An osmoregulatory role for angiotensin II was investigated in the euryhaline European eel Anguilla anguilla L., plaice (Pleuronectes platessa) and dab (Limanda limanda). 1. Ile5 - and val5 -AII increased blood pressure in all species. Ile5 -AII produced a greater effect than val5 - AII, at equal concentrations, in eels, however in plaice and dab, this trend was reversed. Papaverine reduced blood pressure, followed by recovery to control in all cases. 2. Both AII sequences increased drinking rates except ile5 -AII in dab. ile5 -AII again proved more potent than val5-AII in eels and val5 - was greater than ile5- AII in flatfish. Papaverine increased drinking in all species. Captopril had no effect on eel or dab drinking rates, but reduced those of plaice. 3. 1.0nM and 10.0nM AII increased ANP release from isolated eel myocytes, except from FW atria. At 1.0nM, ventricular release was greater than atrial, however at 10.0nM, AII ANP secretion was similar in both types of myocyte. In all cases ANP release was greater from SW than FW myocytes. 4. Tissue/plasma ratios revealed greatest binding in SW eel liver. Tissue receptor specific binding was also greatest in FW eel liver membranes, however in SW tissues gill was slightly greater than liver. A FW eel liver membrane radioreceptor assay was developed. Binding was optimal at 22°C, 25mM calcium, protein concentration of 700ug, 125I-AII concentration of 25pM and an incubation period of 60 minutes. 6. Initial FW eel liver binding studies indicated two receptor classes with Kd=1. 5x10-11M and 2.46x10-10. However subsequent studies reveal Kd =3.31x10-8M in FW liver and Kd=1.09x10-7M in SW liver preparations. 7. 125I-ile5 -AII produced greater binding than 125I-val5 -AII in eel liver preparations. 125I-val5 -AII produced greater binding in flatfish membranes. Investigations of 125I-ile5 -AII displacement from FW eel liver membranes revealed peptide potencies in the following order, sar-AII > ile5-AII > 5-8AII > ile5-AI > val5-AI > ile4-AIII > val4-AIII > bradykinin > 1-4AII.

by Fung Chak-yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1980. / Bibliography: leaves 181-224.

M.Sc. (Zoology) / Temperature plays a very important role in the metabolic environment of coldblooded animals such as fish. The primary objective of this study was to evaluate the quality of digestive processes and the importance of temperature in the digestive system of Labeo capensis. An important consideration in the choice of the experimental animal was the economic potential and widespread occurrence of Labeo capensis in the riversystems of the Transvaal. The experimental animals were kept at three different acclimation temperatures ( 14, 19 and 25 + 1°C) for a period of six weeks. An assessment of the influence of acclimation temperature on enzyme activity vas made using test kits supplied by BOERINGER-MANNHEIM. No information exists on the morphohistology of Labeo capensis and therefore investigation on the anatomy of the digestive system was carried out in this survey. The ventro-anterior mouth is ideally situated for bottom-feeding. Pharyngeal teeth and a pharyngeal pad (or palatal organ) is situated dorsally at the entrance to the oesophagus. A short oesophagus, which possesses both a supra- and infraoesophageal valve, exists. No stomach is present and the intestinal bulge affixes the intestine to the oesophagus. The exceptionally Iona intestinum proper lies coiled in the abdominal cavity. No rectum can be identified. The micro-anatomy of the intestinal proper and bulge differs minimally. The intestinal bulge possesses longer, slimmer villi in comparrison of the flat thickened villi of the intestine proper. The bulge lacks a longitudinal muscle layer. L. capensis cellulase and dicarrboxylase activty may be contributed to the intestinal microflora and/or foodstuffs present in the digestive system. Amylase possesses the highest and the proteases (trypsin and chymotrypsin) the lowest activity. The effect of acclimation temperature is most evident on amylase, and to a lesser extent on the phosphatases. Trypsin and chymotrypsin activity is less affected by acclimation temperature, although a distinctive loss of activity is recorded for both these enzymes. The loss of acid phosphatase activity is partially contributed to the rise in intestinal pH. The effect of reaction temperature was measured and recorded as AT-values.

