This study analyzed nueleotide sequences from the mitochondrial eytochrome oxidase submit （COI） gene region （450 bp） to investigate the genetic structure of the oriental river prawn （ Macrobrachium nipponense ） ...This study analyzed nueleotide sequences from the mitochondrial eytochrome oxidase submit （COI） gene region （450 bp） to investigate the genetic structure of the oriental river prawn （ Macrobrachium nipponense ） among nine populations from the Yangtze and Lancang Rivers. A total of 79 individuals were collected for this work. Eighty-nine nucleotides were found to be variable, resulting in 46 haplotypes. Among the nine populations, the population from Kunming shows the greatest level of variability （h = 1.000, π = 0.028）, whereas the population from Cbongqing exhibits the lowest level of variability （h = 0.700,π = 0.008）. Analysis of molecular variance suggested that of the total genetic diversity, 9.66% was attributable to inter-population diversity and the remainder （90.34%） to differences within populations. A molecular phylogenetic tree constructed using the Neighbor-joining （N J） method showed that the 46 haplotypes were assigned to two clades associated with geographic regions. These results provide basic information for the conservation and sustainable exploitation of this species.展开更多
A 90-day experiment was conducted to investigate the effects of different dietary linoleic acid （LA; 18：2n-6） and linolenic acid ratios （LNA; 18：3n-3） on growth induces, feed utilization and tissue fatty acid pr...A 90-day experiment was conducted to investigate the effects of different dietary linoleic acid （LA; 18：2n-6） and linolenic acid ratios （LNA; 18：3n-3） on growth induces, feed utilization and tissue fatty acid profile of freshwater prawn, Macrobrachium rosenbergii post-larvae （PL）. The experiment was conducted in cubic indoor fiberglass tanks, each holding 700 L in triplicate. Post-larvae with an average weight of 20.8 ± 0.20 mg were stocked at 80 PL m2. Five experimental isocaloric （15.06 MJ kgl digestible energy）, and isonitrogenous （30.45% digestible protein） diets were formulated by blending of soybean oil and linseed oil to containing five dietary LA/LNA ratios （7.80, 2.75, 1.28, 0.65 and 0.30）. The highest survival values were recorded for prawn PL fed diet containing 0.65 LA/LAN ratios. Growth indices of PL significantly increased （P 〈 0.05） with decreased dietary LA/LAN ratios to 0.65. The same trend was observed for the highest （P ≤ 0.05） protein efficiency ratio, protein productive value, fat retention, energy retention and best feed conversion ratio. The total whole tissue polyunsaturated fatty acid composition of M. rosenbergii PL was dominated by LA followed by LAN. Post larvae fed the diets containing higher LA/LNA ratios showed a higher tissue LA/LNA ratio. The obtained findings revealed that fatty acid patterns ofM. rosenbergii PL were influenced by fatty acid profiles of diets. The diet containing 0.65 LA/LNA ratio is recommended to obtaining optimum growth performance and feed utilization for M. rosenbergii PL.展开更多
In this article, antibiogram and heavy metal resistance profile of bacteria isolated from giant freshwater prawn （Macrobrachium rosenbergii） hatchery in Malaysia are described. Although giant freshwater prawn was in...In this article, antibiogram and heavy metal resistance profile of bacteria isolated from giant freshwater prawn （Macrobrachium rosenbergii） hatchery in Malaysia are described. Although giant freshwater prawn was introduced into Malaysia since the 1980s, there was no database information on antibiogram and heavy metal resistance profile of bacteria from giant freshwater prawn （34. rosenbergii） hatchery in Malaysia. Therefore, this study was carried out to determine the effectiveness of antibiotic and heavy metal resistance profile to control bacterial diseases in M. rosenbergii hatchery. The results can provide valuable information for local M. rosenbergii post-larval producer. Antibiotic sensitivity test was carried out by disk-diffusion method against 15 types of antibiotics as follows： oxolinic acid （2 μg）, ampicillin （10μg）, erythromycin （15μg）, furazolidone （15 μg）, lincomycin （15μg）, amoxicillin （25 μg）, colistin sulphate （25 μg）, doxycycline （30μg）, florfenicol （30 μg）, flumequine （30 lag）, nalidixic acid （30μg）, tetracycline （30μg）, oleandomycin （15μg）, fosfomycin （50μg）, and spiramycin （100 μg）, whereas heavy metal resistance profile of the present bacterial isolates was determined by 2-fold agar dilution technique. In this study, 5 types of bacteria were successfully isolated; they were Aeromonas spp. （n = 77）, Escherichia coli （n = 73）, Edwardsiella spp. （n = 62）, Salmonella spp. （n = 75）, and Vibrio spp. （n = 43）. The result showed that furazolidone was the most effective antibiotic to control the bacteria isolated in this study, approximately 89.7% of the bacterial isolates were sensitive to this antibiotic. Multiple antibiotic resistance （MAR） index indicated that the hatchery water source and M. rosenbergii post-larval and sediment tanks were at high-risk exposure to the tested antibiotic. Furthermore, all the tested heavy metals （Cd2＋, Cr6＋, Hg2＋, and Cu2＋） failed to inhibit the 展开更多
