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The aim of this study was to analyze the effects of production and economic viability of commercial diets with different protein sources associated with a 50% reduction of artemia in the feeding of Penaeus vannamei post-larvae. Four treatments were used in a completely randomized design, with four repetitions: T1—krill flour and salmon extract (78% CP + 50% reduction of artemia); T2—fish meal and mussel meal (70% CP + 50% reduction of artemia); T3—squid meal (63% CP + 50% reduction of artemia); and T4—canola meal (48% CP + 50% reduction of artemia). The commercial feeds were offered into 16 experimental units, for 18 days, from hatching to post-larvae harvest. Total number of larvae, survival, final weight, and biomass were analyzed by ANOVA followed by Tukey test. Greatest survival (51.47%) was achieved by the animals in T1. Biomass was higher in T1 and T2 (18.35 and 20.51 g, respectively) when compared to T3 and T4. We concluded that commercial feed consisting of quality marine protein and protein levels equal to or above 70% provide better zootechnical indexes and financial gains in P. vannamei hatchery, even with a 50% reduction in the supply of artemia. [ABSTRACT FROM AUTHOR]

This study aims to assess the impact of the Coronavirus disease 2019 (COVID-19) pandemic on Thailand's shrimp exports in 2020 by applying the Box-Jenkins forecasting technique. A monthly time series from January 2011 to December 2019, comprising 108 months in total, which is the period before the COVID-19 pandemic, was used to forecast Thailand's shrimp exports of frozen and flavored shrimp from January to December 2020. Subsequently, the impact assessment was calculated by comparing the shrimp export values for the case with and without the effects of the COVID-19 pandemic. The empirical results reveal that the most suitable models for the estimate are (1) SARIMA(4,1,0)(0,1,1)12 for the export volume of frozen shrimp, (2) SARIMA(1,1,0)(0,1,1)12 for the export price of frozen shrimp, (3) SARIMA(2,2,3)(0,1,0)12 for the export volume of flavored shrimp, and (4) SARIMA(2,1,0)(0,1,1)12 for the export price of flavored shrimp. The impact assessment of the COVID-19 pandemic on shrimp exports in Thailand indicates that the COVID-19 pandemic has positively affected frozen shrimp export at an impact valuation of 1325 million baht and flavored shrimp export at an impact valuation of 1632 million baht. The reason for this is due to the demand for shrimp exports from Thailand to replace the sharply reduced shrimp supply in the world market. [ABSTRACT FROM AUTHOR]

This study evaluated the combined use of the brown seaweeds Sargassum filipendula (S) and Undaria pinnatifida (U) dry biomass as feed additive for Pacific white shrimp reared in biofloc system, and its effect on shrimp performance, gut microbiota, hemato-immunological parameters, resistance to acute thermal stress and challenge with White Spot Syndrome Virus (WSSV) associated with thermal fluctuation. Prior to stocking, it filled each tank with water from a biofloc matrix tank (160 L) + seawater (240 L, salinity: 33 g L−1), then stocked with 300 shrimp m−3 (~ 3.8 g). During the experiment (five weeks), shrimp were fed three diets: without (control) and with 1%:2% and 1%:4% (S:U) of seaweed addition (all in quadruplicate); and alkalinity was maintained above 150 mg L−1 with calcium hydroxide and solids between 400–600 mg L−1 using clarifiers. No significant differences were found in survival, feed conversion ratio, and growth among treatments. Shrimp from 1S:2U treatment showed the highest gut bacterial diversity. Additionally, animals from seaweed-fed treatments, especially 1S:2U, displayed lower abundance of Vibrionaceae and higher of Flavobacteriaceae compared to control. Only shrimp from 1S:4U treatment showed higher hemato-immunological parameters (except total hemocyte count) than control. Animals from 1S:2U had lower cumulative mortality (27%) than 1S: 4U (48%) and control (50%) after acute thermal stress. Meanwhile, shrimp from 1S:2U (26%) and 1S:2U (34%) showed lower cumulative mortality after WSSV challenge + thermal fluctuation than control (68%). Therefore, the dietary addition of both brown seaweeds caused beneficial physiological effects for L. vannamei without impairing its performance. [ABSTRACT FROM AUTHOR]

The current study examines the effect of dietary supplementation of ethanolic extract of Arthrospira platensis NIOF17/003, which is mainly natural astaxanthins (97.50%), on the growth performance, feed utilization, bacterial abundance, and immune-related and antioxidant gene expressions of the Pacific white leg shrimp, Litopenaeus vannamei. A total of 360 healthy L. vannamei postlarvae (0.19 ± 0.003 g) were divided into four groups (0, 2, 4, and 6 g natural astaxanthins/kg diet) each in three replicates, at an initial density of 30 PLs per tank (40 L capacity). The shrimp were fed the tested diets three times a day at a rate of 10% of their total body weight for 90 days. Diets supplemented with different astaxanthin levels significantly improved shrimp growth performance and feed conversion ratio compared to the control diet. No significant differences were observed in survival rates among all experimental groups. The immune-related genes (prophenoloxidase , lysozyme , beta-glucan binding protein , transglutaminase , and crustin) mRNA levels were significantly upregulated in groups fed with different concentrations of the natural astaxanthins in a dose-dependent manner. The prophenoloxidase gene is the highest immune-upregulated gene (14.71-fold change) in response to astaxanthin supplementation. The superoxide dismutase mRNA level was significantly increased with increasing dietary astaxanthin supplementation. In addition, increasing astaxanthin supplementation levels significantly reduced the count of heterotrophic bacteria and Vibrio spp. in the culture water and shrimp intestine. Overall, the current results concluded that diet supplementation with natural astaxanthin, extracted from Arthrospira platensis , enhanced the growth performance, immune response, and antioxidant status of L. vannamei. [ABSTRACT FROM AUTHOR]

