Astaxanthin is widely used in aquatic animal feed and has beneficial effects on aquatic animals.Haematococcus pluvialis is one of the most important sources of natural astaxanthin.In this 8-week feeding experiment,the...Astaxanthin is widely used in aquatic animal feed and has beneficial effects on aquatic animals.Haematococcus pluvialis is one of the most important sources of natural astaxanthin.In this 8-week feeding experiment,the impacts of gradient additions of H.pluvialis on the growth and physiological performance of Litopenaeus vannamei before and after acute ammonia nitrogen stress were investigated.The experimental diets were formulated by incorporating gradient levels(0%,0.02%,0.04%,0.08%,0.16%and 0.32%)of H.pluvialis into the feed,namely D0,D0.02,D0.04,D0.08,D0.16 and D0.32,respectively.Each tank housed 30 shrimp,with 4 replicates per group.Significant improvements were observed in weight gain and specific growth rate(P<0.05)in D0.02,D0.04 and D0.08 groups compared with the control group D0.Regression curve analysis indicated that the growth effect of H.pluvialis is maximized at an inclusion level of 0.1006%.The acute ammonia stress test revealed that the addition of H.pluvialis significantly ameliorated the morphology and structure of hepatopancreas in D0.08,D0.16 and D0.32 groups(P<0.05),while attenuating the apoptosis signal in hepatopancreatic cells,thereby indicating a potential alleviation of liver injury and cellular apoptosis induced by acute ammonia stress through the incorporation of a specific proportion of H.pluvialis.The expression levels of ho1 and sod mRNA in the D0.08 group increased after stress,indicating upregulation of antioxidant and immune-related genes(P<0.05).As compared to the control group,the Toll pathway genes exhibited significantly higher expression levels in diets D0.02 and D0.04 prior to stress(P<0.05).After stress,crustin was down-regulated significantly in the H.pluvialis supplemental groups,while tube and relish mRNA expression levels were significantly higher in the D0.32 group compared to the D0 group(P<0.05).The results demonstrated that the growth performance of L.vannamei was enhanced by incorporating 0.02%to 0.08%of H.pluvialis into the diet.Furthermore,dietary supplementation with 0.08%to 0.32%resulted in an increased resistance to ammonia nitrogen stress in L.vannamei.展开更多
A 30-day feeding trial was conducted to assess the effect of three fresh-live polychaetes as diets on growth and reproductive performance,biochemical indices and histology of different tissues in female Pacific white ...A 30-day feeding trial was conducted to assess the effect of three fresh-live polychaetes as diets on growth and reproductive performance,biochemical indices and histology of different tissues in female Pacific white shrimp(Litopenaeus vannamei)broodstock.Two novel polychaete species,Marphysa maxidenticulata(MM group)and Perinereis nuntia(PN group),and a traditional species,Perinereis aibuhitensis(PA group),were used as a single diet and individual experimental groups,respectively.A total of 225 healthy female broodstock shrimp,initial weight of 59.70±0.18 g,were randomly divided into three groups(three replicates of 25 shrimp each).The results showed that the MM group outperformed the PA and PN groups in growth indices,with the highest weight gain,specific growth rate,molting rate,protein efficiency ratio,gonadosomatic index,and lower feed conversion ratio compared to the PN group(P<0.05).Regarding reproductive performance,the MM group had the highest daily number of sexually mature female broodstock shrimp,successful mating count,maturity rate,mating rate,spawning cycle,total number of fertilized eggs,individual fertilized egg yield,area of mature oocytes,total number of nauplii,naupliar yield/shrimp,hatching rate,and the lowest naupliar deformity rate than the other two groups(P<0.05).Moreover,compared to the PA and PN groups,the MM group demonstrated superior activities of lipid metabolism-related enzymes and digestive enzymes,and antioxidant capacity in the hepatopancreas,intestine and serum,as well as reduced malondialdehyde levels.Meanwhile,the ovaries of the MM group showed a significant accumulation of triglycerides,estradiol,and vitellogenin compared to the other groups.Histology revealed more developed secretory cells in the hepatopancreas and largermature oocytes in the MM group compared to the others.In conclusion,M.maxidenticulata can maximize growth,reproductive performance,the activities of lipid metabolism-related enzymes and digestive enzymes,antioxidant and immune ability of female broodstock shrimp.This study demonstrated that M.maxidenticulata could be used as a potential fresh-live diet for the female L.vannamei broodstock.展开更多
This experiment explored the effects of lysophospholipids on hybrid grouper(initial average weight:22.65±0.03 g)hepatic lipid metabolism and immunity at the transcriptome and metabolome levels.A total of 375 hybr...This experiment explored the effects of lysophospholipids on hybrid grouper(initial average weight:22.65±0.03 g)hepatic lipid metabolism and immunity at the transcriptome and metabolome levels.A total of 375 hybrid groupers were divided into 5 groups of 3 replicates of 25 fish each.Five isoproteic and isolipidic diets were formed by adding 0(L_(0),control group),0.05%(L_(0.05)),0.1%(L_(0.1)),0.15%(L_(0.15))and 0.2%(L_(0.2))lysophospholipids,respectively.After 8 wk,compared to the control group,weight gain rate,specific growth rate and protein deposition rate were significantly higher(P<0.05),and the feed conversion ratio was significantly lower in the L_(0.1) group(P<0.011).The total cholesterol and triglyceride contents in the serum and liver of the fish in the L_(0.1) group were significantly lower than those in the L_(0) group(P<0.05).Compared to the L_(0) group,catalase and superoxide dismutase activities were substantially higher,and malondialdehyde content was considerably lower in the L_(0.1) group(P<0.05);complement 3,lysozyme,acid phosphatase,and alkaline phosphatase levels in the L_(0.1) group were significantly higher than those in the L_(0) group(P<0.05).The hepatic lipoprotein lipase activity and gene expression in the L_(0.1) group were significantly higher whereas fatty acid synthase activity and gene expression were