Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 122
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Aquat Toxicol ; 237: 105877, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34090246

RESUMO

Ongoing pollution of aquatic ecosystems with neurochemical compounds warrants an improved understanding of how this affects key organisms. Neurochemicals are shown to alter the behaviour of common study species but it remains difficult to translate these results to biologically meaningful predictions across taxa. This is partly because studies on species with non-generic life-history strategies such as many freshwater crustaceans are currently underrepresented. Here, we use a laboratory experiment to assess baseline behavioural variation (spontaneous activity level and geotaxic behaviour) in the freshwater fairy shrimp Branchipodopsis wolfi and how this is affected by chronic exposure to an environmentally-relevant concentration of the anxiolytic pharmaceutical fluoxetine. The more conspicuously coloured and larger females of the species were overall less active and more benthic than males. Moreover, amongst females, vertical activity was negatively associated with size, while an opposite relationship was found for males. These trade-offs are likely part of an antipredator strategy to reduce the probability of being detected by visual hunters, but disappeared after exposure to fluoxetine. This is of particular interest since it is an effective proof of principle that neurochemicals may impact ecologically-relevant trade-offs between conspicuous morphology and antipredator behaviour. In natural ecosystems, such disturbed antipredator behavioural responses could have far-reaching fitness consequences.


Assuntos
Ecossistema , Poluentes Químicos da Água , Animais , Anostraca , Feminino , Fluoxetina , Água Doce , Masculino , Poluentes Químicos da Água/toxicidade
2.
Chemosphere ; 280: 130652, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34162072

RESUMO

Growing interest in environmental toxicity assessment using Thamnocephalus platyurus as organism has led to an increased availability of acute toxicity data. Despite this growing interest in tests with this organism, however, to the best of our knowledge there are no computational models to predict the acute toxicity in T. platyurus. In view of the limited number of in silico models for this crustacean, we developed Quantitative Structure-Activity Relationship (QSAR) models for the prediction of acute toxicity towards T. platyurus, reflected by the 24h LC50, using publicly available data according to the ISO 14380:2011 guideline. Two models were developed following the principles of QSAR modeling recommended by the Organization for Economic Cooperation and Development (OECD). We used partial least squares and gradient boosting machine techniques, which gave encouraging statistical quality in our data set.


Assuntos
Anostraca , Relação Quantitativa Estrutura-Atividade , Animais , Ecotoxicologia , Água Doce , Compostos Orgânicos
3.
PLoS One ; 16(4): e0243338, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33830990

RESUMO

California's vernal pools are declining ecosystems that support valuable native plant and animal diversity. Vernal pool branchiopods are particularly at risk from vernal pool habitat loss and conservation efforts have targeted their long-term protection through the establishment of preserves and conservation banks. These conservation strategies require repeated, perpetual monitoring of preserved habitat, which is currently carried out through dip-net surveys and visual identification of specimens. Dip-netting may be destructive and frequently requires some sacrifice of protected species. Environmental DNA offers a new, modern method to monitor many protected freshwater organisms. We designed qPCR-based species-specific assays for four of California's vernal pool branchiopods: The Vernal Pool Fairy Shrimp Branchinecta lynchi (BRLY), the Midvalley Fairy Shrimp Branchinecta mesovallensis (BRME), and the Conservancy Fairy Shrimp Branchinecta conservatio (BRCO), and the Vernal Pool Tadpole Shrimp Lepidurus packardi (LEPA). We tested these assays using eDNA sampling protocols alongside traditional dip-net surveys to assess their viability as an alternative method to monitor vernal pool branchiopods. Based on occupancy modeling, each of our assays achieved a 95% or higher detection rate when using optimized sampling protocols.


