Navegando por Assunto "Piaractus mesopotamicus"

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Acesso aberto (Open Access)
Characterization of the acute inflammatory response in the hybrid tambacu (Piaractus mesopotamicus male × Colossoma macropomum female) (Osteichthyes)
(2009-08) MARTINS, Maurício Laterça; Myiazaki, DMY; DIAS, Marcos Tavares; FENERICK JÚNIOR, Jaime; ONAKA, Eduardo Makoto; BOZZO, Fabiana Rizzi; FUJIMOTO, Rodrigo Yudi; MORAES, Flávio Ruas de
This work evaluated the acute inflammatory response induced by injections of 0.5 mL saline solution (control), 500 µg carrageenin and 0.5 mL thioglycollate 3% in the swim bladder of juvenile tambacu hybrid. Fish were distributed in three treatments, three replications and acclimated for a period of 10 days before assay. The cell characterization from the inflammatory exudate was performed in Giemsa and PAS stained smears. Carrageenin, injected in fish, showed an increase on the total number of cells in the inflammatory exudate when compared to saline and thioglycollate injected. Whereas, for carrageenin-injected fish, the percentage of thrombocyte was higher than thioglycollate. On the other hand, granulocyte percentage in thioglycollate-injected fish was higher than the ones injected using carrageenin. Carrageenin provoked the highest migration of macrophage to the inflammatory site. The PAS method confirmed the presence of three types of granulocytes: eosinophilic granular cell (EGC) type 1 with the characteristics of a special granulocytic cell commonly found in the circulating blood; EGC type 2 shorter than the last one and neutrophil. This study contributes to a better understanding of the inflammatory response and infectious processes in native fish.
Acesso aberto (Open Access)
Composição corporal e eficiência de utilização de nutrientes por pacus alimentados com ração suplementada com cromo trivalente
(2007-12) FUJIMOTO, Rodrigo Yudi; CASTRO, Marcello Pardi de; HONORATO, Claucia Aparecida; MORAES, Flávio Ruas de
The objective of this work was to evaluate body composition as well as nutrient efficiency use by pacus fed on diet supplemented with chromium at two stocking densities. The experimental design was completely randomized with 24 treatments, in factorial scheme: four levels of chromium in the diet (0, 6, 12, and 18 mg kg-1), two stocking densities (4 and 20 kg m-3) and three periods (30, 60 and 90 days). Increases in efficiency of crude protein retention and in percentage of crude protein and decrease in efficiency of fat retention and smaller values of fat percentage in the carcass were observed. In the smallest density, the level of 6 mg kg-1 of chromium was enough to make possible the higher accumulation of protein and smaller fat concentration in the carcass. In the density of 20 kg m-3, the need of chromium was higher, 12 mg kg-1, to obtain similar results. Pacus fed on diet supplement with chromium present lean meat, with smaller fat concentration, until 60 days of experiment.
Acesso aberto (Open Access)
Effects of chromium supplementation on the infrapopulations of Anacanthorus penilabiatus (Monogenoidea) and Piscinoodinium pillulare (Dinoflagellida) parasites of Piaractus mesopotamicus (Characidae)
(2010-08) FUJIMOTO, Rodrigo Yudi; CASTRO, Marcello Pardi de; MARTINS, Maurício Laterça; MORAES, Flávio Ruas de; VARELLA, Jamille Elzira de Almeida; DINIZ, Daniel Guerreiro
This study evaluated the parasitism by Anacanthorus penilabiatus (Monogenoidea) and Piscinoodinium pillulare (Dinoflagellida) in the gills of "pacu", Piaractus mesopotamicus supplemented with chromium in the diet. Randomised delineation by using factorial scheme (4x2x2) for Monogenoidea and 4x2x3 for Dinoflagellate with four levels of chromium (0, 6, 12, 18mg/kg diet), two stocking densities (4kg/m3 and 20kg/m3), two classes of length (higher and lower than 17 cm) for a period of 7, 60 and 90 days, and four replicates was used. The fishes in low density which received 12 and 18mg/kg showed decreased monogeneoidea values, seven days after the experiment begin. Six, 12 and 18 mg/kg caused reduction in the dinoflagellate number in the fishes maintained at 20kg/m3. It was possible that chromium supplementation (12 e 18mg/kg) favoured the fishes health by reducing Monogenoidea and Dinoflagellida number in lower and higher densities, respectively.
Acesso aberto (Open Access)
Pesque-solte: pesca repetitiva, variáveis hematológicas e parasitismo no peixe híbrido tambacu
(2013-08) VARANDAS, Daniela Nomura; MARTINS, Maurício Laterça; MORAES, Flávio Ruas de; RAMOS, Fabrício Menezes; SANTOS, Rudã Fernandes Brandão; FUJIMOTO, Rodrigo Yudi
The objective of this work was to evaluate the hematological and parasitological responses of tambacu (Colossoma macropomum x Piaractus mesopotamicus) subjected to catch-and-release stress and to different stocking densities in a catch-and-release system. Two hundred and ten fish with mean initial weight of 785.33±152.02 g and mean total length of 34.43±2.21 cm were maintained in ponds and divided into three groups: without fishing and low density (G1), with fishing and low density (G2), and with fishing and high density (G3). No significant differences were observed between the mean values for hemoglobin concentration, erythrocyte number, differential counting of leukocytes, and glucose. The fish from the G3 group showed higher parasite and thrombocyte numbers, and lower weight gain and hematocrit. The activity of catch-and-release, associated with high stocking density, can disrupt organic balance and animal performance, favoring parasitosis.