Freshwater prawns （Decapoda： Caridea： Macrobrachium） play an important role in domestic fishery resources. Culturing M. rosenbergii and M. nipponense brings great economic benefits, as the two species were widely ...Freshwater prawns （Decapoda： Caridea： Macrobrachium） play an important role in domestic fishery resources. Culturing M. rosenbergii and M. nipponense brings great economic benefits, as the two species were widely farmed in China. M. qilianensis, a native species with natural distribution limited in Gansu province, was classified into genus Macrobrachium based on external morphological characters. In order to understand the molecular genetic differences among the three species of Macrobrachium, i.e., M. rosenbergii, M. nipponense, and M. qilianensis, we analyzed sequences of mitochondrial cytochrome oxidase subunit I （COI） of them. It would provide theoretical basis of exploiting and utilizing Macrobrachium resources rationally. A total of 30 individuals （10 individuals of each species） were collected from Gansu and Zhejiang province. Samples of M. qilianensis were wild, however, that of M. rosenbergii and M. nipponense were cultured. Their mitochondrial COI gene segment sequences were obtained by using the method of PCR amplification and sequencing. After alignment, 649 bp consensus sequences of COI were obtained. One hundred and sixty-nine variable sites were detected in all 30 individuals, accounting for 26.04% of total sequence. A total of seven haplotypes were also detected. Nucleotide diversity was 0.411% within M. rosenbergii, 0.092% within M. nipponense, and 0.031% within M. qilianensis. Genetic diversity of wild M. qilianensis was much lower than that of cultured M. rosenbergii and M. nipponense. Genetic distances between different haplotypes of the three prawns ranged from 19.87% to 23.84%. It suggested that the three species were valid species, because genetic distances among them were quite great. To further determine the taxonomic status of the three prawns in family Palaemonoidae, we downloaded the corresponding COI sequences of Palaemonoidae prawns from Genbank and analyzed the phylogenetic relationships of them. Phylogenetic tree （NJ） showed that M. nipponense, M. rosenbergii an展开更多
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 rosenberg...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.展开更多
A nucleic acid sequence-based amplification（NASBA）assay was established for the detection of Macrobrachium rosenbergii Nodavirus（MrNV）.The specific primers were designed according to the high conserved region of R...A nucleic acid sequence-based amplification（NASBA）assay was established for the detection of Macrobrachium rosenbergii Nodavirus（MrNV）.The specific primers were designed according to the high conserved region of RNA2 sequence of MrNV.The 224 bp specific amplification product was obtained in positive sample determined with 3%agarose gel electrophoresis,while no product was generated from shrimp infected with other viruses including DNA viruses（IHHNV,WSSV）and RNA viruses（TSV,IMNV,YHV）.The detecting limit of the assay was 8pg nucleic acid,which is more sensitive than that of PCR method.展开更多
To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and ...To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and identified as Aeromonas dhakensis by purification culture,biochemical characterization,and 16S rRNA and gyrB gene sequence analysis.The results of the challenge test revealed that the strain was highly pathogenic and the 50%lethal dose(LD_(50))in 72 h to M.rosenbergii was 1.54×10^(5)CFU/mL.The amplification results of virulence genes show that strain DKQ-1 carried 9 virulence genes,including ascV,aexT,aer,act,lip,ompAI,gcaT,acg,and exu,supporting the strong virulence of strain DKQ-1 to M.rosenbergii.Histopathological observation of the hepatopancreas,gills,and intestines indicated that DKQ-1 injection into M.rosenbergii could cause serious tissue damage,which further supported the strong virulence of this strain.In addition,a drug susceptibility test revealed that strain DKQ-1 was sensitive to 16 kinds of antibiotics,resistant to 9 kinds of antibiotics,and had intermediate resistance to spectinomycin and kanamycin.This study is the first report of A.dhakensis isolated from M.rosenbergii and provided a reference for the pathogen identification of bacterial diseases in M.rosenbergii,and for the prevention and treatment caused by A.dhakensis.展开更多