Assuntos
Anostraca/genética , Ecossistema , Nascentes Naturais , Animais , Anostraca/crescimento & desenvolvimento , California
4.
Food Chem ; 351: 129344, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-33647688

RESUMO

Protein oxidation is considered as an important factor affecting the texture quality of surimi. In this work, the myofibrillar protein (MP) from shrimp (Penaeus vannamei) was subjected to a hydroxyl radical generating system at various concentrations of H2O2, to simulate the oxidative environment during surimi processing. After the hydroxyl radical oxidation, it was found that the carbonyl content, surface hydrophobicity, and MP aggregation increased. Meanwhile, the a-helix decreased, but ß-sheet increased after oxidation. The moderate oxidation led to a dense network microstructure, increased water holding capacity (WHC) and decreased water mobility, which ultimately enhanced textural (hardness and springiness increased by 0.51- and 0.06-fold, respectively) and rheological properties of MP gel (MPG). However, excessive oxidation could reduce the mechanical properties of MPG. The microstructure, WHC and water distribution played a key role in the mechanical properties of MPG. This study can provide a theoretical basis for processing of shrimp surimi products.


Assuntos
Anostraca , Fenômenos Químicos , Radical Hidroxila/química , Proteínas Musculares/química , Animais , Géis , Interações Hidrofóbicas e Hidrofílicas , Oxirredução , Reologia , Alimentos Marinhos , Água/química
5.
Zootaxa ; 4908(4): zootaxa.4908.4.8, 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33756605

RESUMO

We report the first record of Branchipodopsis affinis Sars, 1901 (Branchiopoda, Anostraca) from Iran. The specimens were collected in small temporary pools in the Bazargan area located in West Azerbaijan province, in spring 2015. Details on the biogeography, ecology and morphology of this species are provided. The DNA sequence data (COI) for this species is reported for the first time, which can be used in the identification of species on molecular terms and generation of information regarding the evolutionary relationship of the species in future. Also, the new finding is an important contribution to the knowledge of the anostracan fauna from Iran.


Assuntos
Anostraca , Crustáceos , Animais , Azerbaijão , Evolução Biológica , Irã (Geográfico)
6.
PLoS One ; 16(3): e0248574, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33735277

RESUMO

The Dendrocephalus brasiliensis, a native species from South America, is a freshwater crustacean well explored in conservational and productive activities. Its main characteristics are its rusticity and resistance cysts production, in which the hatching requires a period of dehydration. Independent of the species utilization nature, it is essential to manipulate its cysts, such as the counting using microscopes. Manually counting is a difficult task, prone to errors, and that also very time-consuming. In this paper, we propose an automatized approach for the detection and counting of Dendrocephalus brasiliensis cysts from images captured by a digital microscope. For this purpose, we built the DBrasiliensis dataset, a repository with 246 images containing 5141 cysts of Dendrocephalus brasiliensis. Then, we trained two state-of-the-art object detection methods, YOLOv3 (You Only Look Once) and Faster R-CNN (Region-based Convolutional Neural Networks), on DBrasiliensis dataset in order to compare them under both cyst detection and counting tasks. Experiments showed evidence that YOLOv3 is superior to Faster R-CNN, achieving an accuracy rate of 83,74%, R2 of 0.88, RMSE (Root Mean Square Error) of 3.49, and MAE (Mean Absolute Error) of 2.24 on cyst detection and counting. Moreover, we showed that is possible to infer the number of cysts of a substrate, with known weight, by performing the automated counting of some of its samples. In conclusion, the proposed approach using YOLOv3 is adequate to detect and count Dendrocephalus brasiliensis cysts. The DBrasiliensis dataset can be accessed at: https://doi.org/10.6084/m9.figshare.13073240.


