Alexandrium pacificum(A.pacificum)is a typical paralytic shellfish poisonous dinoflagellate.Harmful algal blooms(HABs)caused by this species can bring serious environmental problems and economic losses to the aquacult...Alexandrium pacificum(A.pacificum)is a typical paralytic shellfish poisonous dinoflagellate.Harmful algal blooms(HABs)caused by this species can bring serious environmental problems and economic losses to the aquaculture industry.In this study,transcriptome sequencing and analyses were performed on the neural tissue of Litopenaeus vannamei(L.vannamei)after acute exposure to A.pacificum disrupted solution for 72 h,and differentially expressed genes(DEGs)were identified.The results showed that,compared with the control samples,300 DEGs were identified in the experimental group,of which 194 were up-regulated,and 106 down-regulated.The gene ontology(GO)functional enrichment analysis showed that DEGs were significantly enriched in the cortical cytoskeleton organization,troponin complex,amylo-alpha-1,6-glucosidase and thymidine phosphorylase.Kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis found that DEGs were mainly enriched in the oxidative phosphorylation process,intercellular tight junctions and mitophagy.The results showed that the proteoglycans,signaling pathways,and various metabolic processes that regulate cell proliferation,differentiation,and apoptosis all played an essential role in the response of L.vannamei to A.pacificum toxins.展开更多
Oxidative stress induced by factors such as ammonia nitrogen has become a major issue in shrimp farming.The effects of carotenoids on the growth and antioxidant capability of Litopenaeus vannamei juveniles were invest...Oxidative stress induced by factors such as ammonia nitrogen has become a major issue in shrimp farming.The effects of carotenoids on the growth and antioxidant capability of Litopenaeus vannamei juveniles were investigated in this study using dietary archaeal carotenoids supplementation.For four weeks,shrimp were given diets containing 0 mg/kg(Ctrl)and 55.98 mg/kg(Car)archaeal carotenoids.Dietary archaeal carotenoids significantly enhanced the astaxanthin content in shrimp muscles and carapaces,as well as the superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)activity(P<0.05).The malonaldehyde(MDA)content in Car group significantly decreased(P<0.05).The transcriptome analysis was conducted to determine the molecular processes in response to archaeal carotenoids supplementation.A total of 1536 differentially expressed genes(DEGs)were detected,including 538 upregulated DEGs and 998 downregulated DEGs.GO functional enrichment analysis between Ctrl and Car indicated that 26 GO terms including extracellular region,metabolic process,and proteolysis were enriched.The KEGG pathway enrichment analysis revealed that the amino sugar and nucleotide sugar metabolism,cysteine and methionine metabolism,glycine serine and threonine metabolism,and amino acid biosynthesis were enriched.Archaeal carotenoids influenced the expression of several important genes involved in reactive oxygen species(ROS)generation,Nrf2 signaling,and antioxidant enzymes.Seven DEGs were chosen to confirm the RNA-Seq data using qRT-PCR.The genes and pathways discovered in this work assist to elucidate the molecular processes through which archaeal carotenoid enhances L.vannamei antioxidative system.展开更多
In recirculating aquaculture systems(RASs),the effective treatment of aquaculture tailwater is essential to maintain the health of the RAS.This study investigated the optimal time and method for tailwater treatment du...In recirculating aquaculture systems(RASs),the effective treatment of aquaculture tailwater is essential to maintain the health of the RAS.This study investigated the optimal time and method for tailwater treatment during three periods of the aquaculture of the Litopenaeus vannamei:nursery(0–26 d),middle(27–57 d),and later(57–104 d).The variation of several water parameters during the dissolution of total suspended solid(TSS)in tailwater,applied with the effects of ozone on the microorganism and water quality parameters were investigated.Results showed that the TSS concentrations in tailwater decreased with time,although not significantly(P>0.05),whereas total ammonia nitrogen(TAN),nitrite(NO-2-N),and nitrate(NO_(3)^(-)-N)increased significantly(P<0.05).Therefore,TSS should be removed from the tailwater as early as possible,being most optimal within 4 h.Ozone removed 38.24%–48.95%of TSS,17.78%–90.14%of TAN,and 87.50%–98.90%of NO-2-N after 4 h of treatment.However,it resulted in the significant accumulation of NO_(3)^(-)-N.Moreover,the total number of Vibrio and bacterial counts in aquaculture tailwater was reduced completely by ozone within 4 h.Thus,these results provided technical details and data support for the effective treatment of tailwater from shrimp RAS.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,c...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 II were as follows:pH 8.17 and 7.99;DO 5.16 mg/L and 5.97 mg/L;CODMn 18.45 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 10 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
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
One experiment was conducted to determine the nutritive value of cholesterol for post-larval shrimp, Litopenaeus vannameL Four isoenergetic and isonitrogenous diets supplemented with four levels of cholesterol (D1, D...One experiment was conducted to determine the nutritive value of cholesterol for post-larval shrimp, Litopenaeus vannameL Four isoenergetic and isonitrogenous diets supplemented with four levels of cholesterol (D1, D2, D3 and D4 with 0, 0.5%, 1% and 2% cholesterol, respectively) were fed to triplicate groups of L. vannamei shrimp (mean initial wet weight 0.8 mg) for 27 days. After the trial, shrimp fed the D1 diet had the best growth performance (final body weights: FBW; weight gain: WG; specific growth rate: SGR), while there was no significant difference between diet treatments with respect to survival. The whole body crude protein level in the shrimp decreased with the increase in dietary cholesterol levels, while the whole body crude lipid level in shrimps in the D4 diet treatment was significantly higher (P 〈 0.05) than in other diet treatments. Dietary analysis indicated that the D1 diet contained 0.92% cholesterol prior to supplementation, which may have satisfied the dietary cholesterol requirement of post-larval L. vannamei; excess dietary cholesterol may thus lead to adverse effects on the growth performance of post-larval shrimp.展开更多