Probiotics are live microbial food supplements that have been shown to have beneficial effects on animal health.Endogenous probiotic bacteria have long been used for their proposed health promoting properties and have...Probiotics are live microbial food supplements that have been shown to have beneficial effects on animal health.Endogenous probiotic bacteria have long been used for their proposed health promoting properties and have become a hot research topic in growth improvement in aquaculture.The endogenous probiotic bacteria from intestines of Macrobrachium rosenbergii(giant river prawn)was explored for their probiotic potential,from which 367 bacterial strains were isolated from the intestine of M.rosenbergii.After 16 S rDNA sequence analysis,234 isolates were identified as Lactococcus garvieae,which accounted for 63.76%of the total number of culturable intestinal bacteria,suggesting that this bacterium was the main component of the microbiota.Furthermore,to reveal the probiotic properties of L.garvieae,this isolated bacterial strain was characterized morphologically,physiologically,and biochemically.Its enzyme production capacity,bacteriostatic activity,and resistance to acid,high temperature,and pH,were assessed.In vitro experiments showed that the L.garvieae(No.C 6 a 2)had a fast growth rate and entered the logarithmic phase rapidly.Besides,it had characteristics of acid-production and resistance,enzyme-producing capacity,and strong antibacterial activity against pathogenic Staphylococc us aureus,Aeromonas hydrophila,and Aeromonas veronii.However,it lacked the ability to tolerate high temperature.Our results provide novel data to deepen our understanding of the intestinal bacteria structure of M.rosenbergii and valuable information for probiotic screening and the application for M.rosenbergii.展开更多
The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and cul...The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and culture area in China.Therefore,it is urgent to cultivate a new high quality,high yield variety with improved cold-resistance,but the genetic parameters for cold-resistance traits are unknown in M.rosenbergii.In this study,the cold-resistance of adult M.rosenbergii populations was tested using the indoor artificial cooling method.Individuals were selected from 139 families of Shufeng G3 generation and cultured for 200 days.A linear mixed model was constructed by ASReml-R to evaluate the genetic parameters of the cold-resistance trait(cooling degree hours,CDH)and growth traits(body weight,BW,and body length,BL)based on the restricted maximum likelihood(REML)method.The results show that the heritability of CDH was low(0.12±0.05),while the growth traits(BW and BL)had low to moderate heritability,with 0.20±0.06 for BW and 0.06±0.04 for BL.The phenotypic and genetic correlation between BW and BL was significantly positive,but significantly negative phenotypic and genetic correlations were detected between CDH and BW and between CDH and BL.Furthermore,the analysis of the differences between cold-resistance and phenotypic traits showed that the female reproductive status,exoskeleton hardness and claw number of adult prawns had a great influence on the cold-resistance of M.rosenbergii(P<0.05),indicating that adults with claws and hard exoskeletons are preferred as parents in subsequent breeding selection.The present results can be attributed to the selection and breeding of a new cold-resistant variety of M.rosenbergii.展开更多
Objective:To characterize the major allergens of Macrobrachium rosenbergii.(giant freshwater prawn).Methods:Raw and cooked extracts of the giant freshwater prawn were prepared.The IgE reactivity pattern was identified...Objective:To characterize the major allergens of Macrobrachium rosenbergii.