A piscicultura vem crescendo ao longo dos anos impulsionada pelo aumento da população mundial. A demanda crescente de alimentos faz com que seja necessário o aprimoramento constante das técnicas de manejo, aumentando a produção e diminuindo os custos, tornando a atividade sustentável. Neste contexto, a adesão de recursos tecnológicos que auxiliem no manejo e controle dos viveiros é muito importante. O monitoramento da qualidade da água também é essencial na piscicultura, pois determinadas variáveis, como por exemplo a temperatura, tem relação direta com o metabolismo dos peixes, influenciando na quantidade de ração ingerida pelos mesmos. A aquisição de ração representa até 79% dos custos de produção, tornando-se vital a obtenção da máxima conversão alimentar. Após levantamento realizado com um grupo de piscicultores da região Oeste do Paraná, visando investigar se estes levam em consideração a qualidade da água em seus viveiros como forma de otimizar o manejo, e se os mesmos utilizam recursos tecnológicos em seu processo produtivo, constatou-se que a maioria não leva em consideração a qualidade da água em seu processo produtivo, assim como também não fazem uso de recursos tecnológicos para auxiliar no manejo. Os resultados deste levantamento motivaram o desenvolvimento de um sistema de monitoramento da qualidade da água através de uma boia sensorial autônoma, interligada a um software de apoio ao manejo e gestão dos viveiros produtivos. A fim de testar o sistema e verificar o seu potencial econômico, realizou-se um experimento durante 26 semanas, envolvendo dois grupos de quinze tilápias distribuídas aleatoriamente em dois tanques, um dotado do sistema de monitoramento, e outro não. O processo de arraçoamento foi baseado em tabelas utilizadas pelos piscicultores entrevistados no levantamento, sendo o arraçoamento no tanque dotado do sistema de monitoramento calculado com base na temperatura e peso dos animais, enquanto que no outro tanque o cálculo levou em consideração apenas o peso das tilápias. Durante o experimento, foram registrados o peso médio, a quantidade de ração ingerida, e o comprimento padrão, os quais foram analisados por meio de estatística descritiva, teste de normalidade de Anderson-Darling e teste t de Student para comparação de médias de amostras independentes. Também foi obtido o valor da conversão alimentar, que foi calculado mediante a divisão da quantidade de ração consumida por cada grupo de tilápias pelo ganho de peso adquirido pelos mesmos. Como resultado, observou-se que a conversão alimentar no tanque monitorado foi maior em relação ao tanque não monitorado, acarretando uma economia no consumo de ração por quilo (Kg) de tilápia produzida durante o período experimental. Observou-se também que não houve diferença significativa entre os pesos médios e os comprimentos padrão das tilápias dos dois tanques ao final do experimento. A boia sensorial e os softwares interligados a ela se mostraram eficazes durante todo o experimento, mostrando-se aptos a serem instalados em viveiros produtivos reais. Estes resultados evidenciaram a viabilidade econômica do sistema de monitoramento proposto, tornando-se uma excelente alternativa para o aumento da renda na piscicultura. / Fish farming has been growing over the years driven by increasing world population. The increasing demand of food production makes it necessary to constantly improve management techniques, increasing production and reducing costs, making the activity sustainable. In this context, the adhesion of technological resources that assist in the management and control of nurseries is very important. The monitoring of water quality is also essential in fish farming, since certain variables, such as temperature, are directly related to the fish metabolism, influencing the amount of feed consumed by them. The acquisition of ration represents up to 79% of the production costs, making it vital to obtain maximum feed conversion. After a survey, that was carried out with a group of fish farmers from the western region of Paraná to investigate whether they consider the quality of water in their nurseries to optimize management, and if they use technological resources in their production process, it was verified that most do not consider the quality of water in their production process, nor do they make use of technological resources to aid in their management. The results of this survey motivated the development of a water quality monitoring system through an autonomous sensorial buoy, linked to a software to support the management of productive nurseries. To test the system and to verify its economic potential, an experiment was carried out for 26 weeks, involving two groups of fifteen tilapias distributed randomly in two tanks, one endowed with the monitoring system, and another not. The process of feeding was based on feeding tables used by the fish farmers interviewed in the survey, with the feeding in the tank with the monitoring system calculated based on the temperature and weight of the animals, while in the other tank the calculation considered only the weight of tilapias. During the experiment, mean weight, amount of feed intake, and standard length were recorded, which were analyzed by means of descriptive statistics, Anderson-Darling normality test and Student's t-test for comparison of independent sample means. The value of feed conversion was also obtained, which was calculated by dividing the amount of feed consumed by each tilapia group by the weight gain acquired by them. As a result, it was observed that the feed conversion in the monitored tank was higher in relation to the unmonitored tank, resulting in a saving of the ration consumption per kilogram (kg) of tilapia produced during the experimental period. It was also observed that there was no significant difference between the average weights and the standard tilapia lengths of the two tanks at the end of the experiment. The sensory buoy and the software connected to it proved to be effective throughout the experiment, showing that they could be installed in real productive nurseries. These results evidenced the economic viability of the proposed monitoring system, making it an excellent alternative for increasing income in fish farming.

