Shrimp Performance Research Articles

Growth performance and survival rate of vannamei shrimp (Litopenaeus vannamei) post-larva stages in a super intensive cultivation system with varied densities

Vannamei shrimp (Litopenaeus vannamei) holds significant economic importance in Shrimponesia as a prominent shrimp commodity. The post-larval stage often encounters challenges, primarily due to the shrimp's limited ability to adapt and survive in a new environment. Stocking density is a crucial factor influencing the growth and production performance of vannamei shrimp culture. This study aims to assess the optimal stocking density for achieving optimal growth and survival in L. vannamei. A 40-day maintenance trial was conducted at UD Mina Rahayu Kalianda to investigate the impact of different stocking densities on water quality in the maintenance media. The study utilized containers with varying stocking densities: treatment A (1 shrimp/L), treatment B (1.5 shrimp/L), and treatment C (2 shrimp/L), each with three replications. The findings revealed survival rates (SR) of 83.33% for treatment A, 62.78% for treatment B, and 58.33% for treatment C. Mean Body Weight (MBW) values were recorded as 1.2592 g/shrimp for treatment A, 1.1216 g/shrimp for treatment B, and 0.7728 g/shrimp for treatment C. Average Daily Growth (ADG) results showed 0.0313 g/shrimp for treatment A, 0.0279 g/shrimp for treatment B, and 0.0192 g/shrimp for treatment C. Based on the study, the recommended stocking density for white vannamei shrimp is 40 shrimp/L, demonstrating improved growth and survival rates for this species.

Evaluation of polyurethane sponge biocarrier effects on Litopenaeus vannamei cultivation in zero water exchange systems based on water quality, shrimp performance and bacterial community analysis

Evaluation of polyurethane sponge biocarrier effects on Litopenaeus vannamei cultivation in zero water exchange systems based on water quality, shrimp performance and bacterial community analysis

Haematococcus pluvialis biomass as a replacement for fish meal in the diet of Macrobrachium amazonicum post-larvae (Heller, 1862)

The current study evaluates the effect of partial or total replacement of fish meal with Haematococcus pluvialis microalgae, cultivated in an NPK culture medium, on the growth performance of Macrobrachion amazonicum shrimp post-larvae. Four diets were formulated: control (without microalgae), 25, 50 and 100% H. pluvialis replacement. Only crude protein weight gain showed no interaction and was not selected for principal components analysis. The 25% fishmeal replacement in the diet was not effective, being similar to the control. However, the complete replacement of fishmeal with H. pluvialis promoted elevated survivability, length, weight and protein retention, making it the most relevant treatment for M. amazonicum post-larvae. Therefore, it is possible to completely replace fishmeal with the microalgae H. pluvialis in the diet of M. amazonicum shrimp, which improves growth performance.

Effects of Dietary β-Glucan Feeding Strategy on the Growth, Physiological Response, and Gut Microbiota of Pacific White Shrimp, Litopenaeus vannamei, under Low Salinity.

An eight-week feeding trial was conducted to investigate the effects of a dietary β-glucan application strategy on the growth performance, physiological response, and gut microbiota of Pacific white shrimp (Litopenaeus vannamei) (0.49 ± 0.17 g) under low salinity. Six feeding strategies were established, including a continuous β-glucan-free diet group (control), a continuously fed group with a 0.1% β-glucan diet (T1), and groups with the following intermittent feeding patterns: 1 day of β-glucan diet and 6 days of β-glucan-free diet (T2), 2 days of β-glucan diet and 5 days of β-glucan-free diet (T3), 3 days of β-glucan diet and 4 days of β-glucan-free diet (T4), and 4 days of β-glucan diet and 3 days of β-glucan-free diet (T5) each week. No significant differences in growth performance among all the groups were found, although the condition factor was significantly higher in the T3 group than in the T1 and T5 groups (p < 0.05). The T-AOC and GPX activities were significantly lower in the T3 group than in the control group (p < 0.05). The MDA content was also significantly lower in the T2 group than in the T3 and T4 groups (p < 0.05). Additionally, the mRNA expression of the Pen3a gene was significantly upregulated in the hepatopancreas of the T4 group compared to the control and T5 groups (p < 0.05), and the Toll gene was also significantly upregulated in the T3 group compared to the T1 and T2 groups (p < 0.05). Dietary β-glucan induced changes in the alpha diversity and composition of the gut microbiota in different feeding strategies. The beta diversity of the gut microbiota in the T2 group was significantly different from that in the control group. The results of a KEGG analysis showed that gut function in the carbohydrate metabolism, immune system, and environmental adaptation pathways was significantly enhanced in the T3 group. These findings provide evidence that the intermittent feeding strategy of β-glucan could alleviate immune fatigue, impact antioxidant ability, and change gut microbiota composition of L. vannamei under low salinity.

