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Rhizophora is one of the incredibly potent medicinal mangrove plants with abundant store of secondary metabolites. This study is directed towards the effect of Rhizophora mucronata leaf extract against Penaeus stylirostris penstyldensovirus I (PstDVI)/ Infectious hypodermal hematopoietic necrosis virus (IHHNV), a common potential aquaculture pathogen in shrimp, listed by the World Organization for Animal Health (WOAH). The antiviral property of R. mucronata extract was confirmed through in vitro studies in PmLyO-Sf9 cell line and in vivo studies in P. monodon post larva conducted in batches of 20 post larvae (Juveniles) of 15-mm size for a period of 40 days in a rearing system having the gross parameters such as pH, alkalinity, hardness, ammonia, and nitrite measured and regulated. IHHNV-free status of experimental animals was confirmed by selecting random animals from the pool and testing them for IHHNV genes by diagnostic PCR. The extract showed virucidal property and inhibited virus attachment and replication both in PmLyO-Sf9 cells and P. monodon post larva. A significant reduction in IHHNV capsid gene expression was observed through qPCR analysis. All the three concentrations studied (1 mg mL−1, 0.5 mg mL−1, 0.25 mg mL−1) showed virus replication inhibition. Virus attachment inhibition was prominent at 1 mg mL−1 and 0.5 mg mL−1, but ineffective at 0.25 mg mL−1 plant extract. Meanwhile, virucidal property of the extract was significant at 1 mg mL−1 of the plant crude extract. Transmission electron microscopy images (TEM) of P. monodon larval tissue treated with the extract followed by the IHHNV infection did not show any cytological changes as the cells remained apparently normal. GC–MS profiling of the crude extract showed the presence of 28 phytochemicals which have contributed to the activity. From the study, it is evident that R. mucronata methanolic extract contains discrete compounds/molecules having anti-IHHNV property and can potentially serve as a source of natural therapeutics against the pathogen. [ABSTRACT FROM AUTHOR]

We screened the gill and somatic muscle of 152 wild-caught invasive giant tiger prawns (GTPs), Penaeus monodon Fabricius, 1798 (Penaeoidea: Penaeidae) for infection by white spot syndrome virus (WSSV), infectious hypodermal and hematopoietic necrosis virus (IHHNV), and Taura syndrome virus (TSV) using molecular methods (PCR and qPCR) and transmission electron microscopy (TEM). The sampled GTPs comprised 1 freshly-collected specimen from Mississippi Sound (Northern Gulf of Mexico) during 2020; 54 frozen specimens originally captured from the Northern Gulf of Mexico off Mississippi, Alabama, and Florida during 2014-2016; 76 frozen specimens originally captured from the Northwestern Atlantic Ocean off North Carolina, South Carolina, Georgia, and Florida during 2014-2020; and 21 museum-accessioned specimens (19 initially ethanol-preserved; 2 initially formalin-fixed) captured from the Gulf of Mexico and Northwestern Atlantic Ocean off Florida during 1988, 2011-2013, and 2016. Molecular viral detection relied upon qPCR with TaqMan chemistry for WSSV, conventional PCR for IHHNV, and rt-PCR for Taura virus. TEM was performed on WSSV qPCR+ positive GTP gill to confirm viral infection. A total of 18 GTPs were positive for WSSV by qPCR, 1 was positive for IHHNV by conventional PCR, and none were positive for Taura virus. This is the first report of a WSSV or IHHNV infection in a wild-caught GTP from the Gulf of Mexico or Northwestern Atlantic Ocean and first detection of an IHHNV infection in a wild-caught host in the Northwestern Atlantic Ocean. The phylogenetic analyses indicated that, broadly, sympatric WSSV isolates (unless identical) do not share a recent common ancestor (they are paraphyletic), suggesting that the virus has been repeatedly translocated and introduced into the Gulf of Mexico and Northwestern Atlantic Ocean and that it originated from different localities. [ABSTRACT FROM AUTHOR]

To assess the effects of dietary betaine supplementation on growth performance, feed intake, intestine histology, lipid metabolism, and immune response of Penaeus monodon fed diets containing low and high levels of attractants, four diets were designed: positive control with a high level of attractant (P), negative control with a low level of attractant (N), positive control with betaine (PB), and negative control with betaine (NB). Four replicates with 30 shrimp per replicate and an initial body weight of (0.23 ± 0.00) g proceeded to a 56-day feeding trial. Results showed that raw feed attractants significantly improved the survival rate, total protein of hemolymph, total superoxide dismutase activity, the expression level of imd in the hepatopancreas, and the expression level of pi3k and myd88 in the intestine. But the muscle thickness of the intestine and the expression level of ampk and fas were reduced by the raw feed attractants. Dietary betaine supplementation significantly promoted the expression levels of ampk and acs in the hepatopancreas, fold width and muscle thickness of the intestine, and the expression levels of pi3k, myd88, relish, ror, and imd in the intestine, while the crude lipid content of the whole body and muscle and the expression levels of fas and cpt in the hepatopancreas were reduced by betaine. Present findings revealed that raw feed attractant supplementation positively influenced the survival rate, the anti-oxidation ability, and immune-related gene expressions of the hepatopancreas and intestine. Dietary betaine supplementation positively influenced intestine histology, lipid metabolism, and immune gene expression in the intestine. [ABSTRACT FROM AUTHOR]

Purpose: Although shrimp aquaculture in Sri Lanka has mainly been plagued by recurrent outbreaks of White Spot Syndrome Virus (WSSV), recent symptomatic and analytical field data of shrimps were incoherent with typical WSSV infections. As transboundary infection of new diseases is not uncommon in world shrimp aquaculture, the possibility of new diseases established in the country surfaced. Hence, the present study was aimed at evaluating the stock health of shrimps in Sri Lanka for additional six diseases commonly available in the Asian region, namely Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV), Infectious Myonecrosis Virus (IMNV), Taura Syndrome Virus (TSV), Yellow Head Virus (YHV), Acute Hepatopancreatic Necrosis (AHPND) and Necrotizing Hepatopancreatitis Bacterium (NHPB). Research Method: Sampling was performed using broodstocks, postlarvae, cultured Penaeus monodon, wild P. semisulcatus, P. indicus and P. monodon from different locations and broodstock collecting areas in the country. Other crustacean species were also collected as possible carrier species. The presence of pathogenic organisms was identified by Polymerase Chain Reaction using respective IQ 2000TM test kits and a total of 2060 PCR tests were conducted. Findings: Of all the samples tested, no samples were positive for IMNV, TSV, YHV, AHPND and NHPB. However, confirmatory evidence was found in Sri Lanka for the presence of IHHNV with the prevalence of 31.3% in broodstock samples, 24.07% in hatchery-produced postlarvae and 18.03% in cultured shrimps. WSSV was also recorded with a prevalence of 10.34% in broodstock samples and 55.56% in cultured shrimp samples collected. None of the wild collected samples was positive for any of the tested diseases. Originality/value: Reinstating the presence of WSSV in the Sri Lankan shrimp industry, provides confirmatory evidence of the presence of IHHNV in the country, highlighting the possibility of the emergence of new diseases in shrimp farming in Sri Lanka. Also, commonly suggested disease carriers seem to be not the major cause of disease spread during the sampling time. This study, therefore, provides much-needed information about the stock health of shrimps in Sri Lanka. [ABSTRACT FROM AUTHOR]

