Probiotic supplementation enhances the abundance of gutassociated Rhodobacteraceae species,critical symbionts contributing to the health and physiological fitness of Litopenaeus vannamei.Understanding the role of Rhod...Probiotic supplementation enhances the abundance of gutassociated Rhodobacteraceae species,critical symbionts contributing to the health and physiological fitness of Litopenaeus vannamei.Understanding the role of Rhodobacteraceae in shaping the shrimp gut microbiota is essential for optimizing probiotic application.This study investigated whether probiotics benefit shrimp health and fitness via the recruitment of Rhodobacteraceae commensals in the gut.Probiotic supplementation significantly enhanced feed conversion efficiency,digestive enzyme activity,and immune responses,thereby promoting shrimp growth.Additionally,probiotics induced pronounced shifts in gut microbial composition,enriched gut Rhodobacteraceae abundance,and reduced community variability,leading to a more stable gut microbiome.Network analysis revealed that the removal of Rhodobacteraceae nodes disrupted gut microbial connectivity more rapidly than the removal of nonRhodobacteraceae nodes,indicating a disproportionate role of Rhodobacteraceae in maintaining network stability.Probiotic supplementation facilitated the migration of Rhodobacteraceae taxa from the aquatic environment to the shrimp gut while reinforcing deterministic selection in gut microbiota assembly.Transcriptomic analysis revealed that up-regulation of amino acid metabolism and NF-κB signaling pathways was positively correlated with Rhodobacteraceae abundance.These findings demonstrate that probiotic supplementation enriches key Rhodobacteraceae taxa,stabilizes gut microbial networks,and enhances host digestive and immune functions,ultimately improving shrimp growth performance.This study provides novel perspectives on the ecological and molecular mechanisms underlying the beneficial effects of probiotics on shrimp fitness.展开更多
Matrix metalloproteinases(MMPs)play essential roles in the metabolism of collagens;however,information regarding MMPs in aquatic animals is limited.To elucidate the specific role of MMPs in shrimp muscle degradation,p...Matrix metalloproteinases(MMPs)play essential roles in the metabolism of collagens;however,information regarding MMPs in aquatic animals is limited.To elucidate the specific role of MMPs in shrimp muscle degradation,proteinases with gelati-nolytic activity were identified in the hepatopancreas of Litopenaeus vannamei(Lv).The gelatinolytic activity was suppressed by metalloproteinase inhibitors EDTA and EGTA to some degree,suggesting the existence of metalloproteinases.Then the catalytic do-main of LvMMP-2(LvMMP-2c)was cloned and expressed heterologously in the Pichia pastoris expression system.rLvMMP-2c(re-combinant LvMMP-2c)demonstrated optimal gelatinolytic activity at pH 8.0 and 50℃,and its activity could be enhanced by Ca^(2+)and Ba^(2+).Type I collagen and myofibrillar proteins from shrimp were effectively hydrolyzed by rLvMMP-2c not only at 37℃,but also at 4℃,indicating its involvement in the postmortem tenderization of shrimp muscle.Our present study provided new informa-tion to elucidate the role of metalloproteinase underlying shrimp meat softening during cold storage,and suggested new strategies to prevent shrimp quality decrement during cold storage.展开更多
Inland culture of shrimp integrated with irrigation could be one of the most feasible livelihood options for many households nearby saline land.Compared with seawater and most of reported brackish water used for shrim...Inland culture of shrimp integrated with irrigation could be one of the most feasible livelihood options for many households nearby saline land.Compared with seawater and most of reported brackish water used for shrimp culture,the sulfate content was higher in both surface and ground water in the central Asia.We evaluated the effects of salinity,the SO_(4)^(2-)/Cl^(-)ratio and their interaction on the growth,oxygen consumption,Na+/K+-ATPase activity,total antioxidant capacity(T-AOC),and hepatopancreas histology of Litopenaeus vannamei reared in artificial seawater.The experiment lasted for 30 d,two salinity levels(20 and 10)and four SO_(4)^(2-)/Cl^(-)ratios(0.14,0.577,1.127,and 2.225 mg/mg)of waters were set.Results show no significant differences in survival among groups.Salinity and its interaction effects with SO_(4)^(2-)/Cl^(-)ratio did not significantly affect the final body weight,weight gain,and specific growth rate of shrimps,whereas the SO_(4)^(2-)/Cl^(-)ratio did(P<0.05).Shrimp mean weight gain and specific growth rate at water SO_(4)^(2-)/Cl^(-)ratio of 2.225 were significantly lower than at ratio of 0.14.At salinity 20,the shrimp final body weight at water SO_(4)^(2-)/Cl^(-)ratio of 2.225 was significantly lower than at other ratios(P<0.05),whereas there was no significant difference in final body weight among treatments at salinity 10(P>0.05).Oxygen consumption,Na^(+)/K^(+)-ATPase activity,and T-AOC increased with increasing SO_(4)^(2-)/Cl^(-)ratio at both salinities.L.vannamei exposed to water SO_(4)^(2-)/Cl^(-)ratio of 2.225 at salinity 20 showed severe histopathological changes.This study indicated that L.vannamei has strong tolerance to sulfate in brackish water environment.The shrimp is more adaptable to SO_(4)^(2-)/Cl^(-)ratios below 2.225 at lower salinity,and the optimal SO_(4)^(2-)/Cl^(-)range for the growth is 0.14–0.577(mg/mg)regardless of salinity level.展开更多
Genetic variations of three species from primary parent （OI Q,SIS Q,Kona Bay Q） and their first filial generation （OI Z,SIS Z,Kona Bay Z） of Litopenaeus vannamei were detected using microsatellite marker technique...Genetic variations of three species from primary parent （OI Q,SIS Q,Kona Bay Q） and their first filial generation （OI Z,SIS Z,Kona Bay Z） of Litopenaeus vannamei were detected using microsatellite marker technique.The amplified products of genomic DNA with 8 microsatellite makers indicated that 8 loci presents polymorphism,the number of total alleles were 28 in 6 species;the number of allele of every loci was 2 to 6;mean allele number （Na） was 3.5;expected heterozygosity value （He） were higher than observed heterozygosity value （Ho）;mean polymorphism information content （PIC） ranged from 0.479 4 to 0.769 9,which showed these 8 loci posses relatively high information content.Through analysis of genetic structure in primary parent and their first filial,allele and effective allele number,observed heterozygosity and expected heterozygosity values and mean polymorphism information content （PIC） in filial generation were little lower than their primary parents.However,genetic diversity of filial generation is not influenced,and still maintains a good heritability.展开更多