Implications of dietary soybean meal replacement with corn gluten meal on growth performance, antioxidant activities, hepatopancreatic histopathology, and intestinal flora of juvenile Pacific shrimp (Litopenaeus vannamei)

This study aimed to investigate the potential of replacing soybean meal (SBM) with corn gluten meal (CGM) in the diet of Pacific white shrimp (Litopaeneaus vannamei). The study examined the effects of a dietary soybean meal replacement on growth, biochemical indices, antioxidant activities, histology, and intestinal flora. A total of 840 juvenile Pacific shrimp were fed seven diets containing different levels of CGM, ranging from diet 1 (diet1) 0% (control), diet2 (3%), diet3 (7%), diet4 (9%), diet5 (11.8%), diet6 (12.7%), and diet 7 (14.4%). The experiment was conducted over 56 days, with three replicate of each group (initial mean weight = 0.13 0.00 g). The results showed that dietary CGM significantly increased final body weight, average weight gain, and specific growth rate. However, the inclusion of dietary CGM decreased with higher levels. The feed conversion ratio of diets 2 and 3 was considerably lower than that of the control group. The activities of alkaline phosphatase and acid phosphatase increased significantly with the feeding of CGM, while the levels of alanine aminotransferase and aspartate aminotransferase decreased significantly. The histology of the hepatopancreas showed an evident epithelial tubule (E, B, R, and F), and the number of intact epithelial cells increased considerably with the increasing inclusion of CGM (P < 0.05). The intestinal flora in the shrimp intestine responded favorably to the replacement of SBM with CGM in the dietary CGM treatment groups, including a number of beneficial bacteria such as Bacteroidetes and Firmicutes. Moreover, with rising CGM levels, diversity indices and richness estimates rose. The regression model with a broken line was found to describing the relationship between the growth rate and the optimal level of CGM required. The results showed that a CGM dose of 3.31% was the most effective for achieving optimal growth performance in juvenile L. vannamei.

Evaluation of growth performance and water quality of vannamei shrimp (Litopenaeus vannamei) in intensive cultivation systems

The success of shrimp cultivation is assessed based on the resulting performance, survival, growth, and total shrimp production. Apart from parent quality and feed quality, water quality is a determining factor in the success of shrimp cultivation. Good water quality will increase cultivation productivity. The research aims to measure the performance of vannamei shrimp using an intensive cultivation system at PT Bumi Cimandala Lestari by paying attention to the quality of cultivation waters. This research uses a descriptive method by following the entire series of cultivation production in the Bumi Cimandala Lestari shrimp pond. The activity lasts three months, from August to November 2022 at PT. Bumi Cimandala Lestari is located at Kp. Cipeundeuy, Surade Village, Sukabumi Regency. The results showed that the average survival rate from 8 cultivation ponds reached 67% with a growth rate of 0.26 g/day. The total production obtained was 55.42 tons with a size of 70-100 fish/kg. Water quality during the study was within the optimal range. The pH value of the water ranges from 7-9 with salinity ranging from 18.1 – 20.4 ppt. Dissolved oxygen value &gt; 5 mg/L, and alkalinity ranges from 122 – 183 mg/L. The research showed that cultivation ponds had a temperature range between 24.8-30.4 and DO ranging from 2.49-8.23 mg/L. Water quality conditions are thought to support the growth and survival of shrimp well