(giant freshwater prawn).Methods:Raw and cooked extracts of the giant freshwater prawn were prepared.The IgE reactivity pattern was identified by sodium dodecyl sulfate polyaerylamide gel electrophoresis(SDS-PAGE)and immunoblotting technique with the sera of 20 skin prick test(SPT)positive patients.The major allergen identified was then characterized using the proteomics approach involving a combination of two-dimensional(2-DE)electrophoresis,mass spectrometry and bioinformatics tools.Results:SDS-PAGE of the raw extract showed 23 protein bands(15-250 kDa)but those ranging from 40 to 100 kDa were not found in the cooked extract.From immunoblotting experiments,raw and cooked extracts demonstrated 11 and 5 IgE-binding proteins,respectively,with a molecular mass ranging from 15 to 155 kDa.A heat-resistant 36 kDa protein was identified as the major allergen of both extracts.In addition,a 42 kDa heat-sensitive protein was shown to be a major allergen of the raw extract.The 2-DE gel fractionated the prawn proteins to more than 50 different protein spots.Of these,10 spots showed specific:IgE reactivity with patients'sera.Matrix assisted laser desorption/ionization-lime of flight(MALDI-TOF)analysis led to identification of 2 important allergens,tropomyosin and arginine kinase.Conclusions:It can be concluded that the availability of such allergens would help in component-based diagnosis and therapy of prawn allergies.展开更多
This study was an attempt to realize the effects of antimony on freshwater swamp shrimp (Macrobrachium nipponense). An experiment of this nature, which have not previously been carried out in this species. First, medi...This study was an attempt to realize the effects of antimony on freshwater swamp shrimp (Macrobrachium nipponense). An experiment of this nature, which have not previously been carried out in this species. First, median lethal concentrations were determined in acute toxicity tests. The 96-h LC50 value was 6.748 (5.728-7.950) mg Sb/l for adult M. nipponense and 1.635 (1.271-2.103) mg Sb/l for juvenile M. nipponense. Juvenile M. nipponense were exposed to 4 different sublethal levels of antimony (0.1, 0.4, 0.8, and 1.2 mg Sb/l) over a 7-d test period and a 7-d recovery period. After 30 min (acute), there was an increase in the amount of oxygen consumed in all exposed groups. On days 3, 7, and 14, decreases in oxygen consumption were significant (p < 0.05) for the higher-exposure level groups (0.8 and 1.2 mg/l). Light microscopy investigations showed histopathological alterations in the hepatopancreas which correlated with exposure concentrations. The alterations included degenerative changes in the lumen, a reduction in the lumen volume, and injury to epithelial cells in the histoarchitecture of hepatopancreas.展开更多
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 amazonicu...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.展开更多
The structural change of the oviduct of freshwater shrimp (Macrobrachium nipponense) during spawning was ex- amined by electron microscopy. The oviduct wall structural characteristics seem to be influenced significant...The structural change of the oviduct of freshwater shrimp (Macrobrachium nipponense) during spawning was ex- amined by electron microscopy. The oviduct wall structural characteristics seem to be influenced significantly by the spawning process. Before the parturition and ovulation, two types of epithelial cells (types I and II) are found in the epithelium. The free surfaces of type I and type II cells have very dense long microvilli. Under the type I and type II cells, are a relatively thick layer of secreting material and a layer of mostly dead cells. After ovulation, two other types of epithelial cells (types III and IV) are found in the oviduct wall epithelium. The free surface of type III cells only has short microvilli scattered on the surface. The thick layer with secreting material and the dead cell layer disappeared at this stage. In some type III cells, the leaking out of cytoplasm from broken cell membrane led to the death of these type III cells. The transformation of all four types of epithelial cells was in the order: IV→I→II→III.展开更多
基金This project was supported partly by Key Research Programof Zhejiang(2005C12006-01,2006C12005)
文摘This study analyzed nueleotide sequences from the mitochondrial eytochrome oxidase submit （COI） gene region （450 bp） to investigate the genetic structure of the oriental river prawn （ Macrobrachium nipponense ） among nine populations from the Yangtze and Lancang Rivers. A total of 79 individuals were collected for this work. Eighty-nine nucleotides were found to be variable, resulting in 46 haplotypes. Among the nine populations, the population from Kunming shows the greatest level of variability （h = 1.000, π = 0.028）, whereas the population from Cbongqing exhibits the lowest level of variability （h = 0.700,π = 0.008）. Analysis of molecular variance suggested that of the total genetic diversity, 9.66% was attributable to inter-population diversity and the remainder （90.34%） to differences within populations. A molecular phylogenetic tree constructed using the Neighbor-joining （N J） method showed that the 46 haplotypes were assigned to two clades associated with geographic regions. These results provide basic information for the conservation and sustainable exploitation of this species.