A piscicultura vem crescendo ao longo dos anos impulsionada pelo aumento da população mundial. A demanda crescente de alimentos faz com que seja necessário o aprimoramento constante das técnicas de manejo, aumentando a produção e diminuindo os custos, tornando a atividade sustentável. Neste contexto, a adesão de recursos tecnológicos que auxiliem no manejo e controle dos viveiros é muito importante. O monitoramento da qualidade da água também é essencial na piscicultura, pois determinadas variáveis, como por exemplo a temperatura, tem relação direta com o metabolismo dos peixes, influenciando na quantidade de ração ingerida pelos mesmos. A aquisição de ração representa até 79% dos custos de produção, tornando-se vital a obtenção da máxima conversão alimentar. Após levantamento realizado com um grupo de piscicultores da região Oeste do Paraná, visando investigar se estes levam em consideração a qualidade da água em seus viveiros como forma de otimizar o manejo, e se os mesmos utilizam recursos tecnológicos em seu processo produtivo, constatou-se que a maioria não leva em consideração a qualidade da água em seu processo produtivo, assim como também não fazem uso de recursos tecnológicos para auxiliar no manejo. Os resultados deste levantamento motivaram o desenvolvimento de um sistema de monitoramento da qualidade da água através de uma boia sensorial autônoma, interligada a um software de apoio ao manejo e gestão dos viveiros produtivos. A fim de testar o sistema e verificar o seu potencial econômico, realizou-se um experimento durante 26 semanas, envolvendo dois grupos de quinze tilápias distribuídas aleatoriamente em dois tanques, um dotado do sistema de monitoramento, e outro não. O processo de arraçoamento foi baseado em tabelas utilizadas pelos piscicultores entrevistados no levantamento, sendo o arraçoamento no tanque dotado do sistema de monitoramento calculado com base na temperatura e peso dos animais, enquanto que no outro tanque o cálculo levou em consideração apenas o peso das tilápias. Durante o experimento, foram registrados o peso médio, a quantidade de ração ingerida, e o comprimento padrão, os quais foram analisados por meio de estatística descritiva, teste de normalidade de Anderson-Darling e teste t de Student para comparação de médias de amostras independentes. Também foi obtido o valor da conversão alimentar, que foi calculado mediante a divisão da quantidade de ração consumida por cada grupo de tilápias pelo ganho de peso adquirido pelos mesmos. Como resultado, observou-se que a conversão alimentar no tanque monitorado foi maior em relação ao tanque não monitorado, acarretando uma economia no consumo de ração por quilo (Kg) de tilápia produzida durante o período experimental. Observou-se também que não houve diferença significativa entre os pesos médios e os comprimentos padrão das tilápias dos dois tanques ao final do experimento. A boia sensorial e os softwares interligados a ela se mostraram eficazes durante todo o experimento, mostrando-se aptos a serem instalados em viveiros produtivos reais. Estes resultados evidenciaram a viabilidade econômica do sistema de monitoramento proposto, tornando-se uma excelente alternativa para o aumento da renda na piscicultura. / Fish farming has been growing over the years driven by increasing world population. The increasing demand of food production makes it necessary to constantly improve management techniques, increasing production and reducing costs, making the activity sustainable. In this context, the adhesion of technological resources that assist in the management and control of nurseries is very important. The monitoring of water quality is also essential in fish farming, since certain variables, such as temperature, are directly related to the fish metabolism, influencing the amount of feed consumed by them. The acquisition of ration represents up to 79% of the production costs, making it vital to obtain maximum feed conversion. After a survey, that was carried out with a group of fish farmers from the western region of Paraná to investigate whether they consider the quality of water in their nurseries to optimize management, and if they use technological resources in their production process, it was verified that most do not consider the quality of water in their production process, nor do they make use of technological resources to aid in their management. The results of this survey motivated the development of a water quality monitoring system through an autonomous sensorial buoy, linked to a software to support the management of productive nurseries. To test the system and to verify its economic potential, an experiment was carried out for 26 weeks, involving two groups of fifteen tilapias distributed randomly in two tanks, one endowed with the monitoring system, and another not. The process of feeding was based on feeding tables used by the fish farmers interviewed in the survey, with the feeding in the tank