A factorial study was conducted to determine the effects of salinity （constant （SO） and fluctuating （S10）） and isoenergetic diet of different protein/carbohydrate ratios （P/C： 4.1, 1.9, 1.0 and 0.6） on the su...A factorial study was conducted to determine the effects of salinity （constant （SO） and fluctuating （S10）） and isoenergetic diet of different protein/carbohydrate ratios （P/C： 4.1, 1.9, 1.0 and 0.6） on the survival and growth of juvenile Litopenaeus vannamei. The experiment lasted for 35 days. The results showed that I） At S0 and S10, specific growth rate and apparent digestibility coefficient exhibited decreasing trend, while food conversion ratio exhibited increasing trend, with decreasing P/C ratio. At SO, food consumption and specific growth rate of the shrimp fed 4.1 P/C were significantly higher than those fed 1.0 and 0.6 P/C, whereas at S10, no significant differences were detected among different treatments; II） At 4.1 and 1.9 P/C, food consumption and specific growth rate were higher in the shrimp maintained at SO as compared with those at S10, while at 1.0 and 0.6 P/C, an inverse trend was observed. Among four P/C ratios, food conversion ratio of the shrimp at SO was the lowest.展开更多
To quantify the response to selection,heritability and genetic correlations between weight and size ofLitopenaeus vannamei,the body weight(BW),total length(TL),body length(BL),first abdominal segment depth(FASD),third...To quantify the response to selection,heritability and genetic correlations between weight and size ofLitopenaeus vannamei,the body weight(BW),total length(TL),body length(BL),first abdominal segment depth(FASD),third abdominal segment depth(TASD),first abdominal segment width(FASW),and partial carapace length(PCL)of 5-month-old parents and of offspring were measured by calculating seven body measurings of offspring produced by a nested mating design.Seventeen half-sib families and 42 full-sib families ofL.vannamei were produced using artificial fertilization from 2-4 dams by each sire,and measured at around five months post-metamorphosis.The results show that heritabilities among various traits were high:0.515±0.030 for body weight and 0.394±0.030 for total length.After one generation of selection,the selection response was 10.70%for offspring growth.In the 5th month,the realized heritability for weight was 0.296 for the offspring generation.Genetic correlations between body weight and body size were highly variable.The results indicate that external morphological parameters can be applied during breeder selection for enhancing the growth without sacrificing animals for determining the body size and breed ability;and selective breeding can be improved significantly,simultaneously with increased production.展开更多
Seven microsatellite markers were used to evaluate the genetic diversity and differentiation of seven stocks of Litopenaeus vannamei, which were introduced from Central and South America to China. All seven microsatel...Seven microsatellite markers were used to evaluate the genetic diversity and differentiation of seven stocks of Litopenaeus vannamei, which were introduced from Central and South America to China. All seven microsatellite loci were polymorphic, with polymorphism information content(PIC) values ranging from 0.593 to 0.952. Totally 92 alleles were identified, and the number of alleles(Na) and effective alleles(Ne) varied between 4 and 21 and 2.7 and 14.6, respectively. Observed heterozygosity(Ho) values were lower than the expected heterozygosity(He) values(0.526–0.754), which indicated that the seven stocks possessed a rich genetic diversity. Thirty-seven tests were detected for reasonable significant deviation from Hardy-Weinberg equilibrium. Fis values were positive at five loci, suggesting that there was a relatively high degree of inbreeding within stocks. Pairwise Fst values ranged from 0.0225 to 0.151, and most of the stock pairs were moderately differentiated. Genetic distance and cluster analysis using UPGMA revealed a close genetic relationship of L. vannamei between Pop2 and Pop3. AMOVA indicated that the genetic variation among stocks(11.3%) was much lower than that within stocks(88.7%). Although the seven stocks had a certain degree of genetic differentiation and a rich genetic diversity, there is an increasing risk of decreased performance due to inbreeding in subsequent generations.展开更多
Shrimps( Litopenaeus vannamei) were intensively cultured in a recirculating aquaculture system for 98 days to investigate effects of 0.3 mg/L Cu on its performance, Cu budget, and Cu distribution. Shrimps in Cu-treate...Shrimps( Litopenaeus vannamei) were intensively cultured in a recirculating aquaculture system for 98 days to investigate effects of 0.3 mg/L Cu on its performance, Cu budget, and Cu distribution. Shrimps in Cu-treated systems had greater mean final weight(11.10 vs 10.50 g), body length(107.23 vs 106.42 mm), survival rate(67.80% vs 66.40%), and yield(6.42 vs 5.99 kg/m 3), and lower feed conversion ratio(1.20 vs 1.29) than those in control systems but the differences were not significant. Vibrio numbers remained stable(10 4 –10 6 colony forming units/mL) in the rearing tanks of both control and treated systems. Total ammonium-N, nitrite-N, nitrate-N, pH, chemical oxygen demand, 5-day carbonaceous biochemical oxygen demand, and total suspended solids were similar in controls and treatments. Dissolved Cu concentration in the treated systems decreased from 0.284 to 0.089 mg/L while in the control systems it increased from 0.006 2 to 0.018 mg/L. The main sources of Cu in the treated systems were the artificially added component(75.7% of total input), shrimp feed(21.0%), water(2.06%), and shrimp biomass(1.22%). The major outputs of Cu occurred via the mechanical filter(41.7%), water renewal(15.6%), and draining of the sediment trap(15.1%). The foam fractionator removed only 0.69% of total Cu input. Harvested shrimp biomass accounted for 11.68% of Cu input. The Cu concentration of shrimps in the Cu-treated systems(30.70 mg/kg wet weight) was significantly higher than that in control systems(22.02 mg/kg). Both were below the maximum permissible concentration(50 mg/kg) for Cu in seafood for human consumption in China. Therefore, recirculating systems can be used for commercial on-growing of Litopenaeus vannamei without loss of shrimp quality, even in water polluted by 0.30 mg/L Cu. The mechanical filter is the main route for Cu removal.展开更多