Assuntos
Anostraca , Aprendizado Profundo , Monitorização de Parâmetros Ecológicos/métodos , Processamento de Imagem Assistida por Computador/métodos , Animais , Água Doce , América do Sul
7.
Front Immunol ; 11: 1511, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32765521

RESUMO

The symbiotic shrimp Rimicaris exoculata dominates the macrofauna inhabiting the active smokers of the deep-sea mid Atlantic ridge vent fields. We investigated the nature of the host mechanisms controlling the vital and highly specialized ectosymbiotic community confined into its cephalothoracic cavity. R. exoculata belongs to the Pleocyemata, crustacean brooding eggs, usually producing Type I crustins. Unexpectedly, a novel anti-Gram-positive type II crustin was molecularly identified in R. exoculata. Re-crustin is mainly produced by the appendages and the inner surfaces of the cephalothoracic cavity, embedding target epibionts. Symbiosis acquisition and regulating mechanisms are still poorly understood. Yet, symbiotic communities were identified at different steps of the life cycle such as brooding stage, juvenile recruitment and molt cycle, all of which may be crucial for symbiotic acquisition and control. Here, we show a spatio-temporal correlation between the production of Re-crustin and the main ectosymbiosis-related life-cycle events. Overall, our results highlight (i) a novel and unusual AMP sequence from an extremophile organism and (ii) the potential role of AMPs in the establishment of vital ectosymbiosis along the life cycle of deep-sea invertebrates.


Assuntos
Anostraca/fisiologia , Peptídeos Catiônicos Antimicrobianos/metabolismo , Peptídeos Catiônicos Antimicrobianos/farmacocinética , Proteínas de Artrópodes/metabolismo , Bactérias Gram-Positivas/fisiologia , Infecções por Bactérias Gram-Positivas/imunologia , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Animais , Peptídeos Catiônicos Antimicrobianos/genética , Ecossistema , Interações Hospedeiro-Patógeno , Estágios do Ciclo de Vida , Oceanos e Mares , Proteínas Citotóxicas Formadoras de Poros/genética , Simbiose
8.
Bull Environ Contam Toxicol ; 104(5): 634-641, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32236702

RESUMO

The aim of this study was to characterize the leachate derived from biochar produced from malt spent rootlets (MSR) and to evaluate the required washing level in order to provide water free from inorganic substances. MSR biochar was placed in a column and subjected to six serial washes with distilled water, and the leachate was analysed for main anions and heavy metals. The 1st wash aliquot contained increased levels of mainly phosphates (980 mg/L) and chlorides (760 mg/L), and lower levels of nitrates, sulfates, fluoride and bromide, which were decreased over washes. Zero concentrations were observed after three washes for most anions. The increased levels of Zn, Be, Cs, Mn, V and Se determined in the 1st wash aliquot were eliminated in the successive washes. The toxic potency of each wash aliquot, determined by the use of the fairy shrimp Thamnocephalus platyurus showed that the 1st and 2nd MSR biochar leachates were toxic with 4.52 and 1.46 toxic units (TU), respectively, followed by a significant elimination of toxicity after further washes.


Assuntos
Carvão Vegetal/química , Metais Pesados/toxicidade , Resíduos Sólidos/análise , Poluentes Químicos da Água/toxicidade , Animais , Anostraca/efeitos dos fármacos , Bioensaio , Relação Dose-Resposta a Droga , Dose Letal Mediana , Metais Pesados/análise , Nitratos/análise , Nitratos/toxicidade , Sulfatos/análise , Sulfatos/toxicidade , Testes de Toxicidade , Poluentes Químicos da Água/análise
9.
Ecotoxicology ; 29(1): 45-57, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31784924