Ammonia,toxic to aquaculture organisms,represents a potential problem in aquaculture systems,and the situation is exacerbated in closed and intensive shrimp farming operations,expecially for Litopenaeus vannamei.Asses...Ammonia,toxic to aquaculture organisms,represents a potential problem in aquaculture systems,and the situation is exacerbated in closed and intensive shrimp farming operations,expecially for Litopenaeus vannamei.Assessing the potential for the genetic improvement of resistance to ammonia in L.vannamei requires knowledge of the genetic parameters of this trait.The heritability of resistance to ammonia was estimated using two descriptors in the present study:the survival time(ST) and the survival status at half lethal time(SS_(50)) for each individual under high ammonia challenge.The heritability of ST and SS_(50) were low(0.154 4±0.044 6 and 0.147 5±0.040 0,respectively),but they were both significantly different from zero(P<0.01).Moreover,these two estimates were basically the same and showed no significant differences from each other(P>0.05),suggesting that ST and SS_(50) could be used as suitable indicators for resistance to ammonia.There were also positive phenotypic and genetic correlation between resistance to ammonia and body weight,which means that resistance to ammonia can be enhanced by the improvement of husbandry practices that increase the body weight.The results from the present study suggest that the selection for higher body weight does not have any negative consequences for resistance to ammonia.In addition to quantitative genetics,tools from molecular genetics can be applied to selective breeding programs to improve the efficiency of selection for traits with low heritability.展开更多
The study aims to determine the effects of graded farming on growth performance and non-specific immunity factors of shrimp Litopenaeus vannamei Boone. Three size groups of shrimp, i.e., the small size group [Gs, with...The study aims to determine the effects of graded farming on growth performance and non-specific immunity factors of shrimp Litopenaeus vannamei Boone. Three size groups of shrimp, i.e., the small size group [Gs, with an average body length (BL) of (3.04 ± 0.36) cm and body weight (BW) (0.412± 0.35) g], the large group [GL, with a BL of (4.29±0.55) cm and BW of (1.098 ±0.42) g], and the ungraded group [Gm, with a BL of (3.47±0.81) cm and BW of (0.611 ±0.79) g], were reared under the same conditions for 8 wk. Growth performance and non- specific immunity factors were measured. The results showed that BW gain, biomass gain and the specific growth rate of body length (SGRL) were significantly influenced by size grading (one-way ANOVA, P 〈 0.05). The peroxidase (POD) and antibacterial (Ua) activities of GL were lower than those of G. Superoxide dismutase (SOD) and lysozyme (U1) activities of Gm were lower than those of G. No significant difference (P = 0.121 〉 0.05) was found on phenoloxidase (PO) activity among the three size groups. Synthetically, size grading could enhance growth and rearing efficiency, and did not have a significant influence on the immunity of L. vannamei Boone. Therefore, graded fanning in L. vannamei Boone was feasible in the culture practice.展开更多
Hemocyte counts and phenoloxidase(PO)activity were examined after hemolymph being incubated in dopamine(DA),noradrenaline(NE)and serotonin(5-HT).Results showed that all the three biogenic amines(BAs)had a significant ...Hemocyte counts and phenoloxidase(PO)activity were examined after hemolymph being incubated in dopamine(DA),noradrenaline(NE)and serotonin(5-HT).Results showed that all the three biogenic amines(BAs)had a significant impact on total hemocyte count(THC),differential hemocyte count(DHC),and intracelluar and extracelluar phenoloxidase(PO)activity.Among these Bas,DA had the strongest effect on the above parameters,whereas 5-HT had the least effect.Preincubation with D1 receptor antagonist SCH23390,D2 receptor antagonist Sulpiride and 1:1 admixture of the two could significantly inhibit the effect of DA on these parameters.SCH23390 showed a stronger inhibitory effect than Sulpiride,and the admixture exhibited the strongest effect.These results suggested that the change of hemocyte count and activation of prophenoloxidase(proPO)system in Litopenaeusvan-namei hemocyte can be regulated by BAs,and DA modulates the two parameters via its receptors.展开更多
White spot syndrome virus(WSSV) is an important viral pathogen that infects farmed penaeid shrimp, and the threat of Vibrio parahaemolyticus infection to shrimp farming has become increasingly severe. Viral and bacter...White spot syndrome virus(WSSV) is an important viral pathogen that infects farmed penaeid shrimp, and the threat of Vibrio parahaemolyticus infection to shrimp farming has become increasingly severe. Viral and bacterial cross or superimposed infections may induce higher shrimp mortality. We used a feeding method to infect L itopenaeus vannamei with WSSV and then injected a low dose of V. parahaemolyticus(WSSV+Vp), or we fi rst infected L. vannamei with a low-dose injection of V. parahaemolyticus and then fed the shrimp WSSV to achieve viral infection(Vp+WSSV). The effect of V. parahaemolyticus and WSSV co-infection on survival of L. vannamei was evaluated by comparing cumulative mortality rates between experimental and control groups. We also spread L. vannamei hemolymph on thiosulfate citrate bile