Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-22T13:24:03Z No. of bitstreams: 2 francisco_vagner_pereira_souza.pdf: 674862 bytes, checksum: 5251dbf5de1a09da84fe52f02a2a8224 (MD5) license_rdf: 21954 bytes, checksum: 8197f94386c8c9a9e551d5deb1b86632 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-22T13:24:36Z (GMT) No. of bitstreams: 2 francisco_vagner_pereira_souza.pdf: 674862 bytes, checksum: 5251dbf5de1a09da84fe52f02a2a8224 (MD5) license_rdf: 21954 bytes, checksum: 8197f94386c8c9a9e551d5deb1b86632 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-22T13:25:26Z (GMT) No. of bitstreams: 2 francisco_vagner_pereira_souza.pdf: 674862 bytes, checksum: 5251dbf5de1a09da84fe52f02a2a8224 (MD5) license_rdf: 21954 bytes, checksum: 8197f94386c8c9a9e551d5deb1b86632 (MD5) / Made available in DSpace on 2014-12-22T13:25:26Z (GMT). No. of bitstreams: 2 francisco_vagner_pereira_souza.pdf: 674862 bytes, checksum: 5251dbf5de1a09da84fe52f02a2a8224 (MD5) license_rdf: 21954 bytes, checksum: 8197f94386c8c9a9e551d5deb1b86632 (MD5) Previous issue date: 2014 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / O objetivo deste trabalho foi avaliar o crescimento, teores, ac?mulo e disponibilidade de n?quel em cinco gram?neas forrageiras. Os experimentos foram instalados em condi??es de casa de vegeta??o do Departamento de Agronomia da Faculdade de Ci?ncias Agr?rias da Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina-MG, Brasil. Panicum maximum cv. Aruana e cv. Tanz?nia e Brachiaria decumbens cv. Basilisk, Brachiaria brizantha cv. Xara?s e cv. Marandu foram crescidas em solu??o nutritiva e em solo e adicionadas de 0, 20, 40, e 100 mg L-1 e 0, 20, 40 e 120 mg kg-1 de cloreto de n?quel, constituindo ensaios independentes em delineamento experimental inteiramente casualizados com quatro repeti??es. O per?odo experimental foi de 90 dias. Determinou-se a massa seca e os teores de Ni na parte a?rea, coleto e ra?zes das gram?neas forrageiras. Os conte?dos de Ni foram calculados com base nos teores e nas produ??es de massa seca em cada parte da planta. O teor de n?quel no solo foi determinado pelos extratores Mehlich-1, DTPA pH 7,3, teor semitotal - USEPA 3051 e teor total - USEPA 3052. O crescimento das gram?neas forrageiras reduziu linearmente em solu??o nutritiva com a adi??o de n?quel, mas no solo aumentou at? a dose de 40 mg kg-1. Apesar da fitotoxidade do Ni, as plantas responderam positivamente quando o metal foi aplicado em baixas doses no solo. A suscetibilidade ao Ni foi diferenciada para os experimentos, devido ?s variadas intera??es que ocorrem no sistema solo-planta. O teor de Ni nas gram?neas forrageiras aumentou em fun??o das doses crescentes de Ni nos diferentes experimentos. Os m?todos de extra??o analisados na aferi??o do Ni no solo apresentaram boa correla??o com os teores de Ni encontrados nas plantas, sendo o DTPA mais eficiente. As gram?neas forrageiras avaliadas nestes experimentos n?o podem ser consideradas acumuladoras de Ni. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2014. / The objective of this study was to evaluate the growth, concentrations, accumulation and availability of nickel in five forage grasses. The experiments were conducted under conditions of a greenhouse of the Department of Agronomy, Faculty of Agricultural Sciences, Federal University of the Jequitinhonha and Mucuri Valleys, Diamantina Minas Gerais, Brazil. Panicum maximum cv. Aruana e cv. Tanz?nia e Brachiaria decumbens cv. Basilisk, Brachiaria brizantha cv. Xara?s e cv. Marandu were grown in nutrient solution and in soil and added 0, 20, 40, and 100 mg L-1 and 0, 20, 40 and 120 mg kg-1 of nickel chloride, constituting separate trials in a completely randomized experimental design with four replications. The experimental period was 90 days. Dry weight and the concentrations of Ni in shoots, stems base and roots of forage grasses were determined. The contents of Ni were calculated based on the amounts and