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As the demand for seafood increases, so does the incidence of seafood fraud. Confirming provenance of seafood is important to combat fraudulent labelling but requires a database that contains the isotopic and elemental "fingerprints" of authentic seafood samples. Local isotopic and elemental databases can be scaled up or combined with other databases to increase the spatial and species coverage to create a larger database. This study showcases the use of isotopic and elemental fingerprints of the black tiger prawn (Penaeus monodon) to develop a database that can be used to securely store the data necessary for determining provenance. The utility of this database was tested through querying and building seven different datasets that were used to develop models to determine the provenance of P. monodon. The models built using the data retrieved from the database demonstrated that the provenance of P. monodon could be determined with >80% accuracy. As the database was developed using MySQL, it can be scaled up to include additional regions, species, or methodologies depending on the needs of the users. Combining the database with methods of determining provenance will provide regulatory bodies and the seafood industry with another provenance tool to combat fraudulent seafood labelling. [ABSTRACT FROM AUTHOR]

The consumption of raw fish has rapidly increased in recent years, but being a highly perishable product, it is characterised by a very short microbiological shelf life. High hydrostatic pressure (HPP) processing is a nonthermal technology has emerged recently as a promising alternative to thermal processing for food pasteurization capable of maintaining fresh-like characteristics and nutritional value. However, the induced changes in product quality should be assessed carefully. The present research aimed to investigate the effect of HPP on different seafood products, namely grey mullet, tiger prawn and rose shrimp, intended for raw consumption. Three pressure levels (400, 500 and 600 MPa) were applied for 10 min. During refrigerated storage, microbiological quality, chemical parameters, colour and texture and fat oxidation were analysed. Results showed that the application of lower pressure was able to inactivate E. coli, pseudomonas and/or positive coagulase staphylococci; however, they were able to recover during storage. In addition, the application of 600-MPa pressure extended the microbiological shelf life by up to 30 days. For all samples, general whitening occurred while the texture was affected in a different way for the three considered species. Fat oxidation was only minimally affected and remained quite low during storage. [ABSTRACT FROM AUTHOR]

Summary: Termites have played havoc on common woodworks in houses especially at sub-continent regions. In this work, freshly prepared chitosan from Tiger prawn (Paneous Monodon) shells was studied for anti-termite growth on vulnerable Kail wood pieces. Prawn shells were systematically processed through deprotenization, demineralization, decolourization and deacetylation to get granulated chitosan powder. Freshly extracted chitin and chitosan were characterized by FTIR, SEM and XRD studies. Effect of different compositions of chitosan in acetic acid and contact time of termite with wood towards reduction in original weight were studied. Results show that 5 wt% chitosan-coated Kail wood pieces with 20 numbers of termite and contact time for 24 hours exhibit remarkable resistance against termite growth by showing just about 0.53 % weight loss. On the other hand, Kail wood without coating of chitosan shows about 52 % reduction in weight i.e. about half of the wooden material was eaten by termite under similar conditions. This work demonstrates the efficient termicidal effect of freshly prepared chitosan from prawn shells and presents a remarkable development of chitosan as a biotermicide material derived from natural resources. [ABSTRACT FROM AUTHOR]

As the demand for seafood increases, so does the incidence of seafood fraud. Confirming provenance of seafood is important to combat fraudulent labelling but requires a database that contains the isotopic and elemental “fingerprints” of authentic seafood samples. Local isotopic and elemental databases can be scaled up or combined with other databases to increase the spatial and species coverage to create a larger database. This study showcases the use of isotopic and elemental fingerprints of the black tiger prawn (Penaeus monodon) to develop a database that can be used to securely store the data necessary for determining provenance. The utility of this database was tested through querying and building seven different datasets that were used to develop models to determine the provenance of P. monodon. The models built using the data retrieved from the database demonstrated that the provenance of P. monodon could be determined with >80% accuracy. As the database was developed using MySQL, it can be scaled up to include additional regions, species, or methodologies depending on the needs of the users. Combining the database with methods of determining provenance will provide regulatory bodies and the seafood industry with another provenance tool to combat fraudulent seafood labelling.