significantly lower than those in the L_(0) group(P<0.05).The gene expression and activities of hepatic catalase and superoxide dismutase in the L_(0.1) group were considerably higher than those in the control group(P<0.05).The mRNA expression of major histocompatibility complex class II molecule and interleukin-10 genes were significantly higher in the L_(0.1) group than in the L_(0) group(P<0.05),while the mRNA expression of interleukin-6 and interferon-g genes in the L_(0) group was significantly higher than those in the L_(0.1) group(P<0.05).The transcriptome and metabolome data showed that the critical genes such as lipoprotein lipase and fatty acid synthase,as well as metabolites such as taurine and docosahexaenoic acid were enriched in the lipid metabolism pathway.In conclusion,0.1%lysophospholipids activated critical genes and metabolites in the adenosine 5-monophosphateactivated protein kinase and peroxisome proliferators-activated receptors signaling pathways to regulate lipid metabolism and immunity in hybrid grouper.展开更多
The hybrid grouper(Epinephelus fuscointestinetatus♀×E.lanceolatus♂)is an important aquaculture marine species in China.The current study was designed to test the effects of methanotroph(Methylococcus capsulatus...The hybrid grouper(Epinephelus fuscointestinetatus♀×E.lanceolatus♂)is an important aquaculture marine species in China.The current study was designed to test the effects of methanotroph(Methylococcus capsulatus)bacteria meal(MBM)on hybrid grouper growth and intestinal health outcomes.Five iso-nitrogenous and iso-lipidic diets were formulated,comprising a control diet(MBM0)with 400 g/kg fish meal(FM)as the main protein source,and four experimental diets,in which FM was replaced at 5%(MBM2),10%(MBM4),20%(MBM8)and 30%(MBM12)with 20,40,80 and 120 g/kg of MBM,respectively.The 450 healthy juvenile hybrid grouper(initial weight 28.84±0.05 g)were randomly allocated into five groups,with three replicates in each group and 30 fish in each replicate.They were fed for eight weeks prior to being sampled for transcriptome and microbiome research.The final body weight(FBW,P<0.001)and weight gain rate(WGR,P<0.001)were obviously enhanced in MBM2 and MBM8 groups compared to MBM0 group,and the specific growth rate(SGR)in the MBM2 and MBM8 groups were significantly enhanced compared to MBM0 group(P<0.001).The condition factor(CF)in MBM4 and MBM8 groups were considerably reduced than that in MBM0 group(P=0.008).The hepatosomatic index(HSI)in MBM8 and MBM12 groups were obviously enhanced than that in the other groups(P<0.001).In the intestinal microflora analysis,the number of operational taxonomic units(OTUs)exhibited a significant linear increase with increasing MBM replacement ratio(P=0.015).Concurrently,the richness of bacterial families and genera showed significant linear enrichment(P=0.023 and P=0.028,respectively).There was a decrease in the relative abundance of the potentially pathogenic genera Photobacterium and Vibrio in the MBM-fed groups compared with the control group.The study has effectively shown that MBM may significantly enhance the health and growth of hybrid groupers by partially replacing FM in diets at the required amount of 3.70%,as determined by WGR regression analysis.展开更多
Several reports have revealed the vital role that probiotics play in fish growth and health.However,few works are available for host gut-derived probiotics on the growth,immunity,and gut microbiota of fish,especially ...Several reports have revealed the vital role that probiotics play in fish growth and health.However,few works are available for host gut-derived probiotics on the growth,immunity,and gut microbiota of fish,especially in hybrid grouper (♀Epinephelus fuscoguttatus×♂Epinephelus lanceolatus) due to their isolation difficulty and functional verification.This study aimed at assessing 3 host gut-derived Bacillus species?effects on the growth,immune and antioxidant-biochemical responses,haematological parameters,intestinal morphology,immune-related gene expression,gut microbiota,and disease resistance against Vibrio harveyi in hybrid grouper.A total of 480 hybrid grouper (initial weight=9.03±0.02 g) were randomly allotted into 4 groups,namely,the group fed a basal diet without probiotic inclusion (control,B0),the group fed the basal diet with Bacillus velezensis GPSAK4 (BV),the group fed the basal diet with Bacillus subtilis GPSAK9 (BS),and the group fed the basal diet with Bacillus tequilensis GPSAK2 (BT) strains at 1.0×10^(9)CFU/g.After a 6-week feeding trial,the results revealed significant improvements (P<0.05) in the growth performance,whole fish-body proximate composition,blood haematological parameters,serum,liver,and intestinal biochemical indexes,intestinal morphology,and protection against V.harveyi pathogen in the probiotic-treated groups compared with the untreated.Additionally,the expressions of intestinal tight junction genes (occludin and ZO1),pro-and anti-inflammatory genes,including IL1β,IL6,IL8,TNFa,MyD88,IL10,and TGFβ,were upregulated (P<0.05) after Bacillus species administration.Host gut-derived Bacillus supplementation shaped the gut microbiota by significantly increasing (P<0.05) the relative abundance of Proteobacteria,Bacteroidetes,Actinobacteria (except the BS group),Acidobacteria(except the BT group),Cyanobacteria (except the BV and BT groups),and Verrucomicrobia phyla,as well as known beneficial genera (Romboutsia,Turicibacter,Epulopiscium,Clostridium_sensu_stricto 1 and 13,Lactobacillus,and Bacillus),but significantly decreased (P<0.05) the abundance of Firmicutes,Chloroflexi,and Fusobacteria phyla,and purported pathogenic genera (Staphylococcus and Photobacterium) compared with the control group.Collectively,the results suggest that B.velezensis GPSAK4,B.subtilis GPSAK9(especially this strain),B.tequilensis GPSAK2 dietary supplementation at 1.0×10^(9)CFU/g has positive effects on the intestinal health of hybrid grouper via microbial composition modulation,thus enhancing the assimilation and absorption of nutrients to boost fish growth,immunity,and disease resistance.展开更多
