129 resultados para Feeding Practices
Resumo:
Among the vectors of Chagas disease, Triatoma patagonica is a species in the process of adaptation to the human environment. However, its vector competence is not well known. This study had the aim of evaluating and comparing feeding and defecation patterns among fifth-instar nymphs of Triatoma patagonica and Triatoma infestans that were fed ad libitum. The results showed that nymphs of Triatoma patagonica had a feeding pattern similar to that of Triatoma infestans. Sixty nine percent and 58% of nymphs of Triatoma patagonica and Triatoma infestans, respectively, produced their first defecation within five minutes after being fed. Triatoma patagonica defecated during feeding, with an average time until first defecation that was shorter than that of Triatoma infestans (3.4 and 6.2 min, respectively). The nymphs of Triatoma patagonica were capable of defecating during or immediately after feeding.
Resumo:
Introduction The aim of this study was to identify the blood feeding sources of Nyssomyia intermedia (Ny. intermedia) and Nyssomyia neivai (Ny. neivai), which are Leishmania vectors and the predominant sandfly species in the Ribeira Valley, State of São Paulo, Brazil, an endemic area for cutaneous leishmaniasis. Methods Specimens were captured monthly between February 2001 and December 2003 on a smallholding and a small farm situated in the Serra district in the Iporanga municipality. The blood meals of 988 engorged females were tested using the avidin-biotin immunoenzymatic enzyme-linked immunosorbent assay (ELISA). Seven blood meal sources were investigated: human, dog, chicken, bovine, pig, horse and rat. Results The results showed that among the females that fed on one or more blood sources, the respective percentages for Ny. intermedia and Ny. neivai, respectively, were as follows: human (23% and 36.8%), pig (47.4% and 26.4%), chicken (25.7% and 36.8%) and dog (3.9% and 0%), and the differences in the blood sources between the two species were statistically significant (p = 0.043). Conclusions Both species had predominant reactivity for one or two blood sources, and few showed reactivity indicating three or four sources. Many different combinations were observed among the females that showed reactivity for more than one source, which indicated their opportunistic habits and eclecticism regarding anthropic environmental conditions.
Resumo:
Introduction The blood meal source of sandflies provides valuable information about the vector/host interaction and allows for an understanding of American cutaneous leishmaniasis (ACL) transmission mechanisms. The aim of this study was to identify the blood meal sources of Lutzomyia (Nyssomyia) intermedia in an endemic area of leishmaniasis in Brazil's State of Paraná using a precipitin test. Methods Sandflies were collected in the rural locality of Epitácio Pessoa within the City of Adrianópolis, State of Paraná, in southern Brazil. A total of 864 female sandflies were captured, and 862 (99.8%) were identified as L. intermedia species. However, two unidentified specimens were considered to be part of the genus Lutzomyia. Results Among the females examined, 396 specimens presented reactions to a certain type of tested antiserum, and most (67.9%) reacted to the simple type. These sandflies fed mainly on the blood of birds, opossums, and rodents, but specimens that fed on the blood of humans, dogs, horses, cattle, and cats were also found. Among the cross-reactions found (32.1%), bird/rodent, bird/opossum, bird/dog, bird/human, and horse/dog cross-reactions were the most common. Conclusions These results demonstrate a tendency in the eclectic feeding behavior of L. intermedia and support its potential role as a vector for ACL in the study area.
Resumo:
Introduction In Triatominae, reproductive efficiency is an important factor influencing population dynamics, and a useful parameter in measuring a species' epidemiological significance as a vector of Trypanosoma cruzi (Chagas, 1909). The reproductive efficiency of triatomines is affected by food availability; hence, we measured and compared the effects of feeding frequency on the reproductive parameters of Triatoma patagonica (Del Ponte, 1929) and Triatoma infestans (Klug, 1934), and the effects of starvation on T. patagonica. Methods Couples from both species were fed weekly, or every 3 weeks; in addition, females in couples of T. patagonica were not fed. Each couple was observed weekly and reproductive efficiency was assessed on the following parameters: fecundity (eggs/female), fertility (eggs hatched/eggs laid), initiation and end of oviposition, initiation of mating, number of matings/week, and number of reproductive weeks. Relative meal size index (RMS), blood consumption index (CI), and E values (eggs/mg blood) were also calculated. Results Changes in feeding frequency affected the reproductive parameters of T. patagonica only, with a decrease in fecundity and number of reproductive weeks for those fed every 3 weeks, or not fed. The reproductive period, RMS index, and CI were lower for T. patagonica than T. infestans. However, despite the lower fecundity of T. patagonica, this species required less blood to produce eggs, with an E values of 2 compared to 2.94 for T. infestans. Conclusions Our results suggest that the differences in fecundity observed between species reflect the availability of food in their natural ecotopes.