This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture of Litopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to ne...This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture of Litopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to near to commercial diet with about 40% protein and 7.5% lipid. Fish meal was replaced by 0, 30%, 40%, 50%, 60%, 70% and 100% of PBM (diets 1-7). The diet with 100% fish meal was used as a control (diet 1). Post-larvae were reared in an indoor semi-closed re-circulating system. Each dietary treatment was tested in 4 replicate tanks (260 L) of 40 shrimp, arranged in a completely randomized design. The shrimps were hand-fed for three times a day to near-satiation (0700, 1200 and 1800) for 60 d. Percentage weight gain, survival, feed conversion ratio (FCR), protein efficiency ratio (PER) and body composition of shrimps were measured. There were no significant differences (P>0.05) in growth performance among shrimps fed diets 1-5 (0-60% fish meal replacement). However, shrimps fed diet 7 (100% fish meal replacement) had significantly lower (P<0.05) growth than those fed diets 1-5 (0-60% fish meal replacement). Shrimp fed diets 2-4 (30%-50% fish meal replacement) showed significantly higher growth than those fed diets 6 and 7 (70% and 100% fish meal replacement, respectively). Survival ranged from 94.7% to 100.0% and did not differ significantly (P>0.05) among different experimental diets. No differences in body composition were found among shrimps fed different diets. These results showed that up to 70% of fish meal protein can be replaced by PBM without adversely affecting the growth, survival, FCR, PER and body composition of Litopenaeus vannamei.展开更多
The phosphatidylinositol 3-kinase(PI3K)-AKT pathway is involved in various cellular functions, including anti-apoptosis, protein synthesis, glucose metabolism and cell cycling. However, the role of the PI3K-AKT pathwa...The phosphatidylinositol 3-kinase(PI3K)-AKT pathway is involved in various cellular functions, including anti-apoptosis, protein synthesis, glucose metabolism and cell cycling. However, the role of the PI3K-AKT pathway in crustaceans remains unclear. In the present study, we cloned and characterized the AKT gene lvakt from Litopenaeus vannamei. The 511-residue LVAKT was highly conserved; contained a PH domain, a catalytic domain and a hydrophobic domain; and was highly expressed in the heart and gills of L. vannamei. We found, using Real-Time Quantitative PCR(Q-PCR) analysis, that lvakt was upregulated during early white spot syndrome virus(WSSV) infection. Moreover, the PI3K-specific inhibitor, LY294002, reduced viral gene transcription, implying that the PI3K-AKT pathway might be hijacked by WSSV. Our results therefore suggest that LVAKT may play an important role in the shrimp immune response against WSSV.展开更多
A 3×3 factorial experiment was conducted to determine the effects of water temperature (22 ℃, 27℃ and 32℃) and dietary carbohydrate (CBH) levels (15.47%, 29.15% and 41.00%) on growth, food consumption, feed ef...A 3×3 factorial experiment was conducted to determine the effects of water temperature (22 ℃, 27℃ and 32℃) and dietary carbohydrate (CBH) levels (15.47%, 29.15% and 41.00%) on growth, food consumption, feed efficiency, apparent digestibility coefficient and energy budget of juvenile Lito- penaeus vannamei. The results showed that, at each dietary CBH level, specific growth rate, food con- sumption and apparent digestibility coefficient generally increased, while feed efficiency decreased with increasing water temperatures. Specific growth rate and food consumption were the highest in the shrimps fed with diet of 29.15% CBH, closely followed by those with 15.47% CBH, and those with 41.00% CBH had the lowest value.展开更多
Extruded soybean meal （ESBM） was evaluated as a protein source for partial replacement of fish meal （FM） in diets of juvenile Litopenaeus vannarnei. In the control diet （Diet 1）, FM protein was replaced with inc...Extruded soybean meal （ESBM） was evaluated as a protein source for partial replacement of fish meal （FM） in diets of juvenile Litopenaeus vannarnei. In the control diet （Diet 1）, FM protein was replaced with increasing dietary levels of ESBM （4.28%, 8.40%, 12.62%, 16.82%, and 25.26%） at 10%, 20%, 30%, 40%, and 60% levels （Diets 2 to 6, respectively）. An eight-week feeding trial was conducted on 720 juvenile shrimp （0.67 g ± 0.01 g mean initial Weight）, and nutrient digestibility of the six diets was determined. ESBM could replace 20% of FM without causing a significant reduction in growth of shrimp, but other dietary treatments strongly affected whole body composition. Crude protein content of the whole body fed Diet 6 was significantly lower than that fed Diet 2 （P〈0.05）, while crude lipid content of the whole body fed Diet 5 or 6 was significantly higher than that fed Diet 2 （P〈0,05）. Protein digestibilities of Diets 5 and 6 were significantly lower than that of Diet 1 （P〈0.05）. Digestibility of lipids ranged from 96.97% in Diet 6 to 98.34% in Diet 3, whereas dry matter digestibility decreased with increasing replacement level. This study indicates that 20% FM replacement with ESBM in the basic diet containing 40% protein and 30% FM is optimal for juvenile L. vannamei.展开更多
This study examined the effect of salinity on the expression of Na+/K+-ATPase(NKA) α-subunit and vacuolar-type H+-ATPase(V-ATPase) β-subunit gene in the gill of Litopenaeus vannamei. Semi-quantitative reverse transc...This study examined the effect of salinity on the expression of Na+/K+-ATPase(NKA) α-subunit and vacuolar-type H+-ATPase(V-ATPase) β-subunit gene in the gill of Litopenaeus vannamei. Semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR) assay showed that the expression of NKA α-subunit and V-ATPase β-subunit gene was significantly influenced by salinity. It was found that the NKA activity significantly varied with salinity in time and dose dependent manner; whereas the V-ATPase activity did not. The abundance of NKA α-subunit gene transcript increased rapidly when the salinity decreased from 26 b to 21, and slowly when the salinity decreased from 26 to 31 within the first 24 h. When the salinity decreased from 26 to 21, the transcription of NKA α-subunit gene in gill epithelium was higher at 12 h than that at 0 h, which was consistent with the result of immunoblotting assay of NKA α-subunit. In addition, salinity had a significant time- and dose-dependent effect on the concentration of biogenic amines in both hemolymph and gill. As compared to other parameters, the concentration of dopamine(DA) and 5-hydroxytryptamine(5-HT) varied in different patterns when the salinity decreased from 26 to 21 or increased from 26 to 31, suggesting that DA and 5-HT played different regulatory roles in osmotic adaption and modulation of shrimp when salinity varies.展开更多