salt sucrose agar plates to determine the number of V ibrio, and the WSSV copy number in L. vannamei gills was determined using an absolute quantitative polymerase chain reaction(PCR) method. L v My D88 and Lvakt gene expression levels were detected in gills of L. vannamei by real-time PCR to determine the cause of the different mortality rates. Our results show that(1) the cumulative mortality rate of L. vannamei in the WSSV+Vp group reached 100% on day 10 after WSSV infection, whereas the cumulative mortality rate of L. vannamei in the Vp+WSSV group and the WSSV-alone control group approached 100% on days 11 and 13 of infection;(2) the number of Vibrio in the L. vannamei group infected with V. parahaemolyticus alone declined gradually, whereas the other groups showed signifi cant increases in the numbers of Vibrio( P <0.05);(3) the WSSV copy numbers in the gills of the WSSV+Vp, Vp+WSSV, and the WSSV-alone groups increased from 10 5 to 10 7 /mg tissue 72, 96, and 144 h after infection, respectively. These results suggest that V. parahaemolyticus infection accelerated proliferation of WSSV in L. vannamei and vice versa. The combined accelerated proliferation of both V. parahaemolyticus and WSSV led to massive death of L. vannamei.展开更多
The aim of the present study is to detect the potential of the base population from diallel crosses of eight introduced strains of the Pacific white shrimp(Litopenaeus vannamei) for improving the yield. Heterosis an...The aim of the present study is to detect the potential of the base population from diallel crosses of eight introduced strains of the Pacific white shrimp(Litopenaeus vannamei) for improving the yield. Heterosis and heritability were estimated for pond survival at commercial farm conditions for the base population that included 207 full-sib families from a nested mating design by artificial insemination. Among all the hybrids,the heterosis ranged from –11.37%(UA1×UA2) to 20.53%(UA3×SIN) with an average of 0.953%. The results showed that more than half of the hybrids(51.85%) have negative heterosis for survival rate, but most of the hybrids with positive heterosis have high estimates. The high proportion of negative heterosis for survival rate reminders us that the survival trait also should be considered in the crossbreeding program to avoid yield decrease. However, high positive heterosis manifested in most of the hybrids for survival indicates the usefulness of these hybrids for improving the survival to obtain higher yield by crossbreeding in this breeding program. The heritability estimate for pond survival was 0.092±0.043 when genetic groups were included in the pedigree, and it was significantly different from zero(P〈0.05). The results from this study also indicated that significant improvement for survival is possible through selection in L. vannamei.展开更多
The Pacific white shrimp(Litopenaeus vannamei)is a marine species commonly farmed worldwide.In northern China,it has been increasingly cultured in high-salinity waters(>40),but exhibits poor growth performance.In t...The Pacific white shrimp(Litopenaeus vannamei)is a marine species commonly farmed worldwide.In northern China,it has been increasingly cultured in high-salinity waters(>40),but exhibits poor growth performance.In this study,postlarval shrimps were acclimated to salinity 55,cultivated for 3 months at this salinity,and compared with a control group reared at general salinity 25.Subsequently,high-throughput RNA sequencing was applied to compare the transcriptomic responses in the gills and hepatopancreas of the shrimps in the control group and the treatment group,while the weights of the shrimps in these two groups were significantly different.The results revealed that 11834 and 2115 genes were significantly differentially expressed in the gills and hepatopancreas,respectively.Additionally,enrichment analysis of the differentially expressed genes indicated that osmoregula-tion-associated Gene Ontology terms and KEGG pathways were similar between the two subgroups of the shrimp maintained at high salinity,suggesting that the growth rate of shrimp at high salinity is independent of osmoregulation.Furthermore,examination of the shrimp with different growth rates(i.e.,weights)at high salinity revealed molt-associated processes,namely,increased expression of ecdysone response genes and downstream effector genes in the gills and hepatopancreas of slow-growing shrimp,suggesting a role of the molt-associated processes in the regulation of shrimp growth at high salinity.Thus,we not only report adaptive transcriptomic responses of L.vannamei to prolonged high-salinity stress,but also provide new insights into the shrimp growth regulation at high salinity.展开更多
In the present study,we isolated the lactic acid bacterium strain SC-01 from Pacific white shrimp(Litopenaeus vannamei)intestine.Using conventional and molecular methods,we identified the bacterium as Enterococcus fae...In the present study,we isolated the lactic acid bacterium strain SC-01 from Pacific white shrimp(Litopenaeus vannamei)intestine.Using conventional and molecular methods,we identified the bacterium as Enterococcus faecium,and found it had the function of feeding attractant and could inhibit the development of Vibrio parahaemolyticus(zone of inhibition:14 mm).The attractant effect of its fermentation broth is significantly better than that of the chemical attractant trimethylamine oxide(TMAO)(P<0.05),and is equivalent to that of dimethyl-beta-propiothetin(DMPT)based on the feeding behavior of shrimp.High performance liquid chromatography(HPLC)analysis suggested that inosine-5’-monophosphate(IMP)may be a component of the attractant.A biosecurity evaluation revealed a negative result in hemolytic assays,and no shrimp mortality was resulted from SC-01 fermentation broth challenge.Feeding trials(60 days)indicated that the SC-01 fermentation broth(viable counts:5.7×109 cfu mL−1)could improve feed intake,weight gain rate(WGR)and specific growth rate(SGR),and decrease the count of Vibrio sp.in the intestine of shrimp.展开更多