文摘A 90-day experiment was conducted to investigate the effects of different dietary linoleic acid （LA; 18：2n-6） and linolenic acid ratios （LNA; 18：3n-3） on growth induces, feed utilization and tissue fatty acid profile of freshwater prawn, Macrobrachium rosenbergii post-larvae （PL）. The experiment was conducted in cubic indoor fiberglass tanks, each holding 700 L in triplicate. Post-larvae with an average weight of 20.8 ± 0.20 mg were stocked at 80 PL m2. Five experimental isocaloric （15.06 MJ kgl digestible energy）, and isonitrogenous （30.45% digestible protein） diets were formulated by blending of soybean oil and linseed oil to containing five dietary LA/LNA ratios （7.80, 2.75, 1.28, 0.65 and 0.30）. The highest survival values were recorded for prawn PL fed diet containing 0.65 LA/LAN ratios. Growth indices of PL significantly increased （P 〈 0.05） with decreased dietary LA/LAN ratios to 0.65. The same trend was observed for the highest （P ≤ 0.05） protein efficiency ratio, protein productive value, fat retention, energy retention and best feed conversion ratio. The total whole tissue polyunsaturated fatty acid composition of M. rosenbergii PL was dominated by LA followed by LAN. Post larvae fed the diets containing higher LA/LNA ratios showed a higher tissue LA/LNA ratio. The obtained findings revealed that fatty acid patterns ofM. rosenbergii PL were influenced by fatty acid profiles of diets. The diet containing 0.65 LA/LNA ratio is recommended to obtaining optimum growth performance and feed utilization for M. rosenbergii PL.
基金funded by Universiti Malaysia Terengganu and Ministry of Science, Technology and Innovation (MOSTI), Malaysia
文摘In this article, antibiogram and heavy metal resistance profile of bacteria isolated from giant freshwater prawn （Macrobrachium rosenbergii） hatchery in Malaysia are described. Although giant freshwater prawn was introduced into Malaysia since the 1980s, there was no database information on antibiogram and heavy metal resistance profile of bacteria from giant freshwater prawn （34. rosenbergii） hatchery in Malaysia. Therefore, this study was carried out to determine the effectiveness of antibiotic and heavy metal resistance profile to control bacterial diseases in M. rosenbergii hatchery. The results can provide valuable information for local M. rosenbergii post-larval producer. Antibiotic sensitivity test was carried out by disk-diffusion method against 15 types of antibiotics as follows： oxolinic acid （2 μg）, ampicillin （10μg）, erythromycin （15μg）, furazolidone （15 μg）, lincomycin （15μg）, amoxicillin （25 μg）, colistin sulphate （25 μg）, doxycycline （30μg）, florfenicol （30 μg）, flumequine （30 lag）, nalidixic acid （30μg）, tetracycline （30μg）, oleandomycin （15μg）, fosfomycin （50μg）, and spiramycin （100 μg）, whereas heavy metal resistance profile of the present bacterial isolates was determined by 2-fold agar dilution technique. In this study, 5 types of bacteria were successfully isolated; they were Aeromonas spp. （n = 77）, Escherichia coli （n = 73）, Edwardsiella spp. （n = 62）, Salmonella spp. （n = 75）, and Vibrio spp. （n = 43）. The result showed that furazolidone was the most effective antibiotic to control the bacteria isolated in this study, approximately 89.7% of the bacterial isolates were sensitive to this antibiotic. Multiple antibiotic resistance （MAR） index indicated that the hatchery water source and M. rosenbergii post-larval and sediment tanks were at high-risk exposure to the tested antibiotic. Furthermore, all the tested heavy metals （Cd2＋, Cr6＋, Hg2＋, and Cu2＋） failed to inhibit the
