Bioscience Evidence 2026, Vol.16, No.4, 264-276 http://bioscipublisher.com/index.php/be 266 acidic conditions (pH 5.4±0.2), all larvae died within 48 h (Liew et al., 2022). Studies on PL5 to early juvenile prawns showed that pH 5 significantly reduced body length and weight, while pH 4 prevented normal metamorphosis, caused extremely uneven body size distribution, and resulted in thinner shells. In contrast, growth performance at pH 6 was similar to the control pH 7.5 group, and the highest survival rate was observed at pH 6 (Kawamura et al., 2015). Laboratory studies indicated that pH 8 promoted the fastest molting and highest growth increase. However, in pond environments, pH fluctuates due to daily photosynthesis and respiration processes, making continuous monitoring more important than single measurements (Habashy and Sharshar, 2020). Nitrogen compounds, especially total ammonia nitrogen and nitrite, are among the most common water quality risks in M. rosenbergii aquaculture. Ammonia nitrogen and nitrite are important monitoring indicators during farming. Even small amounts of ammonia accumulation can disrupt growth stability, while high concentrations may affect enzyme activity, cell membrane permeability, excretion systems, and osmotic balance. In a 165-day experiment in the Philippines, the biofloc system did not change dissolved oxygen, temperature, or pH, but significantly reduced total ammonia nitrogen and nitrate levels while improving weight gain, net production, and specific growth rate (Camarin et al., 2023). Figure 1 1-14 Stage 11 and 12 developmental stages of M. rosenbergii larvae exposed to (a) neutral (pH 7.7 ± 0.4) and (b) mild-acidic (pH 6.4 ± 0.5) conditions (Adapted from Liew et al., 2022) 2.3 Transparency, algae, and ecological balance Water transparency and algal dynamics reflect the balance between pond primary productivity and organic loading, and they are also important ecological indicators connecting dissolved oxygen, pH, and nutrient cycling. In 195-day pond culture systems in the Koraput mountainous region of India, continuous monitoring of transparency, chlorophyll a, nitrate, phosphate, and organic carbon showed significant differences among ponds with different feeds during the culture period. Growth curves showed rapid growth during the first 90 days followed by stabilization, indicating that pond optical properties and nutritional conditions changed together with the culture stage (Khemundu and Banerjee, 2019).
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