ABSTRACT
Introdução: Roedores estão entre as mais importantes pragas do mundo e, quando estes indivíduos ou seus pelos são encontrados nos alimentos, são considerados matérias estranhas indicativas de risco à saúde. Por outro lado, a presença de pelos humanos e dos demais mamíferos é considerada indicativa de falhas das boas práticas. Sendo assim, a caracterização dos pelos dos roedores sinantrópicos e a diferenciação dos pelos das demais espécies de mamíferos mostram-se relevantes e necessárias. Objetivo: Caracterizar os padrões microestruturais dos pelos-guarda das três principais espécies de roedores que infestam ambientes de armazenamento de alimentos e apresentar uma proposta de protocolo para análise tricológica de pelos isolados. Método: Amostras de pelos de roedores das espécies Mus musculus, Rattus rattus e Rattus norvegicus foram coletadas de espécimes colecionados e pelos-guarda íntegros foram selecionados para a preparação de lâminas para observação da microestrutura. No total, 20 pelos-guarda foram analisados para caracterização dos padrões medulares e 91 impressões cuticulares de pelos-guarda foram examinadas para caracterização de padrões cuticulares. Resultados: Observou-se que M. musculus apresentou medula alveolar e cutícula losângica com variações na forma e tamanho das escamas. R. rattus e R. norvegicus apresentaram medula reticulada e cutícula losângica, também com variações. Um protocolo com fluxograma de identificação foi apresentado para a análise dos pelos estudados. Conclusões: Os pelos das espécies de roedores sinantrópicos estudados podem ser diferenciados das demais espécies de mamíferos de interesse sanitário pela presença dos padrões medulares alveolar e reticulado no escudo de pelos-guarda. Para as espécies estudadas, somente o padrão medular do escudo dos pelos-guarda confere caráter diagnóstico.
Introduction: Rodents are among the most important pests in the world and when these individuals or their fur are found in food, they are considered foreign matter indicative of health risk. On the other hand, the presence of human and other mammalian hair is considered indicative of failures in good practices. Thus, the characterization of the hair of synanthropic rodents and its differentiation from other mammal species are relevant and necessary. Objective: To characterize the microstructural patterns of guard hairs of the three main species of rodents that infest food storage environments and to present a proposal for a protocol for the trichological analysis of isolated hairs. Method: Hair samples were plucked from collected specimens of the rodent species Mus musculus, Rattus rattus and Rattus norvegicus. Intact guard hairs were selected for the preparation of slides for observation of the microstructure. In total, 20 guard hairs were analyzed for the characterization of medullary patterns and 91 guard hair cuticular impressions were examined for the characterization of cuticular patterns. Results: It was observed that M. musculus presented alveolar medulla and losangic cuticle with variations in the shape and size of the scales. R. rattus and R. norvegicus presented reticulated medulla and losangic cuticle, also with variations. A protocol with an identification fluxogram was presented for the analysis of the studied hairs. Conclusions: The hairs of the studied synanthropic rodent species can be differentiated from other mammalian species of health interest by the presence of alveolar and reticulated medullary patterns in the guard hair shield. For the studied species, only the medullary pattern of the guard hair shield confers a diagnostic character.
ABSTRACT
This study aimed to identify bovine breeds through trichological morphology and morphometry and to validate this technique by comparing it with genetic characterization. Animals from Caracu, Curraleiro Pé-Duro, Nelore, and Bovino Pantaneiro breeds were studied. Morphological and morphometric analyses of the guard hairs were performed. The cuticular pattern was observed on the shaft and the medulla pattern on the shield of the samples. The cattle genetic characterization was accomplished using microsatellite markers. Statistical analyses were performed using R version 3.2.4 software. Pearson's correlation test showed a high positive and significant correlation between the matrices generated by trichological and genetic analyses (r = 0,996 and p < 0.001). Trichological analysis is a useful method for cattle breed identification. Its potential for identifying other species of interest for animal production should be studied since it is a simple, low-cost, and non-invasive method.
ABSTRACT
The diet of some sympatric carnivore species in three Atlantic Forest remnants of Southern Brazil was studied in order to assess their food niche. We conducted monthly field trips between February 2003 and January 2004 to collect fecal samples that were subsequently examined together with others collected sporadically between November 1994 and January 2003. Of the 416 samples analysed, 198 had the "author" species identified through microscopic analysis guard hairs, which revealed the presence of 10 carnivores and some information about their diet. Puma yagouaroundi had the largest dietary niche breadth, whereas Leopardus tigrinus and Nasua nasua showed the lowest values. Extensive niche overlap was observed between L. tigrinus and N. nasua, L. tigrinus and L. wiedii, and between L. tigrinus and L. pardalis. Data presented here not only increases the understanding of carnivore feeding ecology, but also contributes towards their conservation in the study region and other fragmented landscapes in Brazil and neighboring countries.
Este trabalho apresenta informações sobre a dieta, a amplitude e a sobreposição de nicho alimentar de algumas espécies simpátricas de carnívoros em três fragmentos de Floresta Atlântica do Sul do Brasil. A coleta de material fecal foi realizada com periodicidade mensal de fevereiro de 2003 a janeiro de 2004. No entanto, amostras obtidas esporadicamente entre novembro de 1994 e janeiro de 2003 também foram incluídas nas análises. Das 416 amostras analisadas, 198 possibilitaram a identificação de 10 espécies "autoras" por meio da análise microscópica de pelos-guarda, bem como informações sobre sua dieta. Puma yagouaroundi teve a maior amplitude de nicho, enquanto Leopardus tigrinus e Nasua nasua apresentaram os menores valores. Maiores sobreposições de nicho foram observadas entre L. tigrinus e outras espécies: N. nasua, L. wiedii e L. pardalis. Espera-se que estes dados, além de contribuírem para incrementar o conhecimento sobre a ecologia alimentar de carnívoros neotropicais, possam auxiliar de forma efetiva na conservação das espécies encontradas na região de estudo e em outras paisagens fragmentadas do território brasileiro e países limítrofes.
ABSTRACT
Endocrine disruption in marine populations is a growing concern. One of the best documented examples is imposex, the development of male characteristics in female gastropods, including the development of a penis and/or vas deferens, by exposure to organotins, mainly tributyltin. This syndrome has been an effective and widely used biomarker of organic tin contamination for almost 20 years. However, established imposex evaluation protocols sacrifice all the animals and repeated assessments can result in depletion of populations. To preserve animal lives as much as possible and to have a fast screening of areas subjected to organotin impacts, a non-destructive approach was tested. This approach uses reversible narcotization and a statistical criterion to evaluate the extent of imposex in the populations, instead of imposex indexes, which are based on evaluation of sacrificed, fixed animals. The data consist of two categories: males plus masculinized females in one category and normal females in another. The probability is then calculated that this sample could have been drawn from a normal population. This new method was tested in two contrasting areas of Brazil and with two different species, and the results compared to the conventional evaluation. Narcotization was completely reversed with a survival rate of 98%. Impacted sites could be identified with this technique in the same way as with the conventional one. The only limitation was that female sterility could not be verified. This disadvantage could well be compensated by the minimal mortality in the studied populations.
