RESUMO
Abstract The aim objective of this study was to determine the trophic ecology of juvenile and adult Acestrorhynchus falcirostris during the rising and flood (high-water) period in six island lakes adjacent to the Solimões River. As such, we investigated: i) the trophic position, through the fractional trophic niche; ii) the niche breadth; iii) niche overlap and iv) the food strategy of the species. The specimens were collected during the years 2014 to 2017, using gillnets with mesh sizes ranging from 30 to 120mm between opposite knots. Through the analysis of stomach contents, the preference in the consumption of items of animal origin was observed. Juveniles consumed insects in greater proportions (IAi% = 50%), while adults consumed fish (IAi%=99,98%). Despite the large supply of food items available in the high-water period, juveniles were the only ones to consume items of allochthonous origin, such as insects. Juveniles presented a different dietary strategy and dietary composition to adults. Juveniles were omnivores with a generalist strategy, while adults were piscivores with a specialist strategy. Thus, the food composition, niche breadth, trophic position and feeding strategy of Acestrorhynchus falcirostris change due to the stage of development.
Resumo O objetivo deste estudo foi determinar a ecologia trófica de juvenis e adultos de Acestrorhynchus falcirostris durante o período de enchente e cheia em seis lagos de ilha adjacentes ao rio Solimões. Assim, investigamos: i) a posição trófica, através do nicho trófico fracional; ii) a largura de nicho; iii) sobreposição de nicho; iv) a estratégia alimentar. Os espécimes foram coletados durante os anos de 2014 a 2017, utilizando redes de emalhar com malha variando de 30 a 120mm entre nós opostos. Por meio da análise do conteúdo estomacal, observamos a preferência no consumo de itens de origem animal. Os juvenis consumiram insetos em maiores proporções (IAi% = 50%), enquanto os adultos consumiram preferencialmente peixes (IAi% = 99,98%). Apesar da grande oferta de alimentos disponíveis no período da cheia, os juvenis eram os únicos a consumir itens de origem alóctone, como por exemplo, os insetos. Os juvenis apresentaram uma estratégia alimentar e composição alimentar diferente para os adultos. Os juvenis foram considerados onívoros com uma estratégia generalista, enquanto os adultos foram considerados piscívoros com uma estratégia alimentar mais especialista. Assim, a composição alimentar, amplitude do nicho, posição trófica e a estratégia alimentar de Acestrorhynchus falcirostris muda em função do estágio de desenvolvimento.
Assuntos
Animais , Rios , Caraciformes , Estações do Ano , Lagos , Ecossistema , Cadeia Alimentar , Peixes , Conteúdo GastrointestinalRESUMO
Abstract The aim objective of this study was to determine the trophic ecology of juvenile and adult Acestrorhynchus falcirostris during the rising and flood (high-water) period in six island lakes adjacent to the Solimões River. As such, we investigated: i) the trophic position, through the fractional trophic niche; ii) the niche breadth; iii) niche overlap and iv) the food strategy of the species. The specimens were collected during the years 2014 to 2017, using gillnets with mesh sizes ranging from 30 to 120mm between opposite knots. Through the analysis of stomach contents, the preference in the consumption of items of animal origin was observed. Juveniles consumed insects in greater proportions (IAi% = 50%), while adults consumed fish (IAi%=99,98%). Despite the large supply of food items available in the high-water period, juveniles were the only ones to consume items of allochthonous origin, such as insects. Juveniles presented a different dietary strategy and dietary composition to adults. Juveniles were omnivores with a generalist strategy, while adults were piscivores with a specialist strategy. Thus, the food composition, niche breadth, trophic position and feeding strategy of Acestrorhynchus falcirostris change due to the stage of development.
