A comparative study on the contents of vitamins in the natural and the cultured prawn

A systematically comparative study on the contents of vitamins in the natural and the cultured prawn, Penaeus chinensis, was made by using High-efficiency Liquid Phase Chromatography in 1989. The results show that the vitamin C (Vc) content in the natural prawn was 8. 19% higher than that of the cultured prawn.As the natural prawn's body length increasing, the Vc content in cephalothorax increased continuously, but after August 10, the Vc content in the cultured prawn fell down rapidly. No significant differences in vitamin B1, B2,B6, nicotinic acid (NAc), nicotinamide (NAm) and folio acid (FAc) were found between the natural and the cultured prawn. Therefore, Vc probably is one of major factors limiting the growth and development of Chinese prawn.

Detection of prawn white spot baculovirusby polymerase chain reaction

INTRODUCTIONAprawnbaculovirushasbeenresponsibleformostoftheseriousshrimpdiseaseinChinasince1992.Studiesonthepathology,Pathogenesisandmorphologyofthevirusshowedthatitwasanon-occlUSiontheybaculoviruswhichcouldinfectPenaeusjaponicus,P.nzonham,P.chinests...

TOXIC EFFECTS OF Zn^(2+), Cu^(2+), Cd^(2+)and NH_3 ON CfflNESE PRAWN

This study deals with the toxic effects of Zn2+, Cu2+, Cd2+ and NH3 on Chinese prawn (Penaeus orientalis). The median lethal concentrations of the toxic matters on Chinese prawn were determined. Cd2+】Cu2+】Zn2+】NH3-Nm is the toxic order of these chemicals to Chinese prawn. The toxic order of concentrated Zn2+ and Cd2+ in tissues and organs of Chinese prawn is in the order gill 】 shell + appendage】viscera 】 muscle..

A STUDY ON PATHOGENS OF CHINESE PRAWN (PENAEUS CHINENSIS) VIRUS DISEASES

This pathogenic study shows that the viral diseases of Chinese prawns (Penaeus chinensis. O’sbeck)is due to three kinds of viruses: epithelium envelope baculovirus of Penaeus chinensis (EEBV-PC, de-tected by the authors in 1993), infections hypodermal and hematopoietic necrosis virus, andhepatopancreatic parvo-like virus, and that the first two viruses seem to be the main pathogens of theepidemic in the northern regions in 1993.

Effect of Sodium Tri Polyphosphate (STPP) and Foreign Materials on the Quality of Giant Freshwater Prawn (<i>Macrobrachium rosenbergii</i>) under Ice Storage Condition

There are reports on the use of chemicals like sodium tri polyphosphate (STPP) and foreign materials like pearl tapioca (locally called ‘sagu’), jelly (litchi) to adulterate freshwater prawn (Macrobrachium rosenbergii) prior to freeze processing to increase their weight. Studies were, therefore, undertaken to determine the changes in product quality on the use of different concentrations of STPP, sagu and litchi under ice storage condition. Percent weight gain of prawn was 5.46, 18.87 and 23.50 when dipped in 2%, 4% and 6% STPP solution, respectively. In all cases maximum water uptake by prawn muscle was during the first 6 h with fastest weight gain with STPP solutions containing tap water compared to those of ice and tap water. Organoleptic quality of the STPP treated samples became brown and spongy after 8 h of dipping treatment under iced condition. Quality assessment studies conducted after injecting sagu and litchi in prawn muscle showed little or no difference with those of control samples during the first 6 h, which turned whitish and swollen with severe drip loss after 24 h of ice stored condition, indicating characteristics for easy identification of the injected shrimps by organoleptic method.

Vibrio spp.from Macrobrachium amazonicum prawn farming are inhibited by Moringa oleifera extracts

Objective:To investigate the in vitro antimicrobial potential of extracts of stem,leaves,flowers,pods and seeds of Moringu okifera(M.okifera) against Vibrio spp.from hatchery water and the prawn Mmrobrachium amazonicum.Methods:The ethanol extracts of stem,leaves,pods and seeds and chloroform extract of flowers of M.oleifera were tested against Vibrio cholerue(V.cholerae) serogroups non-O1/non-O139(n=4).Vibrio vulnificus(n=l) and Vibrio mimicus(n=1).Escherichia coli(E.coli)(ATCC(?) 25922) was used as quality control.Vibrio species were obtained from Macmbrachium amazonicum prawns and from hatchery water from prawn farming.The Minimum Inhibitory Concentration(MIC) was determined by broth microdilution method.Results:The best result was obtained with the ethanol extract of pods,which inhibited three strains of the V.choleme,Vibrio vulnificus,Vibrio minimis and E.coli(MIC range 0.312-5.000 mg/mL).The chloroform extract of flowers was effective against all V.chokrae strains and E.coli(MIC range 0.625-1.250 mg/mL).However,the ethanol extracts of stem and seeds showed low effectiveness in inhibiting the bacterial growth.Conclusions:The extracts of pods,flowers and leaves of M.oleifera have potential for the control of Vibrio spp.Further studies are necessary to isolate the bioaetive compounds responsible for this antimicrobial activity.

