Abstract:An 8-week feeding trial in a 3×2 two-factorial design was conducted to study the effects of dietary lipid level(9%, 12% and 15%)and feeding frequency(one time or two times daily)on growth, body composition and lipid deposition in juvenile large yellow croaker[initial average weight(13.57±0.33)g].Compared with those fed once daily, fish fed two times daily had significantly higher final weight, specific growth rate(SGR), but lower feed efficiency ratio(FER)at each dietary lipid level(P < 0.05).When animals were fed two times daily, no significant difference was observed in the SGR and FER among dietary lipid levels(P > 0.05).However, SGR and FER of fish fed once daily increased significantly with the increase of dietary lipid contents(P < 0.05).Compared with that fed once daily, fish fed two times daily had significantly lower body moisture, but higher body crude lipid contents(P < 0.05), regardless of the dietary lipid levels.Body crude lipid contents of fish fed two times daily increased significantly with the increase of dietary lipid contents(P < 0.05).However, body crude lipid contents of fish fed once daily was not affected by dietary lipid contents(P > 0.05).Liver and muscle lipid contents, HSI and VSI were significantly affected by dietary lipid levels.When animals were fed two times daily, lipid contents in liver and muscle, HSI, and VSI increased significantly with the increase of dietary lipid level(P < 0.05).However, no significant difference was found in fish fed once daily(P > 0.05).Significant interactions of dietary lipid level and feeding frequency were only found in growth and FER(P < 0.05), but not in HSI, VSI, body composition and lipid contents in liver and muscle(P > 0.05).

Abstract:Myeloid differentiation factor 88(MyD88)is a universal and crucial adaptor protein of signal transduction activity elicited by TLR(toll-like receptor)superfamily and plays an essential role in the innate immunity response.In this study, a MyD88 gene, AaMyD88, was cloned for the first time from Anguilla anguilla. Its full-length cDNA sequence is 1 539 bp, with an 846 bp open reading frame encoding a protein of 282 aa.The predicted three-dimensional structure of AaMyD88 can be merged well with the crystal structure of the human MyD88 and has the typical death domain and TIR(toll-like/IL-1 receptor)domain of the MyD88 family.In the TIR domain, three conserved boxes, named box 1, box 2 and box 3, are found.According to the comparison with known MyD88 amino acid sequences, the putative protein of AaMyD88 showed the highest identities with Ictalurus punctatus(76.3%), and other bony fishes(67.5%-73.2%), but low identities(61.6%-62.6%)with mammalian.All the sequences were clustered into three main branches in which all MyD