ABSTRACT We tested the effect of fasting on the development of juvenile freshwater angelfish (Pterophyllum scalare). The juveniles were subjected to different fasting periods (0, 3, 6, 9, 12, and 15 days of fasting). Fish from all treatments were fed for 30 days after the fasting period. No difference (P > 0.05) was observed between treatments for final weight and length. There was a significant difference (P < 0.05) in treatments 12 and 15 days fasting for liver and intestine weight. These results may prove that 12 and 15 days of fasting force juveniles to use energy reserves, and these adaptations may also represent a saving energy strategy. The fish subjected to treatments 6, 9, 12, and 15 days of fasting showed different vacuolization in hepatocytes from the ones subjected to 0 and 3 days of fasting (P < 0.05). These results show that during the lack of feeding, juveniles (P. scalare) mobilizes energy stored in the liver. No difference (P > 0.05) was observed between treatments for survival rate. However, the increase in the number of deaths from the eighth day of fasting may indicate that periods with more than 15 days of fasting could be fatal to this species during this life stage. According to our findings, it can be assumed that juvenile freshwater angelfishes have strategies (e.g. a decrease in liver and intestine weight) to resist 15 days of fasting.

O objetivo deste trabalho foi avaliar a remoção de compostos nitrogenados e fosfatados e da carga orgânica poluidora oriunda de cultivo heterotrófico de camarão marinho, por meio de reator anaeróbico. Foi construído um reator com fluxo ascendente, em que os efluentes de entrada e saída foram avaliados continuamente durante 120 horas, com três repetições. Os parâmetros físicos e químicos avaliados foram: temperatura, pH, condutividade, ortofosfato, nitrito, nitrato, amônia, demanda química de oxigênio e sólidos totais. O reator permaneceu estável, com boas condições de retenção de sólidos. O reator anaeróbico removeu 96,7% do nitrogênio amoniacal e 91% de ortofosfatos dos efluentes de cultivo de camarão marinho, o que mostra que os efluentes tratados estão dentro dos limites estabelecidos pela legislação.

The objective of this work was to evaluate the removal of phosphate and nitrogen compounds, and of pollutant, organic load from heterotrophic farming of marine shrimp, using an anaerobic reactor. An upward-flow reactor was constructed, in which input and output wastes were continuously evaluated for 120 hours, with three replicates. The evaluated physical and chemical parameters were: temperature, pH, conductivity, orthophosphate, nitrite, nitrate, ammonia, chemical oxygen demand and total solids. The reactor remained steady, with good conditions for solid retention. The upward-flow anaerobic reactor removed 96.7% ammoniacal nitrogen and 91% orthophosphate from effluents of marine shrimp farming, which shows that effluents are within the limits set by law.

RESUMO O objetivo deste estudo foi caracterizar a florística e calcular os parâmetros fitossociológicos das espécies presentes nas áreas de campo sujo e cerrado sensu stricto na Estação Ecológica de Pirapitinga - MG (ESEC). O estudo foi realizado na ESEC de Pirapitinga no município de Morada Nova de Minas, Estado de Minas Gerais. Para o levantamento da florística e da fitossociologia, foi alocado um total de 190 subparcelas com 100 m2 cada, amostrando-se todos os indivíduos com circunferência à altura do solo (CAS) ≥ 16 cm, em áreas de campo sujo e cerrado sensu stricto. Foram calculados os parâmetros de frequência, densidade, dominância, os valores de importância e os índices de diversidade de Shannon e equabilidade de Pielou. A similaridade florística entre as áreas foi determinada por meio do índice de Sorensen. Nas duas áreas de estudo, foram amostrados um total de 3.224 indivíduos distribuídos em 81 espécies, 70 gêneros e 40 famílias. As famílias mais ricas foram Fabaceae e Vochysiaceae. O cerrado sensu stricto foi a formação vegetal com maior riqueza de espécies (81) e maior densidade (2.257 ind ha-1). Ambas as áreas estudadas apresentam-se com alta diversidade e baixa dominância ecológica e possuem distribuição diamétrica em forma de J-invertido, indicando o predomínio de indivíduos jovens.

ABSTRACT The objectives of this study were to characterize the floristic and to calculate the phytosociological parameters of species present in the areas of 'campo sujo' and 'cerrado' sensu stricto in the Ecological Station of Pirapitinga, Minas Gerais state (ESEC). For the floristic and phytosociologic survey, a total of 190 plots of 100 m2 each were allocated, where all the individuals with circumference at soil level (CSL) ≥ 16 cm in areas of 'campo sujo' and 'cerrado' sensu stricto were sampled. The parameters of frequency, density, dominance, and importance values and Shannon and Pielou indexes were calculated. The floristic similarity between areas was determinated by Sorensen index. In the study areas, a total of 3,224 individuals distributed in 81 species, 70 genera and 40 families were sampled. The richest families were Vochysiaceae and Fabaceae. The cerrado sensu stricto was the vegetal formation with the highest richness of species (81) and highest density (2.257 ind ha-1). Both areas have studied with high diversity and ecological dominance and have low diameter distribution in the form of inverted-J, indicating the predominance of young individuals.