with the monitoring system calculated based on the temperature and weight of the animals, while in the other tank the calculation considered only the weight of tilapias. During the experiment, mean weight, amount of feed intake, and standard length were recorded, which were analyzed by means of descriptive statistics, Anderson-Darling normality test and Student's t-test for comparison of independent sample means. The value of feed conversion was also obtained, which was calculated by dividing the amount of feed consumed by each tilapia group by the weight gain acquired by them. As a result, it was observed that the feed conversion in the monitored tank was higher in relation to the unmonitored tank, resulting in a saving of the ration consumption per kilogram (kg) of tilapia produced during the experimental period. It was also observed that there was no significant difference between the average weights and the standard tilapia lengths of the two tanks at the end of the experiment. The sensory buoy and the software connected to it proved to be effective throughout the experiment, showing that they could be installed in real productive nurseries. These results evidenced the economic viability of the proposed monitoring system, making it an excellent alternative for increasing income in fish farming.

South African marine fish collections and systematic research are relatively young, essentially a product of the 20th century. Their history in South Africa comprises three distinct periods: the emergence of fish collections (before 1895), the beginning of research (1895-1945) and modern research (1945-1999). From the outset of their arrival in South Africa in the mid-17th century, the European settlers of the Cape Colony supplemented their diet with fishes. Therefore it is not surprising that when natural history museums appeared in the 19th century fishes were among the first specimens they procured or received from the public. In these early days, fishes were acquired for display purposes and were curated together with other natural history specimens. There were no fish collections as such and, in many ways, the early history of South African fish collections closely followed the history of the institutions in which they were housed. Major political events in South Africa between 1850-1910 had little effect on the slow growth offish collections as the low influx of specimens from the public did not change. None of the museums did any active fish collecting and no fish research as such took place during these years. The second period in the growth of fish collections in South Africa was characterised by a general shift to collecting for research rather than display. It was also a period during which the need for aquatic research was recognized by and began to attract funding from the South African government, starting with the establishment of the Marine Biological Survey in Cape Town. However, with the exception of the Albany Museum's self-trained J.L.B. Smith, no trained marine fish systematists were working in museums either as curators or as researchers. In the first half of the 20"' century South Africa experienced the fast growth of the fishing industry, the development of academic and applied research in marine biology, and the thriving of sport fishing. These developments created a demand for well-trained professional ichthyologists. J.L.B. Smith was the first to fill this professional gap. The growth rate offish collections increased significantly through the interaction between museum scientists, such as Smith in Grahamstown and K.H. Barnard in Cape Town, with the fishing industry, government biologists and fisheries officers, and anglers. Barnard's review of the South African marine fish fauna was published in mid-I920s. The discovery of the first living coelacanth placed South African ichthyology and Smith on the international stage. The identification of this fish, made by a relatively inexperienced Smith, changed the way ichthyology has been viewed in South Africa. At the beginning of the third period, largely due to the establishment of the Council for Scientific and Industrial Research in 1945, science in South Africa underwent a process of reorganisation. As funding became more available museums were able to enlarge their research staff. Natural history museums hired qualified experts to conduct research and manage collections of specific groups of organisms. For the first time, trained ichthyologists started working in museums and initiated research projects that were the main contributors to the growth of fish collections around the country. Furthermore it was a period of consolidation offish collections resulting in two large marine fish collections, one at the South African Museum, Cape Town, and another at the J .L.B. Smith Institute of Ichthyology, Grahamstown. This period also witnessed the establishment of the latter as a research institute dedicated to the study