Whiteleg Shrimp Penaeus Vannamei Research Articles

Investigating the impact of chlorine dioxide in shrimp-rearing water on stomach microbiome, gill transcriptome, and infection-related mortality in shrimp.

This study aimed to assess the effects of chlorine dioxide (ClO2) in water on whiteleg shrimp Penaeus vannamei, evaluating its impact on stomach microbiota, gill transcriptome, and pathogens. ClO2 was added to the aquarium tanks containing the shrimp. The application of ClO2 to rearing water was lethal to shrimp at concentrations above 1.2 ppm. On the other hand, most of the shrimp survived at 1.0 ppm of ClO2. Microbiome analysis showed that ClO2 administration at 1.0 ppm significantly reduced the α-diversity of bacterial community composition in the shrimp stomach, and this condition persisted for at least 7 days. Transcriptome analysis of shrimp gill revealed that ClO2 treatment caused massive change of the gene expression profile including stress response genes. However, after 7 days of the treatment, the gene expression profile was similar to that of shrimp in the untreated control group, suggesting a recovery to the normal state. This 1.0-ppm ClO2 significantly reduced shrimp mortality in artificial challenges with an AHPND-causing Vibrio parahaemolyticus and white spot syndrome virus, which were added to rearing water. The use of ClO2 at appropriate concentrations effectively eliminates a significant portion of the bacteria in the shrimp stomach and pathogens in the water. The results of this study provide fundamental knowledge on the disinfection of pathogens in water using ClO2 and the creation of semi germ-free shrimp, which has significantly decreased microbiome in the stomach.

Astaxanthin supplementation enhances low-temperature stress tolerance, immune-related genes, and resistance to Vibrio parahaemolyticus in Whiteleg Shrimp Penaeus vannamei

Astaxanthin supplementation enhances low-temperature stress tolerance, immune-related genes, and resistance to Vibrio parahaemolyticus in Whiteleg Shrimp Penaeus vannamei

Improved genome assembly of the whiteleg shrimp Penaeus (Litopenaeus) vannamei using long- and short-read sequences from public databases.

The Pacific whiteleg shrimp Penaeus (Litopenaeus) vannamei is a highly relevant species for the world's aquaculture development, for which an incomplete genome is available in public databases. In this work, PacBio long-reads from 14 publicly available genomic libraries (131.2 Gb) were mined to improve the reference genome assembly. The libraries were assembled, polished using Illumina short-reads, and scaffolded with P. vannamei, Feneropenaeus chinensis, and Penaeus monodon genomes. The reference-guided assembly, organized into 44 pseudo-chromosomes and 15,682 scaffolds, showed an improvement from previous reference genomes with a genome size of 2.055 Gb, N50 of 40.14 Mb, L50 of 21, and the longest scaffold of 65.79 Mb. Most orthologous genes (92.6%) of the Arthropoda_odb10 database were detected as "complete," and BRAKER predicted 21,816 gene models; from these, we detected 1,814 single-copy orthologues conserved across the genomic references for Marsupenaeus japonicus, F. chinensis, and P. monodon. Transcriptomic-assembly data aligned in more than 99% to the new reference-guided assembly. The collinearity analysis of the assembled pseudo-chromosomes against the P. vannamei and P. monodon reference genomes showed high conservation in different sets of pseudo-chromosomes. In addition, more than 21,000 publicly available genetic marker sequences were mapped to single-site positions. This new assembly represents a step forward to previously reported P. vannamei assemblies. It will be helpful as a reference genome for future studies on the evolutionary history of the species, the genetic architecture of physiological and sex-determination traits, and the analysis of the changes in genetic diversity and composition of cultivated stocks.