Resumo O objetivo deste estudo foi determinar a ecologia trófica de juvenis e adultos de Acestrorhynchus falcirostris durante o período de enchente e cheia em seis lagos de ilha adjacentes ao rio Solimões. Assim, investigamos: i) a posição trófica, através do nicho trófico fracional; ii) a largura de nicho; iii) sobreposição de nicho; iv) a estratégia alimentar. Os espécimes foram coletados durante os anos de 2014 a 2017, utilizando redes de emalhar com malha variando de 30 a 120mm entre nós opostos. Por meio da análise do conteúdo estomacal, observamos a preferência no consumo de itens de origem animal. Os juvenis consumiram insetos em maiores proporções (IAi% = 50%), enquanto os adultos consumiram preferencialmente peixes (IAi% = 99,98%). Apesar da grande oferta de alimentos disponíveis no período da cheia, os juvenis eram os únicos a consumir itens de origem alóctone, como por exemplo, os insetos. Os juvenis apresentaram uma estratégia alimentar e composição alimentar diferente para os adultos. Os juvenis foram considerados onívoros com uma estratégia generalista, enquanto os adultos foram considerados piscívoros com uma estratégia alimentar mais especialista. Assim, a composição alimentar, amplitude do nicho, posição trófica e a estratégia alimentar de Acestrorhynchus falcirostris muda em função do estágio de desenvolvimento.
RESUMO
The aim objective of this study was to determine the trophic ecology of juvenile and adult Acestrorhynchus falcirostris during the rising and flood (high-water) period in six island lakes adjacent to the Solimões River. As such, we investigated: i) the trophic position, through the fractional trophic niche; ii) the niche breadth; iii) niche overlap and iv) the food strategy of the species. The specimens were collected during the years 2014 to 2017, using gillnets with mesh sizes ranging from 30 to 120mm between opposite knots. Through the analysis of stomach contents, the preference in the consumption of items of animal origin was observed. Juveniles consumed insects in greater proportions (IAi% = 50%), while adults consumed fish (IAi%=99,98%). Despite the large supply of food items available in the high-water period, juveniles were the only ones to consume items of allochthonous origin, such as insects. Juveniles presented a different dietary strategy and dietary composition to adults. Juveniles were omnivores with a generalist strategy, while adults were piscivores with a specialist strategy. Thus, the food composition, niche breadth, trophic position and feeding strategy of Acestrorhynchus falcirostris change due to the stage of development.
Assuntos
Caraciformes , Rios , Animais , Ecossistema , Peixes , Cadeia Alimentar , Conteúdo Gastrointestinal , Lagos , Estações do AnoRESUMO
Eimeria bovis, Eimeria zuernii, Eimeria ellipsoidalis, Eimeria auburnensis, Eimeria canadensis and Eimeria alabamensis were identified on different dairy farms in Uruguay. The most prevalent species were E. bovis and E. zuernii, which were mainly found in the feces of calves with diarrhea. The dynamics of oocyst excretion were evaluated via the weekly determination of oocysts per gram (OPG) values in fecal samples from 97 calves over seven months. Three groups of calves were formed according to their age in days: Group 1 (1-20 days old), Group 2 (21-40 days old) and Group 3 (41-65 days old). In Group 1, the median OPG was zero, and the maximum OPG was 1,680. In Group 2, the median OPG was between zero and 8,240, and the maximum OPG was 428,800. In Group 3, the median OPG was between zero and 220, and the maximum OPG was 16,000. For the evaluation of the relationship between OPG and age group, a proportional odds model was built. Two samples from 60 bovines evaluated in Group 2 and in Group 3 were selected. OPG was categorized as negative, moderate (lower than or equal to 4,000) or high (greater than 4,000). Calves of Group 2 (21-40 days old) were significantly (p < 0.001) more affected by eimeriosis than calves of Group 3 (41-65 days old). Considering that diarrhea in calves is a multifactorial disease, eimeriosis should be considered when evaluating the control measures for diarrhea syndrome, particularly in calves of 21-40 days of age.