of fishes and its rise to international prominence. The last 55 years at J.L.B. Smith Institute of Ichthyology can be divided into two distinct periods, 1945-1967 and 1968-1999, each consisting of similar elements of research work and objectives. These included the research and production of major reviews of the fish faunas of South Africa, the western Indian Ocean and the Southern Ocean, as well as research on the coelacanth. While in the former period the work was done by one scientist, J.L.B. Smith, the latter period has been characterised by collaborative projects including scientists from South Africa and abroad. As this history shows, the establishment of a viable, long-lasting collection is a lengthy process. For about 60 years the durability of fish collections depended on the enthusiasm and persistence of individual curators and scientists who were not ichthyologists. More often than not, enthusiasm disappeared when such individuals left their museums. This dependence existed until Rhodes University College established the Department of Ichthyology (1947) and the South African Museum created a post specifically for the curation of the fish collection (1957) and thus ensured continuity. The continuity of biosystematic research in South Africa has been a minor concern for the nation's systematists for decades. The threats to marine fish systematics have been of a financial, political and professional nature. The latter has been the most serious one because of the dearth of South Africans trained in marine fish systematics. After J.L.B. Smith's death in 1968 M.M. Smith had to work hard to convince the Council for Scientific and Industrial Research and Rhodes University that she could step into her late husband's shoes. Realizing that there was nobody to take over from her she initiated the first and only postgraduate programme in ichthyology in South Africa. The teaching started in the academic year of 1970171 at the J.L.B. Smith Institute of Ichthyology, but to date only one student has completed a thesis in marine fish systematics. Due to the government's transformation policy all the practising marine fish systematists in South Africa will be retiring in the course of the present decade. Consequently, if no aspiring, motivated students appear on the scene in the next couple of years marine fish systematics in this country will be in a deep crisis by the year 2010, possibly even earlier.

M.Sc. / Please refer to full text to view abstract

Os corpos hídricos estão entre os ambientes mais prejudicados pelo crescimento desordenado da população humana. Considerando-se a grande importância de rios e lagos, tanto para os organismos residentes, quanto para a saúde da população humana, são necessárias estratégias que incluam, concomitantemente, a produtividade e a sustentabilidade em um mesmo ambiente, visando o equilíbrio ecológico. Assim, o presente trabalho teve como objetivo avaliar diferentes tipos de poluição ao longo do Rio Jirau Alto, no município de Dois Vizinhos, PR, por meio de biomarcadores genéticos em peixes da espécie Astyanax bifasciatus, em duas estações do ano (verão e inverno). Foram empregados o teste de Alterações morfológicas nucleares (ENA) associado ao teste de micronúcleos e Ensaio Cometa em sangue e fígado como biomarcadores genéticos. As coletas foram realizadas em duas estações (verão e inverno de 2016) em quatro pontos amostrais ao logo do rio Jirau alto, e um ponto controle em uma APP. Os biomarcadores empregados foram o ensaio cometa com eritrócitos e hepatócitos, e frequência de alterações morfológicas nucleares (ENA). O teste de micronúcleo písceo foi utilizado para determinar as quebras irreversíveis nos cromossomos de eritrócitos dos peixes e também alterações morfológicas nucleares de vários tipos. O ensaio cometa é uma técnica bastante eficiente nos estudos de agentes tóxicos que causam danos ao material genético, e por sua vez permite quantificar as quebras de DNA. Os resultados obtidos demostraram evidências de contaminação nesse rio, os dados obtidos pelo teste de micronúcleo mostraram danos elevados, em todos os pontos amostrais quando comparados ao ponto controle, em ambas as estações. No teste de ensaio cometa, os valores de danos estiveram mais elevados, principalmente no verão e se mostrando com maior significância especialmente no ponto P2. No entanto, essa resposta foi não linear, evidenciando variações também entre os pontos e estações. Assim, pesquisas de monitoramento se tornam indispensáveis para a avaliação dos efeitos da poluição ambiental sendo necessária a conscientização da população, devido a ameaça de contaminação nesse rio, uma vez que desempenha papel importante no abastecimento público da cidade de Dois Vizinhos. / The water bodies are among the environments most affected by the disorderly growth of the human population. Considering the great importance of rivers and lakes, both for the resident organisms and for the health