White spot syndrome virus endogenous viral elements (EVE) revealed by circular viral copy DNA (cvcDNA) in shrimp

Circular, viral copy DNA (cvcDNA) can reveal the existence of endogenous viral elements (EVE) in shrimp genomic DNA. Here we describe isolation and sequencing of cvcDNA from a breeding stock of the whiteleg shrimp Penaeus vannamei. The stock was developed by onward breeding and selection for white spot syndrome virus (WSSV)-free individual survivors of white spot disease outbreaks. The stock exhibits high tolerance to WSSV. A pool of DNA extracted from 10 shrimp from this stock was subjected to cvcDNA isolation and amplification followed by high throughput sequencing. This revealed DNA fragments corresponding to locations covering much of the 300,000 bp WSSV genome. However, high frequency-read-fragments (HFRF) mapped to a surprisingly small region of approximately 1400 bp. We hypothesized that the HFRF reflected their selection due to provision of tolerance to WSSV. Four PCR primer sets were designed to cover the 1365 bp mapped region. One pair (Set 1) targeted the whole 1365 bp mapped region, while another 3 primer sets (Set 2–4), targeted regions within the 1365 bp target. All 4 primer sets were used with DNA samples from each of 36 shrimp from the same breeding stock (including the 10 used for cvcDNA preparation). Individual positive PCR results varied from shrimp to shrimp, ranging from only 1 primer set up to 4 primer sets. Only 1 specimen gave an amplicon of 1365 bp, while others gave single to multiple positive amplicons in both continuous and discontinuous regions. This indicated that the amplicons did not arise from contiguous targets and might vary in insertion length. The results also confirmed that none of the shrimp were infected with WSSV. Sequencing of the PCR amplicons of expected sizes revealed sequence identity to extant WSSV genomes. This data will be used to screen the breeding stock for EVE that provide WSSV tolerance.

A Comparison of Resources Usage for Two White-Leg Shrimp (Penaeus vannamei) Farming Systems (Earthen Pond System and Round Tank System)

Shrimp farming plays an important role in providing nutritious food and generating livelihoods for many millions of people worldwide. Asia is the biggest producer of shrimp contributing nearly 80% of the global shrimp aquaculture production. Black tiger shrimp (Penaeus monodon) is the main brackish water aquaculture species in Sri Lanka before 2018. White-leg shrimp (Penaeus vannamei) was a new species that was introduced in 2018 expecting a rapid increase in production in the country. Shrimp farming is classified into several categories: extensive, semi-intensive, intensive, and super-intensive based on the intensity of management practices such as stocking density, supply of feed and fertilizer, and management of water qualities. The round tank system is round-shaped and is a type of lined pond that uses an impermeable geomembrane for the retention of water. It belongs to the super-intensive category. The earthen pond is a water body that is basically enclosed by the earth. It belongs to the intensive category. The purpose of this study was to assess the amounts of land, water, and energy required per ton of harvested shrimp in two different production systems and identify the most sustainable system that is used minimum natural resources. The round tank system is located in the Erukkalampiddy area in the Mannar district, Sri Lanka. The earthen pond system is located in the Maikkulama area in the Puttalam district, Sri Lanka. Data on water usage, electricity usage, land area usage, and weight of harvested shrimp were collected during two cycles of production from August 2021 to May 2022. The t-tests were performed to compare resource usages. Land usage of the earthen pond system (950.00 m2/t shrimp, 1266.67 m2/t shrimp) is significantly greater than the round tank system (190.77 m2/t shrimp, 139.33 m2/t shrimp). Water usage of the earthen pond system (950.00 m3/t shrimp, 1266.67 m3/t shrimp) is significantly greater than the round tank system (190.77 m3/t shrimp, 139.33 m3/t shrimp). Energy usage of the round tank system (473.84 kWh/t shrimp, 591.46 kWh/t shrimp) is significantly greater than the earthen pond system (119.91 kWh/t shrimp, 154.78 kWh/t shrimp). It concludes that less land and water resources and high energy usage are required for a round tank system compared to an earthen pond system. Although establishing a round tank system will need more capital, compared to that of an earthen pond system, it is evident that the round tanksystem is more environmentally sustainable. 
 Keywords: Shrimp farming, Round tank system, Earthen pond system, White-leg shrimp (Penaeus vannamei)

Ecytonucleospora hepatopenaei proliferate in Procambarus clarkii: A warning for crayfish and shrimp aquaculture

