Water Quality, Nutritional, Hematological, and Growth Profiles of Ompok pabda Fish Fry Reared in Biofloc Technology and Traditional Culture System with Different Stocking Densities.

Abstract

The present study evaluated water quality, immune responses, nutritional condition, and production of Ompok pabda fry (0.29-0.31 g) reared in a Biofloc technology (BFT) system (C:N = 20:1; molasses as organic carbon source), compared to the traditional culture system (TS; farmer's practice). The experiment had stocking densities for the treatments of 17 (TS1) and 22 (TS2), 17 (BFTS1), 22 (BFTS2), and 27 (BFTS3) fish/m2. The fishes were fed at 3-10% of their body weight, and reared in cemented tanks for 90 days. Regarding water quality, dissolved oxygen (DO), pH, and total ammonia nitrogen (TAN) levels varied significantly (p < 0.05) between the traditional and BFT tanks. The highest specific growth rate (SGR) was in the BFTS1-reared fishes (4.11 ± 0.17) but the lowest was in the TS2-fish (3.51 ± 0.05). The fish reared in BFT had higher levels of protein, lipids, polyunsaturated fatty acids, essential amino acids, hematocrit, and neutrophil than the fish reared in TS tanks. Moreover, 98.33% survival was recorded in the BFTS1 while 86.67% was in the TS2. The highest BCR was estimated for the BFTS2 (1.22). Taking into account FCR and BCR values, a stocking density of 22 fry/m2 is likely practicable for an O. pabda BFT system.