KONINKLIJKE ACADEMIE VOOR OVERZEESE WETENSCHAPPEN ...
KONINKLIJKE ACADEMIE VOOR OVERZEESE WETENSCHAPPEN ...
KONINKLIJKE ACADEMIE VOOR OVERZEESE WETENSCHAPPEN ...
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— 291 —<br />
The results show no statistically significant differences (p > 0.05) in fecundity,<br />
fertilization and hatching rates between pituitary gland hormone concentration<br />
levels of 8 to 12 mg/kg. The mean fecundity fluctuated around 662,689 to<br />
742,045 eggs/kg. The lowest fecundity and fertilization rate obtained<br />
662,689 eggs/kg and 79.3 % respectively which were observed at the hormone<br />
concentration level of 9 mg/kg, and the highest of 731,704 eggs/kg and 93.5 %<br />
respectively were observed at concentration of 1 0 mg/kg.<br />
3.1.4.4. Experiment 2: Nursing Climbing Perch: from Larvae to Fingerlings<br />
— Water Quality Parameters in Nursing Systems<br />
The water quality parameters in all experimental nursing systems are showed<br />
in tables 6 and 7.<br />
Treatment<br />
parameters<br />
Water temper. (°C)<br />
DO (mg/1)<br />
Parameters<br />
Table 6<br />
Water quality parameters for the experiments in concrete tanks<br />
I II III<br />
AM PM AM PM AM PM<br />
27.5 ± 0.8<br />
3.12 ± 0 .5<br />
29.5 ± 0.7<br />
3.58 ± 0.7<br />
28.2 ± 0.4<br />
4.05 ± 0.5<br />
Table 7<br />
29.8 ± 0.4<br />
4.05 ± 0.5<br />
27.0 ± 0.6<br />
4.15 ± 0.8<br />
Water quality parameters for the experiments in earthen ponds<br />
Nursing periods (days)<br />
29.2 ± 0.3<br />
4.00 ± 0.7<br />
3 10 17 24 31 38 45<br />
Water temper. (°C) 29.0 29.5 29.5 30.0 31.0 32.0 30.0<br />
Dis. oxygen (mg/1) 3.44 3.2 2.0 2.64 2.96 3.28 2.08<br />
COD (ppm) 9.2 8 9.6 23.2 23.2 17.6 10<br />
N-NH4* (ppm) 0.16 0.16 1.50 0.21 1.69 1.30 0.06<br />
P-POj' (ppm) 0.06 0.07 0.10 0.45 0.07 0.08 0.06<br />
During nursing periods, the water quality parameters in concrete tanks and<br />
earthen ponds such as water temperature and dissolved oxygen ranged from 27-<br />
29.8 °C, 3.1-4.6 ppm and 29-32 °C, 2.0-3.4 ppm respectively. The concentrations<br />
of chemical oxygen demand, ammonia and phosphorus in earthen pond<br />
system fluctuated from 8-23.2 ppm, 0.06-1.69 ppm and 0.06-0.45 ppm respectively.<br />
Throughout the biological and ecological characteristics of climbing<br />
perch in the nature, most of water quality parameters were acceptable for fish<br />
growth and development in culture systems (P e k a r et al. 1998, X u a n et al. 1994,<br />
K h a n h et al. 1999).