The pacific whiteleg shrimp (Penaeus vannamei) and the crayfish (Procambarus clarkii) are the most productive aquatic animals in the world. The prevalence of the microsporidium Ecytonucleospora hepatopenaei (EHP), an intracellular spore-forming unicellular parasite which leading retarded growth of P. vannamei, has caused severe economic losses in most shrimp farming country. In this study, we found that the wild P. clarkii, living in shrimp ponds with EHP outbreak, excreted white feces after temporary laboratory culture. The hepatopancreas (HP) of symptomatic crayfish exhibited a lighter color and severely atrophied. H&E-stain showed tissue lesions in both hepatopancreas and intestine, and clustered microsporidian spores were filled in the cytoplasm of the cells. PCR using EHPptp2 and two microsporidian-universal primers sets demonstrated the existence of EHP in the hepatopancreas, intestine and the white feces of P. clarkii. The EHP loads of 103–104 copies of EHPptp2/50 ng HPgDNA were detected by qPCR. Developing stages and mature spores of EHP were observed in hepatopancreas of P. clarkii through indirect-immunofluorescence assay (IFA) and transmission electron microscopy (TEM). Considering the large-scale cultivation of P. vannamei and P. clarkii, overlap farming areas between these two species as well as the ability of crayfish to crawl on land and water, our finding indicates the potential role of P. clarkii in the transmission of EHP, and it is an early warning for crayfish and shrimp farming.

Microfibers from cigarette butts can induce exoskeletal alteration in whiteleg shrimp (Penaeus vannamei)

Cigarette butts (CB) are a source of microfibers (MFs) in aquatic environments, posing a risk to the health of aquatic organisms. Research has been focused on examining the toxicity of CBs on ecological receptors, including invertebrates. More focus has been on death, growth, or movement inhibition of but less on exoskeletal effects in malacostracans. We evaluated the alteration in the carapace structure of whiteleg shrimp (Penaeus vannamei Boone, 1931) caused by MFs derived from CBs (CB-MF). Exposure to CB-MF damaged the gills, the main organs adsorbing calcium in shrimps to generate a hard carapace, disturbing calcium uptake via respiration. Rapid ecdysis caused on CB-MF exposure reduced the environmental adaptation capacity of crustaceans in the absence of normal pigments in the chromatophore of the carapace. These findings indicate that MFs released from CBs released into the aquatic environment can adversely affect exoskeletal alteration within the overall ecosystem.

Genomic characterization and comparative genomic analysis of pathogenic Vibrio isolated from aquaculture-grown white-leg shrimp (Penaeus vannamei) in Guangdong and Jiangsu, China

The proliferation of opportunistic pathogens Vibrio parahaemolyticus, Vibrio alginolyticus, and Vibrio owensii have impeded the rapid development of aquaculture farming. The study aimed to analyze the whole genome of pathogenic Vibrio strains associated with hepatopancreatic necrosis in Penaeus vannamei. The analysis included genomic characterization, virulence genes profiling, antibiotic resistance genes (ARGs) identification, antimicrobial resistance phenotypes, clustered regularly interspaced short palindromic repeats (CRISPR) and prophage prediction, multi-locus sequence typing, and pan-genome analysis of Vibrio isolates from Guangdong and Jiangsu provinces, China. Sequence analysis of the specimens revealed 29 V. parahaemolyticus isolates, three V. alginolyticus isolates, and one V. owensii isolate. Their genomes are 4.9–5.9 Mbp in size, with a GC content of 44.4–45.4%. Each Vibrio isolate harbored >120 virulence genes. Out of the 33 isolates, 13 (39%) demonstrated multidrug-resistant (MDR). Notably, at least 14 isolates exhibited heightened resistance to sulfamethoxazole, erythromycin, and amoxicillin, with a cumulative detection of 20 ARGs. Nevertheless, no significant correlation was found between the composition of ARGs and the observed antimicrobial resistance phenotypes. All Vibrio isolates differed in the presence of prophage and CRISPR sequences; and two of these prophages harbored virulence genes but not ARGs. The study identified 17 distinct sequence types (STs) in V. parahaemolyticus isolates, primarily ST415 (n = 5), while two Vibrio isolates were classified as ST3. Using the 117 V. parahaemolyticus strains available in the National Center for Biotechnology Information database as a reference, pan-genomic analysis and phylogenetic analysis of the core genome revealed that clinical isolates of the same STs clustered into the same clade, irrespective of isolation date and geographic origins. In summary, these data enhance our understanding of the molecular characteristics and epidemiological risk of Vibrio strains in southern China, especially regarding shrimp aquaculture.