RESUMO

The bottom sediments in catchment areas behind dams play a significant role in water ecosystems. On the other hand, the structure of sediments makes them a natural geosorbent, in which pollutants introduced to the aquatic environment accumulate. The use of biotests is recognised as an important approach for the assessment of the quality of bottom sediments, as the chemical analysis of sediment samples alone does not provide evidence of the impact of contaminants on biota. The aim of the study was to apply the chemical and ecological indices to determine the potential risk posed by trace elements in the bottom sediments and to evaluate sediment toxicity using organisms belonging to two taxonomic groups, i.e., plants (Phytotoxkit) and crustaceans (Rapidtoxkit). The 46 sediment samples were taken from the Roznów Dam Reservoir in Southern Poland. The mean concentration of the trace elements in the sediments was 5.22 mg As; 0.26 mg Cd; 63.23 mg Cr; 28.65 mg Cu; 37.11 mg Ni; 11.15 mg Pb; 69.69 mg Zn and 0.09 mg Hg ∙ kg-1 d.m. The mean probable effect concentration quotient (PECq) value among different sampling sites ranged between 0.04 and 0.33 suggested moderate potential toxicity to the biological communities in bottom sediments. The Ni was potentially the most toxic element for biota in the Roznów Reservoir. The sensitivity of organisms formed the following order: Thamnocephalus platyurus >Lepidium sativum >Sinapis alba >Sorghum saccharatum. For the plants, the stimulating effect of bottom sediments on root growth was often indicated, while a toxic effect was demonstrated for T. platyurus in 80% of the samples. However, the correlation analysis and PCA results showed that trace elements that originated from similar sources were associated to the toxicity of sediments towards T. platyurus, while ecotoxicity for plants could not be explained by the content of trace elements in bottom sediments. T. platyurus is a good indicator for predicting the toxicity of bottom sediments from the Roznów Reservoir. However, our study found that both chemical and ecotoxicological analyses are important for a comprehensive evaluation of the quality of bottom sediments.


Assuntos
Monitoramento Ambiental , Oligoelementos/análise , Poluentes Químicos da Água/análise , Aliivibrio fischeri , Animais , Anostraca , Crustáceos , Ecologia , Ecossistema , Ecotoxicologia , Sedimentos Geológicos/química , Lepidium sativum , Metais Pesados , Polônia , Medição de Risco , Sinapis , Oligoelementos/toxicidade , Poluentes Químicos da Água/toxicidade
10.
Zootaxa ; 4683(1): zootaxa.4683.1.3, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31715935

RESUMO

A detailed morphological comparison was carried out among specimens of several samples of Archaebranchinecta Rogers Coronel, 2011 from the Altiplano of Peru, Bolivia, and Argentina. Surprisingly, striking differences were found between Peruvian samples collected near the western shore of Lake Titicaca, and those from Bolivia taken southwardly, near the east coasts of River Desaguadero and Lake Poopó. Accordingly, the new species Archaebranchinecta aimara sp. nov. is described, representing the second specific entity of a genus that so far included only A. pollicifera (Harding, 1940). The main differential features between both species include: (a) size and shape of the three processes of basal segment of the male second antenna; (b) shape and protrusion degree of the pair of medioventral bulges in the male genital segments; (c) presence or absence of strong ventrolateral spine on the second genital segment of female; and (d) presence or absence of a pair of ventrolateral outgrowths in the brood pouch. This research contributes to our understanding of the biodiversity and endemism of the unique Altiplano region of South America.


Assuntos
Anostraca , Animais , Argentina , Bolívia , Feminino , Masculino , Peru , América do Sul
11.
Zootaxa ; 4646(1): zootaxa.4646.1.8, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31717031

RESUMO

Branchinecta sandiegonensis is a passively dispersed species that occurs in the vernal pool complexes of southern California, the USA, and northwestern Baja California, México. The fragmented distribution of these vernal pool complexes could limit the gene flow, generating high genetic structure and morphometric variation across the landscape. Here we estimate the genetic and phenotypic variation of B. sandiegonensis in the southern part of its range. We sampled 15 vernal pools from four geographic regions of the Baja California Peninsula. We genotyped 150 individuals using nuclear microsatellites and 31 individuals using the mitochondrial COI region. We also conducted a morphometric analysis on a sample of 232 individuals. We found moderate levels of genetic diversity and different patterns of structure depending upon the spatial scale of analysis. Demographic models suggest contrasting trends among populations. Phenotypically, we found high levels of heterogeneity in body size of fairy shrimps within and across the regions. Our findings highlight that vernal pools in Baja California are important reservoirs of genetic and phenotypic diversity for B. sandiegonensis. The interplay between gene flow and genetic drift may have influenced the patterns we detected in the southern part of the range of this species.