Functional Effects of Hydrolyzable Tannins on the Growth, Health Status, and Hepatopancreas Histology of Pacific White Shrimp Penaeus vannamei Reared under Commercial Pond Conditions

In the present study, the functional effects of hydrolyzable tannins (HT) extracted from the sweet chestnut tree Castanea sativa were evaluated either by directly incorporating them into the diet or by using a top-dressing application on the growth, body composition, total hemocyte counts, lysozyme activity, and histomorphological condition of the hepatopancreas of Pacific white shrimp Penaeus vannamei. Shrimp was confined in hapa nets installed within commercial outdoor ponds for 90 days. Eight experimental diets included a basal formulated diet (BD) with varying inclusion levels of HT (BD-0%, BD-0.1%, BD-0.2%, and BD-0.3%), a low fish meal (FM) diet with reduction on the inclusion level of FM from 10% to 7.5% and labeled as LFM 0.3% HT, a top-dressing HT application (TC) on basal diet (BDTD-0.4% HT), and a commercial diet (CDTD-0% HT and CDTD-0.4% HT). The final body weight (FBW), percentage weight gain (PWG), thermal growth coefficient (TGC), average daily growth (ADG), and feed conversion ratio (FCR) were significantly better in the group of shrimp fed with BD-0.3% HT compared to BD-0% HT. The administration of CD-0.4% HT was able to enhance the growth performance of shrimp compared to BD-0% HT and CD without HT. Higher protein and fat contents were found in the body of shrimp fed with graded levels of HT compared to shrimp fed with BD or CD without HT. Numerically, the direct inclusion and top-dressing process of HT increased the total hemocyte count and lysozyme activity in shrimp. Both BDTD-0.4% HT and CDTD-0.4% HT were also able to support a better hepatopancreatic condition with reference to histomorphology and integrity. These results indicated that BD-0.3% HT inclusion could significantly improve the growth performance and prevent the alteration in health and histomorphological condition of the hepatopancreas of shrimp P. vannamei cultured in hapa nets under commercial farm conditions, but also 0.4% HT could be used as a supplementation dosage for the top-dressing process in diets.

Concentration of suspended solids in superintensive culture of the Pacific white shrimpLitopenaeus vannameiwith biofloc technology (BFT): A review

AbstractMicrobial flocs (bioflocs) present in the water of intensive culture tanks are formed by a variety of microorganisms and other kinds of particulate organic matter, such as faeces and uneaten feed. During shrimp culture, biofloc concentrations increase. It has been reported that some level of control over biofloc levels, which can be quantified by the concentration of total suspended solids (TSS), is necessary for the adequate performance of the system. Some authors suggest that TSS concentrations below 600 mg L−1are more appropriate for the superintensive culture of the Pacific white shrimpLitopenaeus vannameiin biofloc technology (BFT). However, subsequent research results contradict some of the arguments supporting the suggested solids limits, for example, the impact of increased solids on gill obstruction and subsequent shrimp survival. Recent studies have also shown the relationship between the control of solids and other important aspects of the system not considered so far, such as the control of opportunistic bacteria. Therefore, this topic seems worthy of revisiting, and it will be helpful to find new guidance toward understanding the levels of bioflocs that should be kept inL. vannameiculture tanks. In this review, we addressed the reasons that led to the establishment and limitations of the current biofloc levels forL. vannameiculture. The effects of maintaining low and high levels of bioflocs on both shrimp performance and the culture system are also analysed. Finally, perspectives on the management of biofloc levels are discussed, highlighting the advantages and disadvantages of each proposed strategy.