Simple Summary: In biofloc technology systems, organic matter and inorganic substances accumulate in the culture unit mainly due to low water exchange, feed input, high stocking densities, and the level of organic carbon that subsequently increase the bacterial biomass. The organic and inorganic matter in suspension are maintained in a limited concentration to avoid negative effects on animal performance and water quality. This requires the occasional removal of excess solids, which produces an effluent enriched in nutrients, such as nitrogen and phosphorus. The use of integrated aquaculture in which the residues of one species are used as a source of nutrients for another species is an approach which aims to minimize this production of waste. Still, there are aspects of integrated cultures that have to be studied, such as the provision of feed for the different species. Therefore, we evaluated the addition or not of fish feed and microalgae in an integrated shrimp and fish culture regarding animal growth performance and water quality. We found that biofloc is nutritive for fish, but feed is necessary to improve its growth. Moreover, microalgae improved fish survival. However, both of factors did not affect the solids production. This study aims to evaluate a Pacific white shrimp and Nile tilapia integrated system using biofloc technology with or without the addition of the microalgae Scenedesmus obliquus and with or without fish feed supplementation in a two-factor 62-day experiment. The shrimp (2.16 ± 0.01 g) were reared under a density of 400 shrimp m−3 and the fish (1.53 ± 0.12 g) were reared under a density of 522 fish m−3. The microalgae was added to the culture water two times a week. Growth performance, sludge production, and water microbiology were evaluated. Fish feed and the microalgae addition improved fish final biomass in 58% and 14%, respectively (p < 0.05). Fish survival was significantly higher when microalgae was added (93.9 ± 1.8%) compared with the treatments without microalgae addition (86.2 ± 7.6%) (p < 0.05). The yield of the overall system was higher in the treatments with fish feed supplementation (4.2 ± 0.2 kg m−3) compared with no addition (3.9 ± 0.2 kg m−3) (p < 0.05). These results suggest that fish feed supplementation at the rate of 1% of the biomass and microalgae inoculation can improve fish growth performance and system yield, without affecting sludge production and water microbiology. This work is an expansion of a conference paper with the same title. [ABSTRACT FROM AUTHOR]

The current study examines the effect of dietary supplementation of ethanolic extract of Arthrospira platensis NIOF17/003, which is mainly natural astaxanthins (97.50%), on the growth performance, feed utilization, bacterial abundance, and immune-related and antioxidant gene expressions of the Pacific white leg shrimp, Litopenaeus vannamei. A total of 360 healthy L. vannamei postlarvae (0.19 ± 0.003 g) were divided into four groups (0, 2, 4, and 6 g natural astaxanthins/kg diet) each in three replicates, at an initial density of 30 PLs per tank (40 L capacity). The shrimp were fed the tested diets three times a day at a rate of 10% of their total body weight for 90 days. Diets supplemented with different astaxanthin levels significantly improved shrimp growth performance and feed conversion ratio compared to the control diet. No significant differences were observed in survival rates among all experimental groups. The immune-related genes (prophenoloxidase, lysozyme, beta-glucan binding protein, transglutaminase, and crustin) mRNA levels were significantly upregulated in groups fed with different concentrations of the natural astaxanthins in a dose-dependent manner. The prophenoloxidase gene is the highest immune-upregulated gene (14.71-fold change) in response to astaxanthin supplementation. The superoxide dismutase mRNA level was significantly increased with increasing dietary astaxanthin supplementation. In addition, increasing astaxanthin supplementation levels significantly reduced the count of heterotrophic bacteria and Vibrio spp. in the culture water and shrimp intestine. Overall, the current results concluded that diet supplementation with natural astaxanthin, extracted from Arthrospira platensis, enhanced the growth performance, immune response, and antioxidant status of L. vannamei.

The shrimp industry has historically been affected by viral and bacterial diseases. One of the most recent emerging diseases is Acute Hepatopancreatic Necrosis Disease (AHPND), which causes severe mortality. Despite its significance to sanitation and economics, little is known about the molecular response of shrimp to this disease. Here, we present the cellular and transcriptomic responses of Litopenaeus vannamei exposed to two Vibrio parahaemolyticus strains for 98 h, wherein one is non-pathogenic (VpN) and the other causes AHPND (VpP). Exposure to the VpN strain resulted in minor alterations in hepatopancreas morphology, including reductions in the size of R and B cells and detachments of small epithelial cells from 72 h onwards. On the other hand, exposure to the VpP strain is characterized by acute detachment of epithelial cells from the hepatopancreatic tubules and infiltration of hemocytes in the inter-tubular spaces. At the end of exposure, RNA-Seq analysis revealed functional enrichment in biological processes, such as the toll3 receptor signaling pathway, apoptotic processes, and production of molecular mediators involved in the inflammatory response of shrimp exposed to VpN treatment. The biological processes identified in the VpP treatment include superoxide anion metabolism, innate immune response, antimicrobial humoral response, and toll3 receptor signaling pathway. Furthermore, KEGG enrichment analysis revealed metabolic pathways associated with survival, cell adhesion, and reactive oxygen species, among others, for shrimp exposed to VpP. Our study proves the differential immune responses to two strains of V. parahaemolyticus, one pathogenic and the other nonpathogenic, enlarges our knowledge on the evolution of AHPND in L. vannamei , and uncovers unique perspectives on establishing genomic resources that may function as a groundwork for detecting probable molecular markers linked to the immune system in shrimp. • Differential histology was observed between pathogenic and non-pathogenic Vibrio treatments. • Mortality rate was high in shrimp exposed to V. parahaemolyticus causing AHPND. • Ras-signaling pathways were enriched between Vp treatments and control comparison. • Apoptotic genes were up-regulated in shrimp exposed to pathogenic V. parahaemolyticus. • KLHL5 with potential antimicrobial function was up-regulated in pathogenic Vibrio treatment. [ABSTRACT FROM AUTHOR]