Iso-nitrogenous and iso-lipidic diets containing 0%,3%,6%,9%,and 12%hydrolyzed porcine mucosa(namely,HPM0,HPM3,HPM6,HPM9,and HPM12)were prepared to evaluate their effects on the growth performance,muscle nutrition com...Iso-nitrogenous and iso-lipidic diets containing 0%,3%,6%,9%,and 12%hydrolyzed porcine mucosa(namely,HPM0,HPM3,HPM6,HPM9,and HPM12)were prepared to evaluate their effects on the growth performance,muscle nutrition composition,texture property,and gene expression related to muscle growth of hybrid groupers(Epinephelus fuscoguttatus\Epinephelus lanceolatus_).Groupers were fed to apparent satiation at 08:00 and 16:00 every day for a total of 56 days.It was found that the weight gain percentage in the HPM0,HPM3,and HPM6 groups did not differ(P>0.05).The cooking loss and drip loss of the dorsal muscle in the HPM3 group were lower than those in the HPM6 and HPM9 groups(P<0.05).The hardness and chewiness of the dorsal muscle in the HPM3 group were higher than those in the HPM0,HPM9,and HPM12 groups(P<0.05).The gumminess in the HPM3 group was higher than that in the HPM9 and HPM12 groups(P<0.05).The total essential amino acid content of the dorsal muscle in the HPM12 group was higher than that in the HPM0 group(P<0.05).The contents of total n-3 polyunsaturated fatty acid and total n-3 highly unsaturated fatty acid,as well as the ratio of n-3/n-6 polyunsaturated fatty acid in the dorsal muscle was higher in the HPM0 group than in all other groups(P<0.05).The relative expressions of gene myogenic factor 5,myocyte enhancer factor 2c,myocyte enhancer factor 2a,myosin heavy chain,transforming growth factor-beta 1(TGF-b1),and follistatin(FST)were the highest in the dorsal muscle of the HPM3 group.The results indicated that the growth performance of hybrid grouper fed a diet with 6%HPM and 27%fish meal was as good as that of the HPM0 group.When fish ingested a diet containing 3%HPM,the expression of genes TGF-β1 and FST involved in muscle growth were upregulated,and then the muscle quality related to hardness and chewiness were improved.An appropriate amount of HPM could be better used in grouper feed.展开更多
The utilization efficiency of soy protein is affected by its 2 anti-nutritional substancesdthe antigens bconglycinin and glycinin.This study investigated their effects on the growth performance,intestinal immune defen...The utilization efficiency of soy protein is affected by its 2 anti-nutritional substancesdthe antigens bconglycinin and glycinin.This study investigated their effects on the growth performance,intestinal immune defense,andmicrobiome in juvenile pearl gentian groupers(Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂).Three isonitrogenous and isolipidic diets were formulated containing fishmeal supplemented with 70 g/kgβ-conglycinin or 100 g/kg glycinin,or no supplementation(control).Each experimental diet was fed to quadruplicate groups with 30 fish in each tank for 8 weeks.Dietary inclusion of eitherβ-conglycinin or glycinin significantly reduced weight gain and specific growth rates,and cell proliferation of the distal intestine.Histological evaluation of the intestine tract revealed the inflammation signs,characterized by reducing of plica height and width as well as the number of the goblet cells,and widening of the lamina propria.The group fed theβ-conglycinin diet had reduced lysozyme activity,contents of immunoglobulin M and complements 3 and 4.Increased activities of caspase-3 and-9 were observed in the group fed the bconglycinin diet compared to the other 2 groups.In the intestinal microbiota,the relative abundances of the potentially pathogenic genera Photobacterium and Vibrio were significantly higher in the glycinin group than those in others.Therefore,the existence of soybean antigens(β-conglycinin or glycinin)could damage the structural integrity of the intestine,reduce immune defense,reshape the intestinal microbiome and,ultimately,impair growth in fish.展开更多
This experiment aimed to evaluate the impact of dietary hydroxyproline(Hyp)supplementation on the muscle quality of juvenile Pacific white shrimp(Litopenaeus vannamei)fed a low fishmeal diet.Six formulated diets inclu...This experiment aimed to evaluate the impact of dietary hydroxyproline(Hyp)supplementation on the muscle quality of juvenile Pacific white shrimp(Litopenaeus vannamei)fed a low fishmeal diet.Six formulated diets included one high fishmeal(HF;25%fishmeal content)and five low fishmeal diets(10%fishmeal content)with 0%,0.2%,0.4%,0.6%and 0.8%Hyp(LFO,LF2,LF4,LF6 and LF8,respectively).Each diet was assigned to four replicates,and 40 shrimp(0.32±0.00 g)per replicate were fed four times a day for 8 weeks.Dietary Hyp supplementation had little effects on growth performance,but increased the contents of Hyp,prolyl 4-hydroxylases(P4Hs),and collagen.The meat yield,springiness,hardness,chewiness,and cohesiveness of muscle were the highest in the LF4 group among the low fishmeal groups(P<0.05).Cooking loss and freezing loss of muscle were the lowest in the LF4 group(P<0.05).Dietary supplementation with 0.4%Hyp increased the myofiber density and decreased the myofiber diameter of muscle(P<0.05).Supplementation of Hyp in the diet up-regulated the mRNA expression of smyhc5,smyhc15,col1a1,col1a2,igf-1f,tgf-β and tor and down-regulated the mRNA expression of smy hc1,smyhc2,smyhc6a(P<0.05).Supplementation of Hyp in the diet up-regulated the protein expression of P-4E-BP1,P-AKT,AKT and P-AKT/AKT(P<0.05).These results suggested that the addition of 0.4%Hyp to low fishmeal diets improved the muscle quality of L.vannamei.展开更多