in the production of dry matter in each plant. The nickel concentration in the soil was determined by Mehlich-1, DTPA pH 7.3, semitotal content - USEPA 3051 and total content - USEPA 3052. The growth in forage grasses in nutrient solution linearly decreased with the addition of nickel, but in the soil increased up to 40 mg kg-1. The susceptibility to Ni was different for the experiments, due to the variety of interactions that occur in the soil-plant system. The Ni concentration in forage grasses increased as a function of increasing levels of Ni in the different experiments. The extraction methods analyzed in the measurement of Ni in soil correlated well with the Ni concentration found in plants, with the most efficient DTPA. The forage grasses evaluated in these experiments cannot be considered accumulative Ni.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-10T21:22:14Z No. of bitstreams: 1 AlanaRayzaVidalJeronimoDoNascimento_DISSERT.pdf: 2928827 bytes, checksum: d27ed974dc569fc8d3e33d0de625afc7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-13T00:33:56Z (GMT) No. of bitstreams: 1 AlanaRayzaVidalJeronimoDoNascimento_DISSERT.pdf: 2928827 bytes, checksum: d27ed974dc569fc8d3e33d0de625afc7 (MD5) / Made available in DSpace on 2016-05-13T00:33:56Z (GMT). No. of bitstreams: 1 AlanaRayzaVidalJeronimoDoNascimento_DISSERT.pdf: 2928827 bytes, checksum: d27ed974dc569fc8d3e33d0de625afc7 (MD5) Previous issue date: 2015-09-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A minera??o promove altera??es significativas na paisagem e na qualidade do solo, al?m de ser considerada uma das principais fontes antr?picas de metais pesados no ambiente. A aus?ncia de medidas de prote??o sanit?ria e ambiental no controle dos impactos gerados contribui para o aumento do risco de degrada??o n?o apenas na ?rea de lavra, mas em toda a extens?o da ?rea de influ?ncia da minera??o. Neste contexto, diagn?sticos de qualidade do solo e dos res?duos da minera??o s?o imprescind?veis para orientar medidas que promovam a redu??o dos impactos e a recupera??o das ?reas degradadas. No munic?pio de Currais Novos, localizado na regi?o semi?rida do Estado do Rio Grande do Norte, algumas mineradoras realizam a explora??o da scheelita desde a d?cada de 1940. A mina Olho d??gua foi desativada em 1976 e a mina Barra Verde est? em atividade. Nessas minas, as atividades de lavra e de beneficiamento da scheelita geraram pilhas de est?ril e rejeito que est?o depositadas no solo sem qualquer medida de prote??o. Este trabalho teve como objetivo avaliar atributos f?sicos e qu?micos do solo e os teores de metais pesados nas minas Barra Verde e Olho d??gua a fim de identificar est?gios de degrada??o nas ?reas mineradas e estabelecer indicadores de qualidade que facilitem a recupera??o e monitoramento ambiental na regi?o. Os resultados demonstraram que a aus?ncia de medidas de controle e de recupera??o nas minas contribui para a intensifica??o dos processos erosivos, o que amplia o potencial de difus?o de contaminantes para os demais componentes da bacia hidrogr?fica. As ?reas de deposi??o de est?ril e rejeito na mina ativa apresentaram n?vel de degrada??o do solo mais acentuado dentre as ?reas mineradas. Na mina desativada, o crescimento espont?neo da vegeta??o tem favorecido a pedog?nese dos substratos remanescentes da minera??o e a recupera??o da qualidade do solo, indicando que a t?cnica de revegeta??o ? adequada para estabiliza??o e recupera??o das fun??es ecossist?micas das ?reas mineradas. Os teores de Cd, Cu e Pb acima dos valores de investiga??o estabelecidos pela legisla??o brasileira apontam para a necessidade de medidas de remedia??o nas ?reas mineradas. A sensibilidade na distin??o entre a ?rea natural e minerada dos atributos f?sforo dispon?vel, pH, acidez potencial, argila, nitrog?nio total, mat?ria org?nica, densidade do solo, porosidade total e densidade de part?culas e os metais Cd, Cu e Pb faz com que sejam considerados