基金supported by the National Natural Science Foundation of China(30600456)Commission of Science and Technology of Shanghai(08391910300)Project of Keji Xiong Nong (2008-7-2) of Shanghai,China
文摘Freshwater prawns （Decapoda： Caridea： Macrobrachium） play an important role in domestic fishery resources. Culturing M. rosenbergii and M. nipponense brings great economic benefits, as the two species were widely farmed in China. M. qilianensis, a native species with natural distribution limited in Gansu province, was classified into genus Macrobrachium based on external morphological characters. In order to understand the molecular genetic differences among the three species of Macrobrachium, i.e., M. rosenbergii, M. nipponense, and M. qilianensis, we analyzed sequences of mitochondrial cytochrome oxidase subunit I （COI） of them. It would provide theoretical basis of exploiting and utilizing Macrobrachium resources rationally. A total of 30 individuals （10 individuals of each species） were collected from Gansu and Zhejiang province. Samples of M. qilianensis were wild, however, that of M. rosenbergii and M. nipponense were cultured. Their mitochondrial COI gene segment sequences were obtained by using the method of PCR amplification and sequencing. After alignment, 649 bp consensus sequences of COI were obtained. One hundred and sixty-nine variable sites were detected in all 30 individuals, accounting for 26.04% of total sequence. A total of seven haplotypes were also detected. Nucleotide diversity was 0.411% within M. rosenbergii, 0.092% within M. nipponense, and 0.031% within M. qilianensis. Genetic diversity of wild M. qilianensis was much lower than that of cultured M. rosenbergii and M. nipponense. Genetic distances between different haplotypes of the three prawns ranged from 19.87% to 23.84%. It suggested that the three species were valid species, because genetic distances among them were quite great. To further determine the taxonomic status of the three prawns in family Palaemonoidae, we downloaded the corresponding COI sequences of Palaemonoidae prawns from Genbank and analyzed the phylogenetic relationships of them. Phylogenetic tree （NJ） showed that M. nipponense, M. rosenbergii an
文摘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.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201103034)Huzhou Science and Technology Project(2012GN08,2011ZD2005)Science and Technology Innovation Team Project of Freshwater Aquaculture of Zhejiang Province(2012R10026-11)
文摘A nucleic acid sequence-based amplification（NASBA）assay was established for the detection of Macrobrachium rosenbergii Nodavirus（MrNV）.The specific primers were designed according to the high conserved region of RNA2 sequence of MrNV.The 224 bp specific amplification product was obtained in positive sample determined with 3%agarose gel electrophoresis,while no product was generated from shrimp infected with other viruses including DNA viruses（IHHNV,WSSV）and RNA viruses（TSV,IMNV,YHV）.The detecting limit of the assay was 8pg nucleic acid,which is more sensitive than that of PCR method.
