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Turtles and Tortoises Are in Trouble
No full textCraig Stanford and colleagues review the threats to the world's turtles and tortoises. © 2020 Elsevier Inc.Turtles and tortoises (chelonians) have been integral components of global ecosystems for about 220 million years and have played important roles in human culture for at least 400,000 years. The chelonian shell is a remarkable evolutionary adaptation, facilitating success in terrestrial, freshwater and marine ecosystems. Today, more than half of the 360 living species and 482 total taxa (species and subspecies combined) are threatened with extinction. This places chelonians among the groups with the highest extinction risk of any sizeable vertebrate group. Turtle populations are declining rapidly due to habitat loss, consumption by humans for food and traditional medicines and collection for the international pet trade. Many taxa could become extinct in this century. Here, we examine survival threats to turtles and tortoises and discuss the interventions that will be needed to prevent widespread extinction in this group in coming decades. © 2020 Elsevier Inc
Analysis of suspended sediment in the Anavilhanas Archipelago, Rio Negro, Amazon Basin
Get PDFThis article analyzes the flows of water and total suspended sediment in different reaches in the lower course of the Negro River, the largest fluvial blackwater system in the world. The area under study is the Anavilhanas Archipelago, which is a complex multichannel reach on the Negro River. Between the years 2016 and 2019, data about water discharge, velocity, and concentration of total suspended solids (TSS) were acquired in sample sections of the Negro River channels located upstream, inside, and downstream of the Anavilhanas Archipelago. In the study area, the Negro River drains an area greater than 700,000 km2, and the mean water discharge observed before the Anavilhanas was about 28.655 m3s1, of which 97% flows through two channels of the Archipelago close to the right and left banks. The mean TSS concentration of the Negro River upstream and downstream the Archipelago was 3.28 mg•L1 and 1.63 mgL1, respectively. Within the Archipelago, we observed more TSS in the channel on the left bank of the Negro River (mean of 4.50 mg•L1). The total suspended sediment discharge of the Negro River before (3.14 Mt•year-1) and after (1.43 Mt•year1) the Anavilhanas Archipelago indicates a 55% retention of the suspended load due to the low water slope and reduced flow velocity caused by the backwater effect of Solimoes River on the Negro River. The hydro-sedimentary scenario of the low course of the Negro River characterized in this study indicates a slow and continuous sedimentation process in the Anavilhanas Archipelago. The results presented will serve as a baseline to assess the impacts of the dams on the Branco River, the main tributary for both water and sediment in the Negro River basin. © 2020 by the authors
Marcadores moleculares e descritores morfo-agronômicos na avaliação da diversidade genética de bucha(Luffa cylindrica)
No full textA population genomics appraisal suggests independent dispersals for bitter and sweet manioc in Brazilian Amazonia
Get PDFAmazonia is a major world centre of plant domestication, but the genetics of domestication remains unclear for most Amazonian crops. Manioc (Manihot esculenta) is the most important staple food crop that originated in this region. Although manioc is relatively well-studied, little is known about the diversification of bitter and sweet landraces and how they were dispersed across Amazonia. We evaluated single nucleotide polymorphisms (SNPs) in wild and cultivated manioc to identify outlier SNPs putatively under selection and to assess the neutral genetic structure of landraces to make inferences about the evolution of the crop in Amazonia. Some outlier SNPs were in putative manioc genes possibly related to plant architecture, transcriptional regulation and responses to stress. The neutral SNPs revealed contrasting genetic structuring for bitter and sweet landraces. The outlier SNPs may be signatures of the genomic changes resulting from domestication, while the neutral genetic structure suggests independent dispersals for sweet and bitter manioc, possibly related to the earlier domestication and diversification of the former. Our results highlight the role of ancient peoples and current smallholders in the management and conservation of manioc genetic diversity, including putative genes and specific genetic resources with adaptive potential in the context of climate change. © 2019 The Authors. Evolutionary Applications published by John Wiley & Sons Lt
Checklist das libélulas (Insecta: odonata) do Estado do Amazonas, Brasil
Get PDFHere we provide a checklist of the odonates from Amazonas state, Brazil. We registered 324 species and 101 genera, making Amazonas the Brazilian state with the most Odonata species recorded. The families with the highest number of species were Coenagrionidae with 32 genera and 101 species, followed by Libellulidae with 28 genera and 100 species and Gomphidae with 12 genera and 45 species. Some regions of Amazonas state remain poorly explored, such as the southern area, and large municipalities, such as São Gabriel da Cachoeira. This work underlines the importance of the biological diversity from Amazonas state and the Amazonian Biome for Odonata species richness in Brazil and shows that many areas in the world’s largest tropical forest have not yet been sampled. © 2020, Universidade Estadual de Campinas UNICAMP. All rights reserved
