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1.
Mycologia ; 116(5): 848-864, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38990778

RESUMO

Species of the ectomycorrhizal (ECM) family Cortinariaceae (Agaricales, Agaricomycetes, Basidiomycota) have long been considered impoverished or absent from lowland tropical rainforests. Several decades of collecting in forests dominated by ECM trees in South America's Guiana Shield is countering this view, with discovery of numerous Cortinariaceae species. To date, ~12 morphospecies of this family have been found in the central Pakaraima Mountains of Guyana. Here, we describe three of these as new species of Cortinarius and two as new species of Phlegmacium from forests dominated by the ECM tree genera Dicymbe (Fabaceae subfam. Detarioideae), Aldina (Fabaceae subfam. Papilionoideae), and Pakaraimaea (Cistaceae). Macromorphological, micromorphological, habitat, and DNA sequence data are provided for each new species.


Assuntos
Agaricales , DNA Fúngico , Fabaceae , Micorrizas , Filogenia , Guiana , DNA Fúngico/genética , Micorrizas/classificação , Micorrizas/genética , Agaricales/classificação , Agaricales/genética , Agaricales/isolamento & purificação , Fabaceae/microbiologia , Análise de Sequência de DNA , DNA Espaçador Ribossômico/genética , Cortinarius/classificação , Cortinarius/genética , Cortinarius/isolamento & purificação , Ecossistema , DNA Ribossômico/genética , Esporos Fúngicos/citologia , Esporos Fúngicos/classificação
2.
Artigo em Inglês | MEDLINE | ID: mdl-38928926

RESUMO

Multidrug- and artemisinin-resistant (ART-R) Plasmodium falciparum (Pf) parasites represent a challenge for malaria elimination worldwide. Molecular monitoring in the Kelch domain region (pfk13) gene allows tracking mutations in parasite resistance to artemisinin. The increase in illegal miners in the Roraima Yanomami indigenous land (YIL) could favor ART-R parasites. Thus, this study aimed to investigate ART-R in patients from illegal gold mining areas in the YIL of Roraima, Brazil. A questionnaire was conducted, and blood was collected from 48 patients diagnosed with P. falciparum or mixed malaria (Pf + P. vivax). The DNA was extracted and the pfk13 gene was amplified by PCR. The amplicons were subjected to DNA-Sanger-sequencing and the entire amplified fragment was analyzed. Among the patients, 96% (46) were from illegal mining areas of the YIL. All parasite samples carried the wild-type genotypes/ART-sensitive phenotypes. These data reinforce the continued use of artemisinin-based combination therapies (ACTs) in Roraima, as well as the maintenance of systematic monitoring for early detection of parasite populations resistant to ART, mainly in regions with an intense flow of individuals from mining areas, such as the YIL. This is especially true when the achievement of falciparum malaria elimination in Brazil is planned and expected by 2030.


Assuntos
Antimaláricos , Artemisininas , Resistência a Medicamentos , Malária Falciparum , Mineração , Plasmodium falciparum , Artemisininas/uso terapêutico , Artemisininas/farmacologia , Brasil/epidemiologia , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Humanos , Antimaláricos/uso terapêutico , Antimaláricos/farmacologia , Resistência a Medicamentos/genética , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Masculino , Adulto , Feminino , Pessoa de Meia-Idade , Adulto Jovem , Adolescente , Genótipo
3.
Foods ; 13(7)2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38611377

RESUMO

Beekeeping directly depends on the floral biodiversity available to honey bees. In tropical regions, where nectar and pollen resources are numerous, the botanical origin of some honey is still under discussion. A precise knowledge of plants foraged by honey bees is useful to understand and certify the botanical origin of honey. In this study, attention was paid to honey samples from the French Guiana Atlantic coast where beekeepers generally place their hives in four types of biotopes: seaside vegetation, mangrove, savannah, and secondary forest. Pollen analysis of 87 honey samples enabled the identification of major plants visited by Africanized honey bees during the dry season (approximately from July to January). Through melissopalynologic analysis, 51 pollen types were identified and classified according to their relative presence. Frequently observed pollens (with relative presence > 50%) in French Guiana kinds of honey were those from Mimosa pudica, Cocos sp., Rhyncospora sp., Avicennia germinans, Paspalum sp., Spermacoce verticillata, Tapirira guianensis, Cecropia sp., Myrtaceae sp., Mauritia flexuosa sp., Solanum sp., and Protium sp. In many honeys, only M. pudica was over-represented (relative frequency > 90%). Color and electrical conductivity in French Guiana honeys exhibit significant variations, with color ranging from 27 mm to 110 mm Pfund, and electrical conductivity ranging from 0.35 to 1.22 mS/cm.

