Avaliação da densidade de estocagem de pós-larvas de camarões Penaeus Vannamei em sistema simbiótico de cultivo

Abstract

Within the group of crustaceans cultivated in the world, stands out the white shrimp (Penaeus vannamei). Its world production has increased from 8,286 tonnes in 1980 to 5,446,216 tonnes in 2020, equivalent to approximately 77% of total world shrimp production (FAO, 2020). With the increase in production, it is necessary to implement more efficient technologies that help in the intensification of culture systems, in order to promote environmental and economic sustainability for the activity. Synbiotic systems are one of the methods used in these intensifications of culture systems, this methodology is based on the provision of probiotics and prebiotics in a combined way, in order to favor the growth of beneficial organisms, improving the survival and colonization of these microorganisms in the environment cultivation and in the digestive tract of cultivated animals. Thus, the present work aimed to evaluate the efficiency of the synbiotic system in the intensive cultivation of P. vannamei post-larvae, during the nursery phase, in salt water, with minimum exchange water. The experiment was conducted at the Laboratory of Aquaculture Biotechnology of the Federal Institute of Education, Science and Technology of Ceará (LABIAq-IFCE), Acaraú campus. Nine circular suspended HDPE (High Density Polyethylene) tanks were used, with a useful volume of 10,000 L, individually interconnected to an 80 L sedimentable solids control system. The entire culture system was mounted inside a 360 L aquaculture greenhouse square meters for temperature control. The water used in the culture underwent a preparation from the rice bran fermentation process, with the use of probiotics, to maintain the synbiotic system. A total of 360,000 Pl's of P. vannamei in each experiment, with an average weight of 0.003 g, were stored in triplicate at densities of 2, 4 and 6 Pl's per liter and fed 6 times a day with an interval of 2 hours between feedings, during 30 days. To verify the influence of stocking densities with and without population support on the symbiotic system, microbiological analyses were carried out at the beginning and end of cultivation and analyzes of water quality throughout the experiment. The concentration of colonies of Vibrios spp. and Bacillus in experiments 1 and 2 did not show significant differences between treatments, but showed variations when comparing the initial and final times. In experiment 1 (with bonus) the factors of final average weight, survival, productivity and ACF of shrimps did not show significant differences between treatments (P>0.05). In experiment 2 (without bonus) the shrimp cultivated at the lowest density (2pl/L) had a final average weight of 0.48 ± 0.018g (P<0.05) higher and higher survival rates of 80 ± 0.03% (P<0.05), when compared to the highest densities (4pl/L and 6pl/L). The data indicate that the symbiotic system helps to maintain the system's water quality parameters, even at the highest storage densities. However, the stocking densities with the influence of the population bonus, influence the zootechnical performance of the cultivated animals.