Resumo:
Introduction This study was conducted in Brazil and Colombia,where dengue is endemic and vector control programs use chemical insecticides. Methods We identified knowledge, attitudes, and practices about dengue and determined the infestation levels of Aedes aegypti in one Brazilian and four Colombian communities. Results The surveys show knowledge of the vector, but little knowledge about diagnosis, prognosis, and treatment. Vector infestation indices show Brazil to have good relative control, while Colombia presents a high transmission risk. Conclusions Given the multidimensionality of dengue control, vertical control strategies are inadequate because they deny contextualized methods, alternative solutions, and local empowerment.
Resumo:
Abstract INTRODUCTION: This study investigated the knowledge of users of primary healthcare services living in Ribeirão Preto, Brazil, about dengue and its vector. METHODS: A cross-sectional survey of 605 people was conducted following a major dengue outbreak in 2013. RESULTS: Participants with higher levels of education were more likely to identify correctly the vector of the disease. CONCLUSIONS: The results emphasize the relevance of health education programs, the continuous promotion of educational campaigns in the media, the role of the television as a source of information, and the importance of motivating the population to control the vector.
Resumo:
A Socioecological Field Study.This monograph reports on a 26 month socioecological study of black spider monkeys (Ateles paniscus paniscus)in the Raleigh-vallen — Voltzberg Nature Reserve, Surinam. It recognizes the fundamental importance of food to the behavior and the regulation of population density fox this primate. It clarifies the complex temporal and spatial effects of tropical rain forest food sources on the behavior of a group of spider monkeys, concentrating on food category, food plant identity and phenology, and quantity, density and dispersion of the most important food sources. In addition, the present study describes habitat choice, optimal feeding strategy and sexual behavior of the spider monkey, and discusses implications of diet for social behavior. This study is also fundamental to conservation. Specialized in eating mature fruits, the spider monkey is a very important dispersal agent for many trees and lianes, particularly canopy species. However, the spider monkey is probably the most vulnerable monkey species in Surinam and it is disappearing rapidly throughout the remainder of its range. Unfortunately, it is large and noisy and can be easily tracked and hunted. It is largely restricted to undisturbed high forest, and consequently habitat destruction has more effect on it than on most other species. Together with its slow reproductive rate (a female gives birth only once every four or five years), this means that the species is poorly adapted to recover from exploitation. In order to implement proper measures for conservation, data on forest type preferences, diet and social behavior of the species, or on closely related species, in undisturbed areas, such as the one described in this monograph, are essential tools for assessing the potential of proposed protected areas.
Resumo:
The geographical distribution of the African Tilapia Oreochromis mossambicusin Suriname is restricted to a narrow strip of land along the Atlantic coast. Within the coastal plain, O. mossambicusoccurs in brackish lagoons, oligohaline canals, and shell-sand pit lakes. Physico-chemical characteristics and phytoplankton composition of representative Tilapia water bodies are described. Blue-green algae and fine flocculent detritus are dominant food items in the diet of the Tilapia, while Rotifera and microcrustacea are also important in the diet of larvae and juveniles. Intraspecific diet overlap among ontogenetic stages of the Tilapia did not differ significantly from 1, which means that these diets showed complete overlap. Interspecific diet overlap between the Tilapia and the indigenous armoured catfish Hoplosternum littoralewere moderate or low. The results are discussed in relation to recent developments in the Surinamese fisheries and aquaculture sector.
Resumo:
The alimentary preferences of five species of wood-feeding termites of the genus Nasutitermes that coexist in the inundated forests of the floodplains of the Amazon river várzea for species of fresh wood and for wood in different stages of decomposition was evaluated in laboratory tests. Wood of low density was generally preferred; the decay stages were preferred over fresh wood. The five termite species differ in the amplitude of their choices, indicating a strong differentiation in food choice among them. Differences in feeding preferences may be a niche-separating factor for these five Nasutitermes species of the floodplains.