4.
Biota Neotrop. (Online, Ed. ingl.) ; 24(1): e20231533, 2024. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1533968

RESUMO

Abstract The Amazon has the richest freshwater ichthyofauna of the planet, with tens of new species being described annually. Although studies on Amazonian fish in the literature are increasingly common recently, there are still significant gaps concerning primary data on the ichthyofauna. One such gap is the state of Roraima and its main drainage, Rio Branco. There is a single book published in 2007 on fishes of Rio Branco, and although it presents a rather complete list of over 580 species known until then, the information is now a little outdated and many species found in some of its affluents are not listed in the book. Due to the scarcity of published data on the fish diversity of Roraima and taking into account that ichthyofaunal surveys are important tools towards freshwater conservation, we carried out an inventory of the ichthyofauna in the region of Caracaraí (RR) in 18 sampling sites including seven affluents of both left and right margins of Rio Branco. We recorded a total of 64 species of 41 genera and 18 families of five orders that occur in the Neotropical region, representing more than 11% of the species previously registered in the book for the entire Rio Branco basin. Twelve species were added to the list presented in the book, with four representing first records for the basin, one of them a new record for Brazil. Two of the 64 species are putative new taxa in need of further taxonomic studies. The order with the highest diversity was Characiformes (40 species), with highlights for the family Characidae (24 of these species), followed by Cichliformes (11 species) and Siluriformes (9 species). The richest collecting sites had 23 species, and the least rich site had only two species. Hyphessobrycon bentosi and Nannostomus marginatus occurred in more than 60% of the sites. There has been a significant difference in the exclusive ichthyofauna from affluents of both margins of Rio Branco, with the number of exclusive species in left margin tributaries approximately five times higher. Results presented herein complement data from the literature regarding the still poorly known ichthyofauna from Roraima.


Resumo A Amazônia possui a mais rica ictiofauna de água doce do planeta, com dezenas de novas espécies sendo descrita anualmente. Apesar de estudos sobre os peixes amazônicos serem cada vez mais comuns na literatura, ainda existem lacunas importantes com relação aos dados primários da ictiofauna. Uma dessas lacunas é o estado de Roraima e sua principal bacia hidrográfica, o Rio Branco. Até hoje, há apenas um livro publicado em 2007 sobre os peixes do Rio Branco, e apesar de apresentar uma lista bastante completa com pouco mais de 580 espécies conhecidas até então, atualmente as informações estão um pouco desatualizadas e diversas espécies de peixes encontradas em alguns de seus afluentes não constam do livro. Devido a escassez de dados publicados sobre a diversidade de peixes de Roraima e levando em consideração que levantamentos de ictiofauna são ferramentas importantes para mensurar o potencial de conservação dos corpos d'água, nós fizemos um levantamento da ictiofauna da região de Caracaraí (RR) em 18 pontos incluindo sete afluentes das margens esquerda e direita do Rio Branco. Foram registradas ao todo 64 espécies de 41 gêneros e 18 famílias de peixes de cinco ordens que ocorrem na região Neotropical, representando pouco mais de 11% das espécies registradas no livro para toda a bacia do Rio Branco. Doze espécies foram adicionadas à lista apresentada no livro, sendo quatro registradas pela primeira vez neste estudo, uma delas registrada pela primeira vez no Brasil. Duas das 64 espécies representam possíveis espécies ainda não descritas, necessitando de estudos taxonômicos mais aprofundados. A ordem com maior diversidade foi Characiformes (40 espécies), com destaque para a família Characidae (24 destas espécies), seguida de Cichliformes (11 espécies) e Siluriformes (9 espécies). Os pontos com maior riqueza apresentaram 23 espécies e o com menor riqueza apresentou apenas duas espécies. Hyphessobrycon bentosi e Nannostomus marginatus ocorreram em mais de 60% dos pontos. Houve diferença significativa na ictiofauna exclusiva entre os afluentes das duas margens do Rio Branco, com o número de espécies exclusivas da margem esquerda sendo aproximadamente cinco vezes maior. Os resultados apresentados aqui complementam os dados presentes na literatura a respeito da ainda pouco estudada ictiofauna de Roraima.