bons indicadores de qualidade do solo a serem utilizados em programas de recupera??o e monitoramento ambiental das ?reas mineradas. / Mining promotes significant changes in the landscape and soil quality, and is considered one of the major anthropogenic sources of heavy metals in the environment. The absence of measures of health and environmental protection in controlling the impacts generated contributes to the increased risk of degradation not only in the mined area, but in the full extent of the area affected by mining. In this context, soil quality and mining waste diagnostics are essential to guide measures that promote the reduction of impacts and the recovery of degraded areas. In the municipality of Currais Novos, located in the semi-arid region of the state of Rio Grande do Norte, some mining companies exploit the scheelite ore since 1940s. Olho d??gua mine was shut down in 1976 and Barra Verde mine is in operation. These mines, the mining and beneficiation activities of scheelite generated piles of tailings and overburden that are deposited in the soil without any protective measure. This study aimed to evaluate physical and chemical properties of soil and heavy metal content in Barra Verde and Olho d??gua mines to identify stages of degradation in mined areas and establish quality indicators for facilitate recovery and environmental monitoring in the region.The results showed that the absence of control and recovery measures in the mines contributes to the intensification of erosion, which increases the potential spread of contaminants to the other componentes of the watershed. The overburden deposition and tailings areas in the active mine showed stronger level of land degradation among the mined areas. In the disabled mine, the spontaneous growth of vegetation has favored the pedogenesis of the remaining substrates mining and recovery of soil quality, indicating that the revegetation technique is suitable for stabilization and recovery of ecosystem functions of mined areas. Cd, Cu and Pb beyond values of investigation established by Brazilian law indicate to need for remediation measures in mined areas. The sensitivity in distinguishing between the natural and mined area of available phosphorus, pH, potential acidity, clay, total nitrogen, organic matter, bulk density, total porosity, particle density Cd, Cu and Pb makes them good soil quality indicators to be used in recovery and environmental monitoring programs of mined areas.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-12-18T18:25:58Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) mariana_generoso_ferreira.pdf: 1487910 bytes, checksum: 5d8038ca69034b764ba796a3a18d0907 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-01-03T17:13:11Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) mariana_generoso_ferreira.pdf: 1487910 bytes, checksum: 5d8038ca69034b764ba796a3a18d0907 (MD5) / Made available in DSpace on 2018-01-03T17:13:11Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) mariana_generoso_ferreira.pdf: 1487910 bytes, checksum: 5d8038ca69034b764ba796a3a18d0907 (MD5) Previous issue date: 2017 / O agricultor deve adequar-se ?s exig?ncias da nova legisla??o ambiental brasileira, quanto ? recupera??o de ?reas de preserva??o permanente e reserva legal. Um dos problemas que o produtor pode enfrentar ? a recupera??o de ?reas degradadas, que podem conter, entre outros contaminantes, res?duos de herbicidas. O 2,4-D e picloram s?o herbicidas hormonais mimetizadores de auxina. Entre os grupos vegetais, as esp?cies das matas ciliares t?m sido pouco relatadas quanto aos efeitos de res?duos desses herbicidas no ambiente. As an?lises micromorfol?gicas e micromorfom?tricas s?o ferramentas importantes no aux?lio do diagn?stico precoce da inj?ria, visto que modifica??es vis?veis podem aparecer em fase tardia da intoxica??o. Objetivou-se com este trabalho avaliar o desenvolvimento inicial de dez esp?cies arb?reas em substrato