Impacts of acute ammonia-N exposure on the muscle quality of whiteleg shrimp (Penaeus vannamei): Novel insights into lipid and protein oxidation

This study explored the effect of ammonia-N exposure on the muscle quality of Penaeus vannamei and the underlying mechanisms based on the oxidation of lipids and proteins. Acute ammonia-N exposure reduced the hardness but increased the centrifugal loss and drip loss of the shrimp muscle. Meanwhile, reactive oxygen species and reactive nitrogen species were overproduced, thereby increasing the free fatty acid (FFA) content, fluorescent compound content, peroxide value (PV), and thiobarbituric acid reactive substance (TBAR) value. In addition, lipid peroxidation byproducts and free radicals could reduce sulfhydryl (SH) content and intrinsic fluorescence intensity. They may also increase carbonyl concentration, disulfide bond (SS) content, and surface hydrophobicity, and degrade myofibrillar protein, leading to the unfolding and conformational alterations in proteins in shrimp muscle. This study provided significant insights into the mechanisms underlying the impacts of ammonia toxicity on the quality of shrimp muscle.

Hypoxia reduces thermotolerance in the postlarvae of the whiteleg shrimp Penaeus vannamei Boone, 1931 (Decapoda: Dendrobranchiata: Penaeidae)

Abstract The thermal responses and tolerance of organisms can be influenced by synergistic interactions with other environmental stresses. Although the heat sensitivity of the whiteleg shrimp (Penaeus vannamei Boone, 1931 = Litopenaeus vannamei) has been extensively researched, little is known about how hypoxia impacts the thermal tolerance of the species. We assessed the thermotolerance of P. vannamei postlarvae under combined hyperthermia and hypoxia conditions. Simultaneous hypoxia significantly decreased the thermotolerance (LT50) of the postlarvae at temperatures close to the upper thermal limit of the species.

Impacts of long-time transportation on whiteleg shrimp (Penaeus vannamei) muscle quality and underlying biochemical mechanisms.

Shrimp is widely consumed around the world. Since muscle is the primary edible component of shrimp, muscle quality (particularly texture) has a direct impact on the economic value of shrimp products. However, reports on the shrimp muscle quality influenced by transportation are rather limited, and the underlying mechanism remains unknown. During the simulated transportation, the water pH and total ammonia-nitrogen content and un-ionized ammonia contents were elevated. Furthermore, reductions in shrimp muscle water-holding capacity, hardness, and shear value with intensive myofibrillar protein degradation were detected. Simulated transportation decreased the pH and glycogen content of shrimp muscle while increasing lactic dehydrogenase activity and lactate content, resulting in an elevated level of free calcium ions and increased μ-calpain and general proteolytic activities. Water exchange could improve the water quality and reduce the mortality of shrimp during transportation, as well as decrease muscle textural softening by alleviating these stress responses. Maintaining water quality and, in particular, reducing ammonia are critical to improving shrimp survival and muscle quality during live transportation. This study is of great significance for the better maintenance of the textural properties of shrimp meat. © 2023 Society of Chemical Industry.

