63 resultados para pisciculture


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The detention and infiltration ponds of urban drainage system has function to protect the population from undesirable effects of floods. In general these ponds are not completly used and it potential is wasted. As it are disseminated at different places at cities it can reduce costs with water transport and permit water preservation of best quality. Some it utilities includes use in green areas irrigation, industrial among than cooling towers and boiler, soil compaction, cleaning urban road, pisciculture and fire fighting system. The quality these water is influenced by anauthorized sewage in the drainage system. This study was performed in six detention and infiltration ponds at drainage system of Natal, which aim was to verify the non-portable use these ponds on urban environment. As indirect aim would to incentive the water utilization these ponds as a water source to another uses in urban environment. These ponds represents the characteristics of detention and infiltration of Natal city and consequently of Brazil. As the water quality, the ponds presents following characteristics: three has apparently good quality, other showed intermediate condition and two had water polluted. Were performed twenty sample in each ponds and the following parameters assessed: pH, temperature, dissolved oxygen, turbidity, electrical conductivity, coliform thermotolerant, ammonia, organic nitrogen, TKN, nitrate, total phosphorus and alkalinity, bicarbonate, chloride, total hardness, calcium and magnesium hardness, total solids, TSS, TDS, COD and SAR°. To utilization on pisciculture we recommend use in ponds which presents the best quality. Only one pond presented higher pollutants and it not being appropriated for use in cooling tower. The content of solids suspension restricted the water use in all ponds in boilers. As water use in soil compaction, cleaning urban road and fire fighting system the water from these ponds are not appropriated. However, the recommended limits from literature are to domestic sewage, due to this, the parameters are restrictive to diminish the sanitary risk that could be offered with it utilization. The infiltration velocity of water these assessed ponds restrict a moderato use, however the effects are potentiated only in soil less sandy, which not occur in Natal. It is recommend the unrestricted irrigation utilization in ponds with best quality of water, and a restricted irrigation to ponds with worst quality of water. As load of pollutants, it is recommended a complementary treatment in those ponds whit higher load to diminish sanitary risks. In only one pond was found one helminth eggs and due to the convention formula of results, it was found for all ponds less than 1 helminth/liter eggs.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Sixty-six trairão (Hoplias lacerdae) fingerlings (average weight of 2.0±0.5 g and total length of 5.8±0.2 cm), trained to accept dry rations, were allotted to six 15-L aquariums, with aeration and controlled temperature (24.0±0.5°C), in a density of 0.7 juveniles/L, aiming to evaluate the effects of darkness on fish productive performance. The treatments consisted of two photoperiods: 12 hours light: 12 hours dark (12L:12D) and 0 hour light: 24 hours dark (OL:24D), with three replicates. Fingerlings were fed ad libitum a commercial extruded diet (42% CP), twice a day. The aquariums were cleaned daily for excrement withdrawal through siphoning, exchanging 1/4 total volume. At the end of the experiment (30 days), weight gain, feed:gain ratio and survival and cannibalism rates were evaluated. The results showed that darkness did not affect the productive performance of trairão juveniles.

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The effects of inclusion of whole yeast, autolyzed yeast and yeast cell wall on hematological parameters and gut villus perimeter were evaluated in juvenile Nile tilapia, after 80 experimental days. Isoproteic (32.0% DP) and isoenergetic (3200 kcal DE kg -1) practical diets were supplemented with three levels of whole yeast or autolyzed yeast (1.0, 2.0 and 3.0%) and three levels of yeast cell wall (0.1, 0.2 and 0.3%), plus a control diet (with no test microingredients). Red blood cell count, hemoglobin concentration, total plasmatic protein, hematocrit percentage, mean corpuscular volume, mean corpuscular hemoglobin concentration and gut villus perimeter were evaluated. Variations on hematological parameters in animals fed diets with whole yeast; autolyzed yeast and yeast cell wall were observed to be within normal ranges for this species. There was significant influence (p<0.05) of different levels of yeast and derivatives on intestinal villus perimeter. Results showed that experimental period and proposed levels of whole yeast, autolyzed yeast and yeast cell wall do not provide undesirable alterations on standard hematological parameters to Nile tilapia and can be safely used to compound diets for this species. Results also showed that supplement of yeast cell wall provide higher intestinal villus perimeter.

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A escape of the fiddler crab Uca rapax (Smith, 1870), in the state of Minas Gerais is reported for the first time. This record was made more than 200 km away from its original habitat, a mangrove area in the state of Rio de Janeiro. The species has been introduced in ponds in the study area, located in the largest ornamental pisciculture/aquaculture center of Brazil. Male individuals of U. rapax were observed engaged in territorial and courtship displays around their burrows. Despite this, there is no well-established population of the species in the area, due to the physiological dependence of the larvae on brackish water. © 2007 Instituto de Ciências Biológicas - UFMG.

