Prenursery of the Pacific white shrimp in a biofloc system using different artificial substrates

This study evaluated different artificial substrates during pre-nursery of Pacific white shrimp in a biofloc system. Post-larvae (PL 5–80 PL L^?1) were raised in 60 L tanks filled with 52 L of chlorinated seawater (35‰) and 6 L of the microalga Chaetoceros muelleri. Four treatments were performed, including control (no artificial substrate), Bidim^® (geotextile), mosquito net screen (2 mm mesh) and Needlona^® (polyester fiber). The total surface area of artificial substrate comprised 100% of the tank area (0.89 m²). PLs were fed nine times a day using commercial feed. Molasses was added in all treatments four times a day at an average carbon:nitrogen ratio of 14.7:1. The experiment was carried out until the PLs reached PL20, and during this time, water quality, survival, weight gain and survival to salinity stress were all evaluated. Water quality parameters remained within the accepted levels for shrimp rearing, with the exception of total suspended solids (TSS) in mosquito net screen and control, which had the highest values (507 ± 5.50 mg L^?1 and 565 ± 23.46 mg L^?1, respectively). Using Needlona^® as artificial substrate increased the survival rate (91 ± 11.6%) and reduced TSS (42%) when compared to the control. No significant differences were observed in final weight and survival to salinity stress. Among the different substrates, Needlona^® was the most suitable for application in Pacific white shrimp prenursery in the biofloc system, essentially because it could maintain levels of solids suspended in water without the use of clarifiers or water exchange, resulting in higher survival.