5.
Malar J ; 22(1): 237, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37587474

RESUMO

Scaling-up an experimental intervention is always a challenge. On the border between French Guiana, Brazil and Suriname, an interventional study demonstrated the effectiveness of distributing self-diagnosis and self-treatment kits (Malakits) to control malaria in mobile and hard-to-reach populations. Its integration into the Suriname's National Malaria Elimination Plan after a 2-year experiment faced numerous challenges, including human resources to cope with the additional workload of coordinators and to maintain the motivation of community health workers. The economic recession in Suriname, the Covid pandemic, and logistical issues also hampered the scale-up. Finally, thanks to the commitment of stakeholders in Suriname and French Guiana, the integration of Malakit distribution into the Surinamese national programme was proved possible.


Assuntos
COVID-19 , Humanos , Guiana Francesa , Suriname , Pesquisa , Brasil
6.
Heliyon ; 9(8): e18526, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37554807

RESUMO

Various honeys from French Guiana were collected and analyzed to investigate their volatile fraction composition and antioxidant activity. Volatile composition was assessed using HS-SPME/GC, GC-MS technique. Oxygenated monoterpenes like hotrienol (0.5-45.3%) were found as major molecules, followed by non terpenic compounds like phenylacetaldehyde (0.8-18.2%) or 3-hydroxy-4-phenyl-2-butanone (0.1-29.3%). Three chemical groups using statistical analysis were classified within investigated honey samples: norisoprenoids/shikimates, mevalonate and their combination. Total phenolics content (TPC) was determined by Folin-Ciocalteu method. Antioxidant activity was assessed by oxygen radical absorbance capacity (ORAC) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. TPC and anti-radical activity were compared with multifloral honeys from neighboring regions, indicating the possible presence of compounds from the polyphenol family. These results are promising for further biological studies involving honeys from French Guiana.

7.
Zool Stud ; 60: e29, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36245915

RESUMO

Invasive ants are usually harmful taxa and are considered a potential problem to biodiversity due to their negative ecological impacts, as they can outcompete native ant species. Ten such species are reported in Brazil. In this study, we report for the first time the Asian tramp ant Technomyrmex vitiensis Mann, 1921 at the municipality of Oiapoque, in the Brazilian Amazon. The colony studied contained workers, intercastes, males and larvae, which provided sperm structure and cytogenetic data. Considering the unprecedented report of the genus Technomyrmex as well as the recent finding of the primarily Australian genus Leptomyrmex in Brazil, we present a revised key for the workers of Brazilian Dolichoderinae genera. Technomyrmex vitiensis presented 2n = 16 chromosomes; all metacentrics and comparative cytogenetics on the genus is provided. A single rDNA 18S site located in intrachromosomal region was observed in this species, which is a common trait in ants. The spermatozoa of T. vitiensis had a filiform shape, with 78.13 (± 1.96) µm of total length and 11.43 (± 0.51) µm of nucleus length. Total and nucleus sperm size length fit with the known variation observed in other ant species. The occurrence of T. vitiensis in Brazil is probably a result of traffic between French Guiana and the Amapá state. Cytogenetics and sperm structures of T. vitiensis enhance the biological knowledge of this tramp species. We highlight the scarce knowledge of ant diversity in the state of Amapá and the consequences that the presence of this species may have in this region.

8.
Mycologia ; 114(3): 626-641, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35605135

RESUMO

Polydiscidium is an enigmatic, monotypic, and rarely reported genus of Ascomycota of uncertain placement. The morphologically unique Polydiscidium martynii grows on dead wood and forms compound ascomata composed of thick, black, gelatinous somatic tissue that branches out from a common base. Multiple apothecia are located on the branches, mostly toward the tips, and are composed of 8-spored asci and paraphyses embedded in a gelatinous matrix that turns blue in Melzer's reagent. The species was previously known from only three collections from Guyana (holotype), Trinidad, and the Democratic Republic of the Congo and no sequences exist. Due to its peculiar morphology, taxonomic affinities of Polydiscidium have been debated, with different authors having placed it in Helotiaceae, Leotiaceae, or Leotiomycetes incertae sedis. Recent collections of this species resulting from long-term field work in Guyana and Cameroon led us to revisit the morphology and phylogenetic position of this fungus. Newly generated sequences of P. martynii were added to an Ascomycota-wide six-locus data set. The resulting phylogeny showed Polydiscidium to be a member of order Sclerococcales (Eurotiomycetes). Next, a four-locus (18S, ITS, 28S, mtSSU) phylogenetic reconstruction revealed that Polydiscidium is congeneric with Sclerococcum. A new combination is proposed for this species, Sclerococcum martynii. Micromorphological features, including the gelatinous hymenium composed of asci with amyloid gel cap and septate brown ascospores, are in agreement with Sclerococcum. New combinations are proposed for two additional species: Sclerococcum chiangraiensis and S. fusiformis. Finally, Dactylosporales is considered a later synonym of Sclerococcales.