Assuntos
Anostraca , Crustáceos , Animais , California , DNA Mitocondrial , Variação Genética , México , Filogenia
12.
Environ Pollut ; 252(Pt A): 715-722, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31185361

RESUMO

Concerns about possible environmental implications of nano- and micro-plastics are continuously raising. Hence, comprehensive understanding of their behaviour, bioaccumulation and toxicity potential is required. Nevertheless, systematic studies on their fate and possible effects in freshwaters, as well as the influence of particle-specific and environmental factors on their behaviour and impacts are still missing. The aims of the present study are thus two-fold: (i) to examine the role of the surface charge on nanoplastic stability and acute effects to freshwater zooplankton; (ii) to decipher the influence of the refractory natural organic matter (NOM) on the nanoplastic fate and effects. Amidine and carboxyl-stabilized polystyrene (PS) spheres of 200 nm diameter characterized by opposite primary surface charges and neutral buoyancy were selected as model nanoplastics. The results demonstrated that the surface functionalization of the polystyrene nanoplastics controls their aggregation behaviour. Alginate or Suwannee River humic acid (SRHA) modified significantly the surface charge of positively-charged amidine PS nanoplastic and the aggregation state, while had no significant influence on the negatively-charged carboxyl PS nanoplastic. Both amidine and carboxyl PS nanoplastics were ingested by the zooplankton and concentrated mainly in the gut of water flea Daphnia magna and larvae Thamnocephalus platyurus, and the stomach of rotifer Brachionus calyciflorus. Amidine PS nanoplastic was more toxic than carboxyl one. The toxicity decreased in the order D. magna (48 h -immobilization) > B. calyciflorus (24 h - lethality) > T. platyurus (24 h - lethality). Alginate or SRHA reduced significantly the toxicity of both amidine and carboxyl PS nanoplastics to the studied zooplankton representatives. The implications of this laboratory study findings to natural environment were discussed.


Assuntos
Nanopartículas/toxicidade , Plásticos/toxicidade , Poliestirenos/toxicidade , Zooplâncton/efeitos dos fármacos , Animais , Anostraca/efeitos dos fármacos , Anostraca/metabolismo , Daphnia/efeitos dos fármacos , Daphnia/metabolismo , Água Doce , Gastrópodes , Substâncias Húmicas , Larva , Rotíferos/efeitos dos fármacos , Rotíferos/metabolismo , Zooplâncton/metabolismo
13.
Zootaxa ; 4700(2): zootaxa.4700.2.9, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-32229988

RESUMO

Over the course of my career I have described nine Branchiopod genera and one subgenus, either alone or with other researchers. From these, four genera and the subgenus belong to Anostraca. But I was remiss in designating type species for one of those taxa which caused the name to become unavailable. This short communication is to rectify this unfortunate error on my part.


Assuntos
Anostraca , Animais
14.
Ecotoxicology ; 27(6): 635-640, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29796722

RESUMO

In International guidelines for standard ecotoxicological bioassays, Daphnia magna is the most applied microcrustacea for assessing toxicity of different pollutants. However, in research realized in tropical and subtropical areas, autochthonous species must be prioritized because they are adapted to the specificities of ecosystems. In this sense, the present study aimed to assess and compare (with D. magna) the sensitivity of the tropical species Dendrocephalus brasiliensis as alternative test species for monitoring of contaminants in tropical and subtropical freshwaters, by carrying out acute toxicity tests with different pollutants. According results, D. brasiliensis presented EC50-48 h values lower than D. magna for all substances tested, indicating higher sensitivity of the tropical organism in relation to the temperate organism. Furthermore, comparing the results obtained with data from other studies, D. brasiliensis is more sensitive to the chemicals tested than D. magna and has similar sensitivity to Pseudosida ramosa and Ceriodaphnia dubia, common species in tropical areas. In view of this, we suggest that D. brasiliensis can be used as alternative test species for monitoring of contaminants in tropical and subtropical freshwaters.