Prediction of meat yield in the Pacific whiteleg shrimp Penaeus vannamei

Meat yield, the percentage of net meat weight, is considered to be an important target trait for genetic improvement in the Pacific whiteleg shrimp Penaeus vannamei. The development of nondestructive methods for predicting meat yield in live shrimp holds great promise. With the objective of improving meat yield more efficiently in whiteleg shrimp, this study established prediction models for meat yield and net meat weight from body measurements (weight, height, length and width), and estimated genetic parameters for these traits. Forty full-sib families were produced and used for a 60-day growth-out test, and then 1560 shrimp were harvested for measurements. Individual meat yield ranged from 44.38% to 59.20%. Multiple linear regression models for meat yield and net meat weight were constructed through stepwise regression analysis. Models assumed for both traits shared the same independent variables (body weight, body length, total abdominal segment length and the third abdominal segment width), but the prediction accuracy reached 0.991 for net meat weight and only 0.450 for meat yield. Heritability estimates of observed (0.231 ± 0.059) and predicted (0.222 ± 0.057) meat yield were significantly lower than those of observed and predicted net meat weight (0.653 ± 0.108) and most of body traits (0.494 ± 0.094–0.656 ± 0.108) (P < 0.05). Genetic correlations of meat yield with other body traits were mainly moderate (0.370 ± 0.165–0.641 ± 0.124), and lower than those for predicted meat yield (0.844 ± 0.066–0.910 ± 0.039) and those for net meat weight (> 0.95). Our results indicate that simple body traits of whiteleg shrimp can be used to accurately predict net meat weight, but not meat yield. Without slaughter, still, relatively accurate meat yield can be indirectly obtained by measuring body weight and predicting net meat weight from body measurements. Although heritability of meat yield is not high, genetic improvement through direct selection on it is feasible.

Effect from Combinations of Yucca schidigera extract with Bacillus Strains on the Growth of White Leg Shrimp (Penaeus vannamei), Density of Vibrio sp., and on the Ammonia and Nitrite Content of Culture Water

The water quality including toxic gas parameters and Vibrio density is a serious problem in intensive shrimp culture. Yucca schidigera extract and Bacillus sp. are considered as a practical solution to improve the water quality. The aim of our study was to determine the effect of combination of Yucca schidigera extract and Bacillus spp. on total ammonia nitrogen (TAN) and nitrite contents, Vibrio count, and the growth performance of white leg shrimp (Penaeus vannamei). Shrimp (PL12) were assigned to seven treatments (triplicates) including treatments with combination of yucca extract and single strain of Bacillus (AY, B2Y, B3Y), combination of yucca extract and Bacillus consortium (ABBY), yucca extract only (Y), Bacillus consortium (ABB), and control treatment (C). Vibrio count was carried out by the spread plate technique every 7 days. TAN and nitrite contents were determined by using sodium nitroprusside, and sulphanilic acid with N-(1-naphthyl) ethylenediamine, respectively, at 24 hours and 168 hours after adding Bacillus strains and yucca extract. The shrimp growth parameters include the final biomass, final body weight (FBW, g), weight gain rate (WGR, %), survival rate (SR, %), and feed conversion ratio (FCR) were recorded after 5 weeks. The results showed that the water quality (0.073 – 0.179 ppm of TAN, 0.187 – 0.934 ppm of nitrite, and Vibrio count of 2.552 – 3.038 log CFU/ml) of tanks treated with combination of yucca extract and single strain of Bacillus (AY, B2Y, B3Y) or Bacillus consortium (ABBY), and Bacillus consortium (ABB) was significantly controlled compared to the control and yucca extract only treatments. The ABBY treatment most significantly improved the shrimp growth parameters (FBW, biomass, WGR, FCR, and SR – 0.424 ± 0.010 g, 40.202 ± 1.510 g, 14048.902 ± 328.756 %, 1.100 ± 0.040, and 94.667 ± 1.856 %, respectively) compared to the other treatments. Overall, our study concluded that the combination of yucca extract and Bacillus consortium could control water quality (0.036 – 0.105 ppm of TAN, 0.187 – 0.604 ppm of nitrite, and Vibrio count of 2.553 – 2.624 log CFU/ml), reduce 46.49% of FCR and significantly increase the growth performance (approximately 92.73% of FWB, 163.19% of biomass, 93.93% of WGR, 46.49% of FCR) of P. vannamei (PL12) with density of 100 individuals/100L.

