Evaluation of different salinities in polyculture of tilapia Oreochromis sp., and white shrimp Litopenaeus vannamei in a biofloc system.

Resumen

Objective: Polyculture in aquaculture is considered an effective strategy for improving production yields per unit area, and the use of biofloc systems represents a viable alternative for mitigating the negative environmental impacts associated with aquaculture discharges. This study evaluated the effect of different salinities on a polyculture of Litopenaeus vannamei post-larvae and Oreochromissp. hatchling in a biofloc system.

Design/Methodology/approach: The experiment lasted 60 days, during which, four different salinities (T1 = 5 g/L, T2 = 10 g/L, T3 = 15 g/L, T4 = 20 g/L) were tested in triplicate, in addition to a control treatment (TC = 2 g/L). The stocking density was 60 tilapia fry and 20 white shrimp post-larvae per treatment. The parameters evaluated included growth (weight and length) and survival of both organisms.

Results: Regarding growth, no significant differences were observed among treatments for any of the species (p > 0.05). The average growth values ​​for tilapia were 8.51 ± 2.76 g and 5.92 ± 0.85 cm, and for shrimp 1.73 ± 2.55 g and 5.84 ± 1.98 cm, with no differences among treatments. However, significant differences were found in survival. Treatments T1 (5 g/l) and T2 (10 g/l) showed higher survival for tilapia (96.43 ± 1.19%) and shrimp (90.97 ± 1.69%) compared to T3 (15 g/l) and T4 (20 g/l), which showed lower survival (tilapia: 73.10 ± 5.11%, shrimp: 74.47 ± 15.65%). The control treatment (CT) showed similar survival to treatments T1 and T2 for both species (p < 0.05).

Limitations on study/implications: The scale of the study, conducted in experimental tanks, could limit the direct extrapolation of the results to larger-scale commercial conditions.

Findings/conclusions: The results highlight the effectiveness of biofloc systems in combination with polycultures, especially under low to moderate salinity conditions, as a sustainable, economical, and efficient strategy for aquaculture production.