Assuntos
Ascomicetos , Ascomicetos/genética , Guiana , Filogenia , Esporos Fúngicos , Madeira/microbiologia
9.
PeerJ ; 9: e11612, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34178472

RESUMO

BACKGROUND: Human encroachment and overexploitation of natural resources in the Neotropics is constantly increasing. Indigenous communities all across the Amazon, are trapped between a population rise and a hot debate about the sustainability of hunting rates. The Garden Hunting hypothesis states that shifting cultivation schemes (conucos) used by Amazon indigenous communities may generate favorable conditions, increasing abundance of small and medium wildlife species close to the 'gardens' providing game for indigenous hunters. METHODS: Here, we combined camera trap surveys and spatially explicit interview dataset on Pemón indigenous hunting scope and occurrence in a mosaic of savanna and forest in the Gran Sabana, Venezuela to evaluate to what extent the wildlife resource use corresponds to Garden Hunting hypothesis. We applied the Royle-Nichols model and binomial regression in order to: (1) assess whether abundance of small and medium wildlife species is higher close to conucos and (2) evaluate whether hunters select hunting localities based on accessibility to wildlife resources (closeness to conuco) more than wildlife abundance. RESULTS: We find mixed evidence supporting the Garden Hunting hypothesis predictions. Abundance of small and medium species was high close to conucos but the pattern was not statistically significant for most of them. Pemón seem to hunt in locations dominated by forest, where species abundance was predicted to be higher, than in close vicinity to conucos. Hunting scope was focused on the most abundant species located close to the conuco (Cuniculus paca), but also in less abundant and unavailable species (Crax alector, Tapirus terrestris and Odocoileus virginianus). CONCLUSIONS: Our research provided the first attempt of a systematic sampling survey in the Gran Sabana, generating a quantitative dataset that not only describes the current pattern of wildlife abundance, but sets the base-line to monitor temporal and spatial change in this region of highland Amazon. We discuss the applicability of the estimates generated as a baseline as well as, environmental challenges imposed by economic, social and cultural changes such as mining encroachment for wildlife management.

10.
Curr Trop Med Rep ; 8(3): 164-172, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34178576

RESUMO

PURPOSE OF REVIEW: Although the chikungunya virus was discovered more than 60 years ago, it has only really been studied since the outbreak in La Reunion in 2005-2006. Ten years later, between 2014 and 2015, the chikungunya virus spread throughout the Americas, affecting millions of people. The objective of this review is to describe the contributions of research on chikungunya virus infection gained from epidemic in the West Indies and the Guiana Shield. RECENT FINDINGS: Prevalence data were similar to those found in the Indian Ocean or Asia during epidemics. Clinically, there is now a better understanding of the typical, atypical, and severe forms. Several studies have insisted on the presence of neurological forms of chikungunya infection, such as encephalitis or Guillain-Barré syndrome. Cases of septic shock due to chikungunya virus as well as thrombotic thrombocytopenic purpura were described for the first time. Given the magnitude of the epidemic and the large number of people affected, this has led to a better description and new classifications of chikungunya virus infections in specific populations such as pregnant women, the elderly, and children. Several studies also described the behavior of populations faced with an emerging disease. SUMMARY: Current epidemiological data from tropical regions highlights the risk of spreading emerging diseases at higher latitudes, especially concerning arboviruses, since the vector Aedes albopictus is already established in many parts of northern countries. A better understanding of the disease and its epidemic dynamics will foster better management, the crucial importance of which was demonstrated during the COVID-19 epidemic.

