Production of Pacific white shrimp juveniles in different stocking densities in a low salinity biofloc system during winter

This study compared the production of P. vannamei juveniles reared in a low salinity biofloc system during winter in northeastern Brazil in three stocking densities (75, 150, and 301 shrimp m⁻²), focusing on water quality and growth performance parameters. Shrimp (0.038 ± 0.08 g) were reared for 75 days in 700-L tanks without artificial heating for water temperature control and fed three times daily. Results illustrated that the treatment with 301 shrimp m⁻² had higher mean values of total ammonia nitrogen compared with 75 shrimp m⁻², while the treatment with 150 shrimp m⁻² had values similar to both other treatments. Treatments with 150 and 301 shrimp m⁻² produced higher settleable solids volumes compared with 75 shrimp m⁻². Other water quality parameters did not differ significantly among treatments. The treatment with 75 shrimp m⁻² was more effective in producing P. vannamei juveniles, achieving a survival rate above 82 %, higher growth rate, higher final weight, and a lower feed conversion ratio compared to the treatments with 150 and 301 shrimp m⁻². However, overall performance across all treatments was limited by the combined effects of low salinity and low temperature. Thus, maintaining water temperature within the optimal range for P. vannamei is crucial to optimize production and minimize losses, especially in low salinity conditions.