To construct an effective circular mix-culture model and investigate its culture capacity,we established one small and one large systems,with white shrimp(Litopenaeus vannamei)and razor clam(Sinonovacula constricta)cu...To construct an effective circular mix-culture model and investigate its culture capacity,we established one small and one large systems,with white shrimp(Litopenaeus vannamei)and razor clam(Sinonovacula constricta)cultured in separate ponds.The culture water from the L.vannamei was pumped to the S.constricta,and the culture water from the S.constricta overflowed back into the L.vannamei via gravity.In trial I,we tested four culture densities(groups 1–4),and monitored water quality,growth indices,and digestive and immune enzyme activities.From the results,the nitrogen and phosphorus levels generally increased then declined after 56 days,and were lower in groups 1 and 2.The specific growth rate of group 2 was the highest.After 56 days,activities of four digestive enzymes were increased in group 2,and lysozyme activity was significantly decreased in S.constricta in groups 1–4;Alkaline phosphatase activity of L.vannamei was increased in group 3,but decreased in S.constricta in groups 2–4;Acid phosphatase activity was significantly higher in groups 1–3(P<0.05),while SOD and CAT activities were significantly elevated in group 2(P<0.05).Thus,we applied group 2 density for trial II.In trial II,nitrogen and phosphorus concentrations declined significantly during the latter stages,and growth indices were higher than the control(P<0.05).The yields of L.vannamei and S.constricta were significantly higher than the control(P<0.05).The results revealed a good circular mix-culture system with the optimal culture capacity for L.vannamei(40 ind m^(−2))and S.constricta(300 ind m^(−2)),which provided a reference for the future culture of them.展开更多
Heritability estimates may be severely biased when a large common environmental effect on a family arises from a longlasting separate rearing at early stages(SRES)in traditional selective breeding programs,especially ...Heritability estimates may be severely biased when a large common environmental effect on a family arises from a longlasting separate rearing at early stages(SRES)in traditional selective breeding programs,especially when bred populations have weak genetic ties.Communal rearing at early stages(CRES)may reduce common environmental effect since all families are reared in the same environment immediately after hatching.Here,we compared the effects of CRES and SRES strategies on genetic parameter estimation for harvest body weight in a selective breeding population of Litopenaeus vannamei with a small number of half-sib families.Genetic parameters of each strategy were estimated by using animal models excluding and including the common environmental effect(Model 1 and Model 2,respectively).Heritability estimates for body weight were 0.21±0.06(P<0.05)and 0.69±0.09(P<0.05)for CRES and SRES,respectively,in Model 1,and 0.21±0.06(P<0.05)and 0.52±0.27(P>0.05)in Model 2.The ratio of common environmental variance to phenotypic variance was 0.002±0.000 and 0.071±0.112 for CRES and SRES,respectively.Neither strategy precisely partitioned the common environmental variance according to likelihood ratio test.Lower heritability for body weight in CRES than in SRES implied that a large common environmental variance was confounded with additive genetic variance and was not effectively partitioned in SRES.Moreover,genetic correlation of body weight between the two strategies was 0.75±0.15,indicating that family rankings truly changed.The CRES should be followed in the selective breeding program of shrimp,especially in a population with a shallow pedigree and weak genetic ties between families.展开更多
[Objective] On the basis of previous researches, this experiment aimed to analyze the effect of K* and the interaction of K+ , salinity ( s), Ca2+ , Mg2+ on growth and adenosine triphosphatase (ATPase), which ...[Objective] On the basis of previous researches, this experiment aimed to analyze the effect of K* and the interaction of K+ , salinity ( s), Ca2+ , Mg2+ on growth and adenosine triphosphatase (ATPase), which was closely related to growth, of Litopenaeus vannamei. [Method] 5 -week Litopenaeus vannamei breeding experiment was performed according to L16(215) orthogonal experiment design. Then the effect of K+ and the interaction of K+ , salinity, Ca2+ , Mg2+ in water on survival, growth and ATP enzyme activity of Litopenaeus vannamei. [Result] K+ had signifi- cant effect on survival rate, length and weight gain, ATP enzyme activity in Litopenaeus vannarnei. The highest survival rate was at K" of 150 rng/L. The fastest growth rate was at 50 mg/L, as well as the activities of Na* - K+ -ATPase, Mg2+ -ATPase, Ca+ -ATPase. The interaction of salini- ty, Ca2+ , Mg2+ , K + in water also had significant effect on survival rate, length and weight gain, ATP enzyme activity in Litopenaeus vannamei. [Conclusion] Among the horizontal combinations of factors in the experiment, the optimal combination for Litopenaeus vannamei survival rate was salinity of 15, K+ of 150 mg/L, Ca2+ of 100 mg/L, Mg2+ of 300 mg/L, the optimal combination for growth rate was salinity of 15, K+ of 50 mg/L, Ca2+ 100 mg/L, Mg2+ 100 mg/L, the optimal combination for Na+ -K* -ATPase, Mg2+ -ATPase, Ca2+ -ATPase activity in Litopenaeus van- namei was salinity of 5, K+ of 50 mg/L, Ca2+ of 100 mg/L, Mg2+ of 100 mg/L.展开更多
基金supported by the Modern Seed Industry Park for Whiteleg Shrimp of Guangdong Province(No.K22226)the National Natural Science Foundation of China(No.32102796)+3 种基金the Natural Science Foundation of Guangdong Province(No.2020A1515110086)the Program for Scientific Research Start-up Funds of Guangdong Ocean University(Nos.060302022102,060302022201)the Program of Shrimp Aquaculture Talent Development(No.B22424)the Undergraduate Innovation Team of Guangdong Ocean University(No.CXTD2023002).
