Evaluation of High Stocking Densities on the Water Quality and Growth Performance of Pacific White Shrimp Litopenaeus vannamei Reared in a Mixotrophic Biofloc Nursery System
Table 1
The results (mean ± SE, minimum, and maximum) of water quality monitoring in different treatments after 21 days of L. vannamei intensive culture during the nursery phase.
Parameters
Treatments
p-Value
G5000
G4000
G3000
Temperature (°C)
31.66 ± 0.17 (29.4, 32.9)
32.00 ± 0.14 (29.6, 32.9)
32.10 ± 0.13 (29.7, 32.9)
0.118
Salinity (ppt)
34.78 ± 23b (31.68, 36.55)
34.57 ± 16b (33.06, 36.55)
35.71 ± 23a (33.36, 37.89)
0.001
DO (mg/l)
6.07 ± 0.08 (4.83, 6.61)
6.04 ± 0.05 (5.37, 6.63)
6.05 ± 0.04 (5.60, 6.57)
0.953
DOS (%)
97.71 ± 1.18 (79.20, 104.10)
98.10 ± 0.74 (88.50, 103.80)
98.92 ± 0.56 (92.10, 103.70)
0.609
Free CO2 (mg/l)
4.27 ± 0.64 (2.99, 7.17)
3.86 ± 0.43 (2.60, 5.33)
3.84 ± 0.41 (2.42, 5.32)
0.801
pH
7.78 ± 0.02 (7.58, 8.01)
7.81 ± 0.02 (7.62, 8.05)
7.84 ± 0.01 (7.66, 8.06)
0.172
pHmV
−67.65 ± 1.64 (−81.7, −55.60)
−69.51 ± 1.48 (−83.7, −57.80)
−71.80 ± 1.12 (−84.3, −60.4)
0.128
TDS (mg/l)
31,205 ± 188b (28,691, 32,608)
31,034 ± 135b (29,840, 32,604)
31,941 ± 187a (30,076, 33,690)
0.001
EC (µS/cm)
48,008 ± 290b (44,140, 50,167)
47,745 ± 208b (45,908, 50,160)
49,141 ± 288a (46,272, 51,832)
0.001
ORP (mV)
86.54 ± 3.75 (65, 149.80)
84.31 ± 3.36 (61.70, 142)
82.91 ± 3.17 (59.50, 136.20)
0.754
SSG (sigma-t, σT)
21.88 ± 0.27ab (20.2, 23.50)
21.67 ± 0.17b (20.41, 23.30)
22.44 ± 0.26a (20.66, 24.30)
0.076
Alkalinity (mg/l CaCO3)
128.31 ± 7.87 (70.59, 158.62)
131.79 ± 5.34 (86.27, 144.83)
135.13 ± 4.36 (109.8, 158.62)
0.729
TAN (mg/l)
0.21 ± 0.05 (0.00, 1.5)
0.22 ± 0.0.05 (0.00, 1.34)
0.11 ± 0.0.02 (0.00, 0.65)
0.225
NO2-N (mg/l)
4.12 ± 0.96 (0.06, 9.15)
4.56 ± 1.08 (0.02, 11.03)
3.97 ± 0.98 (0.06, 9.23)
0.913
NO3-N (mg/l)
9.74 ± 2.15 (0.09, 15.96)
9.02 ± 2.29 (0.14, 15.17)
8.10 ± 2.41 (0.05, 14.42)
0.881
SS (ml/l)
3.34 ± 1.21 (0.1, 8.50)
2.68 ± 0.94 (0.1, 6.50)
1.18 ± 0.96 (0.1, 2.80)
0.062
Note: Treatments included: G5000, 5,000 PL/m3; G4000, 4,000 PL/m3; G3000, 3,000 PL/m3. Different superscript letters imply significant differences at . DO, dissolved oxygen; DOS, dissolved oxygen saturation level; TDS, total dissolved solids; EC, electrical conductivity; ORP, oxidation-reduction potential; SSG, seawater specific gravity; TAN, total ammonia nitrogen; SS, settleable solids.
