964 resultados para Post-feeding Larval Dispersal


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Blowflies utilize discrete and ephemeral sites for breeding and larval nutrition. After the exhaustion of food, the larvae begin dispersing to search for sites to pupate or for additional food source, process referred as postfeeding larval dispersal. Some aspects of this process were investigated in Lucilia cuprina (Wiedemann, 1830), utilizing a circular arena to permit the radial dispersion of larvae from the food source in the center. To determine the localization of each pupa, the arena was split into 72 equal sectors from the center. For each pupa, distance from the center of arena, weight and depth were determined. Statistical tests were performed to verify the relation among weight, depth and distance of burying for pupation. It was verified that the larvae that disperse farthest are those with lowest weights. The majority of individuals reached the depth of burying for pupation between 7 and 18 cm. The study of this process of dispersion can be utilized in the estimation of postmortem interval (PMI) for human corpses in medico-criminal investigations.

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Among the vectors of Chagas disease, Triatoma patagonica is a species in the process of adaptation to the human environment being recently registered in urban and suburban zones. However, its importance as a vector of Chagas disease is unknown. The aim of this work was to evaluate two aspects of vectorial competence: the feeding behaviour and the defaecation pattern. These processes were studied in females of T. patagonica fed ad libitum on a restrained pigeon. The results showed that the blood meal size was negatively correlated with the time of first defaecation (r = -0.42). The first defaecation was emitted before the first 10 min and defaecations during feeding were frequent. A total of 73% of females, defaecated during the first 30 min post-feeding. These results suggest that if this species subsequently colonizes the domicile, it would be capable of transmitting Trypanosoma cruzi.

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Blowflies utilize discrete and ephemeral sites for breeding and larval nutrition. After the exhaustion of food, the larvae begin dispersing to search for sites to pupate or to additional food source, process referred as postfeeding larval dispersal. Some of the most important aspects of this process were investigated in Chrysomya megacephala, utilizing a circular arena to permit the radial dispersion of larvae from the center. To determinate the localization of each pupa, the arena was split in 72 equal sectors from the center. For each pupa, distance from the center of arena, weight and depth were determined. Statistical tests were performed to verify the relation among weight, depth and distance of burying for pupation. It was verified that the larvae that disperse farther are those with higher weights. The majority of individuals reached the depth of burying for pupation between 7 and 18 cm. The study of this process of dispersion can be utilized in the estimation of postmortem interval (PMI) for human corpses in medico-criminal investigations.

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Chrysomya albiceps and Chrysomya megacephala are exotic blowfly species known by producing myiasis in humans and other animals and by transmitting pathogens mechanically. C. albiceps stand out by being a facultative predator of other dipteran larvae. In this paper we investigated the influence of larval predation on the dispersal of larvae of C. albiceps and C. megacephala single and double species for three photophases. An experimental acrylic channel graduated and covered with wood shavings was used to observe the larval dispersal. The results showed that C. albiceps attacks C. megacephala larvae during dispersal and keeps an aggregated pattern close to the release point, in single and double species, independently of the different photophases. Chrysomya megacephala single species exhibited the same pattern, but in double species this was changed to a random distribution.

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Seed dispersal by animals is a complex process involving several distinct stages: fruit removal by frugivores, seed delivery in different microhabitats, seed germination, seedling establishment, and adult recruitment. Nevertheless, studies conducted until now have provided scarce information concerning the sequence of stages in a plant's life cycle in its entirety. The main objective of this study was to evaluate the immediate consequences of frugivore activity for Eugenia umbelliflora ( Myrtaceae) early recruitment by measuring the relative importance of each fruit-eating bird species on the establishment of new seedlings in scrub and low restinga vegetation in the Atlantic rainforest, Brazil. We conducted focal tree observations on E. umbelliflora trees recording birds' feeding behaviour and post-feeding movements. We also recorded the fate of dispersed seeds in scrub and low restinga vegetation. We recorded 17 bird species interacting with fruits in 55 h of observation. Only 30% of the handled fruits were successfully removed. From 108 post flight movements of exit from the fruiting trees, 30.6% were to scrub and 69.4% to low restinga forest. Proportion of seed germination was higher in low restinga than in the scrub vegetation. Incorporating the probabilities of seeds' removal, deposition, and germination in both sites, we found that the relative importance of each frugivorous bird as seed dispersers varies largely among species. Turdus amaurochalinus and Turdus rufiventris were the best dispersers, together representing almost 12% probability of seed germination following removal. Our results show the importance of assessing the overall consequence of seed dispersal within the framework of disperser effectiveness, providing a more comprehensive and realistic evaluation of the relative importance of different seed dispersers on plant population dynamics.