com res?duos da mistura de herbicidas 2,4-D+picloram e verificar os efeitos nas modifica??es anat?micas foliares de Mabea fistulifera e Zeyheria tuberculosa. Em delineamento em blocos ao acaso com tr?s repeti??es, foram distribu?dos 40 tratamentos em esquema fatorial 4x10. O primeiro fator foi composto por quatro doses da mistura comercial de 2,4-D+picloram correspondentes a 0,00; 0,166; 0,333 e 0,666 g ha-1 (Tordon?, contendo 240 g de 2,4-D e 64 g de picloram por litro). O segundo fator foi composto por dez esp?cies arb?reas: Machaerium opacum Vogel, Machaerium nyctitans (Vell.) Benth., Cassia ferruginea (Schrad.) Schrad. ex DC., Senna macranthera (DC. ex. Collad.) H.S. Irwin e Barnaby, Anadenanthera colubrina (Vell.), Brenan, Senegalia polyphylla (DC.) Britton e Rose, Piptadenia gonoacantha (Mart.) J.F. Macbr., Dalbergia villosa (Benth.) Benth., Mabea fistulifera Mart. e Zeyheria tuberculosa (Vell) Bureau ex Verl. Avalia??es morfol?gicas e anat?micas em plantas jovens foram realizadas conforme a metodologia padr?o. Para as vari?veis morfol?gicas das dez esp?cies arb?reas foram avaliados: intoxica??o, sobreviv?ncia, altura das pl?ntulas, n?mero de folhas, ?rea foliar, massa seca da parte a?rea e da raiz, di?metro do caule, o volume da raiz, o ?ndice de velocidade de emerg?ncia e a emerg?ncia. Por meio de avalia??es micromorfom?tricas foram medidas, na sec??o transversal das folhas de Mabea fistulifera e Zeyheria tuberculosa, a espessura dos tecidos, a epiderme adaxial e abaxial, par?nquima pali??dico e lacunoso, al?m da l?mina total. Para a ?rea foliar foram realizadas fotografias das folhas e mensuradas com aux?lio do software Image K. As esp?cies arb?reas sobreviveram ? aplica??o do produto, com varia??o na sensibilidade. Os res?duos da mistura dos herbicidas prejudicaram a maioria das esp?cies testadas em rela??o ?s avalia??es do desenvolvimento inicial. M. fistulifera, P. gonoacantha e Z. tuberculosa apresentaram maior toler?ncia ? mistura de herbicidas. Em rela??o ? anatomia e ?rea foliar, de maneira geral, a esp?cie Z. tuberculosa foi afetada negativamente pelos herbicidas. M. fistulifera se mostrou mais tolerante ? presen?a dos contaminantes. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / The farmer must adapt to the requirements of the new brazilian environmental legislation, regarding the recovery of permanent preservation areas and legal reserve. One of the problems that the producer may face is the recovery of degraded areas, which may contain, among other contaminants, herbicide residues. 2,4-D and picloram are auxin mimicking hormonal herbicides. Among the plant groups, the species of the riparian forests have been little reported as to the effects of residues of these herbicides on the environment. Micromorphological and micromorphometric analyzes are important tools to aid in the early diagnosis of injury, since visible changes may appear in the later stages of intoxication. The objective of this work was to evaluate the initial development of ten substrate tree species with residues from of the 2,4-D + picloram herbicide mixture and to verify the effects on the anatomical modifications of Mabea fistulifera and Zeyheria tuberculosa. In a randomized block design with three replicates, 40 treatments were distributed in a 4x10 factorial scheme. The first factor was composed of four doses of the commercial mixture of 2,4-D + picloram corresponding to 0,00; 0,166; 0,336 and 0,666 g ha-1 (Tordon?, containing 240 g of 2,4-D and 64 g of picloram per liter). The second factor was composed of ten tree species: Machaerium opacum Vogel, Machaerium nyctitans (Vell.) Benth., Cassia ferruginea (Schrad.) Schrad. ex DC., Senna macranthera (DC. ex. Collad.) H.S. Irwin e Barnaby, Anadenanthera colubrina (Vell.), Brenan, Senegalia polyphylla (DC.) Britton e Rose, Piptadenia gonoacantha (Mart.) J.F. Macbr., Dalbergia villosa (Benth.) Benth., Mabea fistulifera Mart. and Zeyheria tuberculosa (Vell) Bureau ex Verl. Morphological and anatomical evaluations in young plants were performed according to the standard methodology. For the morphological variables of the ten tree species were evaluated: intoxication, survival, seedling height, number of leaves, leaf area, dry mass of shoot and root, stem diameter, root volume, emergency speed index and emergency. Through micromorphometric evaluations, tissue thickness, adaxial and abaxial epidermis, pali?adic and lacunacetic parenchyma were measured, in the cross section of the leaves of Mabea fistulifera and Zeyheria tuberculosa, in addition to the total lamina. For leaf area, leaf photographs were taken and measured using Image K software. Tree species survived the application of the product, with variation in sensitivity. Residues of the herbicide mixture adversely affected most of the tested species in relation to initial developmental assessments. M. fistulifera, P. gonoacantha and Z. tuberculosa presented greater tolerance to the herbicide mixture. In relation to the anatomy and leaf area, in general, the species Z. tuberculosa was negatively affected by the herbicides. M. fistulifera was more tolerant to the presence of contaminants.

Made available in DSpace on 2014-12-17T15:34:47Z (GMT). No. of bitstreams: 1 AlbertoLFAJ_DISSERT.pdf: 1671046 bytes, checksum: 8699a01f6b8beb7c7731350f466df41d (MD5) Previous issue date: 2013-04-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The control of gastrointestinal nematodes of small ruminants is usually done with anthelmintics. However, due to the emergence of ever-increasing parasite resistance to these drugs, looking up an alternative control parasites. One of this is sought in pasture management, as these are the sources of animals` infection by L3 infective larvae of helminths. The aim of this study was to evaluate the performance of sheep to natural infections by gastrointestinal nematodes grazing Panicum maximum cv. Massai and cv. Aruana, and Brachiaria brizantha cv. Piat? and cv. Marandu. The work was conducted from May to August-2011 with 48 male sheeps SRD versus Santa In?s breed. The animals were naturally infected with gastrointestinal nematodes, and maintained in four different cultivars of tropical forage grasses, naturally contaminated with eggs and larvae of gastrointestinal nematodes. Each week the animals were phenotypically characterized by parasitological examinations (eggs per gram of feces - EPG, and feces culture), hematological (packed cell volume PCV, and blood eosinophil count) method to evaluate the Famacha? colorof ocular mucosa, and the measures of body condition score and weight. In pastures was made the recovery of infective larvae in order to determine the quantity of L3 present in the pasture. The experimental design was a randomized completed block with two replications and before the entry of animals in the paddocks, they have been wormed. The experiment was ended when the animals reached 32.0 kg liveweight, and then were slaughtered and autopsies performed for the recovery and identify parasites of the abomasum, small intestine and large intestine. Results were subjected to analysis of variance, t test and Tukey`s test. The animals kept on pastures of Marandu grass had lower EPG counts, higher percentage of packed cell volume and higher average weight; those who remained in the Piat? pasture had lower eosinophil counts per microliter of blood. About the Famacha?, the highest prevalence was Famacha 2, and the body condition score ranged between 2 and 3. The results of feces cultures and recovery of larvae on pastures showed the presence of larvae of Trichostrongylus sp., and at the necropsy too. This way, it was concluded that the grass cultivars influences the sheep parasite load; the Famacha, together with EPG and packed cell volume are important indicators for use in controlling gastrointestinal nematode infections. The Trichostrongylus sp. was the most