文摘Alexandrium pacificum(A.pacificum)is a typical paralytic shellfish poisonous dinoflagellate.Harmful algal blooms(HABs)caused by this species can bring serious environmental problems and economic losses to the aquaculture industry.In this study,transcriptome sequencing and analyses were performed on the neural tissue of Litopenaeus vannamei(L.vannamei)after acute exposure to A.pacificum disrupted solution for 72 h,and differentially expressed genes(DEGs)were identified.The results showed that,compared with the control samples,300 DEGs were identified in the experimental group,of which 194 were up-regulated,and 106 down-regulated.The gene ontology(GO)functional enrichment analysis showed that DEGs were significantly enriched in the cortical cytoskeleton organization,troponin complex,amylo-alpha-1,6-glucosidase and thymidine phosphorylase.Kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis found that DEGs were mainly enriched in the oxidative phosphorylation process,intercellular tight junctions and mitophagy.The results showed that the proteoglycans,signaling pathways,and various metabolic processes that regulate cell proliferation,differentiation,and apoptosis all played an essential role in the response of L.vannamei to A.pacificum toxins.
基金Supported by the Project of China One-Belt-One-Road Foreign Expert Research Collaboration,Ministry of Science and Technology,China (No.DL2021002001L)the Open Project Program of State Key Laboratory of Food Nutrition and Safety,Tianjin University of Science&Technology (No.SKLFNS-KF-202205)。
文摘Oxidative stress induced by factors such as ammonia nitrogen has become a major issue in shrimp farming.The effects of carotenoids on the growth and antioxidant capability of Litopenaeus vannamei juveniles were investigated in this study using dietary archaeal carotenoids supplementation.For four weeks,shrimp were given diets containing 0 mg/kg(Ctrl)and 55.98 mg/kg(Car)archaeal carotenoids.Dietary archaeal carotenoids significantly enhanced the astaxanthin content in shrimp muscles and carapaces,as well as the superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)activity(P<0.05).The malonaldehyde(MDA)content in Car group significantly decreased(P<0.05).The transcriptome analysis was conducted to determine the molecular processes in response to archaeal carotenoids supplementation.A total of 1536 differentially expressed genes(DEGs)were detected,including 538 upregulated DEGs and 998 downregulated DEGs.GO functional enrichment analysis between Ctrl and Car indicated that 26 GO terms including extracellular region,metabolic process,and proteolysis were enriched.The KEGG pathway enrichment analysis revealed that the amino sugar and nucleotide sugar metabolism,cysteine and methionine metabolism,glycine serine and threonine metabolism,and amino acid biosynthesis were enriched.Archaeal carotenoids influenced the expression of several important genes involved in reactive oxygen species(ROS)generation,Nrf2 signaling,and antioxidant enzymes.Seven DEGs were chosen to confirm the RNA-Seq data using qRT-PCR.The genes and pathways discovered in this work assist to elucidate the molecular processes through which archaeal carotenoid enhances L.vannamei antioxidative system.
基金Supported by the National Key R&D Program of China(No.2019YFD0900502)。
文摘In recirculating aquaculture systems(RASs),the effective treatment of aquaculture tailwater is essential to maintain the health of the RAS.This study investigated the optimal time and method for tailwater treatment during three periods of the aquaculture of the Litopenaeus vannamei:nursery(0–26 d),middle(27–57 d),and later(57–104 d).The variation of several water parameters during the dissolution of total suspended solid(TSS)in tailwater,applied with the effects of ozone on the microorganism and water quality parameters were investigated.Results showed that the TSS concentrations in tailwater decreased with time,although not significantly(P>0.05),whereas total ammonia nitrogen(TAN),nitrite(NO-2-N),and nitrate(NO_(3)^(-)-N)increased significantly(P<0.05).Therefore,TSS should be removed from the tailwater as early as possible,being most optimal within 4 h.Ozone removed 38.24%–48.95%of TSS,17.78%–90.14%of TAN,and 87.50%–98.90%of NO-2-N after 4 h of treatment.However,it resulted in the significant accumulation of NO_(3)^(-)-N.Moreover,the total number of Vibrio and bacterial counts in aquaculture tailwater was reduced completely by ozone within 4 h.Thus,these results provided technical details and data support for the effective treatment of tailwater from shrimp RAS.
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 II were as follows:pH 8.17 and 7.99;DO 5.16 mg/L and 5.97 mg/L;CODMn 18.45 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 10 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.
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 Fund of National Modern Industrial Technology System of Shrimp (nycytx-46)Special Scientific Research Funds for Central Non-profit Institutes, South China Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences (2009TS29, 2010YD02, 2010TS04 and 2011YD01)+2 种基金 the Project of Science and Technology of Guangdong Province(2011A020202007)the Project of Key Science and Technology of Hainan Province (ZDXM20100028)the State 863 Project (2012AA10A409)
文摘One experiment was conducted to determine the nutritive value of cholesterol for post-larval shrimp, Litopenaeus vannameL Four isoenergetic and isonitrogenous diets supplemented with four levels of cholesterol (D1, D2, D3 and D4 with 0, 0.5%, 1% and 2% cholesterol, respectively) were fed to triplicate groups of L. vannamei shrimp (mean initial wet weight 0.8 mg) for 27 days. After the trial, shrimp fed the D1 diet had the best growth performance (final body weights: FBW; weight gain: WG; specific growth rate: SGR), while there was no significant difference between diet treatments with respect to survival. The whole body crude protein level in the shrimp decreased with the increase in dietary cholesterol levels, while the whole body crude lipid level in shrimps in the D4 diet treatment was significantly higher (P 〈 0.05) than in other diet treatments. Dietary analysis indicated that the D1 diet contained 0.92% cholesterol prior to supplementation, which may have satisfied the dietary cholesterol requirement of post-larval L. vannamei; excess dietary cholesterol may thus lead to adverse effects on the growth performance of post-larval shrimp.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A404)the Qingdao Postdoctoral Science Foundation Funded Project(No.Q51201403)+3 种基金the National Natural Science Foundation of China(Nos.31302179,31172402)the 948 Project from the Ministry of Agriculture of China(No.2015-Z17)the Improved Agricultural Breeds Engineering Project of Shandong Province-the Taishan Scholar Program for seed industry "Multi-Tarits Selective Breeding of New Variety and Its Industrialization"the Fundamental Research Funds for the Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences(No.20603022013011)
文摘Ammonia,toxic to aquaculture organisms,represents a potential problem in aquaculture systems,and the situation is exacerbated in closed and intensive shrimp farming operations,expecially for Litopenaeus vannamei.Assessing the potential for the genetic improvement of resistance to ammonia in L.vannamei requires knowledge of the genetic parameters of this trait.The heritability of resistance to ammonia was estimated using two descriptors in the present study:the survival time(ST) and the survival status at half lethal time(SS_(50)) for each individual under high ammonia challenge.The heritability of ST and SS_(50) were low(0.154 4±0.044 6 and 0.147 5±0.040 0,respectively),but they were both significantly different from zero(P<0.01).Moreover,these two estimates were basically the same and showed no significant differences from each other(P>0.05),suggesting that ST and SS_(50) could be used as suitable indicators for resistance to ammonia.There were also positive phenotypic and genetic correlation between resistance to ammonia and body weight,which means that resistance to ammonia can be enhanced by the improvement of husbandry practices that increase the body weight.The results from the present study suggest that the selection for higher body weight does not have any negative consequences for resistance to ammonia.In addition to quantitative genetics,tools from molecular genetics can be applied to selective breeding programs to improve the efficiency of selection for traits with low heritability.