The total petroleum hydrocarbons (TPHs) and polycyclic aromatic hydrocarbons (PAHs) present in some seafood samples namely Tympanostomus fuscatus (periwinkle), Crassostrea rhizophorae (Oyster) and Penaeus monodon (Shrimps) from three riverine communities - Buguma, Krakrama, and Bonny - in Rivers State, Nigeria and associated health risks were analyzed. Three samples of seafood were collected using fishing nets, knife and handpicking. The TPHs and PAHs levels were determined using the Gas Chromatography – Flame Ionization Detector (GC-FID) instrument. The highest concentrations of TPHs were observed in C. rhizosphere (90.60 ± 5.39 mg kg−1) samples from Buguma River, T. fuscatus (86.65 ± 2.92 mg kg−1) and P. monodon (83.90 ± 3.66 mg kg−1) samples from Krakrama River while the least value of 60.60 ± 2.14 mg kg−1 was recorded in P. monodon from Bonny. The highest concentrations of PAHs deposits were observed in T. fuscatus (62.28 ± 0.75 mg kg−1), and C. rhizophorae (50.40 ± 0.73 mg kg−1) samples from Buguma, and P. monodon (53.86 ± 1.66 mg kg−1) sample from Bonny River. The ratio of low molecular weight (LMW)/high molecular weight (HMW) PAH for seafood collected from all the locations was> 1 except T. fuscatus (0.95) collected from Krakama, these results, suggests that the PAH source may be petrogenic. The calculated toxic equivalency quotient (TEQ) values of carcinogenic PAHs ranged from 1.2E-02 to 9.7E-01 which is above the screening value (SV) of 2.5E-03 suggesting possible cancer risk. Risk index (RI) based on carcinogenic (and mutagenic) quotient due to PAHs via consumption of seafood indicate that the congeners present in T. fuscatus and C. rhizophorae obtained from Buguma and P. monodon from Bonny locations can cause cancer in receptors and therefore, the need for quick intervention by environmental agencies.

Feed intake is a crucial factor in promoting aquatic animals' robust and accelerated growth. Recently, plant protein has been used extensively as a replacement for fishmeal in aquaculture diets, potentially causing adverse effects on both feed palatability and animal health. However, incorporating suitable quantities of feed attractants into the diet can enhance feed palatability, stimulate the appetite of aquatic animals, and potentially augment both growth and overall health. A study was conducted to assess the efficacy of various feeding attractant combinations on Penaeus monodon. In this study, these seven diets were formulated consisting of a positive control (labeled as P) based on commercial feed, a negative control (labeled as N) with a low level of feed attractants, and five diets (labeled as A, B, C, D, and E) containing 8% compositional feed attractants. Each of the five attractants (yeast extract, squid visceral powder, fish soluble, squid paste, and shrimp paste) was added in equal amounts to A-E diets. The results showed that compared to the E diet, the A diet significantly improved the final body weight, specific growth rate, weight gain, and feed intake of shrimp and upregulated the expression of pi3k , eif4ela , and raptor in hepatopancreas. Compared to the P diet, the C diet feed significantly increased the activities of glutamate oxaloacetate transaminase and acid phosphatase and upregulated the expression of pi3k , myd88 , and tor in the intestine. In comparison to the N diet, the D diet feed increased the activity of alkaline phosphatase in hemolymph, total superoxide dismutase activity in hepatopancreas, and malondialdehyde content. Additionally, it upregulated the expression of myd88 , pi3k , tor , and ror. Compared to the control group, the feed in the E diet increased the total superoxide dismutase activity in the hemolymph and upregulated myd88 , pi3k , tor , and imd expression levels. Furthermore, C, D, and E diets increased the width of the shrimp's intestinal folds. Regression analysis showed that the weight gain and feed intake increased with the increasing amount of squid paste in the feed and decreased with the addition of shrimp paste. Feed intake increased with the addition of fish-soluble protein and decreased with the addition of yeast extract in the feed. In conclusion, adding attractants (yeast extract, squid viscera powder, fish soluble, and squid paste) to the feed is beneficial for the growth and feeding of shrimp, and it can promote the expression of shrimp intestinal immune-related genes and histological changes, thus promoting shrimp intestinal health. [Display omitted] • The effect of combined feed attractants on growth performance, feed utilization, intestinal organization and immunity of Penaeus monodon. • Dietary A (yeast extract+squid visceral powder+fish soluble+squid paste) positively influenced feed intake and protein synthesis of shrimp. • The addition of squid paste to the diet increased weight gain rate and feed intake, while increasing shrimp paste additions decreased these. [ABSTRACT FROM AUTHOR]

The recent incidence of loose-shell syndrome disease (LSSD) in grow-out shrimp ponds appears to be a major problem in Bangladesh. Therefore, the aims of our study were (i) to observe clinical signs of LSSD to confirm its incidence and (ii) to identify the probable causative agents for LSSD in shrimp. Sampling was conducted randomly from five LSSD-affected ponds and three non-affected ponds near Bakkhali River; ecological parameters were measured. A total of 180 healthy shrimps were used for this experiment, where LSSD-affected shrimp extracts were either injected into the shrimps or mixed with water in the experimental tanks. Finally, microbial examinations were performed to identify the possible LSSD causative agents from the infected individuals. The total shrimp production was higher in ponds with healthy populations (185 kg/ha) than from LSSD-affected ponds (126–146 kg/ha); the survival rate of shrimp at harvest was significantly different (p

The emergence of diseases such as white spot disease has become a threat to Penaeus monodon cultivation. Although there have been a few studies utilizing RNA-Seq, the cellular processes of host-virus interaction in this species remain mostly anonymous. In the present study, P. monodon was challenged with WSSV by intramuscular injection and survived for 12 days. The effect of the host gene expression by WSSV infection in the haemocytes, hepatopancreas and muscle of P. monodon was studied using Illumina HiSeq 2000. The RNA-Seq of cDNA libraries was developed from surviving WSSV-challenged shrimp as well as from normal healthy shrimp as control. A comparison of the transcriptome data of the two groups showed 2,644 host genes to be significantly up-regulated and 2,194 genes significantly down-regulated as a result of the infection with WSSV. Among the differentially expressed genes, our study discovered HMGB, TNFSF and c-Jun in P. monodon as new potential candidate genes for further investigation for the development of potential disease resistance markers. Our study also provided significant data on the differential expression of genes in the survived WSSV infected P. monodon that will help to improve understanding of host-virus interactions in this species.