A comprehensive study in efficacy of Vietnamese herbal extracts on whiteleg shrimp (Penaeus vannamei) against Vibrio parahaemolyticus causing acute hepatopancreatic necrosis disease (AHPND)

Traditional Vietnamese herbal species were examined for their antimicrobial activity and disease resistance in whiteleg shrimp. In-vitro screening, the extracts of ten herbs were conducted to test the inhibition ability against Vibrio parahaemolyticus, causing acute hepatopancreatic necrosis disease. The results showed that five out of ten herbal species, including Pithecellobium dulce, Melaleuca leucadendron, Eucalyptus globulus, Mimosa pirga, and Hibiscus sabdariffa displayed potent antibacterial activity. Besides, three types of extracts of H. sabdariffa, E. globulus, and M. pirga were coated to the pellet feed at a concentration of 1%. After 30 days of feeding, the whiteleg shrimp (Penaeus vannamei) were challenged by V. parahaemolyticus through immersion. The growth performance (such as growth rate in length and weight, survival rate), hematological parameters of total hemocytes (THC), hyaline hemocytes (HC), and granulocytes (GC), and hepatopancreas recovery under the treatments with herbal extracts of the whiteleg shrimp were significantly enhanced as compared with the control (without herbal extract). The mortality and the bacterial density in the hepatopancreas of shrimp decreased. Specifically, the mortality of shrimp in the treatment supplemented with the methanol extract of H. sabdariffa was the lowest, followed by M. pirga and E. globulus. The experimental results also indicated that H. sabdariffa, E. globulus, and M. pirga could improve immune parameters and disease resistance; therefore, they should be employed in sustainable shrimp, practical farming.

The effects of Pandanus tectorius leaf extract on the resistance of White-leg shrimp Penaeus vannamei towards pathogenic Vibrio parahaemolyticus

Pandanus tectorius leaf extract effect on the White-leg shrimp Penaeus vannamei tolerance against Vibrio parahaemolyticus were investigated in this study. Thirty shrimp post-larvae measured at approximately 1 cm were exposed for 24 h to 0.5, 1, 2, 3, 4, 5 and 6 g/L leaf extract and subsequently observed for survival and immune-related genes expression (Hsp70, ProPO, peroxinectin, penaeidin, crustin and transglutaminase), followed by determination of their tolerance and histological tissue profiles upon Vibrio challenge. Survival of shrimps treated with 6 g/L of leaf extract improved by up to 95% to controls. Hsp70, crustin, and prophenoloxidase mRNA levels were observed to be 8.5, 10.4, and 1.5-fold higher, respectively. Histopathological analysis of the hepatopancreas and the muscle tissues revealed major tissue degeneration in Vibrio-challenged shrimps but not in shrimps primed with P. tectorius leaf extract. Of all the dose examined, the best pathogen resistance results were obtained with a 24 h incubation of shrimp in 6 g/L P. tectorius methanolic leaf extract. The tolerance towards V. parahaemolyticus might be associated with the increased regulation of Hsp70, prophenoloxidase and crustin upon exposure to the extract, all immune-related proteins essential for pathogen elimination in Penaeid shrimp. The present study primarily demonstrated that P. tectorius leaf extract is a viable alternative for enhancing P. vannamei post-larvae resistance against V. parahaemolyticus, a major bacterial pathogen in aquaculture.

Dietary protein requirements of whiteleg shrimp (Penaeus vannamei) post-larvae during nursery phase in clear-water recirculating aquaculture systems