Abstract Background Vibrio cholerae non-O1 is a virulent pathogen that causes significant morbidity and mortality in humans. Herein, we report a case of corneal ulcer caused by this pathogen. Case presentation A 59-year-old fisherman with no systemic history was struck in the right eye by a marine shrimp and developed keratitis. Corneal scrapping culture revealed the presence of the V. cholerae non-O1, and its identification was confirmed by Analytical Profile Index 20E system and polymerase chain reaction. He was successfully treated with topical levofloxacin (0.3%) and fortified amikacin (12.5 mg/mL) for 2 weeks. The visual acuity recovered to 20/25 after treatment without complications. Conclusions This is the first case report of keratitis caused by V. cholerae non-O1 strain. Ocular injury by marine creatures and contaminated seawater can contribute to severe corneal ulcer. Early diagnosis can be achieved by meticulous history taking and a comprehensive laboratory workup. Simultaneously, an effective antibiotic therapy can lead to a positive outcome.

The present study was designed to investigate the efficiency of lipid‐enriched brood stock diets on the reproductive performance, such as fecundity, egg volume, fatty acid profile of newly extruded (stage 1) embryos and the starvation threshold of the newly hatched larvae of the marine ornamental 'hinge‐beak' shrimp Rhynchocinetes durbanensis Gordon. Three dietary treatments (50, 100 and 150 g/kg lipids) were formulated to understand their influence on the reproduction of R. durbanensis under captive condition and compared with the wild‐caught shrimps carrying embryos in the abdomen. The reproductive parameters varied significantly between the treatments (captive and wild). Further, the fatty acid profile revealed that essential fatty acid levels of newly extruded embryos in the wild collected shrimps were almost like that of embryos produced in 100 and 150 g/kg of lipid‐enriched diets. The results of linear discriminant analysis (LDA) suggest that the fatty acid profile of embryos has confirmed the separation of four centroids indicating comprehensive differences among the embryos of captive‐reared and wild‐caught shrimps. Hence, it is recommended that the commercial diets formulated with essential nutrients would play a major role in enhancing the reproductive performance of marine ornamental shrimps. [ABSTRACT FROM AUTHOR]

Greenhouse gases (GHG) and their rising atmospheric concentrations have been one of the most important international subjects due to their huge impact on climate change (IPCC, 2022). Aquaculture is of crucial importance to the human food supply and nutrition since it is one of the major sectors providing animal protein, besides reducing the pressure on the fishery stocks from natural resources worldwide (Cai, Zhou, 2019; FAO, 2022). On the other hand, it represents a threat to the environment by generating waste. Thus, this research aims to evaluate the GHG flux dynamics in marine shrimp (Litopenaeus vannamei) monoculture cultures. The study was carried out in two aquaculture farms, both located in the Brazilian semi-arid region. In order to measure the production of greenhouse gases, three cultures of marine shrimp were monitored. The dynamics of the diffusive and ebullitive emission of CO 2 , CH 4 , and N 2 O were monitored in the three units during the daytime (6:00 AM) and nighttime (6:00 PM). The results showed the stocking density as the main regulator for ebullitive CO 2 emissions. A decreasing trend in diffusive CO 2 emissions was observed. Aeration played a crucial role in controlling the diffusive and ebullitive emissions of CH 4 and N 2 O, effectively reducing their release. The diffusive CH 4 emissions exceeded ebullitive emissions and the oxygen content suppressed the anoxic pathway for N 2 O, and the ponds acted as a sink for this gas. This research aims to evaluate the dynamics of greenhouse gas flow in marine shrimp (Litopenaeus vannamei) monoculture cultures in the Brazilian semi-arid region and to verify whether lower stocking densities emit less greenhouse gases when compared to higher densities. [Display omitted] The main findings of our research are listed below: • Higher methane emission was observed via the diffusive pathway. • The of aeration is essential to mitigate the release of CH 4 and N 2 O emissions by controlling their fluxes. • Shrimp ponds can act as sinks for nitrous oxide under suitable aeration conditions, wherein the anoxic pathway is suppressed. [ABSTRACT FROM AUTHOR]