11.
Curr Trop Med Rep ; 8(3): 173-182, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34094813

RESUMO

PURPOSE OF REVIEW: In this review, we report on the state of knowledge about human Q fever in Brazil and on the Guiana Shield, an Amazonian region located in northeastern South America. There is a contrast between French Guiana, where the incidence of this disease is the highest in the world, and other countries where this disease is practically non-existent. RECENT FINDINGS: Recent findings are essentially in French Guiana where a unique strain MST17 has been identified; it is probably more virulent than those usually found with a particularly marked pulmonary tropism, a mysterious animal reservoir, a geographical distribution that raises questions. SUMMARY: Q fever is a bacterial zoonosis due to Coxiella burnetii that has been reported worldwide. On the Guiana Shield, a region mostly covered by Amazonian forest, which encompasses the Venezuelan State of Bolivar, Guyana, Suriname, French Guiana, and the Brazilian State of Amapá, the situation is very heterogeneous. While French Guiana is the region reporting the highest incidence of this disease in the world, with a single infecting clone (MST 117) and a unique epidemiological cycle, it has hardly ever been reported in other countries in the region. This absence of cases raises many questions and is probably due to massive under-diagnosis. Studies should estimate comprehensively the true burden of this disease in the region.

12.
Front Public Health ; 9: 586299, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33777876

RESUMO

Background: The COVID 19 epidemic submerged many health systems in the Amazon. The objective of the present study was to focus on the epidemic curves of the COVID 19 epidemic in different centers, and to look at testing and mortality data. Methods: Publicly available datasets were used. The log10 of the daily cumulated number of cases starting from the day the territory reached 100 cumulated cases was plotted to compare the magnitude, shape and slope of the different curves. The maximum daily testing efforts were plotted for each territory in relation to the maximum daily number of diagnoses. The case fatality rate was computed by dividing the number of COVID 19 deaths by the number of confirmed cases. Results: In the Amazonian regions in general the speed of growth was generally lower than in Europe or the USA, or Southern Brazil. Whereas, countries like South Korea or New Zealand "broke" the curve relatively rapidly the log linear trajectory seemed much longer with signs of a decline in growth rate as of early July 2020. After a very slow start, French Guiana had the lowest slope when compared to other Amazonian territories with significant epidemics. The Amazonian states of Roraima, Amazonas, Parà, and Amapà had among the highest number of cases and deaths per million inhabitants in the world. French Guiana had significantly fewer deaths relative to its number of confirmed cases than other Amazonian territories. French Guiana had a late epidemic surge with intense testing scale-up often exceeding 4,000 persons tested daily per million inhabitants. Brazil was an outlier with low daily testing levels in relation to the number of daily diagnoses. Conclusions: There were marked heterogeneities mortality rates suggesting that socioeconomic, political factors, and perhaps ethnic vulnerability led to striking outcome differences in this Amazonian context.


Assuntos
COVID-19/epidemiologia , COVID-19/mortalidade , Causas de Morte , Surtos de Doenças/estatística & dados numéricos , Epidemias/estatística & dados numéricos , Internacionalidade , Brasil/epidemiologia , Europa (Continente)/epidemiologia , Guiana Francesa/epidemiologia , Humanos , América do Norte/epidemiologia , SARS-CoV-2
13.
Neotrop. ichthyol ; 19(3): e200155, 2021. tab, graf, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1340228

RESUMO

In South America, mercury contamination due to gold mining operations is a threat to both biodiversity and human health. We examined mercury (Hg) concentrations in fishes that constitute important subsistence fisheries from mined and non-mined tributaries in the middle Mazaruni River, Guyana. Mercury concentrations and trophic food web structure (based on carbon and nitrogen stable isotopes) were characterized for primary basal sources and 39 fish species representing seven trophic guilds. Fishes collected at mined sites had higher mercury concentrations; piscivores and carnivores had the highest Hg concentrations and exhibited significant Hg biomagnification. Our results showed that medium- to large-bodied fishes commonly eaten by local people contained Hg values that exceed the World Health Organization (WHO) criteria, and pose a health concern for riverine communities along the Mazaruni River that depend on fish as their main source of protein. Further research to determine the sources of Hg contamination and how it affects human health in this neotropical river must become a top priority. In addition, more research on how Hg contamination impacts the fishes themselves and overall aquatic biodiversity is also needed in the Mazaruni River which has both high fish endemism and diversity.(AU)