Due to diminishing fish meal(FM)supplies,superb protein(PRO)sources are needed for aquaculture,such as soy-based PRO.However,these can cause enteritis and even intestinal injury in fish when used at high proportions i...Due to diminishing fish meal(FM)supplies,superb protein(PRO)sources are needed for aquaculture,such as soy-based PRO.However,these can cause enteritis and even intestinal injury in fish when used at high proportions in feed.This research examines the effects of substituting soybean protein concentrate(SPC)for FM on the growth performance and intestinal balance of pearl gentian groupers and investigates the mechanism of SPC-induced enteritis.Experimental fish(n=720)were fed 1 of 3 following diets:(1)a 50%FM diet(control),(2)a diet with 20%of the FM substituted with SPC(group SPC20),and(3)a 40%SPC-substituted diet(SPC40).Fish were fed for 10 wk iso-nitrogenous(50%PRO)and iso-lipidic(10%lipid)diets.Groups SPC20 and SPC40 showed significantly lower developmental performance and intestinal structures than control.Group SPC40 had significantly higher expressions of pro-inflammatory-related genes,such as interleukin 1β(IL1β),IL12,IL17 and tumor necrosis factorαand significantly lower expressions of anti-inflammatory-related genes,such as IL5,IL10 and transforming growth factorβ1.Biochemical and 16S high-throughput sequencing showed that the abundance and functions of intestinal flora in group SPC40 were significantly affected(P<0.05),and there were significant correlations between operational taxonomic unit abundance variations and inflammatory gene expressions at genus level(P<0.05).The second-and third-generation full-length transcriptome sequence was used to analyze the mechanism of SPC-induced enteritis in pearl gentian groupers,which showed that enteritis induced by SPC may be caused by disturbances to intestinal immune function induced by an imbalance in intestinal nutrition and metabolism,such as the intestinal immunity network for IgA production pathway.However,it remains unclear as to which intestinal immune or nutritional imbalance is most important in enteritis development.This study provides a basis for further research into soy PRO-related enteritis in fish.展开更多
Aiming to investigate the impact of different stocking densities on the ability of Pacific white shrimp(Litopenaeus vannamei)to utilize Chlorella sorokiniana(CHL),a 3×2 factorial design stocking experiment was us...Aiming to investigate the impact of different stocking densities on the ability of Pacific white shrimp(Litopenaeus vannamei)to utilize Chlorella sorokiniana(CHL),a 3×2 factorial design stocking experiment was used in this study.Specifically,shrimp was fed with two dietary protein sources(fishmeal[FM]and CHL)at low(LSD;100 per m^(3)),medium(MSD;200 per m^(3))and high(HSD;300 per m^(3))stocking densities for 8 weeks.The growth performance and resistance to Vibrio parahaemolyticus(1.0×10^(7) CFU/mL)of shrimp decreased with the increase of stocking density,but dietary CHL improved this result.Differences between the CHL and FM groups for V.parahaemolyticus resistance were significant only under high-density conditions(P<0.05).Significant interactions between stocking density and protein source were found on the activities of catalase(CAT),superoxide dismutase(SOD)and phenol oxidase(PO),and the contents of malondialdehyde(MDA)in the hepatopancreas and the activities of intestinal amylase,most of which were significantly different between CHL and FM groups only at high stocking density(P<0.05).Analysis of 16S rDNA sequencing showed that dietary CHL increased the alpha diversity of intestinal microbiota,inhibited the colonization of pathogenic bacteria and enhanced the abundance of beneficial bacteria.Transcriptomic results showed that at high stocking densities,differentially expressed genes(DEGs)in the FM vs CHL group were mostly upregulated and primarily enriched in immune and metabolic related pathways including Toll,immune deficiency(Imd)and glycolysis–gluconeogenesis pathways.Pearson correlation analysis revealed significant correlation between the top ten intestinal bacteria at the genus level and markedly enriched DEGs,also more were detected under high density situations.In conclusion,CHL has great potential as a novel protein source in the intensive farming of shrimp.展开更多
With the increasing incorporation of plant-based ingredients into the grouper diet,the issue of aflatoxin B1 (AFB1) contamination in the diet has become a significant concern.In this study,the negative effects of AFB1...With the increasing incorporation of plant-based ingredients into the grouper diet,the issue of aflatoxin B1 (AFB1) contamination in the diet has become a significant concern.In this study,the negative effects of AFB1 on the growth and liver health of hybrid groupers (Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂) were investigated in the context of growth,liver histology,serum biochemical indices,and integrated transcriptomic and metabolomic data.A total of 540 healthy hybrid groupers,initially weighing 11.59±0.03 g,were randomly divided into six groups (three replicates of 30 fish each):the control group was fed a basal diet,and the experimental groups were supplemented with 7 (AF7),30(AF30),111 (AF111),445 (AF445) and 2230μg/kg AFB1 (AF2230) in the basal diet respectively,for 56 days.Groups control,AF445,and AF2230 were selected for subsequent histological,muscle fatty acid,and transcriptomic and metabolomic analyses based on the results of hybrid grouper growth and serum biochemical indices.Compared to the control group,both whole-body crude lipid and muscle crude lipid contents showed significant decreases in the AF2230 group (P<0.05),while only muscle crude lipid content showed a significant decrease in the AF445 group (P=0.001).Liver damage was seen in the histology of the liver of AF445 and AF2230 groups.Muscle fatty acid results showed that the addition of445 and 2230μg/kg AFB1 to the diets increased saturated fatty acids and monounsaturated fatty acids and decreased polyunsaturated fatty acids and highly unsaturated fatty acids in muscle (P<0.05).Transcriptome analyses revealed multiple metabolic pathways associated with AFB1 metabolism,and metabolomics analyses further confirmed changes in the activity of these pathways.The results of the combined transcriptomic and metabolomic analyses indicated that AFB1 causes liver injury mainly by affecting liver retinol metabolism,metabolism of xenobiotics by cytochromes P450,drug metabolismcytochromes P450 and biosynthesis of unsaturated fatty acids.In conclusion,dietary AFB1 levels above 445μg/kg resulted in growth inhibition,liver injury,liver AFB1 accumulation,and reduced muscle polyunsaturated fatty acid content in groupers,thereby affecting muscle quality.This study provides novel insights into the detrimental effects of AFB1 on aquatic species and contributes to the scientific basis for the health and sustainability of aquaculture practices.展开更多
基金supported by the National Key R&D Program of China(2023YFD2402000)the Project of Yunnan Yuncai Jinke Biotechnology Co.,Ltd.,(HT99982023-0347)+1 种基金the Project of Science and Technology of Guangxi Province(AA23062047)the National Key R&D Program of China(2023YFD2401705).