of the human population, strategies are needed that include, simultaneously, productivity and sustainability in the same environment, aiming at ecological balance. The objective of this work was to evaluate different types of pollution along the Jirau Alto River, in the municipality of Dois Vizinhos, PR, by means of genetic biomarkers in fish of the species Astyanax bifasciatus, in two seasons of the year (summer and winter). The Nuclear Morphological Changes (ENA) test associated with the micronucleus test and the Comet Assay in blood and liver were used as genetic biomarkers. The collections were carried out in two seasons (summer and winter of 2016) at four sampling points at the Jirau Alto river, and one control point at an APP. The biomarkers employed were the comet assay with erythrocytes and hepatocytes, and frequency of nuclear morphological changes (ENA). The micronucleus test was used to determine irreversible chromosome breaks in fish erythrocytes as well as nuclear morphological changes of various types. The comet assay is a very efficient technique in studies of toxic agents that cause damage to the genetic material, and in turn allows quantification of DNA breaks. The results obtained showed evidence of contamination in this river, the data obtained by the micronucleus test showed high damages, in all the sampling points when compared to the control point, in both stations. In the comet test, damage values were higher, especially in the summer and showing more significance especially at point P2. However, this response was non-linear, evidencing variations also between points and seasons. Thus, monitoring research becomes indispensable for the evaluation of the effects of environmental pollution and it is necessary to raise awareness of the population due to the threat of contamination in this river, since it plays an important role in the public supply of the city of Dois Vizinhos.

A obtenção de cariótipos de peixes desempenha um papel importante em estudos de citotaxonomia e evolução cromossômica das espécies. No entanto poucos sistemas semi ou completamente automatizados para a obtenção de cariótipo de peixes estão disponíveis. Este trabalho propõe e avalia uma ferramenta baseada em imagens que auxilie a montagem de cariótipos de peixes. As espécies analisadas foram Hoplias malabaricus (Bloch, 1794); Hypostomus ancistroides (Ihering, 1911) e Parauchenipterus galeatus (Linnaeus, 1766); popularmente conhecidas como traíra, cascudo e bagre sapo, respectivamente. Um total de 100 metáfases mitóticas foram analisadas por dois métodos: 1 – geração semiautomática de cariótipo e 2 - geração automática de cariótipo. Os resultados foram analisados por meio da correlação de Pearson, gráficos de diferenças e tabelas de contagens. A avaliação do sistema foi feita utilizando-se como referência a média das contagens feitas por quatro usuários. No método 1 quatro usuários realizaram contagens nas 100 metáfases apresentando correlação interobservador de r ≥ 0.997. O número total de cromossomos identificados pelo método 1 foi 4348 e para o método 2 foi 4135, excluindo 1,3% de falsos positivos, resultando em uma identificação automática de aproximadamente 95,1% dos cromossomos presentes nas imagens. Os falsos negativos representam 4,9% do total de cromossomos. A correlação entre os dois métodos foi de r = 0.93. Os resultados indicam que a ferramenta pode ser inserida no procedimento de cariotipagem de peixes para acelerar o processo com níveis aceitáveis de exatidão. / Fish karyotyping plays an important role in studies of cytotaxonomy and chromosomic evolution of species. However, few semi or completely automated fish karyotyping systems are available. This work proposes and evaluates an image-based tool to assist fish karyotyping. The analyzed species were Hoplias malabaricus (Bloch, 1794), Hypostomus ancistroides (Ihering, 1911), and Parauchenipterus galeatus (Linnaeus, 1766). In Portuguese, these species are commonly refered to as traíra, cascudo and bagre sapo, respectively. A total of 100 metaphases were analyzed by two methods: (1) semi-automatic karyotype generation and (2) automatic karyotype generation. The results were analyzed using Pearson correlation, difference graphs and counting tables. The reference used for the evaluation of the system was the average of the counts made by four experts. In method 1, four users performed counts on the 100 metaphases with interobserver correlation of r ≥ 0.997. The total number of chromosomes identified by method 1 was 4348 and method 2 was 4135, excluding 1,3% false positives, resulting in an automatic identification of approximately 95,1% of the chromosomes present in the images. False negatives represent 4,9% of the total chromossomes. The correlation between the methods was r = 0.93. The results indicate that the tool can be introduced for fish karyotyping procedures contributing for accelerating the process with acceptable accuracy.