Na América do Sul, a contaminação por mercúrio devido às operações de mineração de ouro é uma ameaça à biodiversidade e à saúde humana. Nós examinamos as concentrações de mercúrio (Hg) em peixes que constituem importantes pescarias de subsistência em afluentes minerados e não minerados no médio rio Mazaruni, Guiana. As concentrações de mercúrio e a estrutura trófica da teia alimentar (baseada em isótopos estáveis ​​de carbono e nitrogênio) foram caracterizadas para fontes basais primárias e 39 espécies de peixes representando sete guildas tróficas. Os peixes coletados em locais minerados tiveram maiores concentrações de mercúrio; piscívoros e carnívoros tiveram as maiores concentrações de Hg e exibiram biomagnificação significativa de Hg. Nossos resultados mostraram que peixes de corpo médio a grande comumente consumidos pela população local continham valores de Hg que excedem os critérios da Organização Mundial de Saúde (OMS) e representam uma preocupação para a saúde das comunidades ribeirinhas ao longo do rio Mazaruni que dependem dos peixes como sua principal fonte de proteína. Outras pesquisas para determinar as fontes de contaminação por Hg e como isso afeta a saúde humana neste rio neotropical devem se tornar uma prioridade. Além disso, mais pesquisas sobre como a contaminação por Hg impacta os próprios peixes e a biodiversidade aquática em geral também são necessárias no rio Mazaruni, que tem alto endemismo e diversidade de peixes.(AU)


Assuntos
Animais , Contaminação Química , Peixes/fisiologia , Mercúrio/toxicidade , Cadeia Alimentar , Bioacumulação , Isótopos de Mercúrio/química
14.
Neotrop. ichthyol ; 19(3): e200155, 2021. tab, graf, ilus
Artigo em Inglês | VETINDEX | ID: vti-32703

RESUMO

In South America, mercury contamination due to gold mining operations is a threat to both biodiversity and human health. We examined mercury (Hg) concentrations in fishes that constitute important subsistence fisheries from mined and non-mined tributaries in the middle Mazaruni River, Guyana. Mercury concentrations and trophic food web structure (based on carbon and nitrogen stable isotopes) were characterized for primary basal sources and 39 fish species representing seven trophic guilds. Fishes collected at mined sites had higher mercury concentrations; piscivores and carnivores had the highest Hg concentrations and exhibited significant Hg biomagnification. Our results showed that medium- to large-bodied fishes commonly eaten by local people contained Hg values that exceed the World Health Organization (WHO) criteria, and pose a health concern for riverine communities along the Mazaruni River that depend on fish as their main source of protein. Further research to determine the sources of Hg contamination and how it affects human health in this neotropical river must become a top priority. In addition, more research on how Hg contamination impacts the fishes themselves and overall aquatic biodiversity is also needed in the Mazaruni River which has both high fish endemism and diversity.(AU)


Na América do Sul, a contaminação por mercúrio devido às operações de mineração de ouro é uma ameaça à biodiversidade e à saúde humana. Nós examinamos as concentrações de mercúrio (Hg) em peixes que constituem importantes pescarias de subsistência em afluentes minerados e não minerados no médio rio Mazaruni, Guiana. As concentrações de mercúrio e a estrutura trófica da teia alimentar (baseada em isótopos estáveis ​​de carbono e nitrogênio) foram caracterizadas para fontes basais primárias e 39 espécies de peixes representando sete guildas tróficas. Os peixes coletados em locais minerados tiveram maiores concentrações de mercúrio; piscívoros e carnívoros tiveram as maiores concentrações de Hg e exibiram biomagnificação significativa de Hg. Nossos resultados mostraram que peixes de corpo médio a grande comumente consumidos pela população local continham valores de Hg que excedem os critérios da Organização Mundial de Saúde (OMS) e representam uma preocupação para a saúde das comunidades ribeirinhas ao longo do rio Mazaruni que dependem dos peixes como sua principal fonte de proteína. Outras pesquisas para determinar as fontes de contaminação por Hg e como isso afeta a saúde humana neste rio neotropical devem se tornar uma prioridade. Além disso, mais pesquisas sobre como a contaminação por Hg impacta os próprios peixes e a biodiversidade aquática em geral também são necessárias no rio Mazaruni, que tem alto endemismo e diversidade de peixes.(AU)


Assuntos
Animais , Contaminação Química , Peixes/fisiologia , Mercúrio/toxicidade , Cadeia Alimentar , Bioacumulação , Isótopos de Mercúrio/química
15.
Zootaxa ; 4820(1): zootaxa.4820.1.7, 2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-33056085

RESUMO

Anomaloglossus is a species-rich genus of frogs endemic to the Guiana Shield that still harbours several unnamed species. According to a recent integrative taxonomic survey, the A. stepheni species group includes five valid nominal species and at least four putatively unnamed species, two in Brazil and two in Suriname. In this paper, we describe the two species from Suriname based on adult and tadpole morphology as well as their calls and natural history. Both have exotrophic tadpoles transported by the male to small water bodies. These two new species differ from each other and from other congeners in body size, colouration pattern, call characteristics and breeding sites. Both have narrow distributions and should be considered Endangered according to IUCN criteria.