The single and synergistic effects of dietary arabinoxylan-oligosaccharide(AXOS)and inulin at different doses(2,4,and 8 mg/g diet)on survival,growth performance,gut microbiota,and immune response in Pacific white shri...The single and synergistic effects of dietary arabinoxylan-oligosaccharide(AXOS)and inulin at different doses(2,4,and 8 mg/g diet)on survival,growth performance,gut microbiota,and immune response in Pacific white shrimp Litopenaeus vannamei were assessed.Singular application of either inulin or AXOS at doses of 4 mg/g diet showed the most stimulatory effects on the growth rate and gene expression levels of chitinase,cathepsin L,chymotrypsin,and extracellular signal-regulated kinase(ERK)in each single prebiotic feeding trial.Compared with single prebiotic treatments,simultaneous application of AXOS and inulin at 4 mg/g diet enhanced remarkably the growth parameters of shrimp and the expression of related genes(chitinase,cathepsin L,chymotrypsin,ERK,myeloid differentiation factor 88,and phenoloxidase)after 8-week feeding(P<0.05).Additionally,gut microbiota analysis indicated the dietary supplementation with combined prebiotics increased significantly the bacterial community richness and relative abundance of Bacillus Pseudomonas Bacteriovorax,and Lactobacillus,and reduced the abundance of Vibrio Rhodococcus,and Photobacterium in the digestive tract of L vannamei.Compared with the single prebiotic treatment and the control,combined prebiotics supplementation boosted notably the survival rate and expression levels of immune-related genes in shrimp infected with Vibrio alginolyticus or white spot syndrome virus.Therefore,simultaneous application of AXOS and inulin shall have a great potential of dietary supplement in the culture of L.vannamei.展开更多
Two modes of regulating the water quality of experimental ponds in indoor raceway culture of Litopenaeus vannamei were evaluated using simple water treatment facilities. A self-made water purifying net, aeration stone...Two modes of regulating the water quality of experimental ponds in indoor raceway culture of Litopenaeus vannamei were evaluated using simple water treatment facilities. A self-made water purifying net, aeration stone, composite microbe preparation, and Ceratophyllum demersum were placed in the experimental ponds and the culture water was circulated along the raceway inside the pond using a paddle wheel aerator. In addition, the water quality in the experimental pond was improved by draining effluent from the pipeline at the bottom of ponds 7 and 8 （mode I） and exchanging the circulating water in pond 10 （mode Ⅱ） with the reservoir water in pond 9 using a pump and pipeline. The water quality in the experimental ponds was similar in response to regulation using mode Ⅰ or mode Ⅱ. Water quality parameters in the experimental ponds were controlled within a suitable range by simple facilities during culture period without using any chemical treatments. The rich content of dissolved oxygen was maintained by the circular flow and continuous aeration of the pond water. The respective average values of the main water parameters in experimental ponds 7 and 10 in response to regulation of the water quality using modes Ⅰ and Ⅱwere as follows： pH 8.17 and 7.99; DO 5.16 mg/L and 5.97 mg/L; CODMn18.45 and 12.61 mg/L; TAN （NH3-N） 0.854 mg/L （0.087 mg/L） and 0.427 mg/L （0.012 mg/L）; NO2-N 0.489 mg/L and 0.337 mg/L. Moreover, the average body length and body weight of harvested shrimp of pond 7 and pond l0 were 7.56 cm and 8.99 cm, 5.10 g and 8.33 g, respectively. Furthermore, the survival rate, average biomass yield and average condition factor of the shrimp harvested were 70% and 60%, 2.54 kg/m2 and 2.14 kg/m2, and 0.675 g/cm and 0.927 g/cm, respectively. Linear equations describing the relationship between body length and culture time and cubic or power functions describing the relationship between body weight and body length were obtained based on evaluation of the growth data of shrimps throughout the culture period.展开更多
In this study, the gene encoding hemocyanin subunit L, Lv Hc L, was cloned from Litopenaeus vannamei and the genomic organization was characterized. This gene was diverse with many SNPs and also had at least four isof...In this study, the gene encoding hemocyanin subunit L, Lv Hc L, was cloned from Litopenaeus vannamei and the genomic organization was characterized. This gene was diverse with many SNPs and also had at least four isoforms, while one of them（Lv Hc L4） only had two exons and the exon2 was missed. Transcription analysis showed that these isoforms of Lv Hc L were up-regulated after WSSV challenge in WSSV-resistant shrimp, while the transcriptions were decreased constantly in WSSV-susceptible shrimp. It is suggested that the hemocyanin had rich polymorphism and was involved in the antiviral response. These results could extend our previous findings and provide insights into the immune feature of hemocyanin, which would be helpful for further studies aimed at antiviral mechanism in invertebrate.展开更多
基金supported by the National Natural Science Foundation of China(32371596)Key Natural Science Foundation of Zhejiang Province(Z25C030002)+2 种基金Science and Technology Innovation Yongjiang 2035 Key Research and Development Project of Ningbo(2024Z279)One Health Interdisciplinary Research Project(HZ202404)K.C.Wong Magna Fund in Ningbo University。
文摘Probiotic supplementation enhances the abundance of gutassociated Rhodobacteraceae species,critical symbionts contributing to the health and physiological fitness of Litopenaeus vannamei.Understanding the role of Rhodobacteraceae in shaping the shrimp gut microbiota is essential for optimizing probiotic application.This study investigated whether probiotics benefit shrimp health and fitness via the recruitment of Rhodobacteraceae commensals in the gut.Probiotic supplementation significantly enhanced feed conversion efficiency,digestive enzyme activity,and immune responses,thereby promoting shrimp growth.Additionally,probiotics induced pronounced shifts in gut microbial composition,enriched gut Rhodobacteraceae abundance,and reduced community variability,leading to a more stable gut microbiome.Network analysis revealed that the removal of Rhodobacteraceae nodes disrupted gut microbial connectivity more rapidly than the removal of nonRhodobacteraceae nodes,indicating a disproportionate role of Rhodobacteraceae in maintaining network stability.Probiotic supplementation facilitated the migration of Rhodobacteraceae taxa from the aquatic environment to the shrimp gut while reinforcing deterministic selection in gut microbiota assembly.Transcriptomic analysis revealed that up-regulation of amino acid metabolism and NF-κB signaling pathways was positively correlated with Rhodobacteraceae abundance.These findings demonstrate that probiotic supplementation enriches key Rhodobacteraceae taxa,stabilizes gut microbial networks,and enhances host digestive and immune functions,ultimately improving shrimp growth performance.This study provides novel perspectives on the ecological and molecular mechanisms underlying the beneficial effects of probiotics on shrimp fitness.