Suspended solids removal is a fundamental procedure for improving water quality in super-intensive rearing of Pacific white shrimp Penaeus vannamei under biofloc conditions. The aim of this research was to evaluate a dissolved air flotation (DAF) model for removing total suspended solids in a biofloc system for P. vannamei with zero water exchange. The experiment was carried out using a pilot model, with which different combinations of saturation pressures (4.0, 4.5 and 5.0 bar) and recirculation rates (10%, 15% and 20%) were evaluated, totaling nine treatments. The removal rates were calculated for the variables total organic carbon dissolved, biochemical oxygen demand, phosphate, nitrate, nitrite, total suspended solids, and turbidity. The use of DAF for the removal of suspended solids was feasible reaching 60% removal. In addition, great potential was found in other variables removal, such as turbidity and biochemical oxygen demand, with an average removal of 80% and 50%, respectively. Moreover, alkalinity, pH, temperature and salinity remained unchanged, remaining under ideal conditions for P. vannamei under biofloc conditions. Flotation velocity ranged from 2.99 to 11.74 cm min−1 and air/solids ratio ranged from 0.005 to 0.016 mg air mg solids−1. Considering all water quality parameters analyzed, dissolved air flotation presented better performance with saturation pressure above 4.5 bar and recirculation rate above 15%. • Dissolved air flotation (DAF) for suspended solids removal was feasible. • DAF has the potential to reduce turbidity and biochemical oxygen demand. • DAF kept other critical water quality parameters unchanged. • There were improvements in water quality parameters at saturation pressure 4.5 bar and recirculation rate 15%. [ABSTRACT FROM AUTHOR]

Marine shrimp fishing is an economic activity of global importance due to its high profitability, but it also presents several environmental and socioeconomic problems. In a context of increasing need for fishery sustainability, scientific basis supporting fishery resources management is essential. However, evidence-based information is frequently scarce or generated by developed countries, even when resources are most abundant in areas of developing economy. Here we present a bibliometric analysis to map each country's scientific production in relation to its marine shrimp fishery yield, along with a hurdle model with socioeconomic factors that could influence publication of articles on this subject. We observed a geographic mismatch between research needs and the places that produce them, once tropical and subtropical regions account for most of fishery yield while knowledge is produced in temperate regions where the most developed countries are concentrated. Accordingly, our model reveled that GDP was the most influential factor in number of articles, while population density had a negative effect. Concurrently, key research interests about marine shrimp fisheries tend to be basic biology topics, despite the need for conservation solutions. [ABSTRACT FROM AUTHOR]

Feeding restriction is a strategy in shrimp farming management that may promote compensatory growth after feeding is re‐established. This study aims to evaluate the effects of two feeding restriction regimens on the compensatory growth and digestive enzymes activity of Litopenaeus vannamei reared in biofloc system. Juvenile shrimp (0.46 ± 0.18 g) were stocked (320 individuals/m3) in 310 L tanks. The experiment comprised two phases: (a) Feeding Restriction (30 days) when shrimp were submitted to three feeding regimes, Control (fed daily), R1F1 (repetitively fasted one day and fed one day) and R2F1 (repetitively fasted 2 days and fed 1 day); and (b) Refeeding (28 days) when shrimp were fed daily. In the restriction phase, shrimp growth and digestive enzyme activities were reduced in R2F1 and R1F1. However, during the refeeding phase, enzyme activities and feed conversion improve significantly in R2F1 and R1F1. Control group attained higher final weight, but its final biomass was similar to R1F1. Litopenaeus vannamei exhibited partial compensatory growth, probably due to improved feed conversion efficiency driven by increased enzyme activity. It is possible to reduce feeding by 50% (R1F1) in biofloc systems for 28 days, without compromising the biomass produced at the end of a 30‐day refeeding period. [ABSTRACT FROM AUTHOR]

Our previous work on the mechanism of virulence for the unique isolates of Vibrio parahaemolyticus that cause acute hepatopancreatic necrosis disease (VPAHPND) revealed that it was mediated by a binary Pir-like toxin pair ToxA and ToxB. These toxins are located on the pVA plasmid, a plasmid carried by AHPND-causing strain of V. parahaemolyticus with a size of approximately 69 kbp. Using the coding sequences of ToxA, a one-step PCR detection method for VPAHPND was introduced in June 2014 but had the limitation that attempts to adapt it into a nested PCR protocol were unsuccessful. As a result, low levels of VPAHPND in shrimp or other samples could not be detected without first preparing an enrichment broth culture to allow bacterial growth before extraction of template DNA. Here, we describe the AP4 (abbreviation of AHPND detection version 4) method, a two-tube nested PCR method that targets the tandem genes ToxA and ToxB, including the 12 bp spacer that separates them on pVA plasmid. Testing of the method revealed that it gave 100% positive and negative predictive values for VPAHPND using a panel of 104 bacterial isolates including 51 VPAHPND isolates and 53 non-AHPND isolates, the latter including 34 isolates of V. parahaemolyticus and 19 isolates of other bacteria found in shrimp ponds, including other Vibrio species. The AP4 nested PCR method was 100 times more sensitive (100 fg total DNA template) than the one-step AP3 (10 pg total DNA template) method, and it could detect VPAHPND in experimentally challenged shrimp by 6 h post immersion (n = 2/3), while AP3 could not detect is until 12 h post immersion (n = 1/3). Thus, the AP4 method may be useful in detecting VPAHPND isolates in samples where target material is limited (e.g., small tissue quantity or archived DNA) and enrichment cannot be employed (i.e., frozen samples or samples preserved in alcohol).