Abstract In order to control foodborne pathogens on seafood products, an antimicrobial, thermoplastic starch/polybutylene adipate terephthalate (TPS/PBAT; 40/60) film was produced by coating gelatin (15% v/v) containing lauric arginate (LAE; 0.8 mg/cm2), alone or combination with nisin Z (69.4 AU/cm2) to produce LAE-Gelatin-TPS/PBAT and Nisin-LAE-Gelatin-TPS/PBAT films, respectively. Both films were investigated for control of Vibrio parahaemolyticus ATCC 17802 and Salmonella Typhimurium ATCC 14028 on bigeye snapper (Lutjanus lineolatus) and tiger prawn (Penaeus monodon) slices during long-term (28 days), refrigerated (4 °C; chilled) and frozen (−20 °C) storage up to 90 days. S. Typhimurium ATCC 14028, experimentally inoculated onto bigeye snapper and tiger prawn slices, treated with the LAE-Gelatin-TPS/PBAT film, and stored at 4 °C was reduced 3.2 log 10 CFU/g after 28 days and 7 log 10 CFU/g after 21 days, respectively. Nisin-LAE-Gelatin-TPS/PBAT film reduced S. Typhimurium ATCC 14028 on bigeye snapper and tiger prawn slices 3.5 log 10 CFU/g after 28 days and 7 log 10 CFU/g after 14 days at 4 °C, respectively. The LAE-Gelatin-TPS/PBAT and Nisin-LAE-Gelatin-TPS/PBAT films and storage for 28 days at 4 °C reduced V. parahaemolyticus inoculated on chilled bigeye snapper slices approximately 2.6 and 4.2 log 10 CFU/g, respectively. Both films reduced V. parahaemolyticus inoculated on chilled tiger prawn slices approximately 7.1 log 10 CFU/g after 28 days at 4 °C. The LAE-Gelatin-TPS/PBAT and Nisin-LAE-Gelatin-TPS/PBAT films also reduced S. Typhimurium, inoculated on bigeye snapper and tiger prawn slices, 5.8 and 5.6 log 10 CFU/g, respectively, after 60 days at −20 °C. V. parahaemolyticus was reduced by 5.8 log 10 CFU/g on frozen bigeye snapper and tiger prawn slices after treatment with Nisin-LAE-Gelatin-TPS/PBAT film after 14 and 21 days, respectively. However, the LAE-Gelatin-TPS/PBAT film reduced V. parahaemolyticus 5.8 log 10 CFU/g on both frozen seafood slices after 28 days. The results obtained from this study indicate the LAE-Gelatin-TPS/PBAT and Nisin-LAE-Gelatin-TPS/PBAT films displayed excellent inhibition against S. Typhimurium and V. parahaemolyticus on chilled and frozen seafood. Highlights • Antimicrobial thermo-bioplastic films were developed. • Thermo-bioplastic was composed of cassava starch and polybutylene adipate terephthalate. • Lauric arginate alone or in a combination with nisin Z were coated on thermo-bioplastic. • Antimicrobial thermo-bioplastic effectively controlled pathogens on seafood. [ABSTRACT FROM AUTHOR]

Glucosamine is a compound of amino sugar that is found widely in the cartilage and has a very important role for health and joint flexibility. Glucosamine is generally produced by the hydrolysis of the exoskeletons of marine animals, one of the types of tiger prawns. In the tiger prawn shells contain chitin and chitosan compounds that can be derivatives further into glucosamine HCl. This study aimed to isolate and characterize the content of glucosamine HCl by hydrolysis of chitin and chitosan from the tiger prawns shells. Glucosamine HCl was hydrolyzed chemically using concentrated hydrochloric acid. Characterization glucosamine HCl has done by Fourier Transform Infra Red (FT-IR) spectrophotometry. Glucosamine HCl standard was used as a comparison to calculated match factor (MF). The determination of glucosamine level was performed by UV-Vis spectrophotometry with using glucosamine HCl standard as comparison. The results of the qualitative analysis showed a content of glucosamine HCl in tiger prawn shells either hydrolyzed from chitin and chitosan. It was characterized by the spectrum appears at wave number 1032cm-1, 1537cm-1, 3292cm-1 for chitosan and 1032cm-1, 1539cm-1, 3294cm-1 for chitin that each showed their vibration ether, CH2 and amine group (NH). MF price of chitin and chitosan is 916.66 and 976.74, which shows that the resulting spectra are identical. The results of the quantitative analysis showed that the levels of glucosamine in chitin and chitosan 698.41 and 1,119.31 mg/g, respectively. Thus the level of glucosamine HCl in chitosan is higher than in chitin. [ABSTRACT FROM AUTHOR]