Assuntos
Anuros , Animais , Larva , Masculino , Suriname
16.
Malar J ; 19(1): 360, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33032606

RESUMO

BACKGROUND: Suriname has accomplished a steep decline in malaria burden, even reaching elimination levels. Plasmodium serology data are not available for Suriname and even extremely scarce within the region, therefore malaria serology testing was introduced, country customized cut-off values were determined and a study was performed to explore the antibody status for Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae. METHODS: A cross-sectional survey was conducted between July 2017 and March 2018 in two areas of the interior with different malaria settings: Stoelmanseiland, representing Maroon villages and Benzdorp, a gold mining area, with mostly Brazilian miners. Dried blood spots (DBS) were collected (n = 197) and antibody presence against seven Plasmodium antigens was detected using a multiplex bead-based, IgG antibody assay. Demographic information was gathered through a questionnaire. Country customized cut-off values were generated from a Surinamese malaria-naïve reference population (n = 50). RESULTS: Serological analysis for the reference population revealed cut-off values ranging from 14 MFI for LSA-1 to 177 MFI for PmMSP-119. Seroprevalence against any of the three MSP-119 antibodies was similar in both regions and surpassed 75%. Single seropositivity against PfMSP-119 antibodies was higher in Stoelmanseiland (27.0%) than Benzdorp (9.3%), in line with the historical malaria burden of Stoelmanseiland, while the reverse was observed for PvMSP-119 antibodies. Despite sporadic reports of P. malariae infections, PmMSP-119 antibody presence was 39.6%. A more detailed examination of P. falciparum serology data displayed a higher seroprevalence in villagers (90.7%) than in Brazilians (64.6%) and a highly diverse antigenic response with 22 distinct antibody combinations. CONCLUSIONS: The results on the malaria antibody signature of Maroon villagers and Brazilian miners living in Suriname displayed a high Plasmodium seroprevalence, especially for P. falciparum in villagers, still reflecting the historical malaria burden. The seroprevalence data for both regions and the observed combinations of P. falciparum antibodies provided a valuable dataset from a historically important region to the international malaria serology knowledge. First insight in malaria serology data for Suriname indicated that the use of other target groups and assessment of age-dependent seroprevalence are required to successfully use malaria serology as tool in the national elimination strategy.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/sangue , Imunoglobulina G/sangue , Malária Falciparum/epidemiologia , Malária Vivax/epidemiologia , Malária/epidemiologia , Adulto , Idoso , Brasil/etnologia , Estudos Transversais , Feminino , Humanos , Masculino , Proteína 1 de Superfície de Merozoito/imunologia , Pessoa de Meia-Idade , Mineração , Plasmodium falciparum/fisiologia , Plasmodium malariae/fisiologia , Plasmodium vivax/fisiologia , Prevalência , Estudos Soroepidemiológicos , Suriname/epidemiologia , Adulto Jovem
17.
Neotrop. ichthyol ; 18(2): e200002, 2020. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1135384

RESUMO

A new species of Curimatopsis is described from the highlands of the western Guiana Shield in the río Carapo and río Paragua, tributaries of the río Caroni in the Orinoco basin, southeastern Venezuela. The new species belongs to the Curimatopsis macrolepis clade due to its possession of a long lower jaw that projects past the anterior margin of the upper jaw, and separate first and second hypurals. The new species is diagnosed from remaining species of the Curimatopsis macrolepis clade by having a small-sized inconspicuous dark spot on the midlateral surface of the caudal peduncle, by details of body and fin pigmentation, and by additional morphometric characters. The distribution of C. macrolepis in the Amazon and Orinoco basins is updated based on the examination of museum specimens.(AU)