Grupo coliforme fecal como indicador de balneabilidade em praia de água doce no rio Negro, Amazonas
No full textFeeding of Arapaima sp.: integrating stomach contents and local ecological knowledge
No full textThe giant arapaima (Arapaima sp.) has been described as a fish of change in Amazonia because of its important role in the conservation of floodplains, food security and income generation for rural communities. Nonetheless, despite the cultural, ecological and economic importance of arapaima, data on diet are scarce. Aiming to expand knowledge about arapaima diet in western Amazonia, scientific knowledge was integrated with the knowledge of local dwellers. During the low-water period (September 2018) and the falling-water period (June 2019), arapaima stomachs were collected from 11 floodplain lakes in the middle Juruá River. All fishes were measured [TL (total length)] and sexed. Food items from each stomach were categorized as fishes, invertebrates, plants and bone remains and weighed. Also, in the latter period, experienced local fishers were interviewed about arapaima feeding. This integrated approach revealed that young arapaima eat fish and invertebrates but adult arapaima eat fish of a wide range of species, which were mainly of low and intermediate trophic positions. This study reports the first case of cannibalism for arapaima and also shows that during the low-water period, many individuals had empty stomachs or only some small fish-bone remains and/or plant material. Arapaima sex and TL had no influence on the absence of prey in stomach contents. Overall, it can be concluded that local people had consistent ethnobiological knowledge of arapaima feeding ecology that could be useful within management projects in the region. © 2020 The Fisheries Society of the British Isle
Encapsulation of Amazonian Blueberry juices: Evaluation of bioactive compounds and stability
No full textBioactive compounds of Clidemia japurensis and Clidemia hirta juices were encapsulated in maltodextrin (MD) of different dextrose equivalents (DE – MD10, MD20 AND MD30). Microparticles containing the encapsulated juices were obtained by freeze-drying process. The stability of the encapsulated bioactive compounds was evaluated under different relative humidity (22 and 77%) at 25 °C by DPPH and ABTS methods. Twelve bioactive compounds were identified by UFLC-Q-TOF-MS/MS and classified as organic acids, flavonoids and anthocyanins. The juices presented good antioxidant properties [DPPH value of 943 ± 15 (C. japurensis) and 994 ± 14 μM TE (C. hirta); ABTS value of 1119 ± 24 (C. japurensis) and 1273 ± 18 μM TE (C. hirta)]. Encapsulation Efficiency (EE) ranged from 97.0 to 99.8% (DPPH) and from 87.8 to 99.1% (ABTS). The encapsulated juices did not present activity water (AW) values that could favor microbial growth. The powdered juices prepared using lower DE carrier resulted in better retention and stability of the bioactive compounds due to the low water adsorption According to the ABTS results, the bioactive compounds of C. hirta and C. japurensis encapsulated in MD10 carrier and stored at RH = 22% presented half-life time around 45 and 37 days, respectively. These results represent an interesting possibility of application in food industry. © 202
Aliens in the backyard: Did the American bullfrog conquer the habitat of native frogs in the semi-deciduous atlantic forest?
No full textThe American bullfrog Lithobates catesbeianus has a natural distribution in North America, but was spread by human activities in different regions around the world. It is listed as the most invasive amphibian species, affecting terrestrial and aquatic ecosystems and the community of native species. In addition, the American bullfrog is extensively associated with lethal pathogens, with high correlation of the presence of this species with population declines and extinctions. Here we test if this alien species has spread through the landscape, establishing populations at new locations. We used diverse methods including georeferencing of satellite images, ethnobiological interviews and field data to evaluate the dispersion and effects of L. catesbeianus introduction on amphibian composition, species number, and density of individuals in forest fragments in an Atlantic Forest landscape. We did not find any relationship between density of individuals, number of species or composition of the native anuran assemblages in forest fragments in relation to the presence or proximity of American bullfrog introduction points. Additionally, we found that the dispersion potential of this species in the studied landscape is zero, as it was only found in those fragments where it was specifically introduced 15 years ago. The species has not established new populations in the landscape. Although exotic, L. catesbeianus thrives in lentic habitats and has no apparent effect on the structural metrics of the native anuran assemblage. Despite this alien species exhibiting a capacity to adapt and survive at the point of introduction, its potential for propagation is limited probably by the fragmented terrestrial landscape and regional stream network. © 2020, British Herpetological Society. All rights reserved