基金supported by the National High-TechR&D Program of China (2004BA526B02)the Natural Science Foundation of Qingdao Agricultural Univesity,China (610804)the High Level Talents Fund of Qingdao Agricultural University, China (630628)
文摘The study aims to determine the effects of graded farming on growth performance and non-specific immunity factors of shrimp Litopenaeus vannamei Boone. Three size groups of shrimp, i.e., the small size group [Gs, with an average body length (BL) of (3.04 ± 0.36) cm and body weight (BW) (0.412± 0.35) g], the large group [GL, with a BL of (4.29±0.55) cm and BW of (1.098 ±0.42) g], and the ungraded group [Gm, with a BL of (3.47±0.81) cm and BW of (0.611 ±0.79) g], were reared under the same conditions for 8 wk. Growth performance and non- specific immunity factors were measured. The results showed that BW gain, biomass gain and the specific growth rate of body length (SGRL) were significantly influenced by size grading (one-way ANOVA, P 〈 0.05). The peroxidase (POD) and antibacterial (Ua) activities of GL were lower than those of G. Superoxide dismutase (SOD) and lysozyme (U1) activities of Gm were lower than those of G. No significant difference (P = 0.121 〉 0.05) was found on phenoloxidase (PO) activity among the three size groups. Synthetically, size grading could enhance growth and rearing efficiency, and did not have a significant influence on the immunity of L. vannamei Boone. Therefore, graded fanning in L. vannamei Boone was feasible in the culture practice.
基金supported by the Program for New Century Excellent Talents in University (No. NCET-06-0597)Ministry of Education 111 Project (No. B08049)
文摘Hemocyte counts and phenoloxidase(PO)activity were examined after hemolymph being incubated in dopamine(DA),noradrenaline(NE)and serotonin(5-HT).Results showed that all the three biogenic amines(BAs)had a significant impact on total hemocyte count(THC),differential hemocyte count(DHC),and intracelluar and extracelluar phenoloxidase(PO)activity.Among these Bas,DA had the strongest effect on the above parameters,whereas 5-HT had the least effect.Preincubation with D1 receptor antagonist SCH23390,D2 receptor antagonist Sulpiride and 1:1 admixture of the two could significantly inhibit the effect of DA on these parameters.SCH23390 showed a stronger inhibitory effect than Sulpiride,and the admixture exhibited the strongest effect.These results suggested that the change of hemocyte count and activation of prophenoloxidase(proPO)system in Litopenaeusvan-namei hemocyte can be regulated by BAs,and DA modulates the two parameters via its receptors.
基金Supported by the National Basic Research Program of China(973 Program)(No.2012CB114405)the Special Foundation Under the Construction Program for the“Taishan Scholarship”of Shandong Province of Chinathe Program for Chinese Outstanding Talents in Agricultural Scientific Research
文摘White spot syndrome virus(WSSV) is an important viral pathogen that infects farmed penaeid shrimp, and the threat of Vibrio parahaemolyticus infection to shrimp farming has become increasingly severe. Viral and bacterial cross or superimposed infections may induce higher shrimp mortality. We used a feeding method to infect L itopenaeus vannamei with WSSV and then injected a low dose of V. parahaemolyticus(WSSV+Vp), or we fi rst infected L. vannamei with a low-dose injection of V. parahaemolyticus and then fed the shrimp WSSV to achieve viral infection(Vp+WSSV). The effect of V. parahaemolyticus and WSSV co-infection on survival of L. vannamei was evaluated by comparing cumulative mortality rates between experimental and control groups. We also spread L. vannamei hemolymph on thiosulfate citrate bile salt sucrose agar plates to determine the number of V ibrio, and the WSSV copy number in L. vannamei gills was determined using an absolute quantitative polymerase chain reaction(PCR) method. L v My D88 and Lvakt gene expression levels were detected in gills of L. vannamei by real-time PCR to determine the cause of the different mortality rates. Our results show that(1) the cumulative mortality rate of L. vannamei in the WSSV+Vp group reached 100% on day 10 after WSSV infection, whereas the cumulative mortality rate of L. vannamei in the Vp+WSSV group and the WSSV-alone control group approached 100% on days 11 and 13 of infection;(2) the number of Vibrio in the L. vannamei group infected with V. parahaemolyticus alone declined gradually, whereas the other groups showed signifi cant increases in the numbers of Vibrio( P <0.05);(3) the WSSV copy numbers in the gills of the WSSV+Vp, Vp+WSSV, and the WSSV-alone groups increased from 10 5 to 10 7 /mg tissue 72, 96, and 144 h after infection, respectively. These results suggest that V. parahaemolyticus infection accelerated proliferation of WSSV in L. vannamei and vice versa. The combined accelerated proliferation of both V. parahaemolyticus and WSSV led to massive death of L. vannamei.