Resumo:
The intensity of construction of foraging access holes by two leaf-litter feeding, soil- inhabiting termite species, Syntermes molestus and Syntermes spinosus, in a Central Amazonian rain forest, was observed on consecutive nights for two weeks. Between 11 and 48 nest entrances per m2 were counted. Interaction between the two species was intense; some entrance holes were overtaken by the larger species during the observations; however, both species coexist in the area. A calculated minimum of 35 entrances/m2 is built every year by both species, emphasizing the importance of soil-burrowing termites for soil structure, aeration and water regime.
Resumo:
Information on larval fish feeding is essential for understanding their trophic relations, including the management in conditions totally or partially controlled by humans. An experiment was designed to evaluate the larval diets of three commercially important species. Four varzea-lakes and the adjacent river were sampled with bongo and hand nets from January 1993 to November 1995. Larval diets were evaluated by length-classes and capture sites, and were tested by two factor ANOVA. The larvae were feeding in all habitats, except in the flooded forests. The three species had different diets, which varied with their length and lake. The rotifers were the main initial food item of the three species, replaced by fish larvae in Brycon cephalus, cladocerans in Triportheus elongatus and detritus in Semaprochilodus insignis. The increase of the ingestion limit, as the larvae grew, was higher than the increase in the consumed prey size for the three species.
Resumo:
Macrobrachium carcinus is a Brazilian native prawn with recognized potential for use in aquaculture activities. However, there is little information about the natural diet and feeding habits of this species. The aim of this study was the identification of the diet items of M. carcinus based on the analysis of the stomach contents. Specimens were collected in the Amazon River estuary between January 2009 and January 2010. The stomach analysis was carried out by using the frequency of occurrence (FO), methods of points (MP) and feeding index (FI). It was observed that prawns fed on detritus, animals and plant fragments as the most important food items. Sediment accounted for the main stomach content, accounting for 43.2% by the MP, 44.9% by FI and 100% by the FO. Sexual differences in feeding preferences were not found in this study, and seasonal differences in the frequency of items ingested by M. carcinus were not observed. The results indicated that M. carcinus can be considered omnivorous species, but with an important carnivorous component, similar to that found in other Macrobrachium species.
Resumo:
The conservation of diverse and well-distributed fish taxa, as the genus Leporinus, relies intrinsically on the knowledge of the ecological attributes of its representatives. Aiming to increase this knowledge, studies on diet and ecomorphology are ideal to provide important information about species ecology. Thus, this study aimed to analyze aspects of feeding ecology of L. reticulatus, from the upper Rio Juruena, Mato Grosso State, Brazil. The diet of specimens in different ontogenetic stages was compared, as well as their teeth morphology and ecomorphological attributes. Leporinus reticulatus presented omnivorous diet, with higher consumption of invertebrates by smaller specimens (younger ones), and gradual introduction of plant items in larger specimens (older ones). The items consumed by the individuals and the ecomorphological attributes indicated that the species is generalist and opportunistic, besides its association with the river bottom, evidencing a benthic feeding behavior. This species presents a gradual ontogenetic modification in teeth shape and mouth positioning, ranging from a terminal mouth with tricuspid teeth, in smaller specimens, to an inferior mouth with spatula shaped teeth with no cusps, in larger specimens.The ecomorphological attributes indicate an increasing swimming efficiency, and ability for performing vertical displacements, along the ontogenetic development, which in addition to the morphological ontogenetic alterations in the buccal apparatus, contributes to a better ability to explore another niches.
Resumo:
OBJECTIVE: The aim of this study was to analyze qualitatively how women, who have recovered from anorexia nervosa, perceive and describe their current eating practices, as well as the ones developed during the eating disorder period. METHODS: Seven women were interviewed individually with the objective of investigating their eating practices, transition phases and all relevant aspects that somewhat contributed to the habit-forming; experiences, feelings and perceptions related to mealtime and the influence that food has had over the present subjects' life. The interviews were analyzed by the discourse of the collective subject method. RESULTS: The results brought up the following topics: a) control; b) concerns and feelings; c) deprivation d) beauty dictatorship; e) eating competence; f) importance of food; g) food cacophony. CONCLUSIONS: What stands out is a multiplicity of eating practices, which during the eating disorder were similar to and characterized by restriction; however, after recovery, part of the subjects seem to have developed a higher eating competence, whereas others show a practice similar to the one acquired during the anorexia nervosa, such as the difficulty in realizing when they are satisfied and a feeling of discomfort when facing social interactions.