The emergence of diseases such as white spot disease has become a threat to Penaeus monodon cultivation. Although there have been a few studies utilizing RNA-Seq, the cellular processes of host-virus interaction in this species remain mostly anonymous. In the present study, P. monodon was challenged with WSSV by intramuscular injection and survived for 12 days. The effect of the host gene expression by WSSV infection in the haemocytes, hepatopancreas and muscle of P. monodon was studied using Illumina HiSeq 2000. The RNA-Seq of cDNA libraries was developed from surviving WSSV-challenged shrimp as well as from normal healthy shrimp as control. A comparison of the transcriptome data of the two groups showed 2,644 host genes to be significantly up-regulated and 2,194 genes significantly down-regulated as a result of the infection with WSSV. Among the differentially expressed genes, our study discovered HMGB, TNFSF andc-Jun in P. monodon as new potential candidate genes for further investigation for the development of potential disease resistance markers. Our study also provided significant data on the differential expression of genes in the survived WSSV infected P. monodon that will help to improve understanding of host-virus interactions in this species. [ABSTRACT FROM AUTHOR]

Interleukin-1 receptor associated kinase-4 (IRAK-4) has been identified as a central signal transduction mediator of the Toll-like receptor (TLR) and Toll/interleukin-1 receptor (TIR) pathways both in vertebrate and invertebrate innate immunity. To investigate the role of Toll-pathway in innate immune response of shrimp, Penaeus monodon, expression analysis of IRAK-4 gene in mid-gut of LPS induced shrimps wasdone at five time points. Responses of this gene to LPS by Quantitative real time PCR (qPCR) expression analysis of the IRAK-4 gene wasdone in control and LPS induced P. monodon. Mid-gut tissue expressions of theIRAK-4 gene was significantly up regulatedin the LPS induced group. The study indicatedthe critical role of IRAK-4 in gut immunityof P. monodon. [ABSTRACT FROM AUTHOR]

The recent incidence of loose-shell syndrome disease (LSSD) in grow-out shrimp ponds appears to be a major problem in Bangladesh. Therefore, the aims of our study were (i) to observe clinical signs of LSSD to confirm its incidence and (ii) to identify the probable causative agents for LSSD in shrimp. Sampling was conducted randomly from five LSSD-affected ponds and three non-affected ponds near Bakkhali River; ecological parameters were measured. A total of 180 healthy shrimps were used for this experiment, where LSSD-affected shrimp extracts were either injected into the shrimps or mixed with water in the experimental tanks. Finally, microbial examinations were performed to identify the possible LSSD causative agents from the infected individuals. The total shrimp production was higher in ponds with healthy populations (185 kg/ha) than from LSSD-affected ponds (126-146 kg/ha); the survival rate of shrimp at harvest was significantly different (p < .01) between normal and LSSD-affected ponds. The prevalence of infection with white spot syndrome virus (WSSV) and monodon baculovirus (MBV) was found to be lower than that of the Vibrio infections. During the investigation, 8% of LSSD-affected individuals were WSSV positive and 5% were MBV positive, and 4% were infected by both. Our study suggested that the prevalence of LSSD in tiger shrimp might be associated with multiple Vibrio bacterial infections, poor soil and water quality, as well as poor pond management. [ABSTRACT FROM AUTHOR]

Soil physicochemical properties of the growout ponds of black tiger shrimp (Penaeus monodon) were examined in relation to shrimp yields for one production cycle. The culture ponds were old (>5 years) and new (newly constructed) types. Soil texture was silty clay with low sand content and high proportion of clay for both the pond types with alkaline soil pH (7.87–9.71). Organic matter (OM) concentration was higher (7.48 ± 0.01%) in old ponds and positively related (r = 0.58, P < 0.05) with total nitrogen (TN). The major cations (Ca, Mg, and Na) were higher in the soil of old ponds and did not fluctuate significantly during culture. The majority of trace elements, i.e., Fe (349.22 ± 35.7 ppm), Mn (56.19 ± 30.2 ppm), Zn (88.56 ± 8.09 ppm), Al (454.3 ± 200.6), Pb (1.3 ± 0.96 ppm), Co (3.4 ± 0.2), V (6.56 ± 1.79 ppm), Cr (19.32 ± 0.63 ppm), Ti (82.78 ± 54.3 ppm), As (5.60 ± 0.28 ppm), Ag (0.38 ± 0.5 ppm), and Sb (3.89 ± 0.48 ppm) were found to be higher in new pond soils than the old ponds. Except for soil manganese, no major fluctuations in trace elements were observed during the culture period. Shrimp growth was not significantly different in the two types of ponds, and no distinct correlation between shrimp growth and element content of soils could be drawn. The results indicate that shrimp pond age may not affect production of shrimp if soils are properly managed pre- and postculture. The differences in production in different ponds might be the result of management practice such as quality of shrimp post larvae, pond preparation, water and feed quality, and available live feed in the pond bottom or other environmental factors like water nutrients and physicochemical parameters. [ABSTRACT FROM AUTHOR]

Bacterial community associated with the gastrointestinal (GI) tract of aquaculture animals can play important roles in health, nutrition and disease. Compared with the GI tract of aquatic vertebrates such as fish, crustacean GI tract has unique structures and surfaces in different segments that may contribute to differences in the bacterial communities. This study examined the bacterial composition and distribution in different segments along the GI tract and in digesta of wild-caught adult Penaeus monodon using Automated Ribosomal Intergenic Spacer Analysis (ARISA), real-time quantitative PCR and clone libraries of 16S rRNA genes. Thirty-nine bacterial species in four phyla including Proteobacteria (α, β, ε, γ), Firmicutes, Bacteroidetes and Actinobacteria were represented in the GI tract of adult P. monodon. Proteobacteria comprised over 80% abundance of the bacterial community in most segments of the GI tract, except the middle intestine that was dominated by Firmicutes (~50% abundance). The results also showed that bacterial communities showed significant differences along the GI tract segments, particularly the hindgut ( p < .001) with Vibrio and Ferrimonas as dominant genera. The knowledge about the distribution of bacteria could be useful in understanding interaction of commensal bacteria and pathogens in different segments, and its potential influence on the effectiveness of probiotic bacteria in the GI tract of shrimp. [ABSTRACT FROM AUTHOR]