RELATION BETWEEN WATER TEMPERATURE, WATER EXCHANGE AMOUNT, FEED AND PRAWN DISEASE

High temperature is an important factor inducing bacterial disase of the prawn (Penaeus orientalis).Water temperature over 35℃ apparetly stopped tested baculovirus from multiplying. High contents of ammonia-nitrogen and nitrite-nitrogen poison the prawn’s body, weaken its physique and may induce and worsen the disease.

HYDROCHEMICAL STATE OF INTERMEDIATE CULTURE POND FOR CHINESE PRAWN JUVENILES

This study deals with the hydrochemical state and management measures for the intermediate culturepond for Chinese prawn (Penaeus orientalis) juveniles. The test result showed that the intermediate cultureof Chinese prawn juvenile can be advanced to around March 20 in the Shanghai area if they are culturedin ponds in simple greenhouses of plastic knitting cloth.The density of juveniles introduced was about35 million per hectare, survival was up to 55%.

TIDAL FRONTS AND THEIR INFLUENCE ON PRAWN POSTLARVAE IMMIGRATION IN ALBATROSS BAY, THE GULF OF CARPENTARIA, AUSTRALIA

Studies of dynamics in Albatross Bay, the Gulf of Carpentaria, Australia, show strong tides of which M2is the dominant constituent in the region. Tidal fronts are present and they can be modeled by a 2-Dtidal model. Density currents have also been observed with seasonal variations due to the influence ofwet or dry seasons. This paper reviews the effects of these dynamics on the migration of prawn postlarvae in AlbatrossBay and its estuaries. It is found that through its vertical movement triggered by change of salinity theprawn postlarvae can be transported from the coast to the estuary by tides within 2.8 weeks. Howeverthis horizontal displacement mechanism may be destroyed by the tidal front in Albatross Bay. Densitycurrents may alter prawn postlarvae positions in Albatross Bay on a seasonal scale.

Enterobacteria and Vibrio from Macrobrachium amazonicum prawn farming in Fortaleza,Ceará,Brazil

Objective:To investigate the isolation of enterobacteria associated with Macrobrachium amazonicum(M.amazonicum) farming and evaluate the in vitro antimicrobial susceptibility of Vibrio strains.Methods:Strains were isolated from female M.amazonicum prawns and environmental and hatchery water.Biochemical assays were used to identify bacterial genera and those belonging to the genus Vibrio were submitted to further analyses for species identification,through Vitek 2 automated system and scrotyping.Susceptibility test was performed according to Clinical Laboratory Standards Institute.Results:The following genera of enlerobacteria were recovered:Enterobacter(n=11),Citrobacter(n=10),Proteus(n=2),Serratia(n=2),Kluyvera(n=2),Providencia(n=2),Cedecea(n=1),Escherichia(n=1).Edwardsiella(n=1) and BulliauxeUa(n=1).As for Vibrio,three species were identified:Vibrio cholerae non-O1/non-O139(n=4).Vibrio vulnificus(V.vulnificus)(n=1) and Vibrio mimicus(n=1).Vibrio spp.showed minimum inhibitory concentrations values within the susceptibility range established by Clinical Laboratory Standards Institute for almost all antibiotics,except for V.vulnificus,which presented intermediate profile to ampicillin.Conclusions:Enterobacteria do not seem to be the most important pathogens associated with M.amazonicum farming,whereas the recovery of Vibrio spp.from larviculture,with emphasis on Vibrio cholerae and V.vulnificus,deserves special attention due to their role as potentially zoonotic aquaculture-associated pathogens.Furthermore,the intermediate susceptibility of V.vulnificus to ampicillin reflects the importance of monitoring drug use in prawn farming.

Bioaccumulation of polychlorinated biphenyls in prawns and a mud crab from mixed-aquaculture ponds

