The study was carried out for 138 days to know the growth and survival rate of P. monodon by applying probiotics in Gazi Fish Culture Ltd. Dacope, Khulna, Bangladesh. Six experimental ponds (4000 m 2 in size i.e. one acre) were selected of which three were probiotic ponds and three were controlled. After pond preparation, PL 15 (average weight of each 4.75±0.09 g) was stocked at the rate of 13 per m 2 following polymerase chain reaction (PCR) test. CP NASA shrimp feed was used during the study period. Transparency, salinity, pH, dissolved oxygen (DO), temperature, total Ammonia Nitrogen (TAN) were recorded by standard measurements. The average final body weight of the harvested shrimp is 37.67±1.15 g in probiotics ponds and 27.33±0.58 g in controlled ponds and the difference was significant (P < 0.01) between these two productions. The average survival rate was 90.67±1.15 % in probiotic pond and 71.00±3.0 % in controlled pond. The average daily gain (ADG) in weight was 0.27±0.01 g and 0.19±0.01 g in probiotic and controlled ponds, respectively. The result showed that probiotic plays an important role in maintaining water quality parameters, soil quality and health management as well as increases the growth and survival of shrimp.

An experiment was conducted on environmental implications and its impact on aquatic productivity in the southwest coastal region for a period of 2 months (May-June/2013). Five Rivers such as Pira River, Andarmanik River, Sonatala River, Khaprabhanga River and Rupsaha River were selected for sample collection and were treated as T 1 , T 2 , T 3 T 4 and T 5. Three sampling sites were selected from each River based on salinity. The overall mean values of water temperature were 28.17 ±0.98, 27.41 ±1.21, 28.12 ± 1.11 and 27.13 ± 1.26, 26.62 ± 1.01 0 C in treatment T 1 , T 2 , T 3, T 4 and T 5, respectively. The mean values of water transparency of treatments T 1 T 2 T 3 T 4 and T 5 were 36.00±1.26, 31.0±0.0894, 34.00±1.94, 28.00±1.46 and 31.00±1.86cm, respectively. The overall mean values of water temperature were 6.56 ± 0.12, 6.47 ±0.23, 6.34 ± 0.12, 6.19 ± 0.22, and 6.67 ± 0.29 ppm in treatment T 1 , T 2 , T 3, T 4 and T 5 respectively. pH values were found to fluctuate from 6.72 to 7.64, 6.48 to 7.13, 6.95 to 7.35 and 6.86 to 7.6 in treatment T 1 , T 2 , T 3, T 4 and T 5 respectively . Mean values of total salinity were 2.17 ±0.12, 6.17 ±0.82, 7. respectively. There were no significantly different of temperature, dissolved oxygen pH and alkalinity among the treatments but significance difference found in transparency, salinity, hardness, ammonia, nitrite using ANOVA (P<0.05). Ammonia and nitrite concentration of Rupsha River (T 5 ) higher than other four Rivers due to municipal waste product of Khulna city. A proportionally strong relationship was found among salinity, transparency and hardness. Highest concentration of phytoplankton was found in Rupsha River (lowest salinity) and lowest phytoplankton concentration was found in Khaprabhanga River (highest salinity).

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