基金Supported by the Earmarked Fund for the China Agriculture Research System(No.CARS-48)the Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural Varieties(No.2021 C 02069-4-3)the Major Research&Development Program(modern agriculture)of Jiangsu Province(No.BE 2019352)。
文摘To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and identified as Aeromonas dhakensis by purification culture,biochemical characterization,and 16S rRNA and gyrB gene sequence analysis.The results of the challenge test revealed that the strain was highly pathogenic and the 50%lethal dose(LD_(50))in 72 h to M.rosenbergii was 1.54×10^(5)CFU/mL.The amplification results of virulence genes show that strain DKQ-1 carried 9 virulence genes,including ascV,aexT,aer,act,lip,ompAI,gcaT,acg,and exu,supporting the strong virulence of strain DKQ-1 to M.rosenbergii.Histopathological observation of the hepatopancreas,gills,and intestines indicated that DKQ-1 injection into M.rosenbergii could cause serious tissue damage,which further supported the strong virulence of this strain.In addition,a drug susceptibility test revealed that strain DKQ-1 was sensitive to 16 kinds of antibiotics,resistant to 9 kinds of antibiotics,and had intermediate resistance to spectinomycin and kanamycin.This study is the first report of A.dhakensis isolated from M.rosenbergii and provided a reference for the pathogen identification of bacterial diseases in M.rosenbergii,and for the prevention and treatment caused by A.dhakensis.
基金Supported by the National Natural Science Foundation of China(No.32273121)the Natural Science Foundation of Zhejiang Province(No.LGN22C190019)+1 种基金the Huzhou Natural Science Foundation(No.2021YZ08)the earmarked fund for the China Agriculture Research System of MOF and MARA(No.CARS-48)。
文摘Probiotics are live microbial food supplements that have been shown to have beneficial effects on animal health.Endogenous probiotic bacteria have long been used for their proposed health promoting properties and have become a hot research topic in growth improvement in aquaculture.The endogenous probiotic bacteria from intestines of Macrobrachium rosenbergii(giant river prawn)was explored for their probiotic potential,from which 367 bacterial strains were isolated from the intestine of M.rosenbergii.After 16 S rDNA sequence analysis,234 isolates were identified as Lactococcus garvieae,which accounted for 63.76%of the total number of culturable intestinal bacteria,suggesting that this bacterium was the main component of the microbiota.Furthermore,to reveal the probiotic properties of L.garvieae,this isolated bacterial strain was characterized morphologically,physiologically,and biochemically.Its enzyme production capacity,bacteriostatic activity,and resistance to acid,high temperature,and pH,were assessed.In vitro experiments showed that the L.garvieae(No.C 6 a 2)had a fast growth rate and entered the logarithmic phase rapidly.Besides,it had characteristics of acid-production and resistance,enzyme-producing capacity,and strong antibacterial activity against pathogenic Staphylococc us aureus,Aeromonas hydrophila,and Aeromonas veronii.However,it lacked the ability to tolerate high temperature.Our results provide novel data to deepen our understanding of the intestinal bacteria structure of M.rosenbergii and valuable information for probiotic screening and the application for M.rosenbergii.
基金Supported by the Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural(Aquaculture)Varieties(No.2021C02069-4-3)the Major Research&Development Program(Modern Agriculture)of Jiangsu Province(No.BE2019352)+1 种基金the Earmarked Fund for the China Agriculture Research System(No.CARS-48)the Innovation Project of Postgraduate Scientific Research in Huzhou University in 2022(No.2022KYCX63)。
文摘The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and culture area in China.Therefore,it is urgent to cultivate a new high quality,high yield variety with improved cold-resistance,but the genetic parameters for cold-resistance traits are unknown in M.rosenbergii.In this study,the cold-resistance of adult M.rosenbergii populations was tested using the indoor artificial cooling method.Individuals were selected from 139 families of Shufeng G3 generation and cultured for 200 days.A linear mixed model was constructed by ASReml-R to evaluate the genetic parameters of the cold-resistance trait(cooling degree hours,CDH)and growth traits(body weight,BW,and body length,BL)based on the restricted maximum likelihood(REML)method.The results show that the heritability of CDH was low(0.12±0.05),while the growth traits(BW and BL)had low to moderate heritability,with 0.20±0.06 for BW and 0.06±0.04 for BL.The phenotypic and genetic correlation between BW and BL was significantly positive,but significantly negative phenotypic and genetic correlations were detected between CDH and BW and between CDH and BL.Furthermore,the analysis of the differences between cold-resistance and phenotypic traits showed that the female reproductive status,exoskeleton hardness and claw number of adult prawns had a great influence on the cold-resistance of M.rosenbergii(P<0.05),indicating that adults with claws and hard exoskeletons are preferred as parents in subsequent breeding selection.The present results can be attributed to the selection and breeding of a new cold-resistant variety of M.rosenbergii.
