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.

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-The experiment was performed with 160 tambaqui (Colossoma macropomum) with average weight 11.01±2.08 g and total length 7.8±0.18 cm. Fishes were kept in sixteen aquariums with 56 L of water at 29.1±0.4 o C of temperature, initial stocking density 1.97 g/L and constant aeration. The objective of this study was to assess the influence of photoperiod on fish performance. Treatments consisted of four photoperiods: T1 = 6 hours; T2 = 12 hours; T3 = 18 hours and T4 = 24 hours, with four replicates each. Fishes were fed twice a day with commercial extruded feed (28% of crude protein).The experiment was developed in closed circulation system, with volume of water renewal for each experimental unit equivalent to 40 times daily. Fish biometry was performed at the beginning of the experiment and at every 16 days, in order to follow the effects of treatments on juvenile development. Final weight, total length, standard length, height, feed intake, weight gain, feed conversion, survival, specific growth rate, protein efficiency rate and protein retention efficiency were assessed.Statistical analysis of variables was performed with application of the software SAEG version 9.1, for analysis of variance, regression analysis and Pearson correlation. Positive influence of photoperiod was observed for the studied variables in this study. The studied variables enhanced as the photoperiod increased, mainly between 15 and 22 hours. The photoperiod has significant influence upon growth traits of tambaqui (Colossoma macropomum).

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.

RESUMOAvaliou-se o efeito de diferentes granulometrias do milho da ração no desempenho de juvenis de pacu, Piaractus mesopotamicus. Foram utilizados 120 juvenis com peso inicial de 8,42±0,89, comprimento total de 7,03±0,20cm, comprimento padrão de 6,32±0,13cm e altura de 3,21±0,11cm, distribuídos em 20 aquários (300L), na densidade de seis peixes por unidade experimental (aquário), em delineamento inteiramente ao acaso, com cinco tratamentos constituídos por diferentes granulometrias -850, 710, 500, 300, 150μm -do milho na composição da ração. Cada tratamento tinha quatro repetições. O tratamento que proporcionou melhor desempenho dos animais foi o com granulometria do milho de 150μm, destacando-se a conversão alimentar de 1,38, enquanto no tratamento com maior granulometria a conversão alimentar foi de 1,61. Assim, recomenda-se usar a granulometria de 150μm.Palavras-chave: peixes brasileiros, aquicultura, nutrição de peixes, ração ABSTRACTThe effect of different particle size of corn ration on the performance of juvenile pacu, Piaractus mesopotamicus, was evaluated. A total of 120 juveniles with an initial weight of 8. 42±0.89g, total length 7.03±0.20cm, standard length, 6.32±0.13cm, and height 3.21±0.11cm, were distributed into 20 tanks (300L), at a density of six fish per experimental unit (tank), in a completely randomized design with five treatments consisting of different particle sizes 850, 710, 500, 300, 150μm of corn in the ration composition. Each treatment had four replicates. Among all treatments, the best animal performance was achieved with the ration with corn particle size of 150μm, reaching a feed conversion ratio of 1.38, whereas for larger feed grain size, it was 1.61. Thus, the particle size of 150μm is recommended.

Rev. Bras. Saúde Prod. Anim., Salvador, v.13, n.2, p.569-577 abr./jun., 2012 http://www.rbspa.ufba.br ISSN 1519 9940 569 Digestibilidade aparente de alimentos proteicos e energéticos para Trichogaster leeriApparent digestibility of protein and energy sources for "Trichogaster leeri"

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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.