基金supported by the National Key R&D Program of China(No.2018YFD0901004)the National Natural Science Foundation of China(No.31772049)the Agricultural Guidance Program of Fujian Province(No.2024N0057).
文摘Matrix metalloproteinases(MMPs)play essential roles in the metabolism of collagens;however,information regarding MMPs in aquatic animals is limited.To elucidate the specific role of MMPs in shrimp muscle degradation,proteinases with gelati-nolytic activity were identified in the hepatopancreas of Litopenaeus vannamei(Lv).The gelatinolytic activity was suppressed by metalloproteinase inhibitors EDTA and EGTA to some degree,suggesting the existence of metalloproteinases.Then the catalytic do-main of LvMMP-2(LvMMP-2c)was cloned and expressed heterologously in the Pichia pastoris expression system.rLvMMP-2c(re-combinant LvMMP-2c)demonstrated optimal gelatinolytic activity at pH 8.0 and 50℃,and its activity could be enhanced by Ca^(2+)and Ba^(2+).Type I collagen and myofibrillar proteins from shrimp were effectively hydrolyzed by rLvMMP-2c not only at 37℃,but also at 4℃,indicating its involvement in the postmortem tenderization of shrimp muscle.Our present study provided new informa-tion to elucidate the role of metalloproteinase underlying shrimp meat softening during cold storage,and suggested new strategies to prevent shrimp quality decrement during cold storage.
基金Supported by the Science and Technology Program of Jungar Banner 2021“Demonstration and Promotion of Shrimp Farming Technology in Saline-alkali Land of Jungar Banner”,Science and Technology Program of Hangjin Banner 2023,Shandong Key Laboratory of Marine Ecological Restoration(No.201917)the Central Public-interest Scientific Institution Basal Research Fund,CAFS(No.2023 TD 58)。
文摘Inland culture of shrimp integrated with irrigation could be one of the most feasible livelihood options for many households nearby saline land.Compared with seawater and most of reported brackish water used for shrimp culture,the sulfate content was higher in both surface and ground water in the central Asia.We evaluated the effects of salinity,the SO_(4)^(2-)/Cl^(-)ratio and their interaction on the growth,oxygen consumption,Na+/K+-ATPase activity,total antioxidant capacity(T-AOC),and hepatopancreas histology of Litopenaeus vannamei reared in artificial seawater.The experiment lasted for 30 d,two salinity levels(20 and 10)and four SO_(4)^(2-)/Cl^(-)ratios(0.14,0.577,1.127,and 2.225 mg/mg)of waters were set.Results show no significant differences in survival among groups.Salinity and its interaction effects with SO_(4)^(2-)/Cl^(-)ratio did not significantly affect the final body weight,weight gain,and specific growth rate of shrimps,whereas the SO_(4)^(2-)/Cl^(-)ratio did(P<0.05).Shrimp mean weight gain and specific growth rate at water SO_(4)^(2-)/Cl^(-)ratio of 2.225 were significantly lower than at ratio of 0.14.At salinity 20,the shrimp final body weight at water SO_(4)^(2-)/Cl^(-)ratio of 2.225 was significantly lower than at other ratios(P<0.05),whereas there was no significant difference in final body weight among treatments at salinity 10(P>0.05).Oxygen consumption,Na^(+)/K^(+)-ATPase activity,and T-AOC increased with increasing SO_(4)^(2-)/Cl^(-)ratio at both salinities.L.vannamei exposed to water SO_(4)^(2-)/Cl^(-)ratio of 2.225 at salinity 20 showed severe histopathological changes.This study indicated that L.vannamei has strong tolerance to sulfate in brackish water environment.The shrimp is more adaptable to SO_(4)^(2-)/Cl^(-)ratios below 2.225 at lower salinity,and the optimal SO_(4)^(2-)/Cl^(-)range for the growth is 0.14–0.577(mg/mg)regardless of salinity level.
基金Supported by Technology Innovation Projects from Science and Tech-nology Department of Guangdong Province (2008A023700011)~~
文摘Genetic variations of three species from primary parent （OI Q,SIS Q,Kona Bay Q） and their first filial generation （OI Z,SIS Z,Kona Bay Z） of Litopenaeus vannamei were detected using microsatellite marker technique.The amplified products of genomic DNA with 8 microsatellite makers indicated that 8 loci presents polymorphism,the number of total alleles were 28 in 6 species;the number of allele of every loci was 2 to 6;mean allele number （Na） was 3.5;expected heterozygosity value （He） were higher than observed heterozygosity value （Ho）;mean polymorphism information content （PIC） ranged from 0.479 4 to 0.769 9,which showed these 8 loci posses relatively high information content.Through analysis of genetic structure in primary parent and their first filial,allele and effective allele number,observed heterozygosity and expected heterozygosity values and mean polymorphism information content （PIC） in filial generation were little lower than their primary parents.However,genetic diversity of filial generation is not influenced,and still maintains a good heritability.
