Nursery and fattening of the pink shrimp Farfantepenaeus paulensis in the Lagoa dos Patos Estuary
The works of this dissertation have as target contribute to the development of pink-shrimp, Farfantepenaeus paulensis culture in Patos lagoon estuary. The first work, was developed, looking for alternatives to increase the natural productivity of the tanks, as for instance adding microalgae, and increasing the surface availability for biofilm growing, trying to simulate nurseries conditions in environment. This way, evaluate the effects of the addition of a diatom Thalassiosira fluviatilis on the natural food availability, water quality, survival and growth of shrimp post-larvae. The experiment consisted in two treatments: with and without addiction of phytoplankton. No significant differences (P > 0,05) in the values of growth (115,7 ± 17,6 mg and 117,7 ± 23,4 mg) and survival (95,2% and 84,85%) were found among the treatments (with and without phytoplankton) at the end of the trial. The final results showed a better performance of the shrimp post-larvae in the purposed nursery system. In second work, we compiled data from 28 pens enclosures comparing the effects of different stocking densities on the performance of F. paulensis cultured in pens. The results presented clearly show that the culture of F. paulensis in pen enclosures results in survival rates above 77 %, which may be considered excellent in comparison to the values usually obtained in the traditional pond-based shrimp culture. The higher individual wet weight was achieved in lower stocking densities (5 and 10 shrimp/m2). Higher biomass was obtained in higher stocking densities (60 and 90 shrimp/m2). However, when analyzed the production costs it detected better incomes in stocking densities of 20 and 30 shrimp/m2.