文摘Astaxanthin is widely used in aquatic animal feed and has beneficial effects on aquatic animals.Haematococcus pluvialis is one of the most important sources of natural astaxanthin.In this 8-week feeding experiment,the impacts of gradient additions of H.pluvialis on the growth and physiological performance of Litopenaeus vannamei before and after acute ammonia nitrogen stress were investigated.The experimental diets were formulated by incorporating gradient levels(0%,0.02%,0.04%,0.08%,0.16%and 0.32%)of H.pluvialis into the feed,namely D0,D0.02,D0.04,D0.08,D0.16 and D0.32,respectively.Each tank housed 30 shrimp,with 4 replicates per group.Significant improvements were observed in weight gain and specific growth rate(P<0.05)in D0.02,D0.04 and D0.08 groups compared with the control group D0.Regression curve analysis indicated that the growth effect of H.pluvialis is maximized at an inclusion level of 0.1006%.The acute ammonia stress test revealed that the addition of H.pluvialis significantly ameliorated the morphology and structure of hepatopancreas in D0.08,D0.16 and D0.32 groups(P<0.05),while attenuating the apoptosis signal in hepatopancreatic cells,thereby indicating a potential alleviation of liver injury and cellular apoptosis induced by acute ammonia stress through the incorporation of a specific proportion of H.pluvialis.The expression levels of ho1 and sod mRNA in the D0.08 group increased after stress,indicating upregulation of antioxidant and immune-related genes(P<0.05).As compared to the control group,the Toll pathway genes exhibited significantly higher expression levels in diets D0.02 and D0.04 prior to stress(P<0.05).After stress,crustin was down-regulated significantly in the H.pluvialis supplemental groups,while tube and relish mRNA expression levels were significantly higher in the D0.32 group compared to the D0 group(P<0.05).The results demonstrated that the growth performance of L.vannamei was enhanced by incorporating 0.02%to 0.08%of H.pluvialis into the diet.Furthermore,dietary supplementation with 0.08%to 0.32%resulted in an increased resistance to ammonia nitrogen stress in L.vannamei.
基金supported financially by the National Key R&D Program of China(2023YFD2402000)the Modern Seed Industry Park for Whiteleg Shrimp of Guangdong Province,the Science and Technology Bureau of Zhanjiang(2022A01211).
文摘A 30-day feeding trial was conducted to assess the effect of three fresh-live polychaetes as diets on growth and reproductive performance,biochemical indices and histology of different tissues in female Pacific white shrimp(Litopenaeus vannamei)broodstock.Two novel polychaete species,Marphysa maxidenticulata(MM group)and Perinereis nuntia(PN group),and a traditional species,Perinereis aibuhitensis(PA group),were used as a single diet and individual experimental groups,respectively.A total of 225 healthy female broodstock shrimp,initial weight of 59.70±0.18 g,were randomly divided into three groups(three replicates of 25 shrimp each).The results showed that the MM group outperformed the PA and PN groups in growth indices,with the highest weight gain,specific growth rate,molting rate,protein efficiency ratio,gonadosomatic index,and lower feed conversion ratio compared to the PN group(P<0.05).Regarding reproductive performance,the MM group had the highest daily number of sexually mature female broodstock shrimp,successful mating count,maturity rate,mating rate,spawning cycle,total number of fertilized eggs,individual fertilized egg yield,area of mature oocytes,total number of nauplii,naupliar yield/shrimp,hatching rate,and the lowest naupliar deformity rate than the other two groups(P<0.05).Moreover,compared to the PA and PN groups,the MM group demonstrated superior activities of lipid metabolism-related enzymes and digestive enzymes,and antioxidant capacity in the hepatopancreas,intestine and serum,as well as reduced malondialdehyde levels.Meanwhile,the ovaries of the MM group showed a significant accumulation of triglycerides,estradiol,and vitellogenin compared to the other groups.Histology revealed more developed secretory cells in the hepatopancreas and largermature oocytes in the MM group compared to the others.In conclusion,M.maxidenticulata can maximize growth,reproductive performance,the activities of lipid metabolism-related enzymes and digestive enzymes,antioxidant and immune ability of female broodstock shrimp.This study demonstrated that M.maxidenticulata could be used as a potential fresh-live diet for the female L.vannamei broodstock.
基金supported by the China Agriculture Research System of MOF and MARA(CARS-47)the Guangdong Provincial Higher Education Key Field Special Project(2020ZDZX1034)the Postgraduate Education Innovation Project of Guangdong Ocean University(202331).
文摘This experiment explored the effects of lysophospholipids on hybrid grouper(initial average weight:22.65±0.03 g)hepatic lipid metabolism and immunity at the transcriptome and metabolome levels.A total of 375 hybrid groupers were divided into 5 groups of 3 replicates of 25 fish each.Five isoproteic and isolipidic diets were formed by adding 0(L_(0),control group),0.05%(L_(0.05)),0.1%(L_(0.1)),0.15%(L_(0.15))and 0.2%(L_(0.2))lysophospholipids,respectively.After 8 wk,compared to the control group,weight gain rate,specific growth rate and protein deposition rate were significantly higher(P<0.05),and the feed conversion ratio was significantly lower in the L_(0.1) group(P<0.011).The total cholesterol and triglyceride contents in the serum and liver of the fish in the L_(0.1) group were significantly lower than those in the L_(0) group(P<0.05).Compared to the L_(0) group,catalase and superoxide dismutase activities were substantially higher,and malondialdehyde content was considerably lower in the L_(0.1) group(P<0.05);complement 3,lysozyme,acid phosphatase,and alkaline phosphatase levels in the L_(0.1) group were significantly higher than those in the L_(0) group(P<0.05).The hepatic lipoprotein lipase activity and gene expression in the L_(0.1) group were significantly higher whereas fatty acid synthase activity and gene expression were significantly lower than those in the L_(0) group(P<0.05).The gene expression and activities of hepatic catalase and superoxide dismutase in the L_(0.1) group were considerably higher than those in the control group(P<0.05).The mRNA expression of major histocompatibility complex class II molecule and interleukin-10 genes were significantly higher in the L_(0.1) group than in the L_(0) group(P<0.05),while the mRNA expression of interleukin-6 and interferon-g genes in the L_(0) group was significantly higher than those in the L_(0.1) group(P<0.05).The transcriptome and metabolome data showed that the critical genes such as lipoprotein lipase and fatty acid synthase,as well as metabolites such as taurine and docosahexaenoic acid were enriched in the lipid metabolism pathway.In conclusion,0.1%lysophospholipids activated critical genes and metabolites in the adenosine 5-monophosphateactivated protein kinase and peroxisome proliferators-activated receptors signaling pathways to regulate lipid metabolism and immunity in hybrid grouper.