Vibriosis is one of the important diseases causing economic loss to the shrimp industry worldwide. The present study reports field observations on the immune stimulatory effect of vibrio bacterin in commercial tiger shrimp ( Penaeus monodon) grow-out culture ponds ( n = 62) which were grouped under three stocking densities; low (6-8 nos per m2), medium (9-11 nos per m2) and high (12-14 nos per m2). The bacterin was administered in feed as a top dressing at final concentration equivalent to 2 × 108 CFU per kilogram feed twice a week throughout the culture period. In 20 representative ponds, total haemocyte count and prophenoloxidase activity in shrimp were significantly ( P < 0·05) higher and anatomical deformities like, antennae cut (5·02 ± 2·42), tail rot (5·10 ± 1·74), rostrum cut (4·49 ± 2·19) and soft shell (10·05 ± 5·77) were significantly lower compared to controls in all the studied stocking densities. Significant ( P < 0·05) improvement in production parameters like survival and production (kg ha1) was observed in all treatment ponds while similar improvement in average daily gain and feed conversion ratio could be observed in groups with low and medium stocking densities. Results of the study suggest that, oral administration of vibrio bacterin improves the immunity, reduces anatomical deformities and enhances the production in commercial shrimp culture operations. Significance and Impact of the Study Administration of vibrio bacterin in feed as a top dressing induced immune stimulation as indicated by higher levels of total haemocyte count and prophenoloxidase. Further reduction in percentage of animals with anatomical deformities suggests the protection against subclinical bacterial infections. The overall improvement in the production parameters like, average daily gain, survival, feed conversation ratio and production in different shrimp stocking densities under commercial farming conditions suggested the possible development of an immune stimulant product based on the inactivated vibrio bacteria for improved health and production in Penaeus monodon shrimp farming. [ABSTRACT FROM AUTHOR]

Acute hepatopancreatic necrosis disease (AHPND) of shrimps is a bacterial disease, first appeared in China in 2009 and causes mortality up to 100% which usually occurs early (within approximately first 35 days) after stocking shrimp fry of black tiger shrimp, Penaeus monodon (Fabricius) and white leg shrimp, Litopenaeus vannamei (Boone). The purpose of this study was to isolate and identify the pathogenic strain of V. parahaemolyticus causing AHPND in cultured shrimps (P. monodon) using molecular techniques. After a disease outbreak in April 2017, shrimp samples were collected from three different locations of south-west shrimp farming region of Bangladesh viz. Satkhira, Khulna and Bagerhat districts. In this study, three selective media were used for primary isolation of V. parahaemolyticus. Among 28 primary isolates, representative14 isolates were checked for the species-specific detection of V. parahaemolyticus using ldh primers and all of them were found to be positive. The isolates were further characterized to check their AHPND positivity using AP3 and AP4 primers. Four isolates showed positive results for both AP3 and AP4 which indicated that the isolates were AHPND positive. This study also report that all AHPND positive strains showed sensitivity to the antibiotics Tetracycline and Nalidixic Acid. The results of this study will help the farmers and policy makers to make plan to protect shrimps from AHPND and thereby sustain the shrimp farming in Bangladesh. [ABSTRACT FROM AUTHOR]

The objective of the present study is to evaluate a sensitive indicator of cadmium by measuring oxygen consumption and carotenoid concentration in post larvae of Penaeus monodon. The post larvae of P. monodon were exposed to 0.12 and 0.24 mg/L of cadmium in the laboratory for a period of 30 days. These concentrations represent 1/10th and 1/5th of 96 h LC value for the post larvae. Oxygen consumption and carotenoid concentration were measured at 24, 48, 96 h, 10 and 30 days of cadmium exposure. The results indicated an inhibition of routine oxygen consumption in post larvae at different intervals of exposure from 24 h to 30 days but the effect was statistically significant ( P < 05) at 30 days of exposure at both sub lethal concentrations, where the inhibition was 38.5 % at 0.24 mg/L and 21.6 % at 0.12 mg/L. On the other hand, carotenoid concentrations increased gradually with increasing period of exposure as well as concentration, and this increase was statistically significant ( P < 0.05) from 96 h onwards on exposure to 0.12 mg/L and from 48 h onwards on exposure to 0.24 mg/L of cadmium, with an overall highest increase of 135 %. As carotenoid content is an indicator of tissue oxygen, inhibition of routine oxygen consumption might have resulted in enhancing the levels of carotenoid. From the present data, it is evident that carotenoid concentration can be considered as a sensitive indicator of cadmium toxicity than routine oxygen consumption in the post larvae of P. monodon. The present investigation is also relevant for environmental monitoring of cadmium in coastal waters before it is used for aquaculture. [ABSTRACT FROM AUTHOR]

White spot syndrome virus (WSSV) is one of the major pathogens in shrimp aquaculture. Four proteins of WSSV are predicted to encode a RING H2 domain, which in presence of ubiquitin conjugating enzyme (E2) in shrimps can function as viral E3 ligase and modulate the host ubiquitin proteasome pathway. Modulation of host ubiquitin proteasome pathway by viral proteins is implicated in viral pathogenesis. In the present study, expression profile of Penaeus monodon Ubiquitin conjugating enzyme (PmUbc) was studied at protein level in WSSV challenged shrimp. A time point analysis of the expression of PmUbc was carried out at 0, 3, 6, 12, 24, 48 and 72 h post WSSV challenge in P. monodon. Recombinant PmUbc (rPmUbc) was produced in prokaryotic expression vector, BL21 (DE3) pLys S. The PmUbc expression pattern was studied by ELISA with rPmUbc antibodies raised in rabbit. A significant increase in PmUbc expression at 24 h post infection (hpi) was observed followed by a decline till 72 hpi. Since the up-regulation and a tremendous decline of PmUbc protein expression was observed at 24 and in 72 hpi respectively in ELISA, it can be speculated that these proteins might interact with host ubiquitination pathway for viral pathogenesis. Many findings have shown that viral infection can up-regulate expression of ubiquitin and that the ubiquitin system plays a key role in the course of viral infection. The present study reveals the expression patterns of PmUbc at protein level in WSSV infected P. monodon. However, further studies are to be carried out to unfold the molecular mechanism of interaction between host and virus to devise efficient control strategies for this major culprit in shrimp culture industry. [ABSTRACT FROM AUTHOR]

