Luis Otavio Brito

Stocking densities and feeding strategies in shrimp and tilapia polyculture in tanks

The objective of this work was to evaluate the performance of Pacific marine shrimp (Litopenaeus vannamei) and tilapia (Oreochromis niloticus), in a polyculture in tanks subjected to different stocking densities and feeding strategies, in comparison with monoculture. Two experiments were performed, at the same time, in a completely randomized design with three treatments and four replicates each. Treatments for experiment I were: monoculture with 10 shrimp per m2 (10S:0T); polyculture with 10 shrimp and 0.5 tilapia per m2 (10S:0.5T); and polyculture with 10 shrimp and 1 tilapia per m2 (10S:1T). Shrimp was the main crop, and feed was provided based on shrimp biomass. Treatments for experiment II were: monoculture with 2 tilapia per m2 (2T:0S); polyculture with 2 tilapia and 2.5 shrimp per m2 (2T:2.5S); and polyculture with 2 tilapia and 5 shrimp per m2 (2T:5S). Tilapia was the main crop, and feed was provided based on fish requirements. In the experiment I, tilapia introduction to shrimp culture resulted in lower shrimp growth and poor feed conversion rate. In experiment II, shrimp introduction to tilapia culture did not interfere with fish performance. Polyculture is more efficient with the combination of 2 tilapia and 2.5 or 5 shrimp per m2 and feed based on fish requirements.

Intensive culture system of Litopenaeus vannamei in commercial ponds with zero water exchange and addition of molasses and probiotics

A 16-week trial was carried out to evaluate an intensive culture system of Litopenaeus vannamei in commercial ponds with zero water exchange. Two management ...

Bioremediation of shrimp biofloc wastewater using clam, seaweed and fish

ABSTRACT The aim of this study was to evaluate the bioremediation of effluents in the biofloc culture of shrimp juveniles using clams, seaweed and fish. Four treatments were considered: CLT – without bioremediating organisms; AB – using Anomalocardia brasiliana; GB – using Gracilaria birdiae and ON – using Oreochomis niloticus with 2.5 kg wet weight per m3 of shrimp effluent. In the AB treatment, significant differences were observed in the effluent at the end of the experiment (96 h) for values of nitrite-nitrogen, nitrate, alkalinity, TSS and orthophosphate. The ISS and VSS levels recorded for the AB treatment varied respectively from 336 to 127 mg L−1, and from 505 to 130 mg L−1, with a corresponding gradual reduction of approximately 62% and 74% at the end of the experiment. The use of a clam species to treat effluents in a biofloc system with salinity near 25 g L−1 reduced waste solids and increased the nitrification process from 72 to 96 h, indicating that this clam can be used as a bioremediator and contributes to effluent treatment in shrimp.

Supervivencia de poslarvas de Litopenaeus vannamei sometidas a la prueba de estrés osmótico y su relación con el estado de muda

This study was designed to evaluate the survival of shrimp postlarvae under osmotic stress and its relation with the molt stage. Postlarvae used were in stag...