Protective effects of Chlorella vulgaris as a feed additive on growth performance, immunity, histopathology, and disease resistance against Vibrio parahaemolyticus in the Pacific white shrimp

The present study investigated the effect of Chlorella vulgaris on growth performance, feed consumption, body composition, and immune response of white shrimp (Litopenaeus vannamei) against Vibrio parahaemolyticus infection. Shrimps (4.00 ± 0.04 g) were divided into five groups (3 replicates/20 each) in 15 hapa (1 m3) and cultured for 56 days with five C. vulgaris experimented diets at five different concentrations (0, 15, 20, 25, and 30 g/kg feed). Growth performance, feed utilization, biomass, and body composition (protein, lipid, and ash) were analyzed and revealed significant increase (P < 0.05) in shrimp fed the high C. vulgaris diet. Additionally, the survival rate of shrimp in all experimental feeds was improved, but was not significant. Shrimp fed with C. vulgaris at different concentrations showed significantly (P < 0.05) higher antioxidant activity. The study showed that shrimp fed with a concentration of 30 g/kg C. vulgaris in the diet showed significantly (P < 0.05) highest disease resistance against the pathogen tested. Hence, dietary C. vulgaris might be used to improve growth performance, feed utilization, body composition, and immune biomarker responses, leading to disease resistance in cultured shrimp.

Dietary sodium benzoate improves growth, morphology, antioxidant capacity and resistance against Aeromonas hydrophila of Pacific white shrimp (Litopenaeus vannamei)

Acidifier has become one of the most important substitutes for antibiotics, and its beneficial effects on growth performance and digestive ability have been evidenced. Sodium benzoate is a commonly used acidifier. A 56-day feeding test was carried out to elucidate the effects of dietary sodium benzoate on growth performance, morphology, antioxidant activity and intestinal microflora of juvenile Litopenaeus vannamei with an average initial body weight of 0.55 ± 0.01 g. Six experimental diets were prepared by adding 0, 750, 1000, 1250, 1500 and 1750 mg/kg sodium benzoate to the control diet. The results showed that: The final body weight (FBW) and weight gain (WG) of juvenile shrimp were significantly improved by diet supplemented with 1750 mg/kg sodium benzoate. Dietary 1750 mg/kg sodium benzoate significantly increased the trypsin activity. The activities of catalase (CAT), superoxide dismutase (SOD) and glutathione S-transferase (GST) in the intestine and hepatopancreas of the 1750 mg/kg sodium benzoate group were markedly higher than those of the control group. Furthermore, the expression levels of trypsin (TRY), amylase (AMS), lysozyme (LZM), interleukin-8 (IL8) and interleukin-10 (IL10) genes in the intestine significantly increased when the content of sodium benzoate in the diet was greater than or equal to 1000 mg/kg. The addition of 1500 and 1750 mg/kg sodium benzoate to the feed improved the intestinal and hepatopancreatic tissue structures of juvenile shrimp and enriched the diversity of intestinal microbiota. Sodium benzoate residues were not detected in each sodium benzoate supplemented group. At the end of the Aeromonas hydrophila challenge test, juvenile shrimp in the 1500 and 1750 mg/kg group exhibited significantly higher cumulative survival rates than that in the control group. Conclusively, dietary 1750 mg/kg sodium benzoate could improve the growth performance, antioxidant capacity, morphology, intestinal microflora and disease resistance of juvenile shrimp.

Effects of spray-dried bovine plasma on growth performance, immune system, and survival of white shrimp (Litopenaeus vannamei)

The aquaculture industry in Mexico is searching for food ingredients that increase productivity without negatively affecting overall performance and health. Bovine plasma has been shown to contain a high concentration of bioactive compounds and growth factors that improve intestinal function and nutrient absorption. Therefore, the present study aimed to investigate the effects of spray-dried bovine plasma (SDBP) on growth performance, protein efficiency, immune system, and survival in white shrimp (Litopenaeus vannamei). Four diets were formulated to contain 0%, 1.5%, 3%, and 6% SDBP in isoproteic and isolipidic diets. Then, 120 juveniles of L. vannamei (4.02 ± 0.03) were randomly distributed in 12 ponds of 500-L with filtered seawater under a recirculation system (RAS). The diets were randomly distributed among the experimental tanks, with three ponds assigned per experimental diet. The feed was offered three times a day for eight weeks. At the end of the experiment, shrimp fed the diet with 3% SDBP had significantly (p < 0.05) improved overall performance compared to the other dietary treatments. Also, diets enriched with SDBP presented a significant increase (p < 0.05) of hemocytes compared to the dietary treatment SDBP-0, with a positive correlation between the number of hemocytes and increasing SDBP content. Furthermore, diets with 3% and 6% SDBP had the highest survival rate (90.0% and 93.3%, respectively). In conclusion, SDBP added at 3% in shrimp diets resulted in improved growth, survival, and hemocyte count. Therefore, SDBP is an excellent alternative to maintaining healthy shrimp.