基金supported by The China Agriculture Research System of MOF and MARA(CARS-47)Special Project on Key Fields of Guangdong Colleges and Universities-Special Project on Key Fields of Rural Revitalization(2020ZDZX1034)Science and Technology Project of Zhanjiang City(2020A02001).
文摘The hybrid grouper(Epinephelus fuscointestinetatus♀×E.lanceolatus♂)is an important aquaculture marine species in China.The current study was designed to test the effects of methanotroph(Methylococcus capsulatus)bacteria meal(MBM)on hybrid grouper growth and intestinal health outcomes.Five iso-nitrogenous and iso-lipidic diets were formulated,comprising a control diet(MBM0)with 400 g/kg fish meal(FM)as the main protein source,and four experimental diets,in which FM was replaced at 5%(MBM2),10%(MBM4),20%(MBM8)and 30%(MBM12)with 20,40,80 and 120 g/kg of MBM,respectively.The 450 healthy juvenile hybrid grouper(initial weight 28.84±0.05 g)were randomly allocated into five groups,with three replicates in each group and 30 fish in each replicate.They were fed for eight weeks prior to being sampled for transcriptome and microbiome research.The final body weight(FBW,P<0.001)and weight gain rate(WGR,P<0.001)were obviously enhanced in MBM2 and MBM8 groups compared to MBM0 group,and the specific growth rate(SGR)in the MBM2 and MBM8 groups were significantly enhanced compared to MBM0 group(P<0.001).The condition factor(CF)in MBM4 and MBM8 groups were considerably reduced than that in MBM0 group(P=0.008).The hepatosomatic index(HSI)in MBM8 and MBM12 groups were obviously enhanced than that in the other groups(P<0.001).In the intestinal microflora analysis,the number of operational taxonomic units(OTUs)exhibited a significant linear increase with increasing MBM replacement ratio(P=0.015).Concurrently,the richness of bacterial families and genera showed significant linear enrichment(P=0.023 and P=0.028,respectively).There was a decrease in the relative abundance of the potentially pathogenic genera Photobacterium and Vibrio in the MBM-fed groups compared with the control group.The study has effectively shown that MBM may significantly enhance the health and growth of hybrid groupers by partially replacing FM in diets at the required amount of 3.70%,as determined by WGR regression analysis.
基金supported financially by the General Program of Natural Science Foundation of Guangdong Province(2021A1515011165)the Department of Education of Guangdong Province (2021ZDZX4005)+2 种基金the National Natural Science Foundation of China (31972808)the Research and Demonstration of Precision Functional Compound Feed Technology of Major Cultured Fishes and Shrimps in South China (2021B0202050002)the China Agriculture Research System of MOF and MARA (CARS-47)。
文摘Several reports have revealed the vital role that probiotics play in fish growth and health.However,few works are available for host gut-derived probiotics on the growth,immunity,and gut microbiota of fish,especially in hybrid grouper (♀Epinephelus fuscoguttatus×♂Epinephelus lanceolatus) due to their isolation difficulty and functional verification.This study aimed at assessing 3 host gut-derived Bacillus species?effects on the growth,immune and antioxidant-biochemical responses,haematological parameters,intestinal morphology,immune-related gene expression,gut microbiota,and disease resistance against Vibrio harveyi in hybrid grouper.A total of 480 hybrid grouper (initial weight=9.03±0.02 g) were randomly allotted into 4 groups,namely,the group fed a basal diet without probiotic inclusion (control,B0),the group fed the basal diet with Bacillus velezensis GPSAK4 (BV),the group fed the basal diet with Bacillus subtilis GPSAK9 (BS),and the group fed the basal diet with Bacillus tequilensis GPSAK2 (BT) strains at 1.0×10^(9)CFU/g.After a 6-week feeding trial,the results revealed significant improvements (P<0.05) in the growth performance,whole fish-body proximate composition,blood haematological parameters,serum,liver,and intestinal biochemical indexes,intestinal morphology,and protection against V.harveyi pathogen in the probiotic-treated groups compared with the untreated.Additionally,the expressions of intestinal tight junction genes (occludin and ZO1),pro-and anti-inflammatory genes,including IL1β,IL6,IL8,TNFa,MyD88,IL10,and TGFβ,were upregulated (P<0.05) after Bacillus species administration.Host gut-derived Bacillus supplementation shaped the gut microbiota by significantly increasing (P<0.05) the relative abundance of Proteobacteria,Bacteroidetes,Actinobacteria (except the BS group),Acidobacteria(except the BT group),Cyanobacteria (except the BV and BT groups),and Verrucomicrobia phyla,as well as known beneficial genera (Romboutsia,Turicibacter,Epulopiscium,Clostridium_sensu_stricto 1 and 13,Lactobacillus,and Bacillus),but significantly decreased (P<0.05) the abundance of Firmicutes,Chloroflexi,and Fusobacteria phyla,and purported pathogenic genera (Staphylococcus and Photobacterium) compared with the control group.Collectively,the results suggest that B.velezensis GPSAK4,B.subtilis GPSAK9(especially this strain),B.tequilensis GPSAK2 dietary supplementation at 1.0×10^(9)CFU/g has positive effects on the intestinal health of hybrid grouper via microbial composition modulation,thus enhancing the assimilation and absorption of nutrients to boost fish growth,immunity,and disease resistance.
基金This study was supported by the Fund of The National Key R&D Program of China(2019YFD0900200)Southern Marine Science and Engineering Guangdong Laboratory(Zhanjiang)(No.ZJW2019-06)+1 种基金China Agricultural Research System(CARS-47)Guangdong Modern Agriculture Research System-Innovation Team(2020KJ150).