Assuntos
Doenças dos Bovinos , Coccidiose , Eimeria , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Coccidiose/epidemiologia , Coccidiose/veterinária , Oocistos , Prevalência , Uruguai/epidemiologiaRESUMO
Ascaridiasis by Ascaridia hermaphrodita is a common parasitic disease in blue-fronted Amazon parrots (Amazona aestiva) and the contamination occurs by ingestion of eggs. Illegal trade of wild birds can increase the frequency of visceral erratic migration by this parasite. Hence, this report describes the erratic migration of A. hermaphrodita and associated lesions in a blue-fronted Amazon parrot. This is a retrospective study, which originated from several apprehension of illegal birds in the state of Paraíba, Brazil. Necropsy revealed intense intestinal ascarid infestation. Hepatic lesions were also observed associated with the parasite migration. Stereoscopy allowed the identification of the morphology of the parasites. Summarizing, this condition in wild birds is not fully understood and may be associated with illegal trade.(AU)
Ascaridíase por Ascaridia hermaphrodita é uma doença parasitária comum em papagaios-verdadeiros. Sua contaminação ocorre pela ingestão de ovos. O tráfico de aves silvestres pode facilitar a migração errática visceral desse parasita. Este relato descreve a migração errática de A. hermaphrodita e lesões associadas em papagaio-verdadeiro. Trata-se de um relato retrospectivo, analisado a partir de uma série de apreensões de aves no estado da Paraíba, Brasil. A necropsia revelou intensa infestação ascarídea intestinal. Também foram observadas lesões hepáticas em uma ave, associadas à migração do parasita. A estereoscopia permitiu distinguir a morfologia dos parasitas. Resumidamente, essa condição em aves silvestres é pouco conhecida e pode ser considerada, inclusive, associada à comercialização ilegal.(AU)
Assuntos
Animais , Ascaridia/isolamento & purificação , Amazona/parasitologia , Helmintíase Animal/diagnóstico , Brasil , Crime , Animais Selvagens/parasitologiaRESUMO
Prenatal exposure to glucocorticoids (GC) is a central topic of interest in medicine since GCs are essential for the maturation of fetal organs and intrauterine growth. Synthetic glucocorticoids, which are used in obstetric practice, exert beneficial effects on the fetus, but have also been reported to lead to intrauterine growth retardation (IUGR). In this study, a model of growth restriction in mice was established through maternal administration of dexamethasone during late gestation. We hypothesised that GC overexposure may adversely affect placental angiogenesis and fetal and placental growth. Female BALB/c mice were randomly assigned to control or dexamethasone treatment, either left to give birth or euthanised on days 15, 16, 17 and 18 of gestation followed by collection of maternal and fetal tissue. The IUGR rate increased to 100% in the dexamethasone group (8 mg/kg body weight on gestational days 14 and 15) and pups had clinical features of symmetrical IUGR at birth. Dexamethasone administration significantly decreased maternal body weight gain and serum corticosterone levels. Moreover, prenatal dexamethasone treatment not only induced fetal growth retardation but also decreased placental weight. In IUGR placentas, VEGFA protein levels and mRNA expression of VEGF receptors were reduced and NOS activity was lower. Maternal dexamethasone administration also reduced placental expression of the GC receptor, αGR. We demonstrated that maternal dexamethasone administration causes fetal and placental growth restriction. Furthermore, we propose that the growth retardation induced by prenatal GC overexposure may be caused, at least partially, by an altered placental angiogenic profile.
Assuntos
Dexametasona , Retardo do Crescimento Fetal/metabolismo , Placenta/metabolismo , Placentação , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Modelos Animais de Doenças , Regulação para Baixo , Feminino , Retardo do Crescimento Fetal/induzido quimicamente , Retardo do Crescimento Fetal/fisiopatologia , Regulação da Expressão Gênica no Desenvolvimento , Idade Gestacional , Camundongos Endogâmicos BALB C , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/metabolismo , Placenta/fisiopatologia , Gravidez , Receptores de Glucocorticoides/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
PURPOSE: To assess the efficacy of silver diamine fluoride (SDF) and sodium fluoride (NaF) in inhibiting enamel erosion in primary teeth. METHODS: 80 primary canine teeth were immersed for 24 h in 2% NaF, 10% SDF, or distilled water. Afterward, some of them underwent a 10-min acid challenge using either 1% or 10% citric acid while others did not. Specimens selected for negative controls were immersed in distilled water but not exposed to the acids, whereas those selected for positive controls were not only immersed in distilled water, but also exposed to the acids. Following, 3-mL samples were collected for calcium and phosphorus analysis by an atomic emission spectrometer. RESULTS: 1% acid caused higher phosphorus loss in the positive control group than in the others (no differences between them). Regarding 10% acid, the SDF group showed lower phosphorus loss compared to the positive control and NaF groups. From calcium loss analysis, SDF and NaF groups presented no significant difference when compared to the positive control groups after both acidic challenges. CONCLUSION: Considering phosphorus loss values, 10% SDF seems to be effective in inhibiting enamel erosion after 1% and 10% citric acid challenges, whereas 2% NaF only after 1% citric acid challenge. Regarding calcium loss values, both fluoride agents seem to have no impact on inhibiting enamel erosion after 1% and 10% citric acid challenges.