Assuntos
Anostraca/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Ecotoxicologia/métodos , Testes de Toxicidade Aguda , Animais , Água Doce , Clima Tropical , Poluentes Químicos da Água/toxicidade
15.
Sci Rep ; 8(1): 5983, 2018 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-29654258

RESUMO

Salinity is an important factor affecting freshwater aquatic species distribution and diversity. The semi-arid Eastern Cape Karoo region of South Africa has been earmarked for shale gas development through hydraulic fracturing. The process uses large amounts of water and produces briny wastewater. When not managed properly, these wastewaters may lead to salinisation of surface freshwater bodies in the region. Therefore, the effect of salinity on the hatching success of crustacean resting eggs was examined using sediments from four depression wetlands found in the region. The sediments were exposed for 28 days to salinity levels of 0.5 g L-1, 2.5 g L-1, 5 g L-1 and 10 g L-1. Control aquaria in which no salt was added were also set up. There was a significant decrease in the emerged taxa richness and abundances at salinities of 2.5 g L-1 and above. Anostraca, Notostraca and Spinicaudata hatchlings were abundant at salinities of 0.5 g L-1 and below, while Copepoda, Daphniidae (Cladocera) and Ostracoda were observed in the highest salinity, but their densities were still lower with increased salinities. Given the importance of large branchiopods in the trophic balance of depression wetlands, their loss may alter the ecological balance and function of these ecosystems.


Assuntos
Anostraca/crescimento & desenvolvimento , Copépodes/crescimento & desenvolvimento , Crustáceos/crescimento & desenvolvimento , Reprodução/fisiologia , Animais , Ecossistema , Salinidade , África do Sul , Águas Residuárias , Áreas Alagadas
16.
Zootaxa ; 4394(2): 207-218, 2018 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-29690370

RESUMO

We present an updated taxonomic account of a few of the large branchiopod species present in the collections of the Yale Peabody Museum of Natural History. Our study shows that the Artemia species in the collections is not Artemia salina given the presence of spines at the base of the penis and its frontal knob morphology. This population cannot be assigned to any particular species due to lack of comparative material of other Artemia species and therefore, now reduces the authentic distribution record of Artemia salina to just one in the subcontinent. The morphology of eggs taken from the Streptocephalus longimanus allotype is distinct from what has been described later by having lower number of polygons on the egg surface. The gross morphology of the Triops cancriformis from Punjab, Pakistan resembles those of the Kashmir population from India except for its larger size. Based on the morphological comparison, we show that Eocyzicus deterrana is indeed synonymous to E. hutchinsoni. This work further changes the total species tally of large branchiopods from 44 of the Indian subcontinent to 45.


Assuntos
Anostraca , Animais , Crustáceos , Expedições , Índia , Masculino , Museus , Óvulo , Paquistão
17.
Sci Rep ; 8(1): 1069, 2018 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-29348432

RESUMO

Food allergy is an increasingly important health problem in the world. Several genome-wide association studies (GWAS) focused on European ancestry samples have identified food allergy-specific loci in the HLA class II region. We conducted GWAS of self-reported reactivity with common foods using the data from 11011 Japanese women and identified shrimp and peach allergy-specific loci in the HLA-DR/DQ gene region tagged by rs74995702 (P = 6.30 × 10-17, OR = 1.91) and rs28359884 (P = 2.3 × 10-12, OR = 1.80), respectively. After HLA imputation using a Japanese population-specific reference, the most strongly associated haplotype was HLA-DRB1*04:05-HLA-DQB1*04:01 for shrimp allergy (P = 3.92 × 10-19, OR = 1.99) and HLA-DRB1*09:01-HLA-DQB1*03:03 for peach allergy (P = 1.15 × 10-7, OR = 1.68). Additionally, both allergies' associated variants were eQTLs for several HLA genes, with HLA-DQA2 the single eQTL gene shared between the two traits. Our study suggests that allergy to certain foods may be related to genetic differences that tag both HLA alleles having particular epitope binding specificities as well as variants modulating expression of particular HLA genes. Investigating this further could increase our understanding of food allergy aetiology and potentially lead to better therapeutic strategies for allergen immunotherapies.