文摘Iso-nitrogenous and iso-lipidic diets containing 0%,3%,6%,9%,and 12%hydrolyzed porcine mucosa(namely,HPM0,HPM3,HPM6,HPM9,and HPM12)were prepared to evaluate their effects on the growth performance,muscle nutrition composition,texture property,and gene expression related to muscle growth of hybrid groupers(Epinephelus fuscoguttatus\Epinephelus lanceolatus_).Groupers were fed to apparent satiation at 08:00 and 16:00 every day for a total of 56 days.It was found that the weight gain percentage in the HPM0,HPM3,and HPM6 groups did not differ(P>0.05).The cooking loss and drip loss of the dorsal muscle in the HPM3 group were lower than those in the HPM6 and HPM9 groups(P<0.05).The hardness and chewiness of the dorsal muscle in the HPM3 group were higher than those in the HPM0,HPM9,and HPM12 groups(P<0.05).The gumminess in the HPM3 group was higher than that in the HPM9 and HPM12 groups(P<0.05).The total essential amino acid content of the dorsal muscle in the HPM12 group was higher than that in the HPM0 group(P<0.05).The contents of total n-3 polyunsaturated fatty acid and total n-3 highly unsaturated fatty acid,as well as the ratio of n-3/n-6 polyunsaturated fatty acid in the dorsal muscle was higher in the HPM0 group than in all other groups(P<0.05).The relative expressions of gene myogenic factor 5,myocyte enhancer factor 2c,myocyte enhancer factor 2a,myosin heavy chain,transforming growth factor-beta 1(TGF-b1),and follistatin(FST)were the highest in the dorsal muscle of the HPM3 group.The results indicated that the growth performance of hybrid grouper fed a diet with 6%HPM and 27%fish meal was as good as that of the HPM0 group.When fish ingested a diet containing 3%HPM,the expression of genes TGF-β1 and FST involved in muscle growth were upregulated,and then the muscle quality related to hardness and chewiness were improved.An appropriate amount of HPM could be better used in grouper feed.
基金the National Key R&D Program of China(2019YFD0900200)the China Agriculture Research System of MOFand MARA(CARS-47)+1 种基金the National Natural Science Foundation of China(NSFC 31772864)the Fund of Southern Marine Science and Engineering Guangdong Laboratory(Zhanjiang)(ZJW-2019-06)。
文摘The utilization efficiency of soy protein is affected by its 2 anti-nutritional substancesdthe antigens bconglycinin and glycinin.This study investigated their effects on the growth performance,intestinal immune defense,andmicrobiome in juvenile pearl gentian groupers(Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂).Three isonitrogenous and isolipidic diets were formulated containing fishmeal supplemented with 70 g/kgβ-conglycinin or 100 g/kg glycinin,or no supplementation(control).Each experimental diet was fed to quadruplicate groups with 30 fish in each tank for 8 weeks.Dietary inclusion of eitherβ-conglycinin or glycinin significantly reduced weight gain and specific growth rates,and cell proliferation of the distal intestine.Histological evaluation of the intestine tract revealed the inflammation signs,characterized by reducing of plica height and width as well as the number of the goblet cells,and widening of the lamina propria.The group fed theβ-conglycinin diet had reduced lysozyme activity,contents of immunoglobulin M and complements 3 and 4.Increased activities of caspase-3 and-9 were observed in the group fed the bconglycinin diet compared to the other 2 groups.In the intestinal microbiota,the relative abundances of the potentially pathogenic genera Photobacterium and Vibrio were significantly higher in the glycinin group than those in others.Therefore,the existence of soybean antigens(β-conglycinin or glycinin)could damage the structural integrity of the intestine,reduce immune defense,reshape the intestinal microbiome and,ultimately,impair growth in fish.
基金supported by the fund of the National Natural Science Foundation of China(32373141)the Guangdong Basic and Applied Basic Research Foundation(2023A1515030007)ModernSeed Industry Park for Whiteleg Shrimp of Guangdong Province,program for scientific research start-up funds of Guangdong Ocean University,Science and Technology Bureau of Zhanjiang(2020A05003,2022A 01002).
文摘This experiment aimed to evaluate the impact of dietary hydroxyproline(Hyp)supplementation on the muscle quality of juvenile Pacific white shrimp(Litopenaeus vannamei)fed a low fishmeal diet.Six formulated diets included one high fishmeal(HF;25%fishmeal content)and five low fishmeal diets(10%fishmeal content)with 0%,0.2%,0.4%,0.6%and 0.8%Hyp(LFO,LF2,LF4,LF6 and LF8,respectively).Each diet was assigned to four replicates,and 40 shrimp(0.32±0.00 g)per replicate were fed four times a day for 8 weeks.Dietary Hyp supplementation had little effects on growth performance,but increased the contents of Hyp,prolyl 4-hydroxylases(P4Hs),and collagen.The meat yield,springiness,hardness,chewiness,and cohesiveness of muscle were the highest in the LF4 group among the low fishmeal groups(P<0.05).Cooking loss and freezing loss of muscle were the lowest in the LF4 group(P<0.05).Dietary supplementation with 0.4%Hyp increased the myofiber density and decreased the myofiber diameter of muscle(P<0.05).Supplementation of Hyp in the diet up-regulated the mRNA expression of smyhc5,smyhc15,col1a1,col1a2,igf-1f,tgf-β and tor and down-regulated the mRNA expression of smy hc1,smyhc2,smyhc6a(P<0.05).Supplementation of Hyp in the diet up-regulated the protein expression of P-4E-BP1,P-AKT,AKT and P-AKT/AKT(P<0.05).These results suggested that the addition of 0.4%Hyp to low fishmeal diets improved the muscle quality of L.vannamei.
基金This study received assistance from the National Key R&D Program of China(2019YFD0900200).