Assessment of Bacillus subtilis fermented Caulerpa microphysa byproduct as feed additive on the growth performance, immune regulation and disease resistance of white shrimp (Litopenaeus vannamei)

In this study, the immunomodulatory and antioxidant activity of fermented Caulerpa microphysa byproduct (FCMB) by Bacillus subtilis was evaluated, and its potential as a feed additive for white shrimp (Litopenaeus vannamei) was explored. In vitro experiments showed that the FCMB supernatant contained polysaccharides, polyphenols and flavonoids, and exhibited antioxidant properties as assessed by various antioxidant assays. Additionally, the FCMB supernatant was found to increase the production rate of reactive oxygen species and the activity of phenoloxidase in hemocytes in vitro. Furthermore, the results of the in vivo feeding trial showed that dietary 5 g kg−1 FCMB significantly improved the weight gain and specific growth rate of white shrimp after 56 days of feeding. Although there were no significant differences in total hemocyte count, phagocytosis, superoxide anion production rate, and phenoloxidase activity among the experimental groups, upregulation of immune-related genes was observed, particularly in the hepatopancreas and hemocytes of shrimps fed with 5 g or 50 g FCMB per kg feed, respectively. In the pathogen challenge assay, white shrimp fed with 5 % FCMB exhibited a higher survival rate compared to the control group following Vibrio parahaemolyticus challenge. Therefore, it is concluded that the fermented byproduct of C. microphysa, FCMB, holds potential as a feed additive for enhancing the growth performance and disease resistance against V. parahaemolyticus in white shrimp.

Effect of Biofloc Technology Enriches the Growth of Litopenaeus vannamei (Boone, 1931).

The use of probiotics in shrimp farms has expanded as an alternative to antibiotics, improving shrimp health, growth, disease control and water quality. However, the efficacy of probiotics in intensive systems using biofloc remains uncertain. This study investigated bioremediation and biocontrol of commercial probiotics using biofloc, analysing water quality and bacterial groups influencing shrimp performance. Thirteen microbial colonies were observed in the biofloc samples, and their evolutionary history was inferred using the neighbour-joining method. Analysis using MEGA6 software revealed 99.6% similarity between colony 1P1 and Virgibacillus sp. and 99.8% similarity between colony 2P2 and Bacillus kochii. The study analysed the biochemical and amino acid content of shrimp cultured using biofloc technology for 85days. The study found that biofloc-cultured L. Vannamei flesh had higher levels of moisture (31%), ash (15.2%), protein (34%) and lipid (12.6%). No seasonal variations were observed between biofloc samples in winter and summer seasons. Protein levels were found to be appropriate for shrimp growth in both ex situ and in situ biofloc systems. The average growth rate (kg/m2) of biofloc-cultured shrimp was significantly greater than in normal pond shrimp in both samples. The feed conversion ratio in the biofloc tank was lower than in the usual pond-cultured shrimp, possibly due to lower growth rate, lower feeding frequency (2 times per day) and higher density. The growth of L. vannamei shrimp is influenced by stocking density, with higher stocking density affecting the average weight. The study also examined the growth biochemical and amino acid content of shrimp cultured using biofloc technology.

Biochar for Improving Growth Performance of Shrimp and Environmental Quality in an Inland Saline Culture System.