The objective of the current study is to evaluate the use of adult Artemia franciscana biomass as a feeding additive in the laboratorial culture of the autochthonous species of marine shrimp Litopenaeus schmitti. For 30 days, shrimp (n=20) were fed a commercial ration coated with three different levels of A. franciscana biomass corresponding to 1, 3, and 5% of the daily feed offer. In water, the variables temperature, pH, salinity, luminosity NH3, NO2 - were measured. The absolute weight gain (GPA), the relative weight gain (GPR), the relative growth rate (TCR), and the apparent feed consumption (CAA) of shrimp were used as evaluation criteria. In addition, the physical stability of ration in water after 2 hours and the water content of A. franciscana biomass were measured. The stability of the ration in water was 80.9 ± 0.39%. On the other hand, the water content test indicated that 7.49 ± 0.19% of the A. franciscana biomass represented the body mass which effectively coated the feed pellets. The results obtained for the CAA did not show significant differences (P >0.05) among treatments. However, at the termination of the experiment, the growth performance (GPA, GPR, and TCR) of shrimp in the dietary treatments coated with A. franciscana was significantly better than animals in the control group. In conclusion, the results of the current study indicate that the coating of commercial rations with adult A. franciscana biomass in levels corresponding to 1, 3, and 5% of the daily feed offered, increases the weight gain of juvenile L. schmitti. [ABSTRACT FROM AUTHOR]

Aiming at assessing the cryopreservation potential of Litopenaeus vannamei sperm cells, 74 spermatophores were manually extracted from the sexually mature individuals. After the toxicity test to define the cryoprotectant concentration, suspensions of spermatic cells were cryopreserved in the groups in freezing solutions comprising different cryoprotectants such as dimethyl sulfoxide (DMSO) and ethylene glycol (EG) at 10% concentration. Each treatment was divided in subgroups for storage in liquid nitrogen during 0, 30, 60 and 90 days, in triplicate. After thawing at 25ºC for 40 seconds, cell viability in the suspensions was analyzed under the microscope in eosin-nigrosin stain and flow cytometry. There were no significant differences between the cryoprotectants used. For all the treatments, lower and higher mortalities occurred in the 0 and 90 days, respectively. By applying the eosin-nigrosin technique, lower and higher mortalities were 23.17 and 82.11% for DMSO and 29.94 and 83.72% for EG, while the flow cytometry registered mortalities of 2.42 and 55.13% for DMSO and 0.90 and 55.56% for EG. The Spearman correlation coefficient indicated a positive correlation (R=0.91) between the two techniques used. It was concluded that there was a decrease in cell viability within a longer cryopreservation time.

Few studies have been performed regarding long-term variation of penaeids in coastal areas, especially of the marine shrimpRimapenaeus constrictus, which is distributed along the western Atlantic Ocean (Canada to Brazil). This is the first study ofR. constrictusin the Guanabara Bay, a tropical bay on the southern coast of Rio de Janeiro state, Brazil. We aimed to describe its population structure, focusing on sex ratio, abundance, size class and allometry, as well as its relationship with abiotic factors, over five years. Monthly trawls were carried out from January 2011 to December 2015, using a shrimp fishing boat equipped with a single-rig net. The shrimps were identified and sexed and the carapace length and total weight were measured. A total of 6358 individuals were sampled. Females were more abundant and larger than males, a common pattern found in penaeids. The annual abundance peak, which occurred in 2013, was influenced by total rainfall and seasonal peaks occurred in winter and spring. Abundance was positively related to salinity (rs: 0.31,p < 0.05), suggesting that the shrimp’s presence near shallower coastal regions is due to the presence of marine water at the bottom and/or a stronger stratification of the water column in the bay. A low seasonal variation in female allometry can be the result of a constant investment in gametogenesis, and a high seasonal variation in allometry for males can be due to their short life cycle, as was found in previous studies of the same species in other coastal regions worldwide. [ABSTRACT FROM PUBLISHER]

Bacterial diseases affecting marine shrimp are numerous and cause high economic losses in marine culture sector in Egypt, therefore; this study was conducted for isolation and identification of some bacteria affecting marine shrimp and have emerged as a significant human pathogen related to seafood consumption in Egypt. A total number of 130 marine shrimp samples were collected from different ordinary market in Alexandria governorate during the period from May 2014 till September 2015 and subjected to bacteriological examination. The bacterial isolates were identified morphologically, biochemically by conventional methods and VITEK 2 system, and Matrix assisted laser desorption ionization-time of flight mass spectrometry MALDI-TOF (MS). The results revealed that the bacterial isolates were mainly isolated from hepatopancrease (49.3 %) followed by Gastro intestinal tract (32.87%) and then abdominal muscles (17.8 %). Vibrio species (V. alginolyticus and V. harveyi) could be isolated mainly during summer (33 isolates) (76.74%) followed by spring (23 isolates) (58.97%) then autumn (11isolates) (45.83%) and it was not recorded in winter. Shewanella algae showed higher incidence during winter (4 isolates) (16.7%) and summer (7 isolates) (16.3%) followed by spring (4 isolates) (10.26%) and it was not recorded in autumn. Also, S. putrefaciens showed higher incidence during winter (6 isolates) (25%) then in summer (3 isolates) (6.97%) but it was not recorded in autumn and spring. The most prevalent bacterium (V. alginolyticus) was identified by PCR targeting dnaJ (species-specific gene) and ToxR (virulence gene) which revealed that out of the 14 tested isolates (14 isolates) (100%) give positive bands for dnaJ gene and (10 isolates) (71.4%) gave positive bands for ToxR gene. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the influence of different dietary lipid and fatty acids on the nutritional value of bioflocs used as a feed, as well as shrimp performance and health. A total of 1800 Litopenaeus vannamei juveniles (2.87 ± 0.01 g) were cultured in biofloc technology, with a density of 200 shrimp m−2, and fed with three isoproteic experimental diets at different lipid levels (85 g kg−1, 95 g kg−1 and 105 g kg−1); each treatment was performed in triplicate. After 61 days, no significant difference was observed ( P > 0.05) among the water quality parameters. For the shrimp performance, significant difference was observed ( P = 0.011) among the values of survival, where treatments with lower lipid levels had higher survival (92.5 ± 3.5% and 91.0 ± 2.5%). Although there are significant differences in survival, no significant differences in the total haemocytes count ( THC) were observed. For other growth performance, no differences were observed ( P > 0.05). A positive correlation ( r = 0.75) has been observed between the dietary oleic acid and bioflocs. The bioflocs showed 'long-chain' polyunsaturated fat acids (lc PUFA), especially arachidonic acid. The shrimp showed similar growth and stayed healthy at the end of the experimental period. [ABSTRACT FROM AUTHOR]