文摘Due to diminishing fish meal(FM)supplies,superb protein(PRO)sources are needed for aquaculture,such as soy-based PRO.However,these can cause enteritis and even intestinal injury in fish when used at high proportions in feed.This research examines the effects of substituting soybean protein concentrate(SPC)for FM on the growth performance and intestinal balance of pearl gentian groupers and investigates the mechanism of SPC-induced enteritis.Experimental fish(n=720)were fed 1 of 3 following diets:(1)a 50%FM diet(control),(2)a diet with 20%of the FM substituted with SPC(group SPC20),and(3)a 40%SPC-substituted diet(SPC40).Fish were fed for 10 wk iso-nitrogenous(50%PRO)and iso-lipidic(10%lipid)diets.Groups SPC20 and SPC40 showed significantly lower developmental performance and intestinal structures than control.Group SPC40 had significantly higher expressions of pro-inflammatory-related genes,such as interleukin 1β(IL1β),IL12,IL17 and tumor necrosis factorαand significantly lower expressions of anti-inflammatory-related genes,such as IL5,IL10 and transforming growth factorβ1.Biochemical and 16S high-throughput sequencing showed that the abundance and functions of intestinal flora in group SPC40 were significantly affected(P<0.05),and there were significant correlations between operational taxonomic unit abundance variations and inflammatory gene expressions at genus level(P<0.05).The second-and third-generation full-length transcriptome sequence was used to analyze the mechanism of SPC-induced enteritis in pearl gentian groupers,which showed that enteritis induced by SPC may be caused by disturbances to intestinal immune function induced by an imbalance in intestinal nutrition and metabolism,such as the intestinal immunity network for IgA production pathway.However,it remains unclear as to which intestinal immune or nutritional imbalance is most important in enteritis development.This study provides a basis for further research into soy PRO-related enteritis in fish.
基金supported by the Special Projects in Key Fields of Ordinary University in Guangdong Province (2023ZDZX4010)General Program of Natural Science Foundation of Guangdong Province,China (Grant No.2022A 1515012325)Postgraduate Education Innovation Project of Guangdong Ocean University in 2023 (Grant No.202336).
文摘Aiming to investigate the impact of different stocking densities on the ability of Pacific white shrimp(Litopenaeus vannamei)to utilize Chlorella sorokiniana(CHL),a 3×2 factorial design stocking experiment was used in this study.Specifically,shrimp was fed with two dietary protein sources(fishmeal[FM]and CHL)at low(LSD;100 per m^(3)),medium(MSD;200 per m^(3))and high(HSD;300 per m^(3))stocking densities for 8 weeks.The growth performance and resistance to Vibrio parahaemolyticus(1.0×10^(7) CFU/mL)of shrimp decreased with the increase of stocking density,but dietary CHL improved this result.Differences between the CHL and FM groups for V.parahaemolyticus resistance were significant only under high-density conditions(P<0.05).Significant interactions between stocking density and protein source were found on the activities of catalase(CAT),superoxide dismutase(SOD)and phenol oxidase(PO),and the contents of malondialdehyde(MDA)in the hepatopancreas and the activities of intestinal amylase,most of which were significantly different between CHL and FM groups only at high stocking density(P<0.05).Analysis of 16S rDNA sequencing showed that dietary CHL increased the alpha diversity of intestinal microbiota,inhibited the colonization of pathogenic bacteria and enhanced the abundance of beneficial bacteria.Transcriptomic results showed that at high stocking densities,differentially expressed genes(DEGs)in the FM vs CHL group were mostly upregulated and primarily enriched in immune and metabolic related pathways including Toll,immune deficiency(Imd)and glycolysis–gluconeogenesis pathways.Pearson correlation analysis revealed significant correlation between the top ten intestinal bacteria at the genus level and markedly enriched DEGs,also more were detected under high density situations.In conclusion,CHL has great potential as a novel protein source in the intensive farming of shrimp.
基金supported financially by the Research and Demonstration of Precision Functional Compound Feed Technology of Major Cultured Fishes and Shrimps in South China,China(2021B0202050002)the Department of Education of Guangdong Province,China(2021ZDZX4005)the China Agriculture Research System of MOF and MARA,China(CARS-47).
文摘With the increasing incorporation of plant-based ingredients into the grouper diet,the issue of aflatoxin B1 (AFB1) contamination in the diet has become a significant concern.In this study,the negative effects of AFB1 on the growth and liver health of hybrid groupers (Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂) were investigated in the context of growth,liver histology,serum biochemical indices,and integrated transcriptomic and metabolomic data.A total of 540 healthy hybrid groupers,initially weighing 11.59±0.03 g,were randomly divided into six groups (three replicates of 30 fish each):the control group was fed a basal diet,and the experimental groups were supplemented with 7 (AF7),30(AF30),111 (AF111),445 (AF445) and 2230μg/kg AFB1 (AF2230) in the basal diet respectively,for 56 days.Groups control,AF445,and AF2230 were selected for subsequent histological,muscle fatty acid,and transcriptomic and metabolomic analyses based on the results of hybrid grouper growth and serum biochemical indices.Compared to the control group,both whole-body crude lipid and muscle crude lipid contents showed significant decreases in the AF2230 group (P<0.05),while only muscle crude lipid content showed a significant decrease in the AF445 group (P=0.001).Liver damage was seen in the histology of the liver of AF445 and AF2230 groups.Muscle fatty acid results showed that the addition of445 and 2230μg/kg AFB1 to the diets increased saturated fatty acids and monounsaturated fatty acids and decreased polyunsaturated fatty acids and highly unsaturated fatty acids in muscle (P<0.05).Transcriptome analyses revealed multiple metabolic pathways associated with AFB1 metabolism,and metabolomics analyses further confirmed changes in the activity of these pathways.The results of the combined transcriptomic and metabolomic analyses indicated that AFB1 causes liver injury mainly by affecting liver retinol metabolism,metabolism of xenobiotics by cytochromes P450,drug metabolismcytochromes P450 and biosynthesis of unsaturated fatty acids.In conclusion,dietary AFB1 levels above 445μg/kg resulted in growth inhibition,liver injury,liver AFB1 accumulation,and reduced muscle polyunsaturated fatty acid content in groupers,thereby affecting muscle quality.This study provides novel insights into the detrimental effects of AFB1 on aquatic species and contributes to the scientific basis for the health and sustainability of aquaculture practices.