Most of the life cycle of tiger prawns were estuarine (Delta Mahakam). In the juvenile stage life in estuarine and the adult stage in marine. The research objective is to assess the potential of the tiger prawn fry catches in the Mahakam Delta, as a source of tiger prawn fry in the Mahakam Delta area farms. Research using interviews and descriptive analysis through monitoring with fishermen. The results showed that the fry tiger prawn from the Delta Mahakam there on the beaches or the edge of the sea where the water is shallow and slightly brackish, as in the Delta Mahakam. Fry can be captured by using rumpon. Tiger prawns fry from Delta Mahakam durability is relatively higher than fry from the hatchery. However, the number and continuity of fry very limited because it depends on the season. Abundance of fry is determined by the number of larvae produced in the wild and their survival is greatly influenced by the availability of food. Doi: 10.12777/ijse.6.1.43-46 [How to cite this article: Suroso, B., Hutabarat, J., and Afiati, N. (2013). The Potential of Tiger Prawn Fry from Delta Mahakam, East Kalimantan Indonesia, International Journal of Science and Engineering, 6(1),43-46. Doi: 10.12777/ijse.6.1.43-46

Highlights: [•] Developed GCE/nano CeO2–PANI/DAO biosensor for histamine sensing. [•] First attempt to calculate permeability, fractional saturation, dose response analysis and biosensor efficiency for histamine biosensor. [•] Biosensor showed a linearity of 0.45–1.05mM, LOD of 48.7μM and LOQ of 132.4μM. [•] Sensitivity of the biosensor was found to be 724.94μAcm−2 mM−1. [•] Biosensor exhibited a sharp response time of <1s with a shelf life of 18 days. [Copyright &y& Elsevier]

A total of six wild broodstocks of tiger prawns, Penaeus monodon, were found positive for White Spot Virus (WSV) with an IQ2000 detection kit. Using histopathology, the intranuclear inclusion of haemocyte due to WSV infection was observed in the epithelium cells of the antennal gland, stomach and gills. This result confirmed that the wild broodstocks were positive with WSV without showing any white spot. Additionally, histopathological examination also revealed an accumulation of haemocytes around the hepatopancreatic tubules resulting from bacterial infection. Encapsulation and nodule formation, as well as related necrosis, were also observed around the hepatopancreatic tubules infected with a metazoan parasite. Encysted tylocephalum larval cestodes were observed in the hepatopancreas, with haemocytic aggregation being observed around the infected tubules. These findings showed some bacterial and parasitic infections which, in addition to the viral infection itself, could contribute to the 80% mortality rate in wild broodstocks infected with WSV. [ABSTRACT FROM AUTHOR]

Abstract: A bioeconomic model was developed to evaluate the potential performance of brown tiger prawn stock enhancement in Exmouth Gulf, Australia. This paper presents the framework for the bioeconomic model and risk assessment for all components of a stock enhancement operation, i.e. hatchery, grow-out, releasing, population dynamics, fishery, and monitoring, for a commercial scale enhancement of about 100 metric tonnes, a 25% increase in average annual catch in Exmouth Gulf. The model incorporates uncertainty in estimates of parameters by using a distribution for the parameter over a certain range, based on experiments, published data, or similar studies. Monte Carlo simulation was then used to quantify the effects of these uncertainties on the model-output and on the economic potential of a particular production target. The model incorporates density-dependent effects in the nursery grounds of brown tiger prawns. The results predict that a release of 21million 1g prawns would produce an estimated enhanced prawn catch of about 100t. This scale of enhancement has a 66.5% chance of making a profit. The largest contributor to the overall uncertainty of the enhanced prawn catch was the post-release mortality, followed by the density-dependent mortality caused by released prawns. These two mortality rates are most difficult to estimate in practice and are much under-researched in stock enhancement. [Copyright &y& Elsevier]

Separate batches of tiger prawn, Penaeus monodon, were fed three different diets, and the effect of these nutritional treatments on RNA and DNA concentrations in the ovary was examined. The given diets did not produce any significant difference in the concentrations of the nucleic acids. DNA remained remarkably stable. RNA/DNA ratio varied from 2.18 to 3.62 and largely followed the pattern similar to that of RNA. Differences in the RNA/DNA ratio did not suggest actual quantitative change in DNA per cell. Cause and effect relations need to be differentiated by analysis of nucleic acid contents at cell level for further insights into the possible link between the dynamics of change in the nucleic acids and broodstock nourishment. [ABSTRACT FROM PUBLISHER]