The bioaccumulation of ten polychlorinated biphenyl （PCB） congeners was investigated within different tissues in three prawns （Penaeusorientalis Kishinouce, Laomedia astacina de Haan and Penaeus vannamei Boone） and one mud crab （Scylla serrata Forsskal） from mixed-aquaculture ponds in Taizhou in April 2007. The average concentrations （wet mass） of ∑ PCBs in muscle, head, and rind tissues for mean among these prawn species were 7.04, 21.16, and 11.47 ng/g, respectively. The average concentrations of ∑ PCBs in muscle, branchia, and spawn in Scylla serrata were 6.49, 21.13, and 19.76 ng/g, respectively. The concentrations of CB28 were the highest in prawn tissues （2.40 ng/g）, and accounted for 18.60% of ∑ PCBs. The concentration of CB52 was the lowest. The application of principal component analysis （PCA） for the estimation of PCB sources of contamination resulted in first component main contributions of CB101, CB153 and CB28 in the muscle, head, and rind in combined prawn samples, respectively. The enrichment level of PCBs for different tissues varied greatly. The accumulation coefficient of ∑ PCBs in prawn muscle, head, and rind tissues were 396.35, 1 191.79, and 645.91, respectively. For the Scylla serrata, the accumulation coefficients were 365.81, 1 190.50, and 1 113.31 for muscle, branchia, and spawn tissues, respectively. For prawns, the accumulation coefficient of CB153 was the highest in muscle tissues, while CB155 had the highest coefficients in the head and rind tissues. The CB155 coefficient was the highest in spawn tissues of the mud crab.

Influence of Bleaching Powder on the Quality of Giant Freshwater Prawn (<i>Macrobrachium rosenbergii</i>)

Calcium hypochlorite commercially known as bleaching powder is used as a bleaching agent in shrimp processing industries in many countries and known to effect biochemical alteration in shrimp muscle. Studies were, therefore, undertaken to determine their effect in different concentrations viz., 10, 20, 30, 40 and 50 ppm with different time intervals on the quality of head-on, headless shell-on and peeled giant freshwater prawn (Macrobrachium rosenbergii) by determining biochemical and organoleptic aspects. Myofibrillar protein solubility of fresh head-on, headless shell-on and peeled samples were 90.5%, 90% and 88%, respectively indicating a gradual decrease in protein solubility with increasing concentration of bleaching powder. Decrease in protein solubility was also higher in samples kept at longer duration in different concentration of bleaching powder. At a given concentration of 50 ppm for 30 min treatment, the loss of myofibrillar protein was higher (26.14%) in peeled samples than those of head-on and headless shell-on samples (20.44% and 21.11%). Shelf life of bleaching powder treated prawn samples was found to be reduced to 4 - 5 days in iced condition compared to 6 - 7 days for control samples. Peeled samples were also found to be more susceptible to bleaching powder than that of head-on and headless shell-on samples.

Minicistron from a gene of prawn white spot bacilliform virus(WSBV)and its expression

By the sequencing and analysis of genomic DNA and cDNA of WSBV, it was found that there existed a minicistron in the leading sequence of p204 gene. The minicistron utilized rare codons of genes from prawn and WSBV. The p204 gene could be expressed in Escherichia coli whether a miniciston exited in its leading sequence or not, but the amounts of the expressed products of them were different. The minicistron might be related to the expression of p204 gene.

Effects of β-ecdysone and polypodine-B on moulting and growth of prawn, Penaeus orientalis

Effects of the mixture of β-ecdysone and polypodine -B (2 : 1 W/W) on the moulting and growth of prawn, Penaeus orientaliss were studied in laboratory by rearing the animal with the added compound diets. The results showed that the addition of the moulting hormone (M. H) mixture to compound diets, from 1. 33× 10-6 to 30×10-6, could increase moulting activity and growth rate of the prawn to different extents, among which the 5. 33× 10-6-10. 67×10-6addition had statistically significant effects. However, 60 × 10-6 added diets caused moulting and growth inhibitions and cuticle thickening. The analyses of protein, water and ash contents of the prawn showed no remarkable differences between hormone dosed animals and the control.

Image Repair Strategies in the Pricey Prawn Scandal of Qingdao

The pricey prawn scandal of Qingdao in the 2015 National Day Holiday,not only violates the principle of integrity management,but also seriously damages the image of Qingdao—World Famous Tourist City.This study applies image repair strategies to Qingdao municipal government departments' attempt to restore its damaged image in crisis communication.Through a discourse analysis,it is found that the government departments mainly adopt the following strategies: denial,evasion of responsibility(defeasibility),reduction of offensiveness(bolstering,compensation),corrective action and mortification.Then we evaluate the effectiveness of this image repair effort.

A preliminary assay on the mixed culture of red Florida tilapia and freshwater prawn <i>Macrobrachium americanum</i>stocked in outdoor tanks at different tilapia densities

Red jumbo tilapia and M. americanum prawns were placed in 1000 L units in polyculture at three different densities of tilapia (4/5, 9/5 and 14/5 m2;tilapia/prawn) during 112 days with initial weight of? 6.5 ± 2.8 g for tilapia and 25.9 ± 8.5 g for prawn. Prawn (0/5 m2) and tilapia (4/0, 9/0 and 14/0 m2) controls were included. Tanks were maintained outdoors and under shade. Total weight gain (WG), daily individual weight gain (DWG), specific growth rate (SGR), survival, production of gross mass and food conversion ratios (FCR), ammonia, nitrite and nitrate, and chlorophyll a were measured in all units. Only prawn weight gain was significantly higher in polyculture. For tilapia, the highest survival at the end of the trial was 94% and the lowest was 75%, while prawns had final survival rates from 43% to 86%. No statistical differences were observed in weight increase among treatments at p ≤ 0.05.

