaining to either the estuaries or the malacofauna of South Africa, or to marine bioinvasions in the region. This example serves to demonstrate that invasion biology has a global context and that taxonomic literature is an important source of pertinent data. The fact that a species, which evidently occurs in abundance, can be overlooked for so long is both surprising and sobering. [ABSTRACT FROM AUTHOR]

The arrival and spread of the introduced western pea crab Pinnixa occidentalis Rathbun 1894 in South Africa is documented. The crab originates from the Pacific coast of North America and was first recorded in Saldanha Bay in 2004, although its identification was only confirmed in 2010. Subsequent surveys have shown the crab population to be increasing rapidly in both distribution and density, although it remains confined to the Saldanha Bay–Langebaan Lagoon system. The ecological impacts of the invasion are yet to be determined. [ABSTRACT FROM AUTHOR]

In South Africa, fishes in headwater streams are increasingly being threatened by non-native fish invasions. These invasions originate primarily from source populations in mainstream rivers and impoundments. In the Blindekloof stream, a Swartkops River headwater tributary, the non-native Micropterus salmoides was eradicated from the stream by conservation authorities in 1989. As a result of this eradication subsequent occurrences of non-native fishes are most likely a result of upstream invasions from the mainstream Swartkops River. The Blindekloof stream therefore provided a unique opportunity to investigate whether M. salmoides would reinvade after its removal in 1989 and if the more recently introduced Clarias gariepinus and Tilapia sparrmanii would invade the Blindekloof stream. During snorkel and electrofishing surveys four non-native species were recorded (M. salmoides, M. dolomieu, T. sparrmanii, (2. gariepinus). The large predators, M. salmoides, M. dolomieu and C. gariepinus were neither abundant nor widespread and T. sparrmanii was the only non-native species that had success- fully established in the Blindekloof stream. Where M. salmoides and M. dolomieu were observed, all other fish species were absent. By contrast, the native species were present at all sites where C. gariepinus and T. sparrmanii were found. The Pseudobarbus afer population was predominantly limited to a 1.7 km section of the stream that was not invaded and is located above a waterfall. The limited distribution range of this Endangered species makes it particularly vulnerable to predation by non-native fishes. The results of this study indicate that these non-native fishes rapidly invaded the Blindekloof stream following their introduction into the mainstream. [ABSTRACT FROM AUTHOR]

The article details a study on larval dispersal and recruitment dynamics intertidal mussels and barnacles in the southern Benguella upwelling region located at Cape of Good Hope in South Africa, conducted by Maya C. Pfaff and colleagues. It notes that mussels have strong seasonal recruitment peaks during the summer upwelling season while barnacles during spring. The recruitment dynamics of mussels peaked northwards while the recruitment of barnacles increased southwards. According to this study, mussels and barnacles have the same recruitment patterns. The positive effect of wave exposure on the recruitment dynamics of mussels and barnacles is discussed.

The super-abundance of Lepisiota incisa (Forel) in settlement areas of Kruger National Park, South Africa has raised concerns that it might be exotic and could negatively impact on natural ecosystems. We documented the current distribution of this ant species around the main settlement in Kruger, assessed how ant diversity varies across habitats, and investigated potential mechanisms facilitating dominance by L. incisa. Around the main camp of Skukuza, pitfall traps were set in five habitats differing in anthropogenic influence. Baiting trails were conducted to determine whether L. incisa and native ants differed in numerical and behavioural dominance. Aggression assays were performed on L. incisa to provide information on colony structure. Although L. incisa was found in all habitats, it had a significantly higher abundance in gardens and appears confined to human-disturbed areas. It was numerically dominant recruiting more workers to food baits than all other ant species combined. Aggression levels were low between most nests of L. incisa indicating a potential supercolony structure. More information is urgently needed on the genetics, physiology and origins of L. incisa, and monitoring of its current distribution is recommended. This species warrants attention because there may be significant potential for overseas invasion. [ABSTRACT FROM AUTHOR]