Separate batches of tiger prawn, Penaeus monodon, were fed three different diets, and the effect of these nutritional treatments on RNA and DNA concentrations in the ovary was examined. The given diets did not produce any significant difference in the concentrations of the nucleic acids. DNA remained remarkably stable. RNA/DNA ratio varied from 2.18 to 3.62 and largely followed the pattern similar to that of RNA. Differences in the RNA/DNA ratio did not suggest actual quantitative change in DNA per cell. Cause and effect relations need to be differentiated by analysis of nucleic acid contents at cell level for further insights into the possible link between the dynamics of change in the nucleic acids and broodstock nourishment. [ABSTRACT FROM PUBLISHER]

This study was motivated by the need to find a solution to poor egg quality and the resulting mass mortality of hatchery-produced larvae of the tiger prawn, Penaeus monodon. The approach adopted sought to improve the broodstock condition and determine its effect on egg quality using rates of fertilization, hatching and metamorphosis. Broodstock specimens were given four separate dietary treatments (D1–D4), all of which comprised squid and trash fish plus supplements. D2, D3 and D4 were supplemented with bloodworm, bioencapsulated bloodworm and a commercial broodstock diet, respectively. Tricalcic phosphate (Ca3(PO4)2) was used to enrich the live bloodworm. The bioencapsulated ration performed better than regular bloodworm and other diets. This was evident from the bioencapsulation results which showed the highest rate of hatching, survival of nauplii and larvae metamorphosing into zoea stage. [ABSTRACT FROM AUTHOR]

We describe a statistical method for estimating the effectiveness of a stock enhancement programme using nuclear DNA loci. It is based on knowing the population allele frequencies and the genotypes of the hatchery parents (mother only, or mother and father), and on determining the probability that a wild-born animal will by chance have a genotype consistent with hatchery origin. We show how to estimate the proportion of released animals in the wild population, and its standard error. The method is applied to a data set of eight microsatellite loci in brown tiger prawns ( Penaeus esculentus), prior to the start of a possible enhancement programme. We conclude that, for this particular data set, the effectiveness of such an enhancement programme could be quantified accurately if both maternal and paternal genotypes are known, but not if maternal genotypes only are known. Full paternal genotyping would require offspring genotyping and thus would be expensive, but a partly typed paternal genotype from a mass homogenate of offspring would be almost as effective and much cheaper. The experiment would become feasible based on maternal genotypes alone, if a further three typical microsatellite loci could be found to add to the existing panel of eight. The methods detailed should be of interest to any enhancement project that relies on nuclear DNA markers to provide tags. [ABSTRACT FROM AUTHOR]

Concentrations of a number of heavy metals, including Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb and Zn were determined in samples of water and muscle tissue of tiger prawn (Penaeus monodon) from two farms. One farm was located in Tuaran (farm-A) and the other in Likas (farm-B) near Kota Kinabalu. While Co, Cr, Cu, Fe, Mo, Pb and Zn concentrations were higher in the water from farm-A, other metal concentrations (Cd, Mn and Ni) were higher in farm-B. Tiger prawns raised in farm-A had comparatively higher concentrations of Co, Cr, Cu, Ni and Pb. Those grown in farm-B had higher levels of Cd, Fe, Mn, Mo and Zn. No general correlation between metal levels was discernible in the prawn tissue. The data suggested complexities in uptake and retention of metals in tiger prawn. This animal seemed to resist the build-up of certain metals whereas it allowed the entry of others to the extent of exceeding the proportion that occurred in the environment. Some of the controlling factors include the nature of the metals, environmental factors, the body''s reaction, physiological tolerance, tissue thresholds and regulatory mechanisms. [Copyright &y& Elsevier]

An experimental prawn pond of 600 sq m surface area and 2 m depth was used for the cultivation of tiger prawn. Thirty-thousand 14-day PL flies were stocked. Water treatment systems consisting of primary sedimentation, aerated biofilter and inclined plate final sedimentation were installed for treatment and recycling of the pond water. With complete recycling and reuse of the pond water and occasional replenishing with seawater to make up for losses due to evaporation, water quality was maintained at an acceptable level. Survival rate of the prawn was above 80 %. Prawn yield was estimated to be around 7.6 tonnes/hectare-cycle or 22.8 tonnes/hectare-year. [ABSTRACT FROM AUTHOR]