Interaction of Haematopoietic Tissue Cultures of the Dublin Bay Prawn,Nephrops Norvegicus(L.),with the Causal Agent of Luminous Vibriosis Vibrio Harveyi

Vibrio harveyi cells(dose>103 cells mL-1)and extracellular products(ECP;>25μg mL-1 of total protein concentration)destroyed haematopoietic cultures of Nephrops norvegicus within 24 h of exposure.Cytopathic effects(CPE)started after 4 h of exposure to the bacterial cells,with some granularity in the cytoplasm,mostly in cells in the outer periphe-ry of the explant growth.At the end of the infection,a considerable number of nuclei remained attached to the substrate,apparently unaffected.Following exposure to ECP,initial deterioration was observed at 2 h with the presence of granularity in the cytoplasm of<20%cells,and few cells displayed small vacuoles around the nuclei.Parallel results were obtained using whole animal experiments,with V.harveyi cells being lethal to nephrops within 24 h.

Water Filterable and Particulate Metals and Their Bioaccumulation in Prawns along Veifa Village, Central Province, Papua New Guinea

Toxic metals are released into the river systems from both anthropogenic activities and natural sources. These metals are present in water as filterable and particulate metals. These metals were found to bioaccumulate in prawn samples along Veifa stretch of the Angabanga River. The analytical results showed that As as particulate metal was high in concentration at 86 μg·g^-1 and Pb as filterable metal was high in concentration at 12 μg·g^-1. The metals Pb and As also accumulated in prawns along the Veifa stretch but were within recommended toxic metal standards.

Verification of Drainage Sterilization System Uses Low-Voltage Pulsed Electric Field in a Prawn Farm

It is necessary to take measures against infectious diseases in the Southeast Asian prawn farming industry. In giant tiger prawn （Penaeus monodon） aquaculture, diseases caused by viruses such as white spot syndrome virus （WSSV） and bacteria such as Vibrio have become a menace. Appropriate treatments of prawn culture pond＇s waters are advocated for preventing and controlling pathogens. The purpose of this study was to conduct an antimicrobial water treatment using a low-voltage pulsed electric field sterilization. Here we prepared a mechanical low-voltage pulsed electric field system with copper wire coiling around a titanium ring. The viability of WSSV in seawater was examined by prawn infectivity experiments. We inoculated healthy prawns （approximately 10-15 g） with the WSSV master sample that passed 0-3 times through the system. WSSV infection in prawns decreased according to the number of passes through the system. Healthy prawns survived for〉 10 days without feeding, where as prawns inoculated with the WSSV master sample showed symptoms of white spot and died in about 4 days. Two-thirds of the prawns inoculated with the WSSV master sample that was passed once through the system developed WSSV symptoms and were polymerase chain reaction （PCR） positive. However, no symptoms were observed and prawns were PCR negative when the WSSV master sample was passed three times through the system. Based on these results, we purpose that a low-voltage pulsed electric field system will serve as an efficient pond drainage sterilization system and will replace conventional treatments using chemicals such as sodium hypochlorite.

Productive Performance of Giant Freshwater Prawn （Macrobrachium rosenbergi） Fed Diet Containing Silkworm Pupae （Bombyx mon~ Replacing for Fish Meal

The productive performance of giant freshwater prawn （Macrobrachium rosenbergii de Man） fed diet containing silkworm pupae （Bombyx mori） replacing for fish meal was conducted by focusing on digestibility, growth performance and feed utilization. Five diets of an isonitrogenous of 35 ：e 1% crude protein and isocaloric of digestible energy of 3,200 ±100 kcal/kg were formulated by using silkworm pupae, 0%, 8.6%, 17.2%, 25.8% and 34.7% by weight, replaced for fish meal. Giant freshwater prawn of 19 ± 2.0 g were stocked at 5 ind./m3 in concrete tank of 2.25 ton for three months. The protein digestibility by pepsin enzyme was evaluated in fish meal, silkworm pupae, soybean meal and shrimp meal. The digestibility was significantly difference （P 〈 0.05）. The protein digestibility of fishmeal and soybean meal was higher than silkworm pupae and shrimp meal. The productive performance of prawn in terms of growth rate and feed utilization were not significantly different （P 〉 0.05）. Therefore, silkworm pupae can be replaced for fishmeal in giant freshwater prawn （Macrobrachium rosenbergii de Man） without any adverse effects on productive performance.