The Mediterranean mussel Mytilus galloprovincialis invaded the shores of South Africa in about the mid-1970s. It was first detected at a harbour in Saldanha on the west coast and apparently arrived accidentally. From there, it spread at a rate of about 115 km·year−1 and now occupies the whole of the west coast of South Africa and at least the southern half of Namibia. It was deliberately introduced from the west coast to the south coast for mariculture. In this case study, we record its effects on intertidal rocky shores, cast in terms of predictions based on (a) the history of its invasions elsewhere, (b) its mode of dispersal, (c) its physiological performance relative to indigenous mussels, (d) the role of wave action as a moderator of competition, (e) the influence of relative body sizes, (f) the projected effects of the mussel on infauna, (g) consumption by higher trophic levels, and (h) rates of parasitism.Several properties of M. galloprovincialis itself, and of the recipient community, conspired to favour the spread and establishment of this alien mussel, including high productivity on the west coast of South Africa, prevalently strong wave action, a sparsity of predators, an absence of parasites, the mussel''s fast growth and high reproductive output, and its possession of a planktotrophic larva. It competitively displaces several species because of its physiological performance. Some of the species gain a substitute substratum on the mussels themselves, but only if they are small enough to live and reproduce on the mussels. M. galloprovincialis has had little effect on infauna, but has provided an additional source of food for higher predators, including the rare and endangered African Black Oystercatcher (Haematopus moquini).Nearly all these effects and conditions were forecasted (or, at the least, explainable with hindsight), but despite these successes in predicting the impacts of M. galloprovincialis, its spread was not only unavoidable but was encouraged by its transfer to the south coast for mariculture. Moreover, there was one completely unpredictable effect of M. galloprovincialis—which led to mass mortalities of a swimming crab. Given the failure of even quite detailed and accurate predictions to allow control of M. galloprovincialis once it arrived, prevention rather than cure must be the prime means of avoiding future unwanted introductions of invasive species. [Copyright &y& Elsevier]

• South African shores were invaded by multiple ecosystem engineers from 1980 to 2015. • Ecosystem engineers changed habitat complexity, which impacts native species. • Layered approach used to model impact of habitat complexity on intertidal ecosystem. • Novel plug-in, EcoEngineer, introduced for Ecospace module of Ecopath with Ecosim. • EcoEngineer showed highest success in modelling invasions by multiple engineers. In a prequel to this paper, we used non-spatial temporal modelling to investigate the impact of non-native ecosystem engineers on a small-scale, intertidal rocky shore in Saldanha Bay, on the west coast of South Africa, where invasive species have changed the physical environment between 1980 and 2015. However, we considered this approach incomplete without the direct inclusion of spatial modelling and zonation. To address this, we compared multiple, layered simulations employing the food-web approach of Ecospace, the spatial-temporal module of Ecopath with Ecosim (EwE). Our simulations included a control; a simulation that restricted drivers to depth and habitat preferences; two simulations to account for structural complexity as a function of the biomass of alien ecosystem engineers – the first indirectly via mediation, and the second via a novel plug-in 'Ecoengineer' – and lastly the inclusion of wave action to replicate its effects. Only the simulation that included the Ecoengineer routine matched empirical observations of species diversity indices and the exclusion of the native mussel Choromytilus meridionalis by the arriving alien Mytilus galloprovincialis. Inclusion of mediation did not differ from the model simulation that used only habitat preference and depth to drive the model, and the addition of wave action did not improve model fits. Our results emphasise that when analysing intertidal ecosystems, they should be modelled with an explicit representation of structural habitat complexity over time and space, and we consider that the application of our Ecoengineer plug-in is an effective and novel way of accomplishing this. [Display omitted] [ABSTRACT FROM AUTHOR]

Pseudosuccinea columella is considered invasive and has become an important intermediate host of both Fasciola species in many regions of the world. This systematic review assessed the geographical distribution of P. columella, and its implications in the transmission of Fasciola hepatica and Fasciola gigantica, globally. A literature search was conducted on Google Scholar, JSTOR and PubMed databases using Boolean operators in combination with predetermined search terms for thematic analysis. Results show that P. columella has been documented in 22 countries from Europe (3), Africa (8), Oceania (2), North America (3) and South America (6). Furthermore, this snail species has shown to adapt to and inhabit a vast array of freshwater bodies including thermal lakes and ditches with acidic soils. Studies showed that P. columella transmits F. hepatica, with natural and experimental infections documented in sub-Saharan Africa, Europe, South America and North America. Experimental infection studies in Cuba showed the presence of P. columella populations resistant to F. hepatica infection. Furthermore, some populations of this invasive snail collected from F. hepatica endemic locations in Brazil, Venezuela, Australia, South Africa, Colombia and Argentina were found without Fasciola infection. As a result, the role played by this snail in the transmission of Fasciola spp. in these endemic areas is still uncertain. Therefore, further studies to detect natural infections are needed in regions/countries where the snail is deemed invasive to better understand the veterinary and public health importance of this snail species in Fasciola-endemic areas and determine the global dispersion of resistant populations of P. columella.