基金The National Natural Science Foundation of China under contract No.31302179the Taishan Scholar Program for Seed Industry+4 种基金the Introduction of International Advanced Agricultural Science and Technology Plan under contract No.2016-X39the Special Fund for Basic Scientific Research Business of Central Public Research Institutes under contract No.2015B04XK01China Postdoctoral Science Foundation under contract No.2015M572095Qingdao Scientific Research Foundation under contract No.14-2-4-52-jch5Jiangsu Province Science and Technology Support Project under contract No.BE2014414
文摘The aim of the present study is to detect the potential of the base population from diallel crosses of eight introduced strains of the Pacific white shrimp(Litopenaeus vannamei) for improving the yield. Heterosis and heritability were estimated for pond survival at commercial farm conditions for the base population that included 207 full-sib families from a nested mating design by artificial insemination. Among all the hybrids,the heterosis ranged from –11.37%(UA1×UA2) to 20.53%(UA3×SIN) with an average of 0.953%. The results showed that more than half of the hybrids(51.85%) have negative heterosis for survival rate, but most of the hybrids with positive heterosis have high estimates. The high proportion of negative heterosis for survival rate reminders us that the survival trait also should be considered in the crossbreeding program to avoid yield decrease. However, high positive heterosis manifested in most of the hybrids for survival indicates the usefulness of these hybrids for improving the survival to obtain higher yield by crossbreeding in this breeding program. The heritability estimate for pond survival was 0.092±0.043 when genetic groups were included in the pedigree, and it was significantly different from zero(P〈0.05). The results from this study also indicated that significant improvement for survival is possible through selection in L. vannamei.
基金supported by the National Natural Sci-ence Foundation of China(No.31802269)the Open Fund of Shandong Key Laboratory of Disease Control in Mari-culture(No.KF201901)+2 种基金the Shrimp&Crab Innovation Team of Shandong Agriculture Research System(No.SD AIT-15-011)the High-Level Talent Research Fund of Qing-dao Agricultural University(Nos.663/1119054 and 663/1120027)the First Class Fishery Discipline Program in Shandong Province.
文摘The Pacific white shrimp(Litopenaeus vannamei)is a marine species commonly farmed worldwide.In northern China,it has been increasingly cultured in high-salinity waters(>40),but exhibits poor growth performance.In this study,postlarval shrimps were acclimated to salinity 55,cultivated for 3 months at this salinity,and compared with a control group reared at general salinity 25.Subsequently,high-throughput RNA sequencing was applied to compare the transcriptomic responses in the gills and hepatopancreas of the shrimps in the control group and the treatment group,while the weights of the shrimps in these two groups were significantly different.The results revealed that 11834 and 2115 genes were significantly differentially expressed in the gills and hepatopancreas,respectively.Additionally,enrichment analysis of the differentially expressed genes indicated that osmoregula-tion-associated Gene Ontology terms and KEGG pathways were similar between the two subgroups of the shrimp maintained at high salinity,suggesting that the growth rate of shrimp at high salinity is independent of osmoregulation.Furthermore,examination of the shrimp with different growth rates(i.e.,weights)at high salinity revealed molt-associated processes,namely,increased expression of ecdysone response genes and downstream effector genes in the gills and hepatopancreas of slow-growing shrimp,suggesting a role of the molt-associated processes in the regulation of shrimp growth at high salinity.Thus,we not only report adaptive transcriptomic responses of L.vannamei to prolonged high-salinity stress,but also provide new insights into the shrimp growth regulation at high salinity.
基金the Special Fund for Qingdao Marine Biomedical Science and Technology Innovation Center,China(No.2017-CXZX01-3-13).
文摘In the present study,we isolated the lactic acid bacterium strain SC-01 from Pacific white shrimp(Litopenaeus vannamei)intestine.Using conventional and molecular methods,we identified the bacterium as Enterococcus faecium,and found it had the function of feeding attractant and could inhibit the development of Vibrio parahaemolyticus(zone of inhibition:14 mm).The attractant effect of its fermentation broth is significantly better than that of the chemical attractant trimethylamine oxide(TMAO)(P<0.05),and is equivalent to that of dimethyl-beta-propiothetin(DMPT)based on the feeding behavior of shrimp.High performance liquid chromatography(HPLC)analysis suggested that inosine-5’-monophosphate(IMP)may be a component of the attractant.A biosecurity evaluation revealed a negative result in hemolytic assays,and no shrimp mortality was resulted from SC-01 fermentation broth challenge.Feeding trials(60 days)indicated that the SC-01 fermentation broth(viable counts:5.7×109 cfu mL−1)could improve feed intake,weight gain rate(WGR)and specific growth rate(SGR),and decrease the count of Vibrio sp.in the intestine of shrimp.
基金supported by the National Key Research and Development Plan(No.2019YFD0900400)the Ear marked Fund for Modern Agro-Industry Technology Research System,China(No.CARS-47)sponsored by the K.C.Wong Magna Fund in Ningbo University.