Whiteleg shrimp Penaeus vannamei farming in clear water recirculating aquaculture systems (RAS) is relatively recent, and consequently, knowledge on the shrimp dietary demands is still insufficient, particularly in the initial developmental stages. This study aimed at assessing the dietary protein requirement of whiteleg shrimp post-larvae (PL) in a clear-water recirculating aquaculture system (RAS). Six microdiets were formulated to contain 34%, 44%, 49%, 54%, 58%, and 63% crude protein (P34, P44, P49, P54, P58 and P63, respectively) and were evaluated in triplicates. Whiteleg shrimp PL (3.2 mg wet weight) were reared for 21 days in a clear-water RAS at Riasearch Lda. At the end of the feeding period, the optimal protein requirement was estimated at 47.1%, 46.4%, 47.2%, and 44.0% for weight gain, relative growth rate (RGR), feed conversion ratio (FCR), and survival, respectively. PL fed the P54, P58, and P63 diets achieved significantly higher final body weights than those fed P34. PL fed P34 showed significantly lower RGR and survival and significantly higher FCR values than those fed the remaining diets, suggesting that low protein diets may not be adequate to be used in this stage of shrimp development and/or for the clear-water RAS husbandry conditions. Moreover, diet P34 seemingly reduced the overall antioxidant status of the PL when compared to P44, P49, and P54. However, the P34 diet seems to have stimulated the PL immune mechanisms when compared to P44, P49, and P54, possibly due to increased levels of fish and algae oil. Similarly, despite the good growth performances, a diet containing 63% of protein also seemed to have compromised the overall shrimp PL antioxidant status and stimulate their immune system. Shrimp fed diet P54 showed an apparent overall superior antioxidant status when compared to the remaining diets, evidencing that using protein inclusion levels up to 54% in aquafeeds not only potentiates growth performances and survival but also can potentially be beneficial to the health status of P. vannamei PL grown in a clear-water RAS. Hence, results from this study suggest that a minimum of approximately 47% of protein should be considered when tailoring microdiets for whiteleg shrimp PL grown in a clear-water RAS, but inclusion levels up to 54% can be used with benefits to the PL antioxidant status.

Protein-protein interaction network analysis on the whiteleg shrimp Penaeus vannamei and Vibrio parahaemolyticus host-pathogen relationship reveals possible proteins and pathways involved during infection

Whiteleg shrimp, Penaeus vannamei, is the prime candidate in shrimp aquaculture that significantly contributes to the economic growth of the global aquaculture sector. However, P. vannamei culture is constantly plagued with pathogenic infection of Vibrio spp., including Vibrio parahaemolyticus, which impairs shrimp production and consequently results in significant financial losses. Despite this persistent problem, the relationship between P. vannamei and V. parahaemolyticus remains unclear. The discovery of protein-protein interactions (PPIs) between host and pathogen might improve the understanding of bacterial infection in shrimp since most pathogenic bacteria infect hosts through multiple mechanisms. Hence, this study aims to identify the candidate effector proteins of V. parahaemolyticus and their targeted host proteins and potential pathways involved in its infection using a host-pathogen PPI approach. The P. vannamei – V. parahaemolyticus PPI (PVPPI) network was constructed using in silico methods, followed by clustering and pathway enrichment analyses. The constructed PVPPI network consisted of 448871 interactions between 4427 P. vannamei and 18119 V. parahaemolyticus proteins. Clustering analysis identified several effector proteins, i.e., secretion systems proteins, and their targeted proteins, including cell signalling proteins. The bacterial secretion system, mTOR signalling, and endocytosis were among the enriched pathways that might be involved during V. parahaemolyticus infection in P. vannamei. This study reports the first host-pathogen PPI network between P. vannamei and V. parahaemolyticus, where several hosts and pathogen proteins with potential pathways are highlighted. These findings offer new insights into the interaction between V. parahaemolyticus and P. vannamei, a vital aspect that could serve as a baseline for future disease prevention and treatment in the shrimp aquaculture industry.

Comparative life cycle assessment of whiteleg shrimp (Penaeus vannamei) cultured in recirculating aquaculture systems (RAS), biofloc technology (BFT) and higher-place ponds (HPP) farming systems in China

