PACIFIC WHITE SHRIMP AND NILE TILAPIA INTEGRATION IN BIOFLOC SYSTEM UNDER DIFFERENT FISH-STOCKING DENSITIES

Felipe do N. Vieira*, Esmeralda C. Legarda ^a, Marco A. Lorenzo^a, Mateus A. Martins^a, Moisés A. Poli
^aLaboratório de Camarões Marinhos, Departamento de Aquicultura, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina, Brazil. felipe.vieira@ufsc.br

This study aimed to evaluate the effect of different stocking densities of Oreochromis niloticus integrated with Litopenaeus vannamei reared in a biofloc system.

The performances of both species and the ecological efficient of the system were evaluated. Four levels of tilapia stocking density were evaluated: 0, 8, 16 and 24 fish per tank. The initial weight was 4.8 ± 0.1 g and 9.6 ± 0.1 g for shrimp and fish, respectively. The shrimp were fed according the feed table, and the fish were fed with 1% of the fish biomass, stimulating the tilapia to seek food in the biofloc. Results show no difference between average shrimp and fish weight and survival (Table 1). Total yield was higher based on the increase in fish density. The sludge produced per animal biomass (sludge:biomass rate) decreased as fish density increased
(y = - 0.0083x + 0.5995 r²= 0.87). Nitrogen recovery rose linearly with the increase in fish density (y = 0.036x + 0.2725, r² = 0.84), as did phosphorus recovery
(y = 0.00711x + 0.1395, r² = 0.91). Nitrogen and phosporou recovery were 27.9% and 223%, respectively, higher in the treatment with the higher fish stoking density in comparison to shrimp monoculture.

These results demonstrate the feasibility of increasing yield up to 31% by integrating L. vannamei and O. niloticus in a biofloc system. Also, the decrease in the sludge:biomass rate and the resultant increase in nitrogen and phosphorus retention made the cultivation of L. vannamei in a biofloc system more sustainable.