Rural communities in Mexico and other countries with limited economic resources require a low-cost measurement system for the piezometric level and temperature of groundwater for their sustainable management, since anthropogenic action (pumping extractions), natural recharge and climate change phenomena affect the behavior of piezometric levels in the aquifer and its sustainability is at risk. Decrease in the piezometric level under a balanced level promotes salt intrusion from ocean water to the aquifer, salinizing and deteriorating the water quality for agriculture and other activities; and a decrease in water level under the pumps or well drilling depth could deprive communities of water. Water temperature monitoring is essential to determine electric conductivity and dissolved salt content in groundwater. Using IoT technology, a device was developed that monitors both variables inside the well, and the ambient temperature and atmospheric pressure outside the well. The measurements are made in real time, with sampling every second and sending data to a dedicated server every 15 min so that the visualization can be accessed through a device with Internet access. The time series of the variables measured inside and outside the well were obtained over a period of three months in the rural community of Agua Blanca, Guasave, Sinaloa, Mexico. Through these records, a progressive temporary drawdown of the piezometric level is observed, as well as the frequency of pumping. This low-cost IoT system shows potential use in hydrological processes of interest such as the separation of regional and local flow, drawdown rates and recognition of geohydrological parameters.

Probiotics and co-culture of shrimp and tilapia are two strategies to improve yield and ecoefficiency of both species. However, only few studies have analyzed the combination of these two strategies. This study analyzes the effect of a mixture of potential probiotics supplied in the diet at different frequencies in a system of shrimp (10/m2) and tilapia (5/m2) in a trial lasting 84 days. The probiotics mixture was composed of four lactic acid bacteria and one yeast strain that were supplied either daily, every 5 days, or every 10 days in the diet and compared with a control without any supply of probiotics. At the end of the experiment, blood chemistry and hematology of shrimp and tilapia were analyzed as an index of physiological condition. Water quality did not differ between treatments. The final weight, feed conversion ratio, and yield of shrimp were significantly higher with daily supply of probiotics compared to shrimp that did not receive probiotics supply, with intermediate values for treatments with probiotics supply every 5 or 10 days. However, level of supplementation every 5 days could be considered as optimal because no significant differences with daily supply were observed for any variable, whereas the supply each 10 days resulted in a significantly lower yield. Significantly higher final weight, feed conversion ratio, and yield of tilapia occurred with daily supplements. Blood cholesterol in tilapia significantly decreased with increasing frequency of probiotics supplementation. These results indicate that probiotics supplements for shrimp and tilapia cultivated simultaneously improved yields and physiological condition.

Consumer demand for aquatic animals has led to increased interest in using new species for aquaculture purposes. This study appraises the potential for aquaculture of the cauque prawn Macrobrachium americanum using wild juveniles from the west coast of Mexico. Four treatments were applied; treatments A and B consisted of 196 prawns/m2 and treatments C and D of 98 prawns/m2, with and without shelter, respectively. Growth and survival under these conditions were examined for 84 d. The combination of 98 prawns/m2 and shelter resulted in the best survival and growth, whereas the poorest performance was in the treatment with 196 prawns/m2 and no shelter.

This study evaluated the effect of temperature on morphometric features of the egg during the embryonic development of the prawn Macrobrachium americanum and the relationship with hatching and the survival of the larvae. Berried females were grouped (n = 3) and reared at three different temperatures, 26, 29, and 33 °C, for which seven developmental stages were recognized. At each stage, the apical and sagittal diameters of the eggs were measured, the volume was calculated, and the weights were recorded. Additionally, the duration of embryonic development, hatching percentage, and larval survival were determined. At 29 and 33 °C, the eggs’ volume increased by 50%, but at 26 °C, the increase was 25%. Larvae from eggs incubated at 33 °C died one day after hatching. At 29 °C, larvae survived until Zoea VII. Larvae from eggs incubated at 26 °C died at the end of Zoea I. The number of days of embryonic development was 20.5 ± 1.5 (26 °C), 15 ± 1 (29 °C), and 12 ± 1 (33 °C). A temperature of 29 °C was the most favorable for embryonic development in M. americanum.

Biomarkers for monitoring shrimp health have been proposed but scarcely evaluated at the farm level. We analyzed several indicators of energy status in shrimp under farming conditions concerning stocking densities (100 m-2 with biofloc, 15 and 7 m-2). The influence of the year's season (temperature) was also analyzed, and, finally, an unfortunate event of White spot syndrome virus (WSSV) infection occurred on the 7 m-2 farms, adding another condition. At shrimp sampling from ponds, the effect of acute handling stress was also analyzed for indicators typically affected by such procedure with a 3- and 10-fold increase in glucose and lactate levels in hemolymph, respectively, regardless of density. This response was partially blunted at lower temperatures and WSSV incidence. Increased levels of protein in the hepatopancreas, adenylic energy charge (AEC) in both hepatopancreas and muscle and phosphagens in muscle were observed in shrimp from the 100 m-2 farms, suggesting a better nutritional and energetic status in shrimp cultured at high density with biofloc technology. Shrimp with WSSV presented lower hemocyanin levels in hemolymph, most likely associated with its role in the immune response. In WSSV-infected shrimp, the stress response regarding glucose increase was blunted, whereas a stress-induced increase in triglycerides (TG) levels in hemolymph was observed only with WSSV. Increased TG levels in those shrimp hepatopancreas could indicate a switch from carbohydrate to lipid-based metabolism associated with the preferential use of carbohydrates (Warburg effect) for virus replication in the early infection state.