文摘To construct an effective circular mix-culture model and investigate its culture capacity,we established one small and one large systems,with white shrimp(Litopenaeus vannamei)and razor clam(Sinonovacula constricta)cultured in separate ponds.The culture water from the L.vannamei was pumped to the S.constricta,and the culture water from the S.constricta overflowed back into the L.vannamei via gravity.In trial I,we tested four culture densities(groups 1–4),and monitored water quality,growth indices,and digestive and immune enzyme activities.From the results,the nitrogen and phosphorus levels generally increased then declined after 56 days,and were lower in groups 1 and 2.The specific growth rate of group 2 was the highest.After 56 days,activities of four digestive enzymes were increased in group 2,and lysozyme activity was significantly decreased in S.constricta in groups 1–4;Alkaline phosphatase activity of L.vannamei was increased in group 3,but decreased in S.constricta in groups 2–4;Acid phosphatase activity was significantly higher in groups 1–3(P<0.05),while SOD and CAT activities were significantly elevated in group 2(P<0.05).Thus,we applied group 2 density for trial II.In trial II,nitrogen and phosphorus concentrations declined significantly during the latter stages,and growth indices were higher than the control(P<0.05).The yields of L.vannamei and S.constricta were significantly higher than the control(P<0.05).The results revealed a good circular mix-culture system with the optimal culture capacity for L.vannamei(40 ind m^(−2))and S.constricta(300 ind m^(−2)),which provided a reference for the future culture of them.
基金the National Key R&D Program of China(No.2018YFD0901301),the Shandong Province’s Agricultural Seed Improvement Project(No.2017LZN011)the Central Public-interest Scientific Institution Basal Research Fund,CAFS(No.20603022020003)+3 种基金the China Agriculture Research System(CARS-48)the Projects of International Exchange and Cooperation in Agriculture of Ministry of Agriculture and Rural Affairs of China–Science,Technology and Innovation Cooperation Cooperation in Aquaculture with Tropical Countriesthe Introduction of International Advanced Agricultural Science and Technology Plan of China(No.2016-X39)the Major Applied Technology Innovation Project of Agriculture in Shandong Province(No.SD2019YY001).
文摘Heritability estimates may be severely biased when a large common environmental effect on a family arises from a longlasting separate rearing at early stages(SRES)in traditional selective breeding programs,especially when bred populations have weak genetic ties.Communal rearing at early stages(CRES)may reduce common environmental effect since all families are reared in the same environment immediately after hatching.Here,we compared the effects of CRES and SRES strategies on genetic parameter estimation for harvest body weight in a selective breeding population of Litopenaeus vannamei with a small number of half-sib families.Genetic parameters of each strategy were estimated by using animal models excluding and including the common environmental effect(Model 1 and Model 2,respectively).Heritability estimates for body weight were 0.21±0.06(P<0.05)and 0.69±0.09(P<0.05)for CRES and SRES,respectively,in Model 1,and 0.21±0.06(P<0.05)and 0.52±0.27(P>0.05)in Model 2.The ratio of common environmental variance to phenotypic variance was 0.002±0.000 and 0.071±0.112 for CRES and SRES,respectively.Neither strategy precisely partitioned the common environmental variance according to likelihood ratio test.Lower heritability for body weight in CRES than in SRES implied that a large common environmental variance was confounded with additive genetic variance and was not effectively partitioned in SRES.Moreover,genetic correlation of body weight between the two strategies was 0.75±0.15,indicating that family rankings truly changed.The CRES should be followed in the selective breeding program of shrimp,especially in a population with a shallow pedigree and weak genetic ties between families.
基金Key Projects of Science and Technology Promoting Farm in Shanghai City (Shanghai Agricultural Key Project [2010] No.1-6 )Science and Technology Promoting Projects of Science and Technology Promoting Farm in Shanghai City(Shanghai Agricultural Promoting Project [2008]No.5 -1 )Leading Academic Discipline Project of Shanghai Education Commission(J50701)
文摘[Objective] On the basis of previous researches, this experiment aimed to analyze the effect of K* and the interaction of K+ , salinity ( s), Ca2+ , Mg2+ on growth and adenosine triphosphatase (ATPase), which was closely related to growth, of Litopenaeus vannamei. [Method] 5 -week Litopenaeus vannamei breeding experiment was performed according to L16(215) orthogonal experiment design. Then the effect of K+ and the interaction of K+ , salinity, Ca2+ , Mg2+ in water on survival, growth and ATP enzyme activity of Litopenaeus vannamei. [Result] K+ had signifi- cant effect on survival rate, length and weight gain, ATP enzyme activity in Litopenaeus vannarnei. The highest survival rate was at K" of 150 rng/L. The fastest growth rate was at 50 mg/L, as well as the activities of Na* - K+ -ATPase, Mg2+ -ATPase, Ca+ -ATPase. The interaction of salini- ty, Ca2+ , Mg2+ , K + in water also had significant effect on survival rate, length and weight gain, ATP enzyme activity in Litopenaeus vannamei. [Conclusion] Among the horizontal combinations of factors in the experiment, the optimal combination for Litopenaeus vannamei survival rate was salinity of 15, K+ of 150 mg/L, Ca2+ of 100 mg/L, Mg2+ of 300 mg/L, the optimal combination for growth rate was salinity of 15, K+ of 50 mg/L, Ca2+ 100 mg/L, Mg2+ 100 mg/L, the optimal combination for Na+ -K* -ATPase, Mg2+ -ATPase, Ca2+ -ATPase activity in Litopenaeus van- namei was salinity of 5, K+ of 50 mg/L, Ca2+ of 100 mg/L, Mg2+ of 100 mg/L.