Abstract: The cellular signal-transduction process is largely controlled by protein phosphorylation. Shrimp infected with yellow head virus show dramatic changes in their hemocyte phosphoproteomic patterns, and aberrant activation of phosphorylation-based signaling networks has been implicated in a number of diseases. In this study, we focused on phosphorylation of Penaeus monodon myosin regulatory light chain (PmMRLC) that is induced at an early hour post YHV infection and is concomitant with cellular actin remodeling. In shrimp cell cultures, this phosphorylation was inhibited by the myosin light chain kinase (MLCK) inhibitors ML-7 and ML-9, suggesting that PmMLC phosphorylation is MLCK pathway-dependent. Blocking PmMRLC phosphorylation resulted in increased replication of YHV and reduction of phagocytic activities of shrimp hemocytes called semigranular cells (SGC) and granular cells (GC). Injection of MLCK inhibitors prior to YHV challenge resulted in dose-dependent elevation in quantity of YHV-positive GC and cytoplasmic YHV protein, coincident with high shrimp mortality. Altogether, we demonstrated that PmMRLC phosphorylation increases after YHV infection in shrimp and that inhibition of the phosphorylation leads to increased YHV replication, reduced hemocyte phagocytic activity (probably through actin remodeling) and subsequent shrimp death. Thus, further studies on the MLCK activation pathway may lead to new strategies in development and implementation of therapy for YHV infections in shrimp. [Copyright &y& Elsevier]

The study was carried out for 138 days to know the growth and survival rate of P. monodon by applying probiotics in Gazi Fish Culture Ltd. Dacope, Khulna, Bangladesh. Six experimental ponds (4000 m² in size i.e. one acre) were selected of which three were probiotic ponds and three were controlled. After pond preparation, PL15 (average weight of each 4.75±0.09 g) was stocked at the rate of 13 per m² following polymerase chain reaction (PCR) test. CP NASA shrimp feed was used during the study period. Transparency, salinity, pH, dissolved oxygen (DO), temperature, total Ammonia Nitrogen (TAN) were recorded by standard measurements. The average final body weight of the harvested shrimp is 37.67±1.15 g in probiotics ponds and 27.33±0.58 g in controlled ponds and the difference was significant (P < 0.01) between these two productions. The average survival rate was 90.67±1.15 % in probiotic pond and 71.00±3.0 % in controlled pond. The average daily gain (ADG) in weight was 0.27±0.01 g and 0.19±0.01 g in probiotic and controlled ponds, respectively. The result showed that probiotic plays an important role in maintaining water quality parameters, soil quality and health management as well as increases the growth and survival of shrimp. [ABSTRACT FROM AUTHOR]

Among the emerging diseases in shrimp aquaculture, monodon slow growth syndrome (MSGS) is a major concern in South and Southeast Asia. Shrimp farming in Thailand was severely affected during 2000-2002 due to MSGS, which caused an economic loss, of about US$ 300 million. MSGS is characterized by abnormally slow growth with coefficients of size variation of >35 %, that has impacted P. monodon production in Thailand. A new shrimp virus, Laem-Singh virus (LSNV) was identified to be associated in MSGS affected shrimp. LSNV a RNA virus of about 25 nm diameter is phylogenetically related to the insect-borne viruses in the families Barnaviridae, Tymoviridae and Sobemoviridae an important histopathological observation is exclusively noticed in growth-retarded shrimp. The LSNV infections have been confirmed in various organs of infected shrimp such as lymphoid organ, gills and nervous tissues by various diagnostic techniques such as reverse transcription polymerase chain reaction (RT-PCR), in situ hybridization, quantitative real-time RT-PCR and reverse transcription loop-mediated isothermal amplification combined with a lateral flow dipstick (RT-LAMP-LFD) and these tools are available for the diagnosis of LSNV. Recently, an integrase containing element has been identified in absolute association with LSNV in stunted growth shrimp. The transmission of LSNV through horizontal and vertical routes has been experimentally demonstrated. The known natural host-range of LSNV includes P. monodon and other penaeid shrimp. The putative RdRp gene involved in replication of LSNV was targeted for dsRNA-mediated gene silencing and appeared to be effective in a dose-dependent manner. Since the discovery of LSNV in 2006 in Thailand, it has been added to the list of viruses to be excluded from domesticated specific pathogen-free stocks of P. monodon and it has been recommended that shrimp farmers avoid stocking post larvae positive for LSNV to prevent MSGS in their farms. [ABSTRACT FROM AUTHOR]

Abstract: White spot syndrome virus is the most important among the shrimp diseases. It has been devastating the shrimp industry for more than 3 decades. Previous studies reported that greater percentage of yellow colonies on thiosulfate citrate bile salt sucrose agar (yellow vibrios) in the rearing water, abundant supply of natural food such as Chlorella, and the use of the greenwater technology (GW) are some ecological ways of preventing WSSV outbreak. The aim of this study was to investigate the efficiency of the 3 systems against WSSV. Shrimp, experimentally infected with WSSV by feeding with WSSV positive shrimp carcass, was cultured in tanks using three treatments: with tilapia to simulate the GW, seeded with Chlorella, and with molasses added to enhance growth of yellow vibrios. Shrimp cultured in seawater served as the control. Survival was recorded and shrimp were analyzed for WSSV quantification using qPCR upon termination. Analysis showed no significant differences in shrimp survival at 120h post infection in all treatments and the control. However, from the original viral load of 1.40×101 WSSV/mg sample, WSSV decreased and was significantly lowest in shrimp cultured using GW (7.0×100), compared to the control (4.82×105) and the other treatments (3.66×105 for molasses added and 4.64×105 for Chlorella seeded) in which viral load increased 4–5 times. Shrimp survival was highest in Chlorella seeded treatment and lowest in GW. Nitrogenous waste concentrations were lowest in molasses added water and highest in GW. Results suggest that the GW culture technology provides protection against WSSV while addition of molasses lowers nitrogenous waste concentration. The use of GW in combination with the addition of molasses for shrimp culture is suggested. [Copyright &y& Elsevier]

The role of probiotic bacteria in small culture is studied but commercial level is not that much reported especially in giant tiger shrimp, P. monodon. Hence the beneficial effect of probiotics on the commercial culture of Indian major candidate shrimp, P. monodon is studied in a grow out pond. The farm is located on the Northern bank of Uppanar estuary in Maravakadu. An effort was made to evaluate the differences between regular and irregular application of soil probiotics in the P. monodon shrimp farming. Subsequently the performance of using probiotics frequently and the total average yield attained was 1900 Kg /0.5ha. With maximum growth increment of 34.70g, survival of 90.31%, achieved at the DOC 130. Level of ammonia found nil for the entire culture period in the regularly probiotics used ponds. Contrarily, in irregular treated ponds the total yield achieved only 1150 Kg /0.5 ha. With the maximum growth of 27.29 g, survival of 70.68% at the DOC 130 respectively. The level of ammonia found 0.3 mg /L. [ABSTRACT FROM AUTHOR]