In postlarval Penaeus monodon from a hatchery in Asia a baculovirus was detected in the epithelial cells of the hepatopancreas by electron microscopy. The baculovirus was identified as the Monodon baculovirus (MBV). Zusammenfassung Ermittlung eines Baculovirus in der Bären- oder Schiffskielgarnele Penaeus monodon In 28 Tage alten, aus einer asiatischen Garnelenzucht stammenden Penaeus monodon-Larven wurde ein Baculovirus im Hepatopankreasepithel mittels der Elektronenmikroskopie ermittelt und als Monodon Baculovirus identifiziert. [ABSTRACT FROM AUTHOR]

Genetic improvement of tiger prawn Penaeus monodon is challenging due to difficulties in breeding and rearing of this species in captive environments. To date, there have been very limited quantitative genetic studies in this species, especially genotype by environment (G × E) interaction between diverse farming systems (e.g., tank vs. pond). Therefore, the present study ran the long-term captive selection program for tiger prawn and obtained an in-depth pedigree of five generations (including base population and first generation) for genetic assessment of the environment impacts on two economically important traits in this species (i.e., survival and body weight at harvest). Originally, we evaluated the G × E interaction effect on survival and harvest weight between Biosecure Recirculating System (RAS) at the breeding nucleus and outdoor commercial ponds. Quantitative genetic analysis within mixed model methodology framework was carried out on 57,435 individual prawns (phenotype data from three latest generations, G2-G4) to examine possible effects of rearing environments on genetic parameters (heritability and correlations) for survival and body weight at harvest. The heritability (h 2 ) for body weight was moderate (0.31–0.49) and differed slightly between the three testing environments. There were also significant heritable genetic variations of survival (h 2 = 0.37–0.77) across the environments studied. The common full-sib effects accounted for 16 to 21% of total phenotypic variation for body weight and 11 to 18% for survival. Genetic correlations between body weight and survival were positive (0.23–0.46) in this population of tiger prawn. To examine the G × E interaction effect on survival and harvest body weight, the trait expressions in each environment were treated as separate traits and bi-variate models were used to estimate genetic correlations between homologous characters. An important finding of this study was that the between-environment genetic correlations for both body weight and survival were medium to high (0.56–0.70) between outdoor ponds; however, the estimates were low to moderate (0.17–0.31) between indoor RAS in the nucleus and outdoor ponds under field conditions. In summary, the moderate heritability for body weight and survival suggest that long-term response to selection can be achieved in this population of tiger prawn, and that the effects of rearing environments should be taken into consideration when conducting genetic improvement programs for this species, specifically the management of candidate parents to produce the next generation for selection. • Selection in indoor biosecure tank produce genotypes that may not be best suited for outdoor ponds under field conditions, • Genetic correlations between traits in the testing environments were low to moderate, the G×E may be present for body weight. • Maternal and common environmental effects were large for body weight and survival • However, there were substantial heritabilities for both body weight and survival in this population of tiger prawn • Genetic correlations between weight and survival were positive to enable simultaneous improvement of both traits. [ABSTRACT FROM AUTHOR]

World production of farmed crustaceans was 7.8 million tons in 2016. While only making up approximately 10% of world aquaculture production, crustaceans are generally high-value species and can earn significant export income for producing countries. Viet Nam is a major seafood producing country earning USD 7.3 billion in 2016 in export income with shrimp as a major commodity. However, there is a general lack of genomic resources available for shrimp species, which is challenging to obtain due to the need to deal with large repetitive genomes, which characterize many decapod crustaceans. The first tiger prawn (P. monodon) genome assembly was assembled in 2016 using the standard Illumina PCR-based pair-end reads and a computationally-efficient but relatively suboptimal assembler, SOAPdenovo v2. As a result, the current P. monodon draft genome is highly fragmented (> 2 million scaffolds with N 50 length of <1000 bp), exhibiting only moderate genome completeness (< 35% BUSCO complete single-copy genes). We sought to improve upon the recently published P. monodon genome assembly and completeness by generating Illumina PCR-free pair-end sequencing reads to eliminate genomic gaps associated with PCR-bias and performing de novo assembly using the updated MaSurCA de novo assembler. Furthermore, we scaffolded the assembly with low coverage Nanopore long reads and several recently published deep Illumina transcriptome paired-end sequencing data, producing a final genome assembly of 1.6 Gbp (1,211,364 scaffolds; N 50 length of 1982 bp) with an Arthropod BUSCO completeness of 96.8%. Compared to the previously published P. monodon genome assembly from China (NCBI Accession Code: NIUS01), this represents an almost 20% increase in the overall BUSCO genome completeness that now consists of more than 90% of Arthropod BUSCO single-copy genes. The revised P. monodon genome assembly (NCBI Accession Code: VIGR01) will be a valuable resource to support ongoing functional genomics and molecular-based breeding studies in Vietnam. • We present a revised black tiger prawn genome assembly • The first Nanopore long read dataset for the black tiger prawn was generated • Scaffolding of the initial genome assembly with transcriptome data improved genome completeness • PCR introduced strong read depth bias in low-GC regions [ABSTRACT FROM AUTHOR]