We aimed to document the risk of Aeromonas spp. in marine shrimp species cultured in inland low salinity ponds in Thailand. In 14 of 18 shrimp samples retrieved from inland grow-up ponds, Aeromonas spp. were detected at ranges from 4667 to 1,500,000 CFU/g body weight. The phylogenetic tree constructed with the gyrB and cpn60 concatenated sequences indicated that the 87 isolates consisted of Aeromonas veronii (70%) , Aeromonas aquariorum (18%) , Aeromonas caviae (7%) , Aeromonas jandaei (2%), and Aeromonas schubertii (2%). The potential virulence of the isolates was examined by phenotypic and PCR assays. Hemolytic activity and the extracellular activity of lipase, DNase, and gelatinase were observed in most isolates (94–99%). PCR revealed the presence of 9 genes related to virulence in the 87 isolates: act (75%), aer (74%), alt (30%), ast (1%), ascV (34%), aexT (24%), fla (92%), ela (34%), and lip (24%). The susceptibility profiles to 14 antimicrobial agents of isolates were typical for the genus, but resistance to cefotaxime, a third-generation cephalosporin, and imipenem were found in two A. aquariorum and in three A. veronii isolates, respectively. These resistances were confirmed by determining minimum inhibitory concentrations. Our results indicate that the microbiological risk posed by Aeromonas should be considered for marine shrimp species that are cultured in low-salinity ponds. These shrimps may also be a vehicle for the transfer of different genotypes of Aeromonas and antibiotic-resistant determinants to regions worldwide through trade. [ABSTRACT FROM AUTHOR]

Abstract: Most research on biofloc systems has been performed in greenhouses with abundant natural light. The functionality of these systems in an environment devoid of light remains poorly understood, especially with regard to growth and survival of reared animals. This study evaluated the performance of Litopenaeus vannamei reared in a biofloc system with varying levels of light. Treatments were 24h with light (24WL), 12h with light/12h without light (12WL/12WOL), and 24h without light (24WOL), each with four replicate tanks. The 24WL and 12WL/12WOL treatments were supplied with light intensity of 10000lx. Shrimp with mean±SD initial weight of 3.3±0.1g were reared in 850L-tanks at a density of 300shrimpm−3. With the exception of nitrate, TSS, VSS and chlorophyll a, there were no significant differences (P >0.05) in water quality parameters among treatments. Nitrate was higher (P <0.05) in 24WOL treatment than in 24WL but neither was significantly different from 12WL/12WOL. TSS and VSS were higher (P <0.05) in 24WL treatment than 24WOL, but were not significantly different from 12WL/12WOL treatment. Chlorophyll a was higher (P <0.05) in 24WL treatment than in 12WL/12WOL and 24WOL treatments. There were no significant differences (P >0.05) in shrimp survival and feed conversion ratios among the treatments. However, shrimp in 24WL treatment grew at a significantly greater rate and reached a significantly greater final weight than shrimp in 24WOL treatment (P <0.05), but neither was significantly different from 12WL/12WOL. The results demonstrate that shrimp production was higher in the treatment that were exposed to light; however Pacific white shrimp can be raised in total absence of light with acceptable performance. [Copyright &y& Elsevier]

In this study thirty shrimp samples from commercial marine shrimp (L. vannamei) farms of southern region of Brazil were obtained. Hepatopancreas and shell scrapings fragments collected in these animals were processed by transmission electron microscopy using negative staining (rapid preparation), immunoelectron microscopy and immunocytochemistry (immunolabelling with colloidal gold particles) techniques. On the transmission electron microscopy a great number of white spot virus particles, ovoid or bacilliform-to-ellipsoid, measured 230-290 ran in length and 80-160 ran in diameter with intra-nuclear projections were visualized by the negative staining technique in 27 (90%) out of 30 samples examined. Using immunoelectron microscopy technique, the anti-VP 664 serum agllutinatsd a large number of particles formed by antigen-antibody interaction. In the immunocytochemistry technique, the antigen-antibody reaction was styrongly marked by the particles of colloidal gold over the virus. Notably, this is the first report, to our knowledge, describing use of these microscopy techniques to study Brazilian L. vannamei marine shrimp samples; moreover, this methodology also appears to be a viable complementary tool for diagnosing the presence of the white spot virus within shrimp tissues. Importantly, these are the first photoelectron micrographs of the WSSV in Brazil. [ABSTRACT FROM AUTHOR]