基金funded by National Key Project of Scientific and Technical Supporting Programs funded by Ministry of Science & Technology of China (Grant No. 2006BAD09A01, 2006BAD09A06)Jiangsu Provincial Science Foundation for Talent Youths (Grant No. 2006548) Open Fund of Jiangsu Key Laboratory of Marine Biotechnology (Grant No. 2006HS017)
文摘A factorial study was conducted to determine the effects of salinity （constant （SO） and fluctuating （S10）） and isoenergetic diet of different protein/carbohydrate ratios （P/C： 4.1, 1.9, 1.0 and 0.6） on the survival and growth of juvenile Litopenaeus vannamei. The experiment lasted for 35 days. The results showed that I） At S0 and S10, specific growth rate and apparent digestibility coefficient exhibited decreasing trend, while food conversion ratio exhibited increasing trend, with decreasing P/C ratio. At SO, food consumption and specific growth rate of the shrimp fed 4.1 P/C were significantly higher than those fed 1.0 and 0.6 P/C, whereas at S10, no significant differences were detected among different treatments; II） At 4.1 and 1.9 P/C, food consumption and specific growth rate were higher in the shrimp maintained at SO as compared with those at S10, while at 1.0 and 0.6 P/C, an inverse trend was observed. Among four P/C ratios, food conversion ratio of the shrimp at SO was the lowest.
基金Supported by National Higb Technology Research and Development Program of China(863 Program)(No.2006AA10A406)the Key Laboratory of Marine Biology,Instihite of Oceanology,Chinese Academy of Sciences(No.IaF201002)
文摘To quantify the response to selection,heritability and genetic correlations between weight and size ofLitopenaeus vannamei,the body weight(BW),total length(TL),body length(BL),first abdominal segment depth(FASD),third abdominal segment depth(TASD),first abdominal segment width(FASW),and partial carapace length(PCL)of 5-month-old parents and of offspring were measured by calculating seven body measurings of offspring produced by a nested mating design.Seventeen half-sib families and 42 full-sib families ofL.vannamei were produced using artificial fertilization from 2-4 dams by each sire,and measured at around five months post-metamorphosis.The results show that heritabilities among various traits were high:0.515±0.030 for body weight and 0.394±0.030 for total length.After one generation of selection,the selection response was 10.70%for offspring growth.In the 5th month,the realized heritability for weight was 0.296 for the offspring generation.Genetic correlations between body weight and body size were highly variable.The results indicate that external morphological parameters can be applied during breeder selection for enhancing the growth without sacrificing animals for determining the body size and breed ability;and selective breeding can be improved significantly,simultaneously with increased production.
基金supported by the National High Technology Development Project of China under contract No. 2012AA10A404the Recommended International Advanced Agricultural Science and Technology Project of China under contract No. 2012-S5
文摘Seven microsatellite markers were used to evaluate the genetic diversity and differentiation of seven stocks of Litopenaeus vannamei, which were introduced from Central and South America to China. All seven microsatellite loci were polymorphic, with polymorphism information content(PIC) values ranging from 0.593 to 0.952. Totally 92 alleles were identified, and the number of alleles(Na) and effective alleles(Ne) varied between 4 and 21 and 2.7 and 14.6, respectively. Observed heterozygosity(Ho) values were lower than the expected heterozygosity(He) values(0.526–0.754), which indicated that the seven stocks possessed a rich genetic diversity. Thirty-seven tests were detected for reasonable significant deviation from Hardy-Weinberg equilibrium. Fis values were positive at five loci, suggesting that there was a relatively high degree of inbreeding within stocks. Pairwise Fst values ranged from 0.0225 to 0.151, and most of the stock pairs were moderately differentiated. Genetic distance and cluster analysis using UPGMA revealed a close genetic relationship of L. vannamei between Pop2 and Pop3. AMOVA indicated that the genetic variation among stocks(11.3%) was much lower than that within stocks(88.7%). Although the seven stocks had a certain degree of genetic differentiation and a rich genetic diversity, there is an increasing risk of decreased performance due to inbreeding in subsequent generations.
基金Supported by the National Key Technologies R&D Program of China(No.2011BAD13B04)the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-EW-Q212)+3 种基金the Public Service Sectors(Agriculture)Special Project(No.201003024)the Earmarked Fund for Modern Agro-Industry Technology Research Systemthe Shandong Program for Development of Science and Technology(No.2013GHY11514)the Special Scientific Research Funds for Central Non-Profit Institutes,Chinese Academy of Fishery Sciences(No.2014A09XK01)
文摘Shrimps( Litopenaeus vannamei) were intensively cultured in a recirculating aquaculture system for 98 days to investigate effects of 0.3 mg/L Cu on its performance, Cu budget, and Cu distribution. Shrimps in Cu-treated systems had greater mean final weight(11.10 vs 10.50 g), body length(107.23 vs 106.42 mm), survival rate(67.80% vs 66.40%), and yield(6.42 vs 5.99 kg/m 3), and lower feed conversion ratio(1.20 vs 1.29) than those in control systems but the differences were not significant. Vibrio numbers remained stable(10 4 –10 6 colony forming units/mL) in the rearing tanks of both control and treated systems. Total ammonium-N, nitrite-N, nitrate-N, pH, chemical oxygen demand, 5-day carbonaceous biochemical oxygen demand, and total suspended solids were similar in controls and treatments. Dissolved Cu concentration in the treated systems decreased from 0.284 to 0.089 mg/L while in the control systems it increased from 0.006 2 to 0.018 mg/L. The main sources of Cu in the treated systems were the artificially added component(75.7% of total input), shrimp feed(21.0%), water(2.06%), and shrimp biomass(1.22%). The major outputs of Cu occurred via the mechanical filter(41.7%), water renewal(15.6%), and draining of the sediment trap(15.1%). The foam fractionator removed only 0.69% of total Cu input. Harvested shrimp biomass accounted for 11.68% of Cu input. The Cu concentration of shrimps in the Cu-treated systems(30.70 mg/kg wet weight) was significantly higher than that in control systems(22.02 mg/kg). Both were below the maximum permissible concentration(50 mg/kg) for Cu in seafood for human consumption in China. Therefore, recirculating systems can be used for commercial on-growing of Litopenaeus vannamei without loss of shrimp quality, even in water polluted by 0.30 mg/L Cu. The mechanical filter is the main route for Cu removal.