P. monodon juveniles were fed krill meal (KM), krill hydrolysate (KH), whole squid (SQ), and the microbial biomass, Novacq™ (NQ), at 10% inclusion, in practical fishmeal and soybean meal based diets. Diets were fed to apparent satiation as well as restrictively pair-fed (~60% of control diet satiation) for 6 weeks to examine the effects of the test ingredients and feed restriction on shrimp growth, feed efficiency, digestive enzyme activity, nutritional condition, and gut microbiota. All diets when fed to satiety significantly outperformed the control diet, with shrimp fed NQ 87%, SQ 73%, KH 41% and KM 38% larger than shrimp fed the control diet. NQ fed shrimp had the best feed conversion ratio (FCR) and significantly improved retention efficiency (RE) of dietary lipid (RE TL), protein (RE CP) and gross energy (RE GE). SQ significantly promoted feed intake over control and KM fed shrimp, but neither KM, KH nor SQ improved RE TL , RE CP or RE GE. While there was little change in the apparent digestibility (AD) of each diet, the apparent biological value (ABV) of lipid (ABV TL), protein (ABV CP) and gross energy (ABV GE) were significantly improved by inclusion of NQ; and ABV TL and ABV GE were significantly improved by addition of SQ. Feed restriction had a stronger effect on hepatopancreas digestive enzymes and gut microbiota than addition of any feed ingredient. Total protease activity was positively correlated with feed efficiency, including FCR, RE TL and RE GE. Shrimp fed to satiety tended to have high levels of Vibrio whereas those on the restricted ration tended to have higher levels of bacteria in Rhodobacteracaea, Flavobacteriales and Bacteroidales. We conclude that shrimp are more efficient in using digested dietary macronutrients for growth when whole squid and Novacq™ are provided, due to improvements in feed intake and post-absorptive processes. Feeding restriction was shown to be a useful strategy to improve P. monodon feeding efficiency, digestive capacity and modulate gut microbiota, however it reduced the scope for shrimp growth especially on high performing diets. Novacq™ was more effective than some of the known invertebrate meals and a more environmentally sustainable growth and nutrient utilisation promoter for shrimp. • Marine ingredients improved P. monodon juvenile growth beyond a fishmeal-based diet control. • Shrimp more efficiently used digested dietary macronutrients when fed Novacq™ or whole squid. • Novacq™ was the most effective and sustainable growth and feeding efficiency promoter. • Feed restriction reduced growth, but improved feeding efficiency and digestive enzyme activity. • Gut microbiota was modulated to a greater extent by feed restriction than the test diets. [ABSTRACT FROM AUTHOR]

A total of six wild broodstocks of tiger prawns, Penaeus monodon, were found positive for White Spot Virus (WSV) with an IQ2000 detection kit. Using histopathology, the intranuclear inclusion of haemocyte due to WSV infection was observed in the epithelium cells of the antennal gland, stomach and gills. This result confirmed that the wild broodstocks were positive with WSV without showing any white spot. Additionally, histopathological examination also revealed an accumulation of haemocytes around the hepatopancreatic tubules resulting from bacterial infection. Encapsulation and nodule formation, as well as related necrosis, were also observed around the hepatopancreatic tubules infected with a metazoan parasite. Encysted tylocephalum larval cestodes were observed in the hepatopancreas, with haemocytic aggregation being observed around the infected tubules. These findings showed some bacterial and parasitic infections which, in addition to the viral infection itself, could contribute to the 80% mortality rate in wild broodstocks infected with WSV.