We developed and characterized 20 microsatellite primer loci for the northern shrimp Pandalus borealis. All 20 loci were polymorphic with number of alleles ranging from 3 to 36 and with observed heterozygosity between 0.04 and 0.93. In addition, we tested the utility of these markers in three related shrimp species, P. montagui, Atlantopandalus propinqvus and Dichelopandalus bonnieri. These new markers will prove useful in the identification of stock structure and hence, assessment of the commercially important species P. borealis. [ABSTRACT FROM AUTHOR]

Abstract: A dense microbial community develops in the water column of intensive, minimal-exchange production systems and is responsible for nutrient cycling. A portion of the microbial community is associated with biofloc particles, and some control over the concentration of these particles has been shown to provide production benefits. To help refine the required degree of control, this study evaluated the effects of two levels of biofloc management on water quality and shrimp (Litopenaeus vannamei) production in commercial-scale culture systems. Eight, 50m3 raceways were randomly assigned to one of two treatments: T-LS (treatment-low solids) and T-HS (treatment-high solids), each with four replicate raceways. Settling chambers adjacent to the T-LS raceways had a volume of 1700L with a flow rate of 20Lmin−1. The T-HS raceways had 760L settling chambers with a flow rate of 10Lmin−1. Raceways were stocked with 250shrimpm−3, with a mean individual weight of 0.72g, and shrimp were grown for thirteen weeks. Raceways in the T-LS treatment had significantly reduced total suspended solids, volatile suspended solids, and turbidity compared to the T-HS treatment (P ≤0.003). The T-LS raceways also had significantly lower nitrite and nitrate concentrations, and the T-HS raceways had significantly lower ammonia and phosphate concentrations (P ≤0.021). With the exception of nitrate, there were no significant differences between the change in concentration of water quality parameters entering and exiting the settling chambers in the T-LS versus the T-HS treatment. Nitrate never accumulated appreciably in the T-LS raceways, possibly due to denitrification in the settling chambers, bacterial substrate limitations in the raceways, or algal nitrate assimilation. However, in the T-HS raceways nitrate did accumulate. The T-HS settling chambers returned a significantly lower nitrate concentration and significantly greater alkalinity concentration than what entered them (P ≤0.005), indicating that denitrification may have occurred in those chambers. There were no significant differences in shrimp survival, feed conversion ratio, or final biomass between the two treatments. However, shrimp in the T-LS treatment grew at a significantly greater rate (1.7gwk−1 vs. 1.3gwk−1) and reached a significantly greater final weight (22.1g vs. 17.8g) than shrimp in the T-HS treatment (P ≤0.020). The results of this study demonstrate engineering and management decisions that can have important implications for both water quality and shrimp production in intensive, minimal-exchange culture systems. [Copyright &y& Elsevier]

It is a practical approach to select candidate probiotic bacterial stains on the basis of their special traits. Production of digestive enzyme was used as a trait to select a candidate probiotic bacterial strain in this study. In order to select a bacterium with the ability to degrade both starch and protein, an ideal bacterial strain STE was isolated from marine shrimp ( Litopenaeus vannamei) intestines by using multiple selective media. The selected isolate STE was identified on the basis of its morphological, physiological, and biochemical characteristics as well as molecular analyses. Results of degradation experiments confirmed the ability of the selected isolate to degrade both starch and casein. The isolate STE was aerobic, Gram-negative, rod-shaped, motile and non-spore-forming, and had catalase and oxidase activities but no glucose fermentation activity. Among the tested carbon/nitrogen sources, only Tween40, alanyl-glycine, aspartyl-glycine, and glycyl-l-glutamic acid were utilized by the isolate STE. Results of homology comparison analyses of the 16S rDNA sequences showed that the isolate STE had a high similarity to several Pseudoalteromonas species and, in the phylogenetic tree, grouped with P. ruthenica with maximum bootstrap support (100%). In conclusion, the isolate STE was characterized as a novel strain belonging to the genus Pseudoalteromonas. This study provides a further example of a probiotic bacterial strain with specific characteristics isolated from the host gastrointestinal tract. [ABSTRACT FROM AUTHOR]

Abstract: The increasing atmospheric concentration of carbon dioxide (CO2) has been driving all marine organisms to live in increasingly acidic environments. In the present study, we evaluated the long-term effects of increased seawater CO2 on survival, growth, feeding and moulting of the marine shrimp Palaemon pacificus. The shrimps were reared in seawater equilibrated with air containing 1,000 ppmv (parts per million by volume, seawater pH 7.89±0.05) or 1,900 ppmv (pH 7.64±0.09) CO2, the atmospheric CO2 concentrations predicted for the year 2100 and 2300, for 30 and 15 weeks, respectively. Survival was significantly suppressed in both experimental groups compared to respective controls; final survival rates were 55% (experimental) vs. 90% (control) in the 1,000 ppmv experiment, and 65% (experimental) vs. 95% (control) in the 1,900 ppmv experiment. Growth was unaffected in the 1,000 ppmv experiment but significantly depressed compared to the control after 7 weeks in the 1,900 ppmv experiment. Feeding was unaffected by either treatment. Moulting frequency was significantly affected in both 1,000 ppmv (experimental>control) and 1,900 ppmv (experimental