基金Supported by a research grant from UPSI(grant No.UPSI2011-0018-102-01)
文摘Objective:To characterize the major allergens of Macrobrachium rosenbergii.(giant freshwater prawn).Methods:Raw and cooked extracts of the giant freshwater prawn were prepared.The IgE reactivity pattern was identified by sodium dodecyl sulfate polyaerylamide gel electrophoresis(SDS-PAGE)and immunoblotting technique with the sera of 20 skin prick test(SPT)positive patients.The major allergen identified was then characterized using the proteomics approach involving a combination of two-dimensional(2-DE)electrophoresis,mass spectrometry and bioinformatics tools.Results:SDS-PAGE of the raw extract showed 23 protein bands(15-250 kDa)but those ranging from 40 to 100 kDa were not found in the cooked extract.From immunoblotting experiments,raw and cooked extracts demonstrated 11 and 5 IgE-binding proteins,respectively,with a molecular mass ranging from 15 to 155 kDa.A heat-resistant 36 kDa protein was identified as the major allergen of both extracts.In addition,a 42 kDa heat-sensitive protein was shown to be a major allergen of the raw extract.The 2-DE gel fractionated the prawn proteins to more than 50 different protein spots.Of these,10 spots showed specific:IgE reactivity with patients'sera.Matrix assisted laser desorption/ionization-lime of flight(MALDI-TOF)analysis led to identification of 2 important allergens,tropomyosin and arginine kinase.Conclusions:It can be concluded that the availability of such allergens would help in component-based diagnosis and therapy of prawn allergies.
文摘This study was an attempt to realize the effects of antimony on freshwater swamp shrimp (Macrobrachium nipponense). An experiment of this nature, which have not previously been carried out in this species. First, median lethal concentrations were determined in acute toxicity tests. The 96-h LC50 value was 6.748 (5.728-7.950) mg Sb/l for adult M. nipponense and 1.635 (1.271-2.103) mg Sb/l for juvenile M. nipponense. Juvenile M. nipponense were exposed to 4 different sublethal levels of antimony (0.1, 0.4, 0.8, and 1.2 mg Sb/l) over a 7-d test period and a 7-d recovery period. After 30 min (acute), there was an increase in the amount of oxygen consumed in all exposed groups. On days 3, 7, and 14, decreases in oxygen consumption were significant (p < 0.05) for the higher-exposure level groups (0.8 and 1.2 mg/l). Light microscopy investigations showed histopathological alterations in the hepatopancreas which correlated with exposure concentrations. The alterations included degenerative changes in the lumen, a reduction in the lumen volume, and injury to epithelial cells in the histoarchitecture of hepatopancreas.
基金supported by grants from the National Council for Scientific and Technological Development(CNPq:BrazilProcesses445670/2014-2)Coordination Office for the Improvement of Higher Education Personnel(AEl-0052-000650100/11)
文摘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.
基金Project (No. Grant 961102205) supported by the Science and Tech-nology Bureau of Zhejiang Province, China
文摘The structural change of the oviduct of freshwater shrimp (Macrobrachium nipponense) during spawning was ex- amined by electron microscopy. The oviduct wall structural characteristics seem to be influenced significantly by the spawning process. Before the parturition and ovulation, two types of epithelial cells (types I and II) are found in the epithelium. The free surfaces of type I and type II cells have very dense long microvilli. Under the type I and type II cells, are a relatively thick layer of secreting material and a layer of mostly dead cells. After ovulation, two other types of epithelial cells (types III and IV) are found in the oviduct wall epithelium. The free surface of type III cells only has short microvilli scattered on the surface. The thick layer with secreting material and the dead cell layer disappeared at this stage. In some type III cells, the leaking out of cytoplasm from broken cell membrane led to the death of these type III cells. The transformation of all four types of epithelial cells was in the order: IV→I→II→III.
