The Negro river basin is considered the largest area of extractive of ornamental fish in Brazil. This area has fundamental importance for the populations from the Amazon. The present study aimed to describe socioeconomic profile of ornamental fishermen known as “piabeiros” in the Municipality of Barcelos, as well as the ornamental fishery, fisheries area, target species, environments, fishing techniques, equipment, capture techniques and main difficulties faced by the current activity. This study was carried out in municipality of Barcelos, through semi - structured interviews, with artisanal ornamental fishermen (N= 89). The main families of ornamental fish caught and traded were: Characidae, Lebiasinidae, Gasteropelecidae, Cichilidae, Anostomidae, Loricaridae, Potamotrygonidae and Gymnotidae. The main catchment areas were igarapés, lakes, flooded fields, beaches, river banks and igapó forest. Rapiché was the most used equipment in the fisheries both by the fishermen of the urban areas (43.81%) and rural (41.89%). Most of the fishermen are associated with the colony of fishermen of Barcelos (Z33). The data showed that the dynamics of ornamental fishing have changed in a short time and directly affected fishermen, in addition to the low age renewal with the participation of younger fishermen, threatening the transmission of ecological knowledge to future generations. As a result, the increase of the problems related to the productive chain and absence of public power to the activity, since ornamental fishing has already been treated as one of the main economic activities more important for the local communities and for the State of Amazonas.

RESUMOO 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 m 2 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. Palavras-chave: bioma cerrado; floresta natural; unidade de conservação. ABSTRACTThe 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 m 2 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.

The tambaqui (Colossoma macropomum) is a fish of primary importance in South American aquaculture, principally in the Amazon region and has a particularly unique diet in the wild. Oryza spp, or Wild rice as it is commonly known, is native to the floodplains of muddy rivers in the Amazon region. The aim of this study was to analyze the physical performance and the effects of dietary levels of Oryza spp. via the hematological parameters, total food intake, conversion efficiency, growth ratio and swimming performance of this fish. Diets containing 45% Oryza spp. induced the best performance in tambaqui. Diets containing 15% and 30% did not affect these indices, thus indicating that this amount of Oryza can be used as an alternative energy source for this important species within Brazilian aquaculture.

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Photoperiod is considered an environmental factor that influences reproduction and the growth processes of fish throughout the year. In the present study, we subjected dusky grouper Epinephelus marginatus to different photoperiods in order to evaluate growth and survival. Juvenile dusky grouper were randomly distributed in twelve 100 L tanks containing four fish per aquarium. The fish were exposed to continuous light, normal photoperiod or continuous darkness for 50 days. Fish were fed 3% of their total biomass, twice a day, and the diet consisted of ground commercial dry pellets (42% crude protein, 12% humidity, 9% ether extract, 15% mineral matter, 4% crude fiber, 3.5% calcium and 3% vitamin C, in accordance with the manufacturer’s instructions). There was no mortality during the experiment. After 50 days, the best performance was found for exposure to continuous light (24 h artificial light). The final weight of the fish reared under continuous light was significantly higher than that of the fish exposed to continuous darkness. The specific growth rate of the fish exposed to continuous light was significantly higher than that of the fish exposed to the natural photoperiod and to continuous darkness. Modifications to the photoperiod can be a key factor in increasing the efficacy of current production and the improvement of current aquaculture protocols.