The current study, which lasted 45 days, was designed to find a more effective way to use the vast resources of salt-affected land and ground saline water for aquaculture. Biochar made from agrowaste was used as a sediment amendment. The 100 g of biochar was applied to 25 kg of sediment (i.e., 9.0 ton ha-1) in 300L capacity fiber reinforced plastic, and Penaeus vannamei (P. vannamei) (2.74 ± 0.03 g) was stocked at 90 juveniles m-2 in inland ground saline water of salinity 10 ppt fortified with potassium levels that are 50% equivalent to those of seawater. Among different treatments, T1 indicates paddy straw biochar (PSB) application in sediment; T2 indicates sediment amended with KOH-activated PSB; T3 indicates sugar cane bagasse biochar (SBB) application in sediment; and T4 indicates sediment amended with KOH-activated SBB. Compared to the control the potassium (K+), alkalinity, total hardness, calcium/magnesium ratio, and pH of the water increased significantly (P ≤ 0.05) in treatments where biochar was used as an amendment in sediment. The T3 treatment had the best Ca/Mg ratio (1.00:3.12). In water, the magnitude of increase in K+ concentration from high to low followed the order: T2 > T4 > T1 > T3 > control. The concentration of NH4+-N in water was found to be increasing in control, whereas in the rest of the treatments, it decreased significantly from day 1, until the end of the experiment. Compared to control, the bulk density was decreased, and sediment cation exchange capacity and water holding capacity were increased significantly in treatments where biochar was used as an amendment. The soil microbial parameter measured in terms of soil enzyme dehydrogenase was significantly different among treatments at the end of the experiment. Weight gain (%), specific growth rate (SGR), survival (%), and feed conversion ratio of P. vannamei varied significantly in T1, T2, T3, and T4 compared to the control. The SGR (2.38b ± 0.05% day-1) and weight gain (%) in T2, and survival (96.1b ± 2.0%) in T3 treatment were found to be the highest at the end of the experiment. When biochar was mixed with sediment in the inland saline system, an improvement was seen in sediment quality, water quality, and growth characteristics of P. vannamei.

Effects of dietary melatonin on antioxidant and immune function of the Pacific white shrimp (Litopenaeus vannamei), as determined by transcriptomic analysis

Melatonin (MT) is regarded as an antioxidant and immunostimulant that can efficiently scavenge free radicals and activate antioxidant enzymes. The aim of this study was to investigate the effects of dietary MT on the growth performance and immune function of the Pacific white shrimp (Litopenaeus vannamei). Six groups of L. vannamei were supplemented with dietary MT at 0, 22.5, 41.2, 82.7, 165.1, and 329.2 mg/kg levels for 2 months. RNA-Seq analysis was performed to obtain transcriptome data of the control group and the group supplemented with dietary MT at 82.7 mg/kg BW. In total, 1220 DEGs (799 up-regulated and 421 down-regulated) were identified. Pathways and genes related to growth performance and immune function were verified by real-time quantitative polymerase chain reaction. The total hemocyte count, phagocytosis rate, and respiratory burst were significantly increased in the MT (82.7 mg/kg BW) group as compared to the control group. Analysis of antioxidant-related enzymes in the hepatopancreas showed that dietary MT (82.7 mg/kg BW) significantly increased activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase, while dietary MT at 41.2 mg/kg BW significantly increased activities of glutathione S-transferase, lysozyme (LZM), and phenoloxidase (PO). At the transcriptional level, dietary MT up-regulated expression levels of genes associated with antioxidant immunity and growth, which included PO, SOD, LZM, GPx, chitin synthase, ecdysone receptor, calcium–calmodulin dependent protein kinase I, and retinoid X receptor. In conclusion, dietary MT may improve the growth performance and immune function of L. vannamei to some extent.

Effects of dietary dihydromyricetin on growth performance, antioxidant capacity, immune response and intestinal microbiota of shrimp (Litopenaeus vannamei)