prevalent parasite in sheep during the rainy season / O controle dos nematoides gastrintestinais de pequenos ruminantes usualmente ? feito pela administra??o de anti-helm?nticos. Por?m, devido ao aparecimento cada vez mais crescente da resist?ncia parasit?ria a estas drogas, busca-se um controle alternativo e eficaz para as parasitoses. Uma das alternativas est? no manejo das pastagens, j? que estas s?o as fontes de infec??o dos animais pelas larvas infectantes L3 dos helmintos. Assim, o objetivo deste trabalho foi avaliar o desempenho de ovinos frente ?s infec??es naturais por nematoides gastrintestinais mantidos em pastagens de Panicum maximum cv. Massai e cv. Aruana, e Brachiaria brizantha cv. Piat? e cv. Marandu. O experimento foi realizado de Maio a Agosto/2011, com 48 ovinos machos, mesti?os SRD x Santa In?s, naturalmente infectados por nematoides gastrintestinais e mantidos em quatro diferentes cultivares de gram?neas forrageiras tropicais naturalmente contaminadas por ovos e larvas de nematoides gastrintestinais. Semanalmente, os animais foram caracterizados fenotipicamente atrav?s de exames parasitol?gicos (ovos por grama de fezes OPG e coprocultura), exames hematol?gicos (volume globular VG, e contagem de eosin?filos sangu?neos), pelo m?todo Famacha? para avaliar a colora??o da mucosa ocular, e pelas medidas de escore de condi??o corporal e ganho de peso. Nas pastagens foi feita a recupera??o das larvas infectantes, a fim de determinar a quantidade de L3 presentes no pasto. O delineamento experimental usado foi o de blocos casualizados com duas repeti??es, e antes da entrada dos animais nos piquetes, os mesmos foram vermifugados. O per?odo experimental foi finalizado quando os animais atingiram 32,0 kg de peso vivo, e em seguida foram abatidos e realizada a necr?psia para recupera??o e identifica??o dos parasitos do abomaso, intestino delgado e intestino grosso. Os resultados obtidos foram submetidos a an?lise de vari?ncia, teste t e teste de Tukey. Os animais mantidos nas pastagens de capim Marandu apresentaram menores contagens de OPG, maior porcentagem de volume globular e maior m?dia de peso; os que permaneceram na pastagem Piat? apresentaram menores contagens de eosin?filos por microlitro de sangue. O Famacha de maior preval?ncia foi o Famacha 2 e o escore de condi??o corporal oscilou entre os ?ndices 2 e 3. Os resultados das coproculturas e a recupera??o das larvas nas pastagens evidenciou presen?a de larvas de Trichostrongylus sp., bem como na necropsia este tamb?m foi o parasito de maior preval?ncia. Portanto, pode-se concluir que a cultivar forrageira influencia na carga parasit?ria dos ovinos; o Famacha, juntamente com o OPG e VG constituem indicadores importantes para serem utilizados no controle das verminoses gastrintestinais; o Trichostrongylus sp. foi o parasito de maior preval?ncia nos ovinos no per?odo chuvoso

Made available in DSpace on 2014-12-17T14:01:59Z (GMT). No. of bitstreams: 1 EmersonESM.pdf: 931852 bytes, checksum: f768665fe7e8aa27e4023b4def16f98d (MD5) Previous issue date: 2009-03-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Considering their commercial importance, as these are the species of freshwater fish more commercialized in Brazil, their occurence in different kinds of aquatic environments (lakes, rivers and dams) and for being tolerant to a wide range of variation of various physical parameters and chemical water, the fish species Oreochromis niloticus, Cyprinus carpio and Colossoma macropomum were chosen for this study, furthermore, to test the toxicity we used the herbicide Roundup. The fingerlings of tilapia (Oreochromis niloticus), commun carp (Cyprinus carpio) and tambaqui (Colossoma macropomum) were submitted to the herbicide roundup in the following concentrations: 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, 0.0 (control); 13,89; 14,86; 15,83; 16,81 and 17,78 mg.L-1, and 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, respectively, three