Navegando por Assunto "Mapará (Peixe)"

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Acesso aberto (Open Access)
Caracterização estrutural e ultraestrutural das células do epitélio gonadal de Hypophthalmus Marginatus (Valenciennes 1840) durante a espermatogênese
(Universidade Federal do Pará, 2014-09-05) GONÇALVES, Liziane Amaral Barbosa; ROCHA, Rossineide Martins da; http://lattes.cnpq.br/4371300451793081
Hypophthalmus marginatus is a siluriforme, belonging to the family Pimelodidae. This species is highly consumed in eastern Amazonia and has a wide socio-economic importance to the region. Studies on the histological characterization of the reproductive system are still unknown in this species. Therefore, this study serves as a tool for biotechnology techniques, necessary for the production in captivity, since this species is one of the fishing resource most intensively exploited by artisanal fisheries. The aim of this study was to characterize the structural and ultrastructural features of germinal epithelium cells of Hypophthalmus marginatus during spermatogenesis. 168 specimens were collected from December 2011 to December 2012. Macroscopically were identified 69 adult males. In field, ventral incision was held in fishes and fragments of testicles from the median region and semen were removed. Then the material was subjected to processing and analysis of light microscopy, transmission electron microscopy and scanning. The data revealed that the germ cells proliferate inside the spermatic cyst synchronously. Spermatids enter at the spermiogenesis process through three distinct stages of cell differentiation. The nucleus does not move relative to the axis flagellar and the centrioles don't migrate to the nucleus. The spermatozoids showed a spherical head with the highly condensed nucleus and no acrosome. The intermediary piece was short containing a single long flagellum. The axoneme presents the structure of microtubules within the pattern (9 + 2). The nuclear fossa housed the proximal centriole partially. The presence of spermatogenic cells in the same subphase of meiosis inside the cyst is characterized as cystic spermatogenesis, with synchronous growth of the cells. This suggests that spermiogenesis of H. marginatus is of type III and the presence of nuclear fossa is considered a distinctive feature for the species, which differs from other pimelodids.
Acesso aberto (Open Access)
Desidratação osmótica à vácuo do filé de mapará (Hypophthamus edentatus)
(Universidade Federal do Pará, 2014-03-28) MACIEL, Renan de Almeida; RODRIGUES, Antonio Manoel da Cruz; http://lattes.cnpq.br/7524720020580309; PENA, Rosinelson da Silva; http://lattes.cnpq.br/3452623210043423
The aim of this work was to evaluate the process of vacuum osmotic dehydration of mapará fillet (Hypophthamus edentatus). Mapará fillets with dimensions of 5 x 2 x 0.5 cm were subjected to vacuum osmotic dehydration in accordance with a rotational central composite design 24, in which were evaluated the effects of the independent variables temperature, time, vacuum pressure and NaCl concentration on the dependent variables water loss (WL), solids gain (GS) and water activity (aw), order to obtain optimal condition of process with greater PA, lower GS and lower aw. The kinetics of osmotic dehydration of mapará was performed under optimal conditions, where were monitored the parameters PA, GS and aw as a function of process time. The empirical model proposed by Azuara et al. was used to represent the kinetics of mass transfer during the process of osmotic dehydration. The mapará fillet presented 76.70% moisture, 15.57% protein, 5.38% fat and 0.93% ash. The NaCl concentration (linear) was the variable that presented the greatest effect on the dependent variables, being positive on WL and GS and negative about the aw. The models obtained for PA, GS and aw were significant at 95% confidence and showed no significant lack of fit, being useful to predictive purposes. Was determined as optimum condition for the process: NaCl concentration 25%, temperature of 25 ° C and time of 120 min. The model proposed by Azuara et al. showed fit good to the experimental data of PA and GS kinetics of osmotic dehydration of mapará fillet. The fillet mapará had a reduction moisture after osmotic dehydration in optimal conditions, however did not meet the humidity recommended by law for salted fish, since the chloride content increased and attended law for salted fish. In relation the instrumental color were observed, after osmotic dehydration, significant statistically differences in lightness (L *) that decreased, indicating that the mapará darkened and the hue angle (h °) that increased, but still showed a tendency to yellow.