The knowledge of the nutrient requirements and practical diet formulations for Penaeus monodon is fully known. In the production cost, the cost of diet alone comes around 50 to70%. This is mainly because of the addition of lecithin which is a relatively expensive dietary ingredient. It is important to determine the usefulness of lecithin in the growth of P. monodon. In order to keep the diet cost as low as possible this experiment was designed with and without lecithin. The objective of the present study was to assess the growth of shrimp with varying lecithin doses. To study the water quality parameters and to study the growth and survival of animals feed containing different percentage of lecithin. Trials conducted indicated the soybean lecithin did not have any effect on shrimp's growth. The shrimp weight varied from 3.15 to 8g in Control, 2.58 to 6g in Treatment A, 2.87 to 6.62g in Treatment B, 3.1 to 6.75g in Treatment C. These confirm that under a controlled clear water culture system, partial or complete replacement of soybean lecithin in a commercial diet for P. monodon resulted in no detriment in growth. Purge lecithin in the diet may allow for less-expensive diet formulations for P. monodon and may reduce the diet cost for producers, who are supplying feed. As diet cost represents the largest variable cost in a commercial aquaculture operation, increased knowledge of specific dietary requirements is essential for formulating a cost-effective commercial P. monodon diet. [ABSTRACT FROM AUTHOR]

To conquer disease problem in shrimp industries, probiotic biocontrol is a well-known remedy now. The antagonistic ability of separated isolates from different parts of juvenile P. monodon was screened against shrimp Vibrio pathogens, V. parahaemolyticus and V. alginolyticus. The most antagonistic effect was observed for an isolate that primarily identified as Shewanella algae using conventional method followed by Biolog GN and GP microplates. Since adaptability to the host optimum cultural condition of the target organism is of the great importance, response surface methodology, with central composite design, was applied to assess log cell count response of S. algae in different incubation conditions. Therefore, four independent variables were assumed as: temperature (10-50°C), pH (6-10), NaCl concentration (0-50‰) and time (12-60 h). The coefficients of multiple determinations ( R) for the responses log cell count of S. algae being 0.827. Temperature was the merely significant independent variable that affected the log cell count of the candidate probiotic. The candidate probiotic was revealed a reasonable growth response in quite wide range of temperature, pH and NaCl concentration in which the maximum levels were in same range of optimum shrimp culture. [ABSTRACT FROM AUTHOR]

An experiment was conducted to evaluate the effect of a hot water extract of brown seaweeds Sargassum duplicatum and Sargassum wightii on the growth and white spot syndrome virus (WSSV) resistance in shrimp Penaeus monodon postlarvae (PL). Artemia nauplii (instar II) were enriched with both seaweed extracts at various concentrations (250, 500 and 750 mg L−1) and fed to the respective P. monodon (PL15-35) group for 20 days. A control group was also maintained without seaweed extract supplementation. The weight gain of the experimental groups was significantly higher (0.274-0.323 g) than the control group (0.261 g). Similarly, the specific growth rate was also significantly higher (16.27-17.06%) in the experimental groups than in the control group (16.03%). After 20 days of the feeding experiment, the shrimp PL were challenged with WSSV for 21 days. During the challenge test, the control shrimp displayed 100% mortality within 8 days. In contrast, the mortality percentage of the highest concentration (750 mg L−1) of seaweed extract enriched Artemia nauplii fed shrimp was 54-79%. Comparatively, low mortality was observed in S. wightii extract-enriched Artemia nauplii fed shrimp. The polymerase chain reaction analysis indicated the concentration-dependent infection of WSSV in P. monodon PL. [ABSTRACT FROM AUTHOR]

Abstract: Whitespot syndrome virus, WSSV, is the most important among the shrimp diseases. One of the suggested WSSV risk factors is the occurrence of stress since stressors could compromise the shrimp defence system thus increasing the risk of WSSV infection. Stressors are usually related to the physico-chemical properties of both water and pond bottom. This paper investigates the effect of some biotic and abiotic components of the pond ecosystem on WSSV infection and outbreak. Water physico-chemical properties and microflora of 91 production cycles of 8 semi-intensive shrimp farms were analyzed to determine WSSV risk factors, using factor analysis and logistic regression. Fluctuations of temperature and pH are important risk factors that will result to an infection but not necessarily to an outbreak. Exposure to high salinity and high temperature are important factors for an infection to result to an outbreak. The risk of an infection is reduced when the water temperature is high, salinity fluctuations are small, and percentage of yellow Vibrio colonies is greater than the green ones. Further studies are needed to clarify the effects of water depth, water transparency, and various bacterial counts; these factors could be individual or interactive. [Copyright &y& Elsevier]

The article presents a study on the effect of rainfall and atmospheric temperature on the prevalence of the whitespot syndrome virus (WSSV) in pond-cultured Penaeus monodon. It mentions a study that shows that pond lining and increased bio-security reduces WSSVoccurrence and outbreaks but also states that WSSV will remain a risk in outdoor shrimp culture. It suggests cost-effective measures to mitigate the effect of low atmospheric temperature and other natural phenomena.

Penaeus monodon is the mostly exported shrimp in Sri Lanka. This study was conducted to evaluate the effect of gamma irradiation on the microbial, physical and chemical parameters of postharvest P. monodon. Samples from 10 farms were irradiated at 1 kGy, 2 kGy, 3 kGy, 5 kGy and 10 kGy. Total plate count (TPC), yeast and mold count (Y&M), coliform count, Escherichia coli count, color, texture, moisture content, water activity, pH and peroxide value were measured. Average total length and total weight were 12.69 ± 1.42 cm and 15.86 ± 5.70 g respectively. Average TPC of the control was 3.37*104±5.44*103 CFU/g and it was significantly reduced (p < 0.05) by the treatment of 1 kGy–8.58*102±8.09*102 CFU/g. Samples treated with 5 kGy and 10 kGy were almost sterile. Average Yeast and mold count of the control was 9.25*104±1.77*104 CFU/g and it was significantly reduced (p < 0.05) at 1 kGy to 7.42*102±17 CFU/g. At 2 kGy, 3kGy, 5 kGy and 10 kGy the samples became almost sterile. Coliforms and E. coli were not detected in any sample. L*, a*, b*, ΔE and chroma of whole shrimp, peeled shrimp and shrimp muscle were not significantly affected (p > 0.05). Texture, moisture content and water activity were not significantly different (p > 0.05). The pH was significantly different (p < 0.05) and the peroxide values of irradiated shrimps were significantly lower (p < 0.05). Hence, it was concluded that 1 kGy was appropriated for irradiation of postharvest P. monodon. • 1 kGy irradiation dose reduce the microbial growth in Postharvest P. monodon. • Water activity, moisture content and texture were not affected up to 10 kGy. • Colour parameters were not significantly affected by gamma irradiation. • pH of shrimp muscle was significantly affected by irradiation. • Peroxide value was significantly low in the irradiated samples. [ABSTRACT FROM AUTHOR]

