Work

Effects of Stocking Densities on the Growth Performance and Physiology of Juvenile Piaractus brachypomus in Recirculating Aquaculture System

Year: 2025

Type: article

Abstract: The effects of different stocking densities on the growth and physiology of juvenile Piaractus brachypomus were evaluated in two experiments. Experiment I used juveniles weighing 1.5 ± 0.4 g at the following densities for 20 days: D0.68—0.68 kg/m3; D1.45—1.45 kg/m3; D4.41—4.41 kg/m3; and D7.17—7.17 kg/m3. Experiment II used juveniles weighing 6.66 ± 1.3 g at the following densities for 20 days: D1.0—1.00 kg/m3; D1.95—1.95 kg/m3; D5.63—5.63 kg/m3, and D7.90—7.90 kg/m3. Both experiments showed a reduction in dissolved oxygen levels in the water, with Experiment II showing a plateau effect from 2.34 kg/m3 (p < 0.05). Final weight, final length, weight gain, daily weight gain, and specific growth rate were inversely proportional to density (p < 0.05), while final biomass, feed intake, and feed conversion were directly related to density in both experiments (p < 0.05). At the end of Experiment II, plasma triglycerides decreased as stocking density increased (p < 0.05), and hemoglobin and mean corpuscular volume were higher at the lowest density (D1.0) (p < 0.05). High stocking densities reduced dissolved oxygen, characterizing a hypoxic state in both experiments, affecting growth and some physiological parameters. Therefore, studies testing stocking densities for P. brachypomus in normoxic situations are still needed.

Source: Fishes

DOI: 10.3390/fishes10040171