Recirculating aquaculture systems (RAS), biofloc technology (BFT), and higher-place ponds (HPP) are considered as alternative technologies in addressing major environmental challenges linked to conventional Whiteleg shrimp farming systems. Global concern about energy consumption and carbon emission in aquaculture industries, especially in countries like China. The application of life cycle assessment (LCA) in shrimp aquaculture, especially in comparing different shrimp production systems, is being used. In our study, surveys on three RAS, three BFT and nine HPP farms have been conducted, and the data inputs were used to establish a cradle to farm-gate LCA by means of software SimaPro 9.3.0.2 and CML-IA methods to evaluate the environmental performance. The methods are well suited to this LCA, as it focuses mainly on energy consumption input, pollution output, and ecological damage. A ton of live weight shrimp production did generate 4424.2, 4657.2, and 4965.6 kg CO2 eq; 21.8, 25.9, 36.2 kg PO4 eq; 38.7, 40.6 and 43.5 kg SO2 eq in RAS, BFT and HPP systems, respectively. Regarding the characterization and normalization results, eleven categories (abiotic depletion, acidification, eutrophication, etc.) were considered. In most impact categories, the results showed that HPP had the highest environmental impact per unit production when compared to RAS and BFT. Acidification potential (AP) and eutrophication potential (EP) were the top two contributing factors to RAS, BFT and HPP. And AP and EP is closely related to the production of electricity. Electricity was identified as primary contributors in all farming processes. Results indicate that BFT and RAS could be used in combination to reduce environmental impacts. In order to improve the environmental performance of these farming systems, feed ingredients substitution; feeding management and effluent treatment are among the suggested measures. In order to enhanced aquaculture LCI databases and support aquaculture LCA research, the life cycle inventory for shrimp farming were established.

Stutzerimonas frequens strain TF18 with superior heterotrophic nitrification-aerobic denitrification ability for the treatment of aquaculture effluent

Currently, microbial techniques have been comprehensively exploited in aquaculture effluent treatment. However, strains for bioaugmentation face many issues, such as poor adaptability, long colonization time, and unsatisfactory treatment effect. Herein, an efficient heterotrophic nitrifying-aerobic denitrifying bacterium Stutzerimonas frequens strain TF18 was isolated from the Whiteleg shrimp (Penaeus vannamei) mariculture environment. Strain TF18 exhibited strong biofilm formation and auto-aggregation characteristics, which indicated its robust adaptability and short colonization time. Remarkably, the total ammonia nitrogen, NO2--N, and NO3--N removal efficiencies of the strain were 89.21 %, 99.76 %, and 96.16 %, respectively, in the presence of sodium acetate as carbon source and carbon-nitrogen ratio of 10. Most importantly, identification of genes related to nitrogen removal, including nirS, norB, nosZ, nasA, napA, narG, and nirB, and their relative expression further demonstrated the existence of nitrate transformation pathways in strain TF18. These results provided new guidance for practical application of S. frequens strain TF18 in aquaculture effluent treatment.

Effects of replacing fish meal with different levels of Lead tree (Leucaena leucocephala) leaf powder on growth, survival, digestive enzymes activity, muscle biochemical composition and texture of white-leg shrimp Penaeus vannamei Boone, 1931

This study investigated the effects of replacing fish meal with Leucaena leucocephala leaf powder on survival,growth performance, digestive enzyme activities, biochemical body composition and muscle texture of the whiteleg shrimp (Penaeus vannamei Boone, 1931). Five different diets were examined, by replacing fish meal withL. leucocephala leaf powder at 0, 5, 10, 15 and 20%, in triplicates. Shrimps were stocked in 0.5 m3 tanks @ 70 shrimps pertank and fed on the experimental diets for a period of 60 days. The results showed that the survival rate (%), daily weightgain (g day-1), specific growth rate (% day-1), feed intake (% fish-1 day-1), feed conversion ratio, protein efficiency ratio, andprotein retention were not significantly different (p&gt;0,05) among the treatment groups. The values of α-amylase and pepsinin the stomach and chymotrypsin (mU min-1 mg protein-1) in the intestine were not significantly different among treatments.However, the value of α-amylase in the intestine was significantly higher in animals fed diets that replaced fish meal withL. leucocephala leaf powder at 0, 5 and 10% compared to other treatments. The biochemical constituents (except for lipid)and the texture (N) of shrimp meat were not significantly different among treatment groups. The results suggested thatL. leucocephala leaf powder could replace fish meal up to 20% in white-leg shrimp diets. Keywords: Digestive enzyme, Growth, Leucaena leucocephala, White-leg shrimp