基金financial support by grant No. 30871928 from the National Natural Science Foun-dation of China (NSFC)
文摘This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture of Litopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to near to commercial diet with about 40% protein and 7.5% lipid. Fish meal was replaced by 0, 30%, 40%, 50%, 60%, 70% and 100% of PBM (diets 1-7). The diet with 100% fish meal was used as a control (diet 1). Post-larvae were reared in an indoor semi-closed re-circulating system. Each dietary treatment was tested in 4 replicate tanks (260 L) of 40 shrimp, arranged in a completely randomized design. The shrimps were hand-fed for three times a day to near-satiation (0700, 1200 and 1800) for 60 d. Percentage weight gain, survival, feed conversion ratio (FCR), protein efficiency ratio (PER) and body composition of shrimps were measured. There were no significant differences (P>0.05) in growth performance among shrimps fed diets 1-5 (0-60% fish meal replacement). However, shrimps fed diet 7 (100% fish meal replacement) had significantly lower (P<0.05) growth than those fed diets 1-5 (0-60% fish meal replacement). Shrimp fed diets 2-4 (30%-50% fish meal replacement) showed significantly higher growth than those fed diets 6 and 7 (70% and 100% fish meal replacement, respectively). Survival ranged from 94.7% to 100.0% and did not differ significantly (P>0.05) among different experimental diets. No differences in body composition were found among shrimps fed different diets. These results showed that up to 70% of fish meal protein can be replaced by PBM without adversely affecting the growth, survival, FCR, PER and body composition of Litopenaeus vannamei.
基金Supported by the Scientific Research Foundation of Third Institute of Oceanography,SOA(No.2011018)the Natural Science Foundation of Fujian Province of China(No.2011J05079)+3 种基金the National Natural Science Foundation of China(No.31001125)the Major State Basic Research Development Program of China(973 Program)(No.2012CB114403)the National High Technology Research and Development Program of China(863 Program)(No.2012AA092205)the China Agriculture Research System-47
文摘The phosphatidylinositol 3-kinase(PI3K)-AKT pathway is involved in various cellular functions, including anti-apoptosis, protein synthesis, glucose metabolism and cell cycling. However, the role of the PI3K-AKT pathway in crustaceans remains unclear. In the present study, we cloned and characterized the AKT gene lvakt from Litopenaeus vannamei. The 511-residue LVAKT was highly conserved; contained a PH domain, a catalytic domain and a hydrophobic domain; and was highly expressed in the heart and gills of L. vannamei. We found, using Real-Time Quantitative PCR(Q-PCR) analysis, that lvakt was upregulated during early white spot syndrome virus(WSSV) infection. Moreover, the PI3K-specific inhibitor, LY294002, reduced viral gene transcription, implying that the PI3K-AKT pathway might be hijacked by WSSV. Our results therefore suggest that LVAKT may play an important role in the shrimp immune response against WSSV.
基金Supported by the Chinese National Agricultural Development Project (No. K2002-15) and the Science Research Council of Shandong Province, China (No. 041656).
文摘A 3×3 factorial experiment was conducted to determine the effects of water temperature (22 ℃, 27℃ and 32℃) and dietary carbohydrate (CBH) levels (15.47%, 29.15% and 41.00%) on growth, food consumption, feed efficiency, apparent digestibility coefficient and energy budget of juvenile Lito- penaeus vannamei. The results showed that, at each dietary CBH level, specific growth rate, food con- sumption and apparent digestibility coefficient generally increased, while feed efficiency decreased with increasing water temperatures. Specific growth rate and food consumption were the highest in the shrimps fed with diet of 29.15% CBH, closely followed by those with 15.47% CBH, and those with 41.00% CBH had the lowest value.
基金financially supported by the Special Fund for Agro-scientific Research in the Public Interest of China(201003020)the Guangdong University Innovation Talents Cultivating Project of China(1009324)+1 种基金the Guangdong Natural Science Foundation of China(S2012 040007863)by the Guangdong Province Universities and College Pearl River Scholar Funded Scheme(GD UPS-2011)
文摘Extruded soybean meal （ESBM） was evaluated as a protein source for partial replacement of fish meal （FM） in diets of juvenile Litopenaeus vannarnei. In the control diet （Diet 1）, FM protein was replaced with increasing dietary levels of ESBM （4.28%, 8.40%, 12.62%, 16.82%, and 25.26%） at 10%, 20%, 30%, 40%, and 60% levels （Diets 2 to 6, respectively）. An eight-week feeding trial was conducted on 720 juvenile shrimp （0.67 g ± 0.01 g mean initial Weight）, and nutrient digestibility of the six diets was determined. ESBM could replace 20% of FM without causing a significant reduction in growth of shrimp, but other dietary treatments strongly affected whole body composition. Crude protein content of the whole body fed Diet 6 was significantly lower than that fed Diet 2 （P〈0.05）, while crude lipid content of the whole body fed Diet 5 or 6 was significantly higher than that fed Diet 2 （P〈0,05）. Protein digestibilities of Diets 5 and 6 were significantly lower than that of Diet 1 （P〈0.05）. Digestibility of lipids ranged from 96.97% in Diet 6 to 98.34% in Diet 3, whereas dry matter digestibility decreased with increasing replacement level. This study indicates that 20% FM replacement with ESBM in the basic diet containing 40% protein and 30% FM is optimal for juvenile L. vannamei.
