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Percorrer por autor "Poidevin, Sidney Alexander"

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  • Improving commercial protocols of Russian sturgeon at larval & fingerling life stages: measuring the effects of weaning on the survival of Russian sturgeon larvae using live feed & measuring the effects of increasing stocking densities on the growth and survival of Russian sturgeon fry
    Publication . Poidevin, Sidney Alexander; Oliviera, Catarina Valente de
    The present study was performed to improve protocols for the commercial production of Russian sturgeon at the larval and fingerling life stages. Two trials were undertaken, the first trial ran for 35 days and focused on reducing mortality rates at the larval stage by implementing a co-feeding strategy using live artemia cultures. 3 different dietary regimes were tested, G1: Mixed Diet (Inert+ Artemia), G2: Inert Diet (Control), & G3 Live Diet (Artemia). The dietary regimes containing live feeds underwent an 11-day weaning period before being replaced completely with commercial inert feeds. Mortality was significantly lower for G1 (Mixed Diet) when compared to the other treatment groups. The mortality rates of G2 were lower than the mortality rates produced by G3, but the differences were not significant. The study revealed a favorable effect of the mixed diet of G1, containing live and inert food on the survival of Russian sturgeon larvae. The production of live food is expensive and laborious, but the results of this trial ensure that it is not necessary for the entire larval stage. The second trial also ran for 35 days and focused on maximizing available space and water at the fingerling life stage by testing the effects of increasing stocking densities on survival and growth. 3 treatment groups were formed containing a different population density, ranging from low to high (Low: 800 ind., Medium: 1,200 ind., High: 1,600 ind.). The results of this trial revealed no significant differences in average body weight, FCR, SGR or weight gain. The biomass density in the high animal density treatment group reached a concentration of 18 kg.m-3, with no negative effects on growth or survival. The results of this trial indicate that the threshold of biomass concentrations at Caviar de Neuvic can be increased without loss of performance.
    2023-11-12Dissertação de mestrado Acesso aberto Ver mais