Precision aquaculture is a new field that allows farmers to have better control over aquaculture processes, facilitating decision-making and improving efficiency. The implementation and evaluation of a low-cost water-quality monitoring system based on open-source hardware, which is easy to rebuild for scientific applications, is reported in this paper. The proposed system measures temperature, dissolved oxygen, and pH, taking records and sending information through a wireless protocol (ZigBee) to a graphical user interface which can display information numerically and graphically, as well as simultaneously storing the information in a database. These variables are very important for aquaculture, as they have a direct influence on critical culture parameters such as growth and survival. Although it is a low-cost system, it offers good quality data and demonstrates efficiency for its use in precision aquaculture.

The present study was focused on assessing the effect of diets formulated with different sources and levels of protein on the production response of white leg shrimp Penaeus vannamei farmed at low salinity (3 g L-1). The protein sources were: soy meal (SM) and fish meal (FM), included at three levels: low (22-25%), medium (32-35%), and high (41-45%). A bioassay of 49 days was done in experimental tanks of 100 L (three tanks per treatment). Juvenile P. vannamei having a mean weight of 1.41 ± 0.30 g were stocked at a density of 100 ind m-3. Shrimp fed diets formulated with FM recorded significantly higher weight gain, specific growth rate (SGR), and protein assimilation efficiency rate (PER). Additionally, it showed a higher concentration of essential amino acids like methionine and threonine, and higher ash, calcium, iodine, phosphorous, and sodium content, which could favor the growth and survival of shrimp. Regression analysis showed that the optimum protein levels for diets formulated with SM and FM were 34.8 and 29.3%, respectively. These findings may help shrimp farmers to implement better feeding strategies for P. vannamei farmed at low salinity and on the use of alternative ingredients to substitute fish meal in the formulated feed.

Shrimp farming is supported by fast-growth and high-resistance genotypes. Protein requirement is important for shrimp perfomance. Fishmeal is the main source, but their limited production increase feed formulation costs for aquaculture. This study evaluated the effect of genotype and protein source on performance of two shrimp genotypes. Shrimps with fast-growth (FG) and high-resistance (HR) were randomly assigned to two dietary treatments (animal and vegetal protein) in a 2 × 2 factorial design. A 36-day bioassay was realised in clear-water hyper-intensive system to compare FG and HR performance using three replicate tanks for each genotype and dietary treatment. Each tank was seeded with 10 shrimp with average initial weight of 2.03 ± 0.10 g for FG genotype and 2.07 ± 0.02 g for HR genotype, at a density of 250 shrimp/m³. A weekly biometry was realised to monitor the shrimp performance. We observed a significant interaction (p < .05) between genotype and diet for shrimp growth performance. Compared with HR shrimp, FG shrimp showed higher growth and better feed efficiency. The maximum weight gain was recorded, FG shrimp was significantly higher than HR shrimp independently of protein source. Diet with different protein source significantly influence the performance of FG shrimp, while in HR shrimp there is no significant difference between dietary treatment. The comparison showed that genotype, diet and their interactions influenced the performance of Litopenaeus vannamei. This research may be useful for improving genetic selection programmes, reducing feed costs for shrimp industry and design-feeding strategies for shrimp genotypes.

This short-term study evaluated the effect of non-lethal high CO2 concentration on the transcriptional response of immune-related genes of Pacific white shrimp (Litopenaeus vannamei) cultured in recirculating aquaculture systems (RAS). Two experimental groups were created: high CO2 (47.67±2.04 mg L−1) and low CO2 (2.0±1.93 mg L−1). Shrimp of 8.85±1.20 g were placed randomly at a density equivalent to 100 individuals m−3 and were monitored at 6, 12, 18, and 24 h. The transcriptional response of immune-related genes was analyzed [...] ABSTRACT This short-term study evaluated the effect of non-lethal high CO2 concentration on the transcriptional response of immune-related genes of Pacific white shrimp (Litopenaeus vannamei) cultured in recirculating aquaculture systems (RAS). Two experimental groups were created: high CO2 (47.67±2.04 mg L−1) and low CO2 (2.0±1.93 mg L−1). Shrimp of 8.85±1.20 g were placed randomly at a density equivalent to 100 individuals m−3 and were monitored at 6, 12, 18, and 24 h. The transcriptional response of immune-related genes was analyzed

An eight-week feeding trial investigated the effects of fishmeal (FM) replacement by soybean meal (SBM) and poultry by-product meal (PBM) in diets supplemented with two methionine sources (DL-Met and AQUAVI®) and their combinations with ECOBIOL® (Bacillus amyloliquefaciens CECT 5940) on growth performance, body composition, and nutrient metabolism of Penaeus vannamei. Four hundred shrimp (0.30 ± 0.04 g) randomly distributed into 20 tanks (20 shrimp tank-1) were fed with five experimental diets (four repetitions per diet). A control diet (CD; 20% FM) and four diets with 50% FM replacement supplemented with different methionine sources and ECOBIOL® combinations: D1 (0.13% DL-MET), D2 (0.06% AQUAVI®), D3 (0.13% DL-MET plus 0.10% ECOBIOL®), and D4 (0.06% AQUAVI® plus 0.10% ECOBIOL®). Shrimp fed D2 and D4 had better growth performance, nutrient utilization, and body composition. Shrimp fed D3 also had good growth performance but higher lipid body composition. Shrimp fed D1 had the worst growth performance, nutrient utilization, and body composition values. Nutrient metabolism-related genes were affected by dietary treatments. Protein synthesis-related genes decreased mostly in shrimp fed D1 and D2 while increased mostly in shrimp fed D3 and D4, lipolysis-related genes had a better transcriptional response in shrimp fed D4 and lipogenesis-related genes were mostly downregulated in shrimp fed D2 while were mostly upregulated in shrimp fed D3 and D4. Results suggested that FM could be partially replaced with SBM and PBM in shrimp feeds supplemented with 0.06% AQUAVI® alone or combined with 0.10% ECOBIOL® without adversely affecting the growth and nutrient metabolism of P. vannamei.