基金supported by the National Natural Sciences Foundation of China (31072193)the Scientific Research Foundation for Outstanding Young Scientists of Shandong Province (2006BS07005)
文摘This study examined the effect of salinity on the expression of Na+/K+-ATPase(NKA) α-subunit and vacuolar-type H+-ATPase(V-ATPase) β-subunit gene in the gill of Litopenaeus vannamei. Semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR) assay showed that the expression of NKA α-subunit and V-ATPase β-subunit gene was significantly influenced by salinity. It was found that the NKA activity significantly varied with salinity in time and dose dependent manner; whereas the V-ATPase activity did not. The abundance of NKA α-subunit gene transcript increased rapidly when the salinity decreased from 26 b to 21, and slowly when the salinity decreased from 26 to 31 within the first 24 h. When the salinity decreased from 26 to 21, the transcription of NKA α-subunit gene in gill epithelium was higher at 12 h than that at 0 h, which was consistent with the result of immunoblotting assay of NKA α-subunit. In addition, salinity had a significant time- and dose-dependent effect on the concentration of biogenic amines in both hemolymph and gill. As compared to other parameters, the concentration of dopamine(DA) and 5-hydroxytryptamine(5-HT) varied in different patterns when the salinity decreased from 26 to 21 or increased from 26 to 31, suggesting that DA and 5-HT played different regulatory roles in osmotic adaption and modulation of shrimp when salinity varies.
基金Supported by the Shanghai Agriculture Applied Technology Development Program,China(Nos.G2014070111,201902080010F01111)。
文摘The single and synergistic effects of dietary arabinoxylan-oligosaccharide(AXOS)and inulin at different doses(2,4,and 8 mg/g diet)on survival,growth performance,gut microbiota,and immune response in Pacific white shrimp Litopenaeus vannamei were assessed.Singular application of either inulin or AXOS at doses of 4 mg/g diet showed the most stimulatory effects on the growth rate and gene expression levels of chitinase,cathepsin L,chymotrypsin,and extracellular signal-regulated kinase(ERK)in each single prebiotic feeding trial.Compared with single prebiotic treatments,simultaneous application of AXOS and inulin at 4 mg/g diet enhanced remarkably the growth parameters of shrimp and the expression of related genes(chitinase,cathepsin L,chymotrypsin,ERK,myeloid differentiation factor 88,and phenoloxidase)after 8-week feeding(P<0.05).Additionally,gut microbiota analysis indicated the dietary supplementation with combined prebiotics increased significantly the bacterial community richness and relative abundance of Bacillus Pseudomonas Bacteriovorax,and Lactobacillus,and reduced the abundance of Vibrio Rhodococcus,and Photobacterium in the digestive tract of L vannamei.Compared with the single prebiotic treatment and the control,combined prebiotics supplementation boosted notably the survival rate and expression levels of immune-related genes in shrimp infected with Vibrio alginolyticus or white spot syndrome virus.Therefore,simultaneous application of AXOS and inulin shall have a great potential of dietary supplement in the culture of L.vannamei.
基金Supported by the Shanghai Commission of Science and Technology (No.063919112073919102)the Shanghai Agricultural Committee (No.2006,9-4)
文摘Two modes of regulating the water quality of experimental ponds in indoor raceway culture of Litopenaeus vannamei were evaluated using simple water treatment facilities. A self-made water purifying net, aeration stone, composite microbe preparation, and Ceratophyllum demersum were placed in the experimental ponds and the culture water was circulated along the raceway inside the pond using a paddle wheel aerator. In addition, the water quality in the experimental pond was improved by draining effluent from the pipeline at the bottom of ponds 7 and 8 （mode I） and exchanging the circulating water in pond 10 （mode Ⅱ） with the reservoir water in pond 9 using a pump and pipeline. The water quality in the experimental ponds was similar in response to regulation using mode Ⅰ or mode Ⅱ. Water quality parameters in the experimental ponds were controlled within a suitable range by simple facilities during culture period without using any chemical treatments. The rich content of dissolved oxygen was maintained by the circular flow and continuous aeration of the pond water. The respective average values of the main water parameters in experimental ponds 7 and 10 in response to regulation of the water quality using modes Ⅰ and Ⅱwere as follows： pH 8.17 and 7.99; DO 5.16 mg/L and 5.97 mg/L; CODMn18.45 and 12.61 mg/L; TAN （NH3-N） 0.854 mg/L （0.087 mg/L） and 0.427 mg/L （0.012 mg/L）; NO2-N 0.489 mg/L and 0.337 mg/L. Moreover, the average body length and body weight of harvested shrimp of pond 7 and pond l0 were 7.56 cm and 8.99 cm, 5.10 g and 8.33 g, respectively. Furthermore, the survival rate, average biomass yield and average condition factor of the shrimp harvested were 70% and 60%, 2.54 kg/m2 and 2.14 kg/m2, and 0.675 g/cm and 0.927 g/cm, respectively. Linear equations describing the relationship between body length and culture time and cubic or power functions describing the relationship between body weight and body length were obtained based on evaluation of the growth data of shrimps throughout the culture period.
基金The National High Technology Research and Development Program(863 Program)of China under contract No.2012AA092205the Major State Basic Research Development Program(973 Program)of China under contract No.2012CB114403+2 种基金the China Agriculture Research System-47the National Natural Science Foundation of China under contract No.31472297 and 31302209the Scientific Research Foundation of Third Institute of Oceanography,SOA under contract No.2011018
文摘In this study, the gene encoding hemocyanin subunit L, Lv Hc L, was cloned from Litopenaeus vannamei and the genomic organization was characterized. This gene was diverse with many SNPs and also had at least four isoforms, while one of them（Lv Hc L4） only had two exons and the exon2 was missed. Transcription analysis showed that these isoforms of Lv Hc L were up-regulated after WSSV challenge in WSSV-resistant shrimp, while the transcriptions were decreased constantly in WSSV-susceptible shrimp. It is suggested that the hemocyanin had rich polymorphism and was involved in the antiviral response. These results could extend our previous findings and provide insights into the immune feature of hemocyanin, which would be helpful for further studies aimed at antiviral mechanism in invertebrate.