Abstract: This paper reports the relative efficiency of gene transfer into Penaeus(Litopenaeus) vannamei shrimp zygotes by microinjection, electroporation, and transfection reagent. The gene constructs, pβactP2-TSV-CP(AS), containing the shrimp beta-actin promoter and the partial sequence of the target gene (493 bp) encoding Taura syndrome virus coat protein (TSV-CP) in antisense orientation, were used in this study. Gene transfer experiments were performed at the one-cell stage (within 50-min postspawning) of fertilized shrimp eggs. Hatching rates were about 3–5%, 25–35%, and 50–60% for microinjection, electroporation, and transfection methods, respectively. Expression of the target gene as determined by reverse transcription-polymerase chain reaction (RT-PCR) showed 10–20% using microinjection, 10–15% using electroporation, and 40–60% using the transfection reagent, jetPEI. In a separate experiment, when shrimp zygotes were transfected with the pβactP2-TSV-CP(AS)/jetPEI complex prior to the formation of the jelly layer (between 8 and 13 min postspawning) and raised until they were 5-months-old, the target gene, Taura syndrome virus coat protein (TSV-CP), was detected in 13 out of 18 transformed shrimp via genomic PCR assay, indicating a 72% gene transfer efficiency. This study demonstrates that treating the shrimp zygotes with the DNA/jetPEI complex at the prejelly layer stage exhibits higher gene transfer efficiency in shrimp. [Copyright &y& Elsevier]

Coastal aquaculture can contribute to eutrophication of receiving waters. New technologies and improved management practices allow the aquaculture industry to be more sustainable and economically viable. Current practices, however, do not provide an additional use for effluent water. Nitrogen, phosphorus and other effluent compounds could be valuable plant nutrients. Inflow and effluent water from an inland, low-salinity shrimp farm, were monitored. Bi-weekly analysis included total nitrogen, ammonia-nitrogen, nitrite-nitrogen, nitrate-nitrogen, total phosphorus, reactive phosphorus, alkalinity, chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (TSS) and volatile suspended solids (VSS), as well as temperature, salinity, dissolved oxygen and pH. Alkalinity and total nitrogen decreased during the in-pond residency. The other parameters increased while in the ponds. The potential benefit of having nutrient enriched wastewater to irrigate field crops was substantial, supplying between 20 and 31% of the necessary nitrogen fertilizer for wheat production. [Copyright &y& Elsevier]

The feasibility and energy efficiency of managing aeration in shrimp culture ponds with automated aeration technology were evaluated. Nine 0.1-ha ponds at the Claude Peteet Mariculture Center, Gulf Shores, Alabama were stocked with white shrimp, Penaeus setiferus, at a rate of 42 post-larvae/m2. All ponds were equipped with one 1-hp (7.1 kW aeration/ha) aspirator pump aerators that were activated manually, with timers, or with automated oxygen sensing devices. Automated aeration was initiated when dissolved oxygen (DO) concentration dropped below 3.2 mg/L (45% saturation) and terminated when DO concentration rose above 4.2 mg/L. Timers were pre-set to initiate aeration after nightfall when DO concentration fell below 3.2 mg/L. Manual operation of aeration involved activating aerators at sundown and terminating operation at about 0800. At harvest there were no significant differences among treatments for gross shrimp yield, mean weight or survival ( P > 0.05). Mean power consumption, measured in kilowatt-hours, was significantly different among treatments (P < 0.05). Automated aeration control ponds used 62% less power than timer-operated ponds and 80% less power than manually operated ponds. Timed operation of aerators used 42% less power than manually operated treatments. The automated control system and timer system reduced power costs over manual operations. The automated system provided the producer with real-time information about DO and temperature regimens. Under more intensive systems as aeration needs increase, expected energy savings from automated control would likely decrease. Initiation of aeration by timers is a good, low-cost alternative to automated controls but without the benefits of automated measurement and real-time viewing of DO. [ABSTRACT FROM PUBLISHER]

Rising demand for shrimp in the developed nations has helped to foster a dramatic growth in marine shrimp aquaculture, particularly in South America and South Asia. In Thailand, Marine shrimp aquaculture is now an important earmer of foreign exchange. The growth in Production has been achieved through the expansion of the culture area and the adoption of intensive production methods. The conversion of near-shore areas to shrimp culture, however, is proving to have many consequences that impinge on the environmental integrity of coastal areas. This paper reviews the development of Thailand's marine shrimp culture industry and examines the nature of the environmental impacts that are emerging. It then discusses the implications these have for rural poor and the long-term viability of the culture industry. [ABSTRACT FROM AUTHOR]

Background: Vibrio cholerae non-O1 is a virulent pathogen that causes significant morbidity and mortality in humans. Herein, we report a case of corneal ulcer caused by this pathogen.Case Presentation: A 59-year-old fisherman with no systemic history was struck in the right eye by a marine shrimp and developed keratitis. Corneal scrapping culture revealed the presence of the V. cholerae non-O1, and its identification was confirmed by Analytical Profile Index 20E system and polymerase chain reaction. He was successfully treated with topical levofloxacin (0.3%) and fortified amikacin (12.5 mg/mL) for 2 weeks. The visual acuity recovered to 20/25 after treatment without complications.Conclusions: This is the first case report of keratitis caused by V. cholerae non-O1 strain. Ocular injury by marine creatures and contaminated seawater can contribute to severe corneal ulcer. Early diagnosis can be achieved by meticulous history taking and a comprehensive laboratory workup. Simultaneously, an effective antibiotic therapy can lead to a positive outcome. [ABSTRACT FROM AUTHOR]