Abstract: Carbonic anhydrase (CA) was identified by differential display PCR analysis as one of the differentially expressed genes in the gills of low salinity stressed (transferred from 25 to 3 ppt) Penaeus monodon. To further characterize the role of CA in the regulation of salinity stress, the cDNA sequence of P. monodon carbonic anhydrase (PmCA) was attained by rapid amplification of cDNA ends and found to have a total length of 1194 bp. The deduced amino acid of PmCA shares 73% sequence identity with the CA homologue recently isolated from the crab, Callinectes sapidus. Real time RT-PCR and enzymatic activity analyses were employed to determine the changes in the PmCA mRNA expression and total CA activity, respectively, after shrimps were transferred from 25 to 3 ppt salinities for up to 2 weeks. Compared to the CA level in the control group (25 ppt), PmCA mRNA was significantly increased in shrimp gills at 24 h after hypo-osmotic stress. In contrast, the epipodites and antennal gland displayed decreased levels of mRNA expression. The gross CA enzymatic activity after hypo-osmotic stress was increased in the shrimp gills but remained stable in the epipodites and antennal gland. [Copyright &y& Elsevier]

Disease outbreak has continued to be a major challenge for shrimp aquaculture industry. In recent years, manipulation of gut microbiota has been shown to improve the health of host shrimp and disease resistance. Therefore, understanding how various factors can shape the gut microbiota of shrimp is crucial for future utilization of gut microbiota as tools for disease controls. The salinity of the rearing environment can potentially affect shrimp gut microbiota as well as the host-microbe interactions. The effects of salinity adaptation on intestinal microbiota and transcriptomes of juvenile black tiger shrimp Penaeus monodon were examined in this experiment. Intestinal microbiota and transcriptomic profiles from juvenile black tiger shrimp of the same cohort adapted to three different salinity levels were examined using 16S rDNA amplicon sequencing and RNA sequencing, respectively. Shrimp were acclimatized from the original 20 ppt salinity to either 10 ppt or 30 ppt over a period of 10 days, and intestinal samples were collected on Day 0, Day 10, and Day 20 after reaching the target salinity. Across all salinity levels, the dominant phyla composition in the intestine of shrimp was relatively similar with Proteobacteria (83.4%), Bacteroidetes (8.1%), Planctomycetes (3.2%), Verrucomicrobia (2.5%), and Firmicutes (1.5%). The most abundant genus was Vibrio. While it can be found at all salinity levels, a relative abundance of Vibrio was lower at 10 ppt than at higher salinity. A shift toward the higher relative abundance of Vibrio ASVs belonging to the Harveyi clade was observed at higher salinity. On the other hand, the relative abundance of Shewanella was higher at 10 ppt than at higher salinity. Other dominant genera in the intestines not affected by the change in salinity were Pseudoaltermonas and Tenacibaculum. The shift in the rearing water microbiota with different salinity levels was also observed. The most abundant intestinal transcripts responding to different salinity levels based on GO classification were intracellular anatomical structure (cellular component), protein binding (molecular function), and organic substance metabolic process (biological function). Genes involved with stress and immune responses were differentially expressed, and correlations between potentially pathogenic Vibrio and genes relating to innate immunity and peritrophic matrix were observed. The results confirmed the influence of rearing water salinity on both the intestinal microbiota and transcriptomes of shrimp. Efforts to shape the microbiota of aquatic animals should take into consideration the rearing salinity to ensure its efficacy. Using multi-omic platform allowed for better understanding of the microbiota and the host-microbe interaction, which will help support the sustainability of aquaculture production. • Salinity effects on microbiota and gene expressions of P. monodon were examined. • Vibrio relative abundance decreased in low salinity environment. • Different ASVs within the Vibrio genus responded differently to salinity change. • Genes involving energy metabolism and immune responses were differentially expressed. [ABSTRACT FROM AUTHOR]

Abstract: Shrimp mortality due to luminous bacteria has been a problem of the shrimp industry worldwide. Polyculture of shrimp with finfish, such as grouper, seabass, snapper, siganid, Tilapia hornorum, and the Genetically Improved Farmed Tilapia (GIFT), could control the growth of luminous bacteria. One way to reduce adverse environmental impact and to reduce bacterial count is through the use of bivalves to filter pond effluents. This study investigated the effect of several bivalves on the growth of luminous bacteria in a simulated shrimp culture environment using concrete tanks. Tanks were stocked with shrimp at a biomass of 100 g/m3 and with brown mussel (158 pcs/m3), green mussel (137 pcs/m3), or oyster (376 pcs/m3). Growth of luminous bacteria decreased to below 101 cfu/ml in tanks with green mussel after 5 d, brown mussel after 16 d, and oyster after 17 d. Bivalves, such as green and brown mussels, and oyster, could be used as an alternative species for polyculture with shrimp to control disease due to luminous bacteria. [Copyright &y& Elsevier]

Aim: To characterize and identify Photobacterium damselae ssp. damselae present in black gill diseased Penaeus monodon collected from east coast of India. Methods and Results: Photobacterium damselae ssp. damselae was isolated from hepatopancreas, muscles and gills by using the thiosulfate citrate bile salts sucrose agar supplemented with 1·5% NaCl (TCBS-1) medium. A total of 32 Ph. damselae ssp. damselae isolates were studied together with two reference strains. The biochemical tests and analysis of ureC and 16S rRNA genes confirmed the phenotypic characterization of the isolates as Ph damselae ssp . damselae. Experimental infection studies revealed that the LD50 values of P. monodon and P. indicus ranged from 2 × 103 to 5 × 105 CFU per shrimp and from 4 × 102 to 2 × 104 CFU per shrimp, respectively. Conclusions: Photobacterium damselae ssp. damselae was found in the internal organs of P. monodon and it showed pathogenic to shrimp. Significance and Impact of the Study: This is the first study on the Ph. damselae ssp. damselae present in the black gill diseased P. monodon in India and therefore might serve as a basis for future studies and diagnosis purpose to shrimp culturists. [ABSTRACT FROM AUTHOR]

Genetic diversity in the Indian population of the tiger shrimp Penaeus monodon was determined by using partial sequence data of the mitochondrial DNA (mtDNA) control region (D-loop) and the 16S rRNA gene. Eight populations from different geographical locations (Mumbai, Kochi, Mangalore, Kakinada, Gopalpur, Chilika, Paradeep and Andaman) were collected and analysed. The amplified polymerase chain reaction products of size 577 bp for the control region and 472 bp for 16S rRNA were sequenced in both directions and data were analysed throughclustal,arlequin,mega andphylip. A significant genetic structure was found among the Indian populations. The mtDNA control region proved to be a powerful marker in comparison with 16S rRNA for population studies of this species. The east coast population was more genetically diverse than the west coast. The Andaman population was found to be the most diverse among all the populations. The populations on the west coast were found to be genetically more structured and differentiated than the populations on the east coast. The results revealed a high level of genetic diversity and also distinct population structuring of P. monodon, suggesting great possibilities of genetic improvement for growth and other economic traits. [ABSTRACT FROM AUTHOR]