Os corpos hídricos estão entre os ambientes mais prejudicados pelo crescimento desordenado da população humana. Considerando-se a grande importância de rios e lagos, tanto para os organismos residentes, quanto para a saúde da população humana, são necessárias estratégias que incluam, concomitantemente, a produtividade e a sustentabilidade em um mesmo ambiente, visando o equilíbrio ecológico. Assim, o presente trabalho teve como objetivo avaliar diferentes tipos de poluição ao longo do Rio Jirau Alto, no município de Dois Vizinhos, PR, por meio de biomarcadores genéticos em peixes da espécie Astyanax bifasciatus, em duas estações do ano (verão e inverno). Foram empregados o teste de Alterações morfológicas nucleares (ENA) associado ao teste de micronúcleos e Ensaio Cometa em sangue e fígado como biomarcadores genéticos. As coletas foram realizadas em duas estações (verão e inverno de 2016) em quatro pontos amostrais ao logo do rio Jirau alto, e um ponto controle em uma APP. Os biomarcadores empregados foram o ensaio cometa com eritrócitos e hepatócitos, e frequência de alterações morfológicas nucleares (ENA). O teste de micronúcleo písceo foi utilizado para determinar as quebras irreversíveis nos cromossomos de eritrócitos dos peixes e também alterações morfológicas nucleares de vários tipos. O ensaio cometa é uma técnica bastante eficiente nos estudos de agentes tóxicos que causam danos ao material genético, e por sua vez permite quantificar as quebras de DNA. Os resultados obtidos demostraram evidências de contaminação nesse rio, os dados obtidos pelo teste de micronúcleo mostraram danos elevados, em todos os pontos amostrais quando comparados ao ponto controle, em ambas as estações. No teste de ensaio cometa, os valores de danos estiveram mais elevados, principalmente no verão e se mostrando com maior significância especialmente no ponto P2. No entanto, essa resposta foi não linear, evidenciando variações também entre os pontos e estações. Assim, pesquisas de monitoramento se tornam indispensáveis para a avaliação dos efeitos da poluição ambiental sendo necessária a conscientização da população, devido a ameaça de contaminação nesse rio, uma vez que desempenha papel importante no abastecimento público da cidade de Dois Vizinhos. / The water bodies are among the environments most affected by the disorderly growth of the human population. Considering the great importance of rivers and lakes, both for the resident organisms and for the health of the human population, strategies are needed that include, simultaneously, productivity and sustainability in the same environment, aiming at ecological balance. The objective of this work was to evaluate different types of pollution along the Jirau Alto River, in the municipality of Dois Vizinhos, PR, by means of genetic biomarkers in fish of the species Astyanax bifasciatus, in two seasons of the year (summer and winter). The Nuclear Morphological Changes (ENA) test associated with the micronucleus test and the Comet Assay in blood and liver were used as genetic biomarkers. The collections were carried out in two seasons (summer and winter of 2016) at four sampling points at the Jirau Alto river, and one control point at an APP. The biomarkers employed were the comet assay with erythrocytes and hepatocytes, and frequency of nuclear morphological changes (ENA). The micronucleus test was used to determine irreversible chromosome breaks in fish erythrocytes as well as nuclear morphological changes of various types. The comet assay is a very efficient technique in studies of toxic agents that cause damage to the genetic material, and in turn allows quantification of DNA breaks. The results obtained showed evidence of contamination in this river, the data obtained by the micronucleus test showed high damages, in all the sampling points when compared to the control point, in both stations. In the comet test, damage values were higher, especially in the summer and showing more significance especially at point P2. However, this response was non-linear, evidencing variations also between points and seasons. Thus, monitoring research becomes indispensable for the evaluation of the effects of environmental pollution and it is necessary to raise awareness of the population due to the threat of contamination in this river, since it plays an important role in the public supply of the city of Dois Vizinhos.