• Rare pre- and post-invasion data were used to model rocky-shore ecosystem change. • 22 model simulations explored trophic interactions, non-trophic effects and wave action. • Aliens dominated trophic effects, but adding non-trophic effects improved model fits. • Aliens transformed habitat complexity, but wave-action effects were unexpectedly minor. • Spatial modelling is needed to further increase ecological realism. Between 1980 and 2012, successive arrivals by three alien ecosystem engineers on a rocky shore community at Marcus Island on the west coast of South Africa led to substantial changes in species composition and diversity. An ecosystem analysis of this open intertidal system was developed using Ecopath with Ecosim to determine the impacts of these aliens and the services they provide on the native community. A baseline Ecopath model of the community in 2015 was generated using values of biomass, production/biomass, consumption/biomass and the dietary composition of 30 functional groups. Ecosim, a time-dynamic modelling routine, was then used to simulate the changes in biomass of native species. A 1980 model (pre-invasion) was constructed and 22 simulations were run up to 2015 by systematically adding (1) biomass time series for non-native species; (2) relative biomass time series for native species; (3) mediation functions that mimicked biomass impacts due to changes in substrate, shelter and feeding grounds created by the alien ecosystem engineers; and (4) the effects of wave action as a source of mortality. Positive or negative influences of these ecological processes on diversity and the final biomasses of all groups in 2015 were assessed. Trophic impacts by the alien species affected diversity and biomass at the end of all simulations, but the addition of shelter or a combination of all three ecosystem services provided by ecosystem engineers (shelter, substrate and feeding grounds) resulted in 2015 model ecosystems that most closely matched the diversity and individual group biomasses empirically measured on Marcus Island in 2015. Wave action had only a minor impact. Marcus Island's rocky shore community was therefore driven mainly by the fixed input of alien species biomass and made more realistic by the incorporation of their ecosystem services. However, structural complexity and zonation, explored in a follow-up paper invoking spatial modelling, need to be represented for a more complete realisation of the ecosystem. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Most pneumococci express a polysaccharide capsule, a key virulence factor and target for pneumococcal vaccines. However, pneumococci showing no serological evidence of capsule expression [nontypeable pneumococci (NTPn)] are more frequently isolated from carriage studies than in invasive disease. Limited data exist about the population structure of carriage NTPn from the African continent. We aimed to characterize carriage NTPn and compare them to previously described invasive NTPn. Carriage and invasive NTPn isolates were obtained from South African cross-sectional studies (2009 and 2012) and laboratory-based surveillance for invasive pneumococcal disease (2003-2013), respectively. Isolates were characterized by capsular locus sequence analysis, multilocus sequence typing, antimicrobial non-susceptibility patterns and phylogenetic analysis. NTPn represented 3.7 % (137/3721) of carriage isolates compared to 0.1 % (39/32 824) of invasive isolates ( P <0.001), and 24 % (33/137) of individuals were co-colonized with encapsulated pneumococci. Non-susceptibility to cotrimoxazole [84 % (112/133) vs 44 % (17/39)], penicillin [77 % (102/133) vs 36 % (14/39)], erythromycin [53 % (70/133) vs 31 % (12/39)] and clindamycin [36 % (48/133) vs 18 % (7/39)] was higher ( P =0.03) among carriage than invasive NTPn. Ninety-one per cent (124/137) of carriage NTPn had complete deletion of the capsular locus and 9 % (13/137) had capsule genes, compared to 44 % (17/39) and 56 % (22/39) of invasive NTPn, respectively. Carriage NTPn were slightly less diverse [Simpson's diversity index (D)=0.92] compared to invasive NTPn [D=0.97]. Sixty-seven per cent (92/137) of carriage NTPn belonged to a lineage exclusive to NTPn strains compared to 23 % (9/39) of invasive NTPn. We identified 293 and 275 genes that were significantly associated with carriage and invasive NTPn, respectively. NTPn isolates detected in carriage differed from those causing invasive disease, which may explain their success in colonisation or in causing invasive disease.

There are at least 98 known pneumococcal serotypes. Invasive pneumococcal disease (IPD) is usually caused by a single serotype, and dual-serotype IPD is rare. To assess factors associated with dual-serotype IPD, patient information obtained through laboratory-based surveillance for IPD from 2005 through 2014 in South Africa was reviewed. Genomes of isolate pairs from coinfected individuals were sequenced to determine their molecular characteristics. For 30 (91%) of 33 patients with dual serotypes, one or both isolates were a pneumococcal conjugate vaccine (PCV13) serotype. Dual-serotype IPD was associated with children <5 years of age (adjusted odds ratio [aOR], 4.7; 95% confidence interval [95% CI], 1.8 to 11.7), underlying illness (other than HIV) (aOR, 2.8; 95% CI, 1.1 to 6.6) and death (aOR, 2.5; 95% CI, 1.08 to 6.09). For each coinfecting pair, isolates were genotypically unrelated, and their genotypes were common among isolates of the same serotype in South Africa. Of 701 accessory genes identified among dual-serotype IPD isolates, four were common between isolate pairs. Coinfecting isolate pairs had different genotypic backgrounds. The association of dual serotypes with death warrants increased awareness of IPD coinfection caused by two or more serotypes., (Copyright © 2017 American Society for Microbiology.)