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The bacterial content of the water of Metapenaeus affinis and Macrobrachium nipponense juvenile shrimp cultured in two salinities (3 and 15 g.L -1 ) were observed during 45 days. The initial and final weights of M. affinis were (0.939 ± 0.069 and 1.581 ± 0.183 g) in 3 g.L -1 , and (0.939 ± 0.065 and 2.274 ± 0.294 g) in 15 g.L -1 . While for M. nipponense, it was (0.914 ± 0.086 and 1.308 ± 0.070 g) in 3 g.L -1 , and (0.908 ± 0.070 and 1.086 ± 0.107 g) in 15 g.L -1 . The environmental factors were temperature 24-29 ˚C, acidity 7-8, and dissolved oxygen 5-10 g.L -1 . Bacterial contamination (CFU m.L -1 10⁶) was evident in treatment D and included four types of bacteria: Bacillus spp., Escherchia coli, Staphylococcus spp., Streptococcus spp., and Enterococcus spp. The survival rates of M. affinis during different breeding periods in the two salinities remained as follows:

The rearing of juvenile shrimp, Macrobrachium nipponense is of importance in the development of aquaculture, especially by using molasses and Bacillus lechniformis to promote growth. The present study aimed to evaluate the rearing of juvenile shrimp, M. nipponense in laboratory breeding ponds without replacing the water in the presence of B. lechniformis using two strategies: i)  Use of molasses (10=A, 50=B, and 100=C mg) with 1 × 10 ⁸ CFUml-1 B. lechniformis to the ponds, with shrimp in initial weight rates (650.00 ± 68.09, 639.67 ± 74.81, 639.67 ± 67.02) mg and final weight rates (695.67 ± 57.33, 825.00 ± 90.14, 761.33 ± 111.02) mg, ii) Use of feed (100=A, 250-B, and 500=C) mg, with shrimp initial weight rates (107.67 ± 21.94, 106.67 ± 20.82, 103.33 ± 18.93) mg and final weight rates (208.33 ± 16.07, 381.67 ± 36.17, 283.33 ± 15.28) mg. Results of statistical analysis for molasses showed significant differences (p < 0.05) in each daily growth (DG), Specific growth rate (SGR), and no significant differences (p > 0.05) in survival rates. As food conversion ratio (FCR), significant differences (p < 0.05) were found between A and B, contrary to C, which showed no significant differences. There were significant differences (p < 0.05) in DG among A, B, and C in using feed. While SGR showed significant differences (p < 0.05) between A and B but did not have significant differences with C and no significant differences (p > 0.05) in the survival rates.  FCR showed significant differences (p < 0.05) between C and both A and B, which showed no significant difference (p > 0.05) between them. The study will help to reduce the cost and waste of water.

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The impacts of different replacement levels of micro silica (MS), fly ash (FA), and the combined usage of MS and FA on the behavior of concrete were investigated. Design of experts has been used incorporating the response surface methodology to find the synergetic effect of FA and MS on fresh and hardened concrete properties. A total of 15 and 30% of the binder content were replaced by FA. As well as a total of 5 and 10% of the binder content were replaced by MS. Experimental results of concrete mixtures have been used to construct ANOVA models. These models have also been confirmed to expect the properties of concrete mixtures based on different fractions of FA ash and MS. All statistical models are significant because P-value is less than 5%, and the difference between predicted R 2 and adjusted R 2 is lower than 20%. The variation between confirmation tests for the optimized mixture and test results are lower than 5%.