Assuntos
Alelos , Alérgenos/imunologia , Epitopos/imunologia , Hipersensibilidade Alimentar/genética , Hipersensibilidade Alimentar/imunologia , Estudo de Associação Genômica Ampla , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Adulto , Animais , Anostraca/imunologia , Biologia Computacional/métodos , Reações Cruzadas/genética , Reações Cruzadas/imunologia , Feminino , Hipersensibilidade Alimentar/diagnóstico , Predisposição Genética para Doença , Humanos , Japão , Polimorfismo de Nucleotídeo Único , Prunus persica/efeitos adversos , Autorrelato
18.
BMC Ecol ; 18(1): 2, 2018 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-29361977

RESUMO

BACKGROUND: Higher temperatures and increased environmental variability under climate change could jeopardize the persistence of species. Organisms that rely on short windows of rainfall to complete their life-cycles, like desert annual plants or temporary pool animals, may be particularly at risk. Although some could tolerate environmental changes by building-up banks of propagules (seeds or eggs) that buffer against catastrophes, climate change will threaten this resilience mechanism if higher temperatures reduce propagule survival. Using a crustacean model species from temporary waters, we quantified experimentally the survival and dormancy of propagules under anticipated climate change and used these demographic parameters to simulate long term population dynamics. RESULTS: By exposing propagules to present-day and projected daily temperature cycles in an 8 month laboratory experiment, we showed how increased temperatures reduce survival rates in the propagule bank. Integrating these reduced survival rates into population models demonstrated the inability of the bank to maintain populations; thereby exacerbating extinction risk caused by shortened growing seasons. CONCLUSIONS: Overall, our study demonstrates that climate change could threaten the persistence of populations by both reducing habitat suitability and eroding life-history strategies that support demographic resilience.


Assuntos
Anostraca/fisiologia , Mudança Climática , Ecossistema , Água Doce , Traços de História de Vida , Zooplâncton/fisiologia , Animais , Modelos Biológicos , Dinâmica Populacional , Estações do Ano , Temperatura
19.
Zootaxa ; 4531(1): 139-141, 2018 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-30651457

RESUMO

As part of preparation for identification keys to the branchiopod crustaceans of the Neotropical Region, we re-examined many species of Anostraca that appeared to be closely related. Our examination caused us to re-evaluate the status and relationship of two branchinectid species.


Assuntos
Anostraca , Crustáceos , Animais
20.
Zootaxa ; 4526(3): 381-391, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30651516

RESUMO

A new species of Chirocephalus collected in temporary freshwater ponds in Northeastern Algeria is described. Chirocephalus sanhadjaensis sp. nov. seems to be restricted to Ain-Magroun and Belkroun pools (Skikda Province). The most similar species is C. marchesonii Ruffo Vesentini, 1957, which is endemic to Italy. The new taxon, belonging to the "diaphanus" species group of the genus Chirocephalus, is identifiable from all congeners primarily by the shape of the antennal appendages and that of the apex of the distal antennomere of the antennae. The resting eggs of C. sanhadjaensis sp. nov. are similar to those of C. diaphanus or C. salinus but are larger (448.24 ± 30.93 µm). The restricted distribution of this species confirms the high biological diversity of the area of the Guerbes-Sanhadja eco-complex.


Assuntos
Anostraca , Argélia , Animais , Crustáceos , Itália , Óvulo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...