03. Unidade Acadêmica de Serra Talhada (UAST)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/2925
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Item Avaliação da taxa de filtração da daphnia magna cultivada em sistema autotrófico (água clara) e sistema mixotrófico (biofloco) com diferentes dietas ofertadas(2022-06-03) Rodrigues, Mônica de Lima; Abreu, Jéssika Lima de; http://lattes.cnpq.br/6237276943114119; http://lattes.cnpq.br/2300244354976388In aquaculture, the larviculture phase of fish farming is one of the main challenges faced, due to the small size of the cultured individuals and the inherent difficulties in feeding and management. The filtration rate is calculated assuming that the nutrient rate of zooplankton is proportional to the concentration of available food. It is relevant to know the filtration rate in order to know how best to produce organisms, verifying if the type of culture will interfere in the filtration rate, and to observe if there is selectivity regarding the diet offered. The culture was performed in autotrophic system, when inorganic carbon and light are used as energy sources; and mixotrophic, in the presence of organic and inorganic carbon, light, and organic compounds as energy sources. Thus, the present research aimed to know the filtration rate of Daphnia magna (cladoceran) in autotrophic and mixotrophic culture being tested different microalgae diets. The experiment was carried out with six treatments with three repetitions each, based on two factors: culture (autotrophic or mixotrophic) and diet (Chlorella vulgaris, Haematococcus pluvialis (green phase/vegetative phase) and red phase/cystic phase). The water quality variables: temperature (°C), dissolved oxygen (mg.L-1 ) and pH were measured twice a day throughout the culture. The variables analyzed for filtration rate were: filtration rate (TF), cell decay with the presence of Daphnia (K Daph ), cell decay without the presence of Daphnia (K sDaph), ratio with Daphnia (C/C0 Daph), ratio without Daphnia (C/C0 sDaph). The growth variables were: specific growth rate (SGR), doubling time (DT), maximum mean density (DMX), yield (R), and day of maximum density (DMD). As for Dissolved Oxygen, there was a significant difference only for the algae factor. However, the other variables pH and temperature showed no statistical difference, with the pH staying around 7.3 and the temperature around 29° C. As for TF, no statistical differences were found in the treatments. However, certain treatments had higher values for H. pluvialis in the cystic phase in both types of cultures and lower values for H. pluvialis in the vegetative phase. The day of maximum density (MDD) was reached on day 7 in the autotrophic culture with the diet of H. pluvialis in the green phase being fed. Thus, H. pluvialis in the green phase was found to be a well utilized food for Daphnia magna