Uma nova espécie de Curimatopsis é descrita da porção oeste do Escudo das Guianas dos ríos Carapo e Paragua, tributários do río Caroni, bacia do Orinoco no sudeste da Venezuela. A nova espécie pertence ao clado Curimatopsis macrolepis por possuir uma maxila inferior longa que se projeta além da margem anterior da maxila superior e primeiro e segundo hipurais separados. A nova espécie é diagnosticada das demais espécies do clado Curimatopsis macrolepis por possuir uma mácula escura pequena, inconspícua na superfície lateral do pedúnculo caudal, por detalhes de pigmentação do corpo e nadadeiras, e por dados morfométricos adicionais. A distribuição geográfica de C. macrolepis nas bacias do rio Amazonas e río Orinoco é atualizada baseada na análise de espécimes depositados em museus.(AU)


Assuntos
Animais , Caraciformes/anatomia & histologia , Caraciformes/classificação , Ecossistema Amazônico , Rios
18.
Neotrop. ichthyol ; 18(2)2020.
Artigo em Inglês | VETINDEX | ID: vti-745609

RESUMO

ABSTRACT A new species of Curimatopsis is described from the highlands of the western Guiana Shield in the río Carapo and río Paragua, tributaries of the río Caroni in the Orinoco basin, southeastern Venezuela. The new species belongs to the Curimatopsis macrolepis clade due to its possession of a long lower jaw that projects past the anterior margin of the upper jaw, and separate first and second hypurals. The new species is diagnosed from remaining species of the Curimatopsis macrolepis clade by having a small-sized inconspicuous dark spot on the midlateral surface of the caudal peduncle, by details of body and fin pigmentation, and by additional morphometric characters. The distribution of C. macrolepis in the Amazon and Orinoco basins is updated based on the examination of museum specimens.


RESUMO Uma nova espécie de Curimatopsis é descrita da porção oeste do Escudo das Guianas dos ríos Carapo e Paragua, tributários do río Caroni, bacia do Orinoco no sudeste da Venezuela. A nova espécie pertence ao clado Curimatopsis macrolepis por possuir uma maxila inferior longa que se projeta além da margem anterior da maxila superior e primeiro e segundo hipurais separados. A nova espécie é diagnosticada das demais espécies do clado Curimatopsis macrolepis por possuir uma mácula escura pequena, inconspícua na superfície lateral do pedúnculo caudal, por detalhes de pigmentação do corpo e nadadeiras, e por dados morfométricos adicionais. A distribuição geográfica de C. macrolepis nas bacias do rio Amazonas e río Orinoco é atualizada baseada na análise de espécimes depositados em museus.

19.
Zootaxa ; 4576(3): zootaxa.4576.3.2, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-31715747

RESUMO

Anomaloglossus is a species-rich genus of frogs endemic to the Guiana Shield that still harbors several unnamed species. Within the A. stepheni species group (which includes four valid nominal species), A. baeobatrachus has an uncertain taxonomic status, notably because the holotype was an unvouchered specimen depicted in a popular journal. Another member of this group, A. leopardus, was only superficially described, lacking information on the sex of specimens in the type series and on advertisement call. Therefore, these two taxa need clarifications in order to allow the description of the extant undescribed species. In this paper, we redescribe A. baeobatrachus based on newly collected material from the species type locality and provide information about its reproductive ecology. We also provide an amended definition of A. leopardus using newly collected material from its type locality. These two species form a clade along with a third species from the Eastern Guiana Shield, which is also described herein. The reproductive biology of A. baeobatrachus and A. stepheni is very similar. Both species have endotrophic and nidicolous tadpoles, despite being distantly related, suggesting independent evolution of this breeding mode. The new species and A. leopardus, on the other hand, have exotrophic tadpoles.


Assuntos
Anuros , Reprodução , Animais , Guiana , Larva
20.
Zootaxa ; 4674(5): zootaxa.4674.5.2, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31715984

RESUMO

We provide here a checklist of the ants of French Guiana, an overseas department of France situated in northern South America, with a very low human population density and predominantly covered by old-growth tropical rainforests. Based on 165 scientific papers, specimens deposited in collections, and unpublished surveys, a total of 659 valid species and subspecies from 84 genera and 12 subfamilies is presented. Although far from complete, these numbers represent approximately 10% of the ant diversity known to occur in the Neotropical realm. Additionally, three ant genera and 119 species are reported for the first time for French Guiana. Finally, five species are recognized as erroneous records for the the department in the literature. This checklist significantly expands the basic knowledge of the ants in the Guiana Shield, one of the world's most important biodiversity hotspots.


Assuntos
Formigas , Animais , Guiana Francesa , Humanos
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