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Blowflies utilize discrete and ephemeral breeding sites for larval nutrition. After the exhaustion of food, larvae begin dispersing in search of sites to pupate or additional food sources, a process referred as postfeeding larval dispersal. Some of the most important aspects of this process were investigated in the blowfly Chrysomya albiceps, employing a circular arena to allow radial dispersion of larvae from the center. The results showed a positive correlation between burial depth and distance, and a negative correlation between distance and pupal weight. These results can be used in forensic entomology for the postmortem interval estimation of human corpses in medico-criminal investigations. (c) 2004 Elsevier B.V.. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The zip folder comprises a text file and a gzipped tar archive. 1) The text file contains individual genotype data for 90 SNPs, 9 microsatellites and the mitochondrial ND4 gene that were determined in deep-sea hydrothermal vent mussels from the Mid-Atlantic Ridge (genus Bathymodiolus). Mussel specimens are grouped according to the population (pop)/location from which they have been sampled (first column). The remaining columns contain the respective allele/haplotype codes for the different genetic loci (names in the header line). The data file is in CONVERT format and can be directly transformed into different input files for population genetic statistics. 2) The tar archive contains NetCDF files with larval dispersal probabilities for simulated annual larval releases between 1998 and 2007. For each simulated vent location (Menez Gwen, Lucky Strike, Rainbow, Vent 1-10) two NetCDF files are given, one for an assumed pelagic larval duration of 1 year and the other one for an assumed pelagic larval duration of 6 months (6m).

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Atlantic Menhaden Brevoortia tyrannus is a commercially and ecologically important forage fish abundant on the Atlantic Coast of the United States. We conducted spatial and temporal analyses of larval Atlantic Menhaden using data collected from two large-scale ichthyoplankton programs during 1977-1987 and 1999-2013 to construct indices of larval abundance and survival over time, evaluate how environmental factors affect early life survival, and examine how larvae are distributed in space to gain knowledge on spawning and larval dispersal. Over time, we found larval abundance to increase, while early life survival declined. Coastal temperature, wind speed, and Atlantic Multidecadal Oscillation were found to potentially explain some of this decline in survival. Over both periods, we found evidence spawning predominantly occurs near shore, from New York to North Carolina, increasing in intensity southwards. While the general spatial patterns were consistent, we observed some localized variation and overall expansion of occupied area by larvae.

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The aim of this study was to determine biofloc contributions to the antioxidant status and lipid nutrition of broodstock of Litopenaeus stylirostris in relationship with their reproductive performance and the health of larvae produced. Shrimp broodstock reared with Biofloc technology (BFT) compared to Clear water (CW) exhibited a higher health status with (i) a better final survival rate during the reproduction period (52.6% in CW against 79.8% in BFT); (ii) higher glutathione level (GSH) and total antioxidant status (TAS), reduced oxidized/reduced glutathione ratio and a higher spawning rate and frequency as well as higher gonado-somatic index and number of spawned eggs. Finally, larvae from broodstock from BFT exhibited higher survival rates at the Zoe 2 (+ 37%) and Post Larvae 1 (+ 51%) stages when compared with those from females from CW treatment. The improved reproductive performance of the broodstock and higher larvae survival rate resulting from BFT treatment may be linked to the dietary supplement obtained by the shrimp from natural productivity during BFT rearing. Indeed, our study confirms that biofloc particulates represent a potential source of dietary glutathione and a significant source of lipids, particularly essential phospholipids and n-3 highly unsaturated fatty acids (HUFA) for shrimps. Thus, broodstock from BFT treatment accumulated phospholipids, n-3 HUFA and arachidonic acid, which are necessary for vitellogenesis, embryogenesis and pre-feeding larval development. The predominant essential fatty acids, arachidonic acid (ARA), eicopentaeonic acid (EPA) and docosahexaenoic acid (DHA), had levels in the eggs that were, respectively, 2.5, 2.8 and 3 fold higher for BFT compared to the CW treatment. Statement of Relevance Today, the influence of biofloc technology on shrimp broodstock is not enough described and no information was available on the larvae quality. Moreover, two key pieces of new information emerge from the present study. Firstly, biofloc is a source of further dietary lipids that can act as energetic substrates, but also as a source of phospholipids and essential fatty acids necessary to sustain reproduction, embryonic and larval development. Second, improving the reproduction of the broodstock also leads to an improvement in the quality of the larvae. We think that our research is new and important to increase knowledge on biofloc topic. We believe the paper will contribute to the development of more efficient and therefore more sustainable systems.

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Tese de Doutoramento, Ciências do Mar, da Terra e do Ambiente, Ramo: Ciências do Mar, Especialização em Ecologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016

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A rapid DNA extraction was used for T. cruzi detection in triatomines dry fecal spots collected on filter paper and analyzed by PCR. Fifty T infestans were fed on experimentally infected Balb/C mice with high T. cruzi parasitemia and divided into five groups of len triatomines, and 100 triatomines were infected with lower parasitemia and divided into five groups of 20 triatomines, One dry fecal spot was analyzed per group on days 1, 2, 3, 4 and 5 post feeding. Amplification targeted T. cruzi TCZ sequence and resulted positive from day 4 after bugs feeding in the two models (high and lower parasitemia). The rapid DNA isolation and PCR proposed are suitable for detection of T. cruzi DNA in in filter paper and should be considered in field research.

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Jornadas "Ciência nos Açores – que futuro? Tema Ciências Naturais e Ambiente", Ponta Delgada, 7-8 de Junho de 2013.

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Jornadas "Ciência nos Açores – que futuro? Tema Ciências Naturais e Ambiente", Ponta Delgada, 7-8 de Junho de 2013.