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Costa D.C.,Federal University of Minas Gerais | de Souza e Silva W.,Federal University of Minas Gerais | Melillo Filho R.,Federal University of Minas Gerais | Miranda Filho K.C.,Federal University of Minas Gerais | And 2 more authors.
Animal Reproduction Science | Year: 2015

The present study describes the capture adaptation and reproduction of wild Lophiosilurus alexandri broodstock in laboratory conditions. There were two periods when capturing was performed in natural habitats. The animals were placed in four tanks of 5m3 with water temperatures at 28°C with two tanks having sand bottoms. Thirty days after the temperature increased (during the winter) the first spawning occurred naturally, but only in tanks with sand on the bottom. During the breeding season, there were 24 spawning bouts with egg mass collections occurring as a result of the spawning bouts that occurred in the tanks. The hatching rates for eggs varied from 0% to 95%. The spawning bouts were mainly at night and on weekends. In the second reproductive period, the animals were sexed by cannulation and distributed in four tanks with all animals being maintained in tanks with sand on the bottom at 28°C. During this phase, there were 36 spawning bouts. Findings in the present study contribute to the understanding of the reproductive biology of this endangered species during captivity. © 2015 Elsevier B.V. Source


Melillo Filho R.,Federal University of Minas Gerais | Takata R.,Federal University of Minas Gerais | Santos A.E.H.,Federal University of Minas Gerais | de Souza e Silva W.,Federal University of Minas Gerais | And 5 more authors.
Aquaculture Research | Year: 2014

This study evaluated the efficiency of the drainage system during the larviculture of Lophiosilurus alexandri. Moreover, we assessed the best feeding rate after feed training for juvenile production. The study was performed in three phases over 87 days. In phase 1 (40 days), larvae were fed live food and posteriorly submitted to feed training in two drainage systems: water drained on the surface (DS), and water drained into a tank column (DI). In the second phase (30 days), using only the DS system juveniles were fed a formulated diet at feeding rates, 2, 4, 6 and 8% of body wet weight. In the third phase (17 days), the fish from the second phase were fed until apparent satiation. At the first phase, the animals in the DS system exhibited greater survival rates and growth. The best feeding rate for daily weight gain, specific growth rate (SGR) and mean body weights were similar: 5.57, 5.13 and 5.68% respectively. In the third phase, an increased SGR was observed in the treatment groups that received lower feeding rates in the second phase (2 and 4%), which could indicate a possible compensatory growth rate. © 2013 John Wiley & Sons Ltd. Source


Gomes M.V.T.,Centro Integrado Of Recursos Pesqueiros E Aquicultura Of Tres Marias Codevasf | de Souza R.R.,Federal University of Sergipe | Teles V.S.,Federal University of Sergipe | Araujo Mendes E.,Centro Integrado Of Recursos Pesqueiros E Aquicultura Of Tres Marias Codevasf
Chemosphere | Year: 2014

The presence of mercury in aquatic environments is a matter of concern by part of the scientific community and public health organizations worldwide due to its persistence and toxicity. The phytoremediation consists in a group of technologies based on the use of natural occurrence or genetically modified plants, in order to reduce, remove, break or immobilize pollutants and working as an alternative to replace conventional effluent treatment methods due to its sustainability - low cost of maintenance and energy. The current study provides information about a pilot scale experiment designed to evaluate the potential of the aquatic macrophyte Typha domingensis in a constructed wetland with subsurface flow for phytoremediation of water contaminated with mercury. The efficiency in the reduction of the heavy metal concentration in wetlands, and the relative metal sorption by the T. domingensis, varied according to the exposure time. The continued rate of the system was 7 times higher than the control line, demonstrating a better performance and reducing 99.6±0.4% of the mercury presents in the water contaminated. When compared to other species, the results showed that the T. domingensis demonstrated a higher mercury accumulation (273.3515±0.7234mgkg-1) when the transfer coefficient was 7750.9864±569.5468Lkg-1. The results in this present study shows the great potential of the aquatic macrophyte T. domingensis in constructed wetlands for phytoremediation of water contaminated with mercury. © 2013 Elsevier Ltd. Source

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