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The aim of the study was to evaluate the serum biochemical parameters of the Nile tilapia (Oreochromis niloticus), Thai Chitralada lineage, raised under an intensive pisciculture system and captured by the cast net technique. Blood samples from 40 individuals were obtained by caudal venopuncture. Mean body weight was 453 ± 52 g. The serum biochemical parameters evaluated were total protein, albumin, globulins, acid uric, creatinine, urea, calcium, inorganic phosphorus, Ca/P ratio, alkaline phosphatase, and magnesium. In general, the data showed similar parameters in comparison to those established for scale fish, exception of the acid uric.

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The present study evaluated the microbiological water quality and tissue lesions in gills from Nile tilapia (Oreochromis niloticus) and hybrid tambacu (Colossoma macropomum female x Piaractus mesopotamicus male). For this, water and gills were collected from fish farming at six locations in Itapecuru- Mirim County, Maranhão State. Microbiological water analyses revealed contamination by total coliforms, Escherichia coli and heterotrophic bacteria. In the gills, we observed a diversity of Gram-positive and Gramnegative bacteria. The tissue lesions were: lamellar fusion, interlamellar hyperplasia, sub-epithelial edema and telangiectasia. Inflammatory lesions were not observed. Significant statistical difference (p > 0.05) was not detected when comparing different gills lesions during rainy and dry season. The correlation between lesion and pond type was statistically different (p < 0.05) for lamellar fusion and interlamellar hyperplasia which occurred more frequently at ground ponds. Regarding the frequency of lesions in the different fish species, there was statistical difference (p < 0.05), and the tambacu was more sensitive to lamellar fusion while tilapia was more sensitive for the other lesions. In relation to the sampling stations, there was statistical difference for all the gill lesions. In conclusion, tissue lesions are nonspecific and function as a defense mechanism against polluted aquatic environments, without infectious character.

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Fish farms' water quality management is analyzed with regard to the management employed and the different trophic states are compared within the system during the dry and rainy seasons. Six sites were marked two in the water supply (P1 and P2), and four within the fish farm (P3 to P6). Whereas sites P1 and P2 (water supply) were characterized as oligotrophic, the others were mesotrophic and eutrotrophic sites. Environmental variables, mainly nutrients, conductivity, COD, BOD5 and TSS tended to increase as from P3 due to management and fertilization. Greater impact has been registered in the fish farm under analysis for variables COD, ammonia, total phosphorus and TSS during the discharge and pond emptying period. Frequent monitoring of water quality should be undertaken in fish breeding and plankton production ponds, especially in those close to P3 and P4. Removal of sediment in decantation lake or P5 is also recommended to decrease nutrient concentrations, especially phosphorus, accumulated on the bottom soil.

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This study evaluated the influence of intensive farming of tilapia on physical and chemical parameters and on the occurrence of Streptococcus spp. in the water of the lake and of cages. Throughout a year, monthly samplings were taken in the rainy and dry seasons for a year, at two sampling sites, lake and net cages. For the determination of water quality, physical and chemical water parameters were evaluated and compared to the standards established by Conama Resolution no. 357/2005. The presence of Streptococcus spp. in the water was determined by plating on blood Agar and biochemical screening. Mean values of water parameters were tested using the Kruskal-Wallis test comparing sampling sites and seasons. Ammoniacal nitrogen (ammoniacal-N), total phosphorus (total-P) levels and occurrence of Streptococcus spp. have increased in the water of the net cages. The mean values of several parameters have decreased during the rainy period, except for pH, temperature and ammoniacal-N. Total-P and dissolved oxygen levels, during dry and rainy periods, respectively, exceeded the standard established for freshwater class 2, recommended for aquaculture, which can be harmful to the fish. Therefore, constant monitoring of the physical,chemical and microbiological water parameters is recommended since the Juara lake is also used for recreational purposes.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pós-graduação em Aquicultura - FCAV

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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O Tambaqui (Colossoma macropomum) é a espécie de peixe mais comumente cultivada em pisciculturas no Brasil. A espécie é altamente adaptada às condições de cativeiro, apresentando rápido crescimento e alta fecundidade. Nos últimos anos tem ocorrido o cruzamento artificial entre espécies de Characiformes, produzindo os híbridos "Tambacu" e "Tambatinga". A identificação de híbridos é uma tarefa difícil, em virtude da grande similaridade morfológica entre as espécies parentais. O presente estudo apresenta uma abordagem molecular inovadora para identificação de híbridos com base em PCR Multiplex de um gene nuclear (α-Tropomiosina), em que foram testados 93 espécimes obtidos em pisciculturas da região norte do Brasil. O sequenciamento de um fragmento de 505 pares de bases da Região Controle permitiu a identificação da linhagem materna de todos os espécimes como sendo de C. macropomum. Inesperadamente foram encontrados apenas dois haplótipos nas 93 amostras, um baixíssimo índice de diversidade para populações cultivadas de Tambaqui. A PCR multiplex identificou 42 híbridos, em contraste aos 23 híbridos citados pelos fornecedores dos peixes, em uma identificação realizada com base na morfologia. Esta ferramenta inovadora possui um grande potencial para o desenvolvimento da aquicultura brasileira dada a possibilidade de identificação sistemática das características genéticas tanto das matrizes produtoras de alevinos quanto dos alevinos e juvenis criados em fazendas.