A 56-day culture trial was conducted to evaluate the effects of dietary dihydromyricetin (DMY) on growth performance, antioxidant capacity, immune response and intestinal microbiota of shrimp (Litopenaeus vannamei). 840 healthy shrimp (1.60 ± 0.21 g) in total were fed with four different levels of DMY diets at 0 (Control), 100 (D1), 200 (D2), and 300 (D3) mg/kg, respectively. Samples were collected after the culture trial, and then, a 7-day challenge experiment against Vibrio parahaemolyticus was conducted. The results demonstrated that DMY significantly enhanced the activity of protease, amylase and lipase as well as the expression of lipid and protein transport-related genes (P < 0.05). The results of plasma lipid parameters indicated that DMY reduced lipid deposition, manifested by significantly (P < 0.05) decreased plasma total cholesterol (T-CHO), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C). The expression of genes involved in fatty acid β-oxidation and triglyceride catabolism was significantly up-regulated (P < 0.05), and genes involved in triglyceride synthesis were significantly down-regulated in DMY groups when compared to control group (P < 0.05). Moreover, dietary DMY also significantly (P < 0.05) increased the total antioxidant capacity (T-AOC), antioxidant enzymes activity and glutathione (GSH) content of shrimp, and a significant increase of total hemocytes count (THC), phagocytic rate (PR), antibacterial activity (AA) and bacteriolytic activity (BA) was observed in DMY groups (P < 0.05). The addition of DMY to the diet significantly augmented immune response by up-regulating the expression of genes related to toll-like receptors (Toll) signaling pathway, immune deficiency (IMD) signaling pathway and intestinal mucin. Furthermore, dietary DMY could modulate the composition and abundance of intestinal microbiota. In conclusion, DMY showed promising potential as a functional feed additive for shrimp to improve the growth performance and physiological health.

Effects of dietary melatonin on growth performance, nutrient composition, and lipid metabolism of Pacific white shrimp (Penaeus vannamei)

The goal of this study was to investigate the effects of dietary melatonin (MT) on the growth physiology and lipid metabolism of Penaeus vannamei (P. vannamei). We prepared six experimental diets with varying MT levels (0 (control), 22.5, 41.2, 82.7, 165.1, 329.2 mg/kg) and fed six groups of shrimp with these diets for 2 months. The highest survival, body length growth rate, weight gain, and specific growth rates occurred in shrimp that were fed the diet containing 82.7 mg/kg MT, and the highest levels of docosahexaenoic acid (DHA) and arachidonic acid (ARA) were also found in this treatment group. Compared with the control group, there were no significant differences in moisture, crude protein, and ash contents in shrimp fed with MT, but the crude lipid content was significantly decreased in the high concentration MT supplemented group. Compared to the control group, shrimp fed 82.7 mg/kg MT had better morphology and structure of the hepatopancreas, whereas the hepatopancreas tissues were damaged in shrimp from the high dose MT groups. Analysis of lipid metabolism-related enzymes and genes in the hepatopancreas showed that dietary MT greatly decreased fatty acid synthase and acetyl-CoA carboxylase activities but increased carnitine palmitoyltransferase 1 activity. At the transcriptional level, dietary MT reduced hepatopancreas fat accumulation by upregulating lipid oxidation genes and downregulating lipid synthesis genes. A broken-line model revealed that the ideal MT concentration was in the range of 59.59–71.97 mg/kg. We found that MT supplementation improved P. vannamei growth performance, enhanced fatty acid β oxidation, and prevented fat deposition in the hepatopancreas.

Effects of noni fruit extract on the growth performance, digestive enzymes, and stress tolerance of juvenile whiteleg shrimp (Litopenaeus vannamei)

The effects of noni (Morinda citrifolia) fruit extract supplementation on the growth, survival, digestive enzymes, and stress tolerance of juvenile whiteleg shrimp (Litopenaeus vannamei) were investigated. Shrimp were separated into four groups, with each group fed diets containing various concentrations of 0 (Control-T0), 0.5 (T1), 1 (T2), and 1.5% (T3) noni extract over a 56-day period. The results indicate that shrimp fed the T3 diet had the highest final weight, weight gain, daily weight gain, and specific growth rate among all groups. The survival rate and biomass of shrimp showed a significant difference in those groups fed noni-supplemented diets when compared to the control. However, the feed conversion ratio value in the control group was much greater than those of the remaining groups.Amylase activity increased significantly with increasing culture duration and concentrations of noni extract supplementation. In the T3 group, amylase and proteaseactivities exhibited the highest and most significant differences when compared to the control group.Moreover, the T3 group also exhibited a significantly higher survival rate in the challenge tests against low salinity or high ammonia. The results of this study indicate that noni fruit extract could be applied to shrimp feed to enhance growth, survival, and resistance to environmental stresses.