for 96 hours. The LC50 - 96h for O. niloticus, C. carpio and C. macropomum was 21,63, 15,33 and 20,06 mg.L-1 of the herbicide roundup, respectively. The results show that this herbicide is classified as slightly toxic to the three species. The values of dissolved oxygen, pH and temperature recorded in the aquarium control and aquarium experimental of the three fish species have remained without significant variations during the tests, which reduces the possibility of death caused by sudden variations of these parameters during the 96 hours the experiment. The values of LC50 between different species of fish were observed, noting that the species O.niloticus, C. carpio and C. macropomum showed no expressive differences. The values of environmental risk of Roundup were calculated to obtain more stringent parameters in assessing the dangerousness of those on nontargets. The risk of environmental contamination by Roundup for the Nile tilapia, common carp, and tambaqui are low for the lowest application rate (1 L.ha-1) and depths (1.5 and 2.0 m). The dilution of 100%, the highest recommended dose (5 L.ha-1) and depths (1.5 and 2.0 m) the risk is moderate for the three species. The values of the Risk Ratio (QR) were greater than 0,1, indicating that the values of the CAE and LC50 are above acceptable levels and there is a need, this study, a refinement in ecotoxicological tests / Considerando a import?ncia comercial, por se tratarem das esp?cies de ?gua-doce mais comercializadas no Brasil, por ocorrerem em diversos tipos de ambientes aqu?ticos (lagos, rios e a?udes) e ainda por serem tolerantes a um amplo espectro de varia??o de diversos par?metros f?sicos e qu?micos da ?gua, as esp?cies de peixes Oreochromis niloticus, Cyprinus carpio e Colossoma macropomum foram escolhidas para este estudo com a finalidade de testar a toxicidade do herbicida roundup. Diante do exposto, o presente trabalho teve como objetivo determinar a toxicidade aguda e avaliar o risco de contamina??o ambiental dessas tr?s esp?cies de peixes pelo herbicida Roundup. Os alevinos de Til?pia do Nilo (Oreochromis niloticus), Carpa-comum (Cyprinus carpio) e Tambaqui (Colossoma macropomum) foram submetidos ao herbicida roundup nas seguintes concentra??es: 0,0 (controle); 18,06; 19,10; 20,14; 21,18 e 22,22 mg.L-1, 0,0 (controle); 13,89; 14,86; 15,83; 16,81 e 17,78 mg.L-1 e 0,0 (controle); 18,06; 19,10; 20,14; 21,18 e 22,22 mg.L-1, respectivamente, os tr?s por 96 horas. A CL50 96h para O. niloticus, C. carpio e C. macropomum foi de 21,63, 15,33 e 20,06 mg.L-1 do herbicida roundup, respectivamente. Os resultados obtidos demonstram que esse herbicida est? classificado como levemente t?xico para as tr?s esp?cies. Os valores de oxig?nio dissolvido, pH e temperatura registrados no aqu?rio controle e nos aqu?rios experimentais das tr?s esp?cies estudadas mantiveram-se sem varia??es significativas ao longo dos testes, o que reduz a possibilidade de mortalidade causada por varia??es bruscas desses par?metros, durante as 96 horas de experimento. Os valores das CL50 entre as diferentes esp?cies de peixes foram observadas, constatando que as esp?cie Oreochromis niloticus, Colossoma macropomum e Cyprinus carpio n?o apresentaram diferen?as expressivas. Os valores de risco ambiental do Roundup foram calculados para a obten??o de par?metros mais rigorosos na avalia??o da periculosidade desses sobre organismos n?o-alvos. O risco de contamina??o ambiental por roundup para a til?pia do Nilo, carpa-comum e tambaqui s?o baixos para a menor dose de aplica??o (1 L.ha-1) e nas profundidades (1,5 e 2,0 m). Na dilui??o de 100%, na maior dose recomendada (5 L.ha-1) e nas profundidades (1,5 e 2,0 m) o risco ? moderado para as tr?s esp?cies. Os valores de Quociente de Risco (QR) foram maiores que 0,1, indicando que os valores da rela??o CAE e CL50 est?o acima dos n?veis aceit?veis, havendo a necessidade de um refinamento nas an?lises ecotoxicol?gicas