Abstract: The present study examined the changes occurring in the pro phenoloxidase system and antioxidant defence status in haemolymph, hepatopancreas and muscle tissue of white spot syndrome virus (WSSV) infected Penaeus monodon. Tiger shrimps (P. monodon) were infected with white spot virus by intramuscular injection of the virus inoculum. Levels of lipid peroxides and the activities of phenoloxidase, glutathione-dependent antioxidant enzymes [glutathione peroxidase (GPX), glutathione-S-transferase (GST)] and antiperoxidative enzymes [superoxide dismutase (SOD) and catalase (CAT)] were determined. WSSV infection induced a significant increase in lipid peroxidation in haemolymph, muscle and hepatopancreas of experimental P. monodon compared to normal controls. This was paralleled by significant reduction in the activities of phenol oxidase, glutathione-dependent antioxidant enzymes and antiperoxidative enzymes. The results of the present study indicate that the tissue antioxidant defence system in WSSV infected P. monodon is operating at a lower rate, which ultimately resulted in the failure of counteraction of free radicals, leading to oxidative stress as evidenced by the increased level of lipid peroxidation. [Copyright &y& Elsevier]

Abstract: Comparison of PCR and dot blot diagnostic techniques for detection of white spot syndrome virus (WSSV) was made on different tissues of infected Penaeus monodon including eye stalk, eye stalk with eye, gills, cuticle, pleopod, periopods, uropods and telson. Dot blots of crude DNA extracted from infected tissue samples showed positive reactions with all the samples; however, the sensitivity of the dot blot was reduced with the purification of DNA samples extracted from pleopod, telson and uropod. PCR was found to be more sensitive when compared to dot blot. Both crude DNA and purified DNA samples extracted from all the tissues except for eye stalk with eye showed single step nested PCR positive reaction. The amplification of all or either of the three bands of 941 bp, 525 bp and 204 bp size varied with the tissues analysed. The severity of infection assessed by PCR amplification was found to be maximum in cuticle and telson followed by gill. Other tissues such as eye stalk, pleopod, periopods and uropod were observed to have mild infection. The maximum intensity of the PCR product was for the smallest amplified product of 204 bp followed by 525 bp and the weakest intensity was observed for the 941 bp size. The limitation of PCR due to inhibiting factors present in tissues could be overcome with the use of dot blot which gave positive reaction from the DNA extracted from eye stalk including the eye but yielded no amplification by PCR. [Copyright &y& Elsevier]

Abstract: This study is to investigate the outbreak of the Taura syndrome (TS) in penaeid shrimps of Thailand. Following the outbreak in 2003, the Taura syndrome virus (TSV) was detected in two closely related penaeids; the Pacific white shrimp, Penaeus vannamei, and the black tiger prawn, Penaeus monodon. Multiple viral infections were detected, we found that the TSV-infected P. vannamei also presented evidence of the White spot syndrome virus (WSSV) as evidenced by histological examination and molecular diagnostic methods. Infections of TSV and WSSV were investigated over a period of ten months between October 2003 and July 2004. TSV infection in shrimps was diagnosed by RT-PCR using the OIE recommended 9195/9992 primers. Positive shrimp gave the expected amplicon of 231 bp. We also amplified and sequenced a fragment of the vp1 gene (354 bp). The pairwise comparisons of vp1 revealed that Thai TSV was phylogenetically related to the Taiwanese strains (98.3% identity). [Copyright &y& Elsevier]

Abstract: White spot syndrome virus (WSSV) is a pathogen of major economic importance in shrimp aquaculture throughout the world. The activities of lipid peroxidation, total reduced glutathione, superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, glutathione reductase and membrane bound ATPases (Na+/K+-ATPase, Ca2+-ATPase, and Mg2+-ATPase) were analyzed in WSSV-infected and uninfected tissues of Penaeus monodon (i.e., hepatopancreas, gill, muscle, heart, eye and haemolymph). In WSSV-infected P. monodon, the activity of lipid peroxidation increased significantly (P <0.05) in all tissues whereas in the activity of antioxidants and membrane bound enzymes declined when compared to controls. This indicated that membrane dynamics may play an important role in the pathogenesis of the WSSV infection. [Copyright &y& Elsevier]

A series of four trials were conducted on inland saline groundwater of 58 g L−1 diluted to lower salinities up to 10 g L−1 and later manipulating its ionic concentrations to enhance the survival and growth of Penaeus monodon postlarvae (PL). In the first experiment, the survival of PL was tested at several salinities (10, 20, 30, 40, 50 and 58 g L−1), and the survival of PL was studied in comparison with natural sea water of similar salinities. Complete mortality of PL was observed at all salinity levels within 144 h. Longest survival for 96 h followed by 72 h was found at 10 and 20 g L−1 salinity respectively. In the second experiment, survival of PL was tested at 10–20 g L−1 salinity at different concentrations of calcium varying between 100 and 300 mg L−1. The survival of PL could be increased to 7 days at 12.5 g L−1 salinity by reducing the calcium level to 200 from 921.8 mg L−1 with magnesium and potassium levels of 208.5 and 30.03 mg L−1 respectively. In the third experiment, the survival of PL could be further enhanced to 18 days at the same salinity by increasing the magnesium level from 208.5 to 400 mg L−1 with potassium held at 30.03 mg L−1. Survival and growth of PL in inland saline water of 12.5 g L−1 salinity similar to performance in sea water of the same salinity was achieved by increasing the potassium concentration from 30.03 to 200 mg L−1 with calcium and magnesium levels of 199.5 and 199.4 mg L−1 respectively. [ABSTRACT FROM AUTHOR]

The emergence of diseases such as white spot disease has become a threat to Penaeus monodon cultivation. Although there have been a few studies utilizing RNA-Seq, the cellular processes of host-virus interaction in this species remain mostly anonymous. In the present study, P. monodon was challenged with WSSV by intramuscular injection and survived for 12 days. The effect of the host gene expression by WSSV infection in the haemocytes, hepatopancreas and muscle of P. monodon was studied using Illumina HiSeq 2000. The RNA-Seq of cDNA libraries was developed from surviving WSSV-challenged shrimp as well as from normal healthy shrimp as control. A comparison of the transcriptome data of the two groups showed 2,644 host genes to be significantly up-regulated and 2,194 genes significantly down-regulated as a result of the infection with WSSV. Among the differentially expressed genes, our study discovered HMGB, TNFSF and c-Jun in P. monodon as new potential candidate genes for further investigation for the development of potential disease resistance markers. Our study also provided significant data on the differential expression of genes in the survived WSSV infected P. monodon that will help to improve understanding of host-virus interactions in this species., Competing Interests: The authors declare there are no competing interests., (©2019 Mohd Ghani and Bhassu.)