Evaluation of Bacillus spp. as Potent Probiotics with Reduction in AHPND-Related Mortality and Facilitating Growth Performance of Pacific White Shrimp (Litopenaeus vannamei) Farms.

Acute hepatopancreatic necrosis disease (AHPND) is a serious bacterial disease affecting shrimp aquaculture worldwide. In this study, natural microbes were used in disease prevention and control. Probiotics derived from Bacillus spp. were isolated from the stomachs of AHPND-surviving Pacific white shrimp Litopenaeus vannamei (22 isolates) and mangrove forest soil near the shrimp farms (10 isolates). Bacillus spp. were genetically identified and characterized based on the availability of antimicrobial peptide (AMP)-related genes. The phenotypic characterization of all Bacillus spp. was determined based on their capability to inhibit AHPND-causing strains of Vibrio parahaemolyticus (VPAHPND). The results showed that Bacillus spp. without AMP-related genes were incapable of inhibiting VPAHPND in vitro, while other Bacillus spp. harboring at least two AMP-related genes exhibited diverse inhibition activities. Interestingly, K3 [B. subtilis (srfAA+ and bacA+)], isolated from shrimp, exerted remarkable inhibition against VPAHPND (80% survival) in Pacific white shrimp and maintained a reduction in shrimp mortality within different ranges of salinity (75-95% survival). Moreover, with different strains of VPAHPND, B. subtilis (K3) showed outstanding protection, and the survival rate of shrimp remained stable among the tested groups (80-95% survival). Thus, B. subtilis (K3) was further used to determine its efficiency in shrimp farms in different locations of Vietnam. Lower disease occurrences (2 ponds out of 30 ponds) and greater production efficiency were noticeable in the B. subtilis (K3)-treated farms. Taking the results of this study together, the heat-shock isolation and genotypic-phenotypic characterization of Bacillus spp. enable the selection of probiotics that control AHPND in Pacific white shrimp. Consequently, greater disease prevention and growth performance were affirmed to be beneficial in the use of these probiotics in shrimp cultivation, which will sustain shrimp aquaculture and be environmentally friendly.

Effects of combined rice flour and molasses use on the growth performance of Pacific white shrimp (Litopenaeus vannamei Boone, 1931) applied biofloc technology

A 63-day completely random experiment with three replications was carried out to compare the effects of five different combination ratios of rice flour (R) and molasses (M) on the growth and survival rates of Pacific white shrimp (Litopenaeus vannamei Boone, 1931) postlarvae applied biofloc technology. Five biofloc (BF) treatments, including R90-M10, R70-M30, R50-M50, R30-M70, and R10-M90, formed with the addition of different combination ratios of rice flour and molasses, i.e., 90% R+10% M, 70% R+30% M, 50% R+50% M, 30% R+70% M, and 10% R+90% M, respectively, with C/N ratios of 15:1, and a control (neither rice flour nor molasses applied) was randomly arranged into the 18 plastic tanks of 1.0 m3 volume (with 0.5 m3 of water) each tank and salinity of 15‰. The postlarvae (0.095 g) were stocked into the tanks at a 150 ind. m−3 density and fed pelleted feed (40% protein). There was an improvement in growth (FMW, WG, DWG, and SGR) for all treatments. Besides, treatments with more than or equal to 30% molasses have improved SR, FCR, and FB. Especially the highest SR (94.2%) was obtained at the R70-M30, which perhaps created the highest FB (1.435 kg m−3) in this treatment. The lowest FCR (1.28) was also observed in the R70-M30 and significantly differed from the control and other treatments. Besides, water quality parameters were within the ranges recommended for Pacific white shrimp health during the experimental period. Our findings indicated the benefits of shrimp culture using the BF system when different combined ratios of rice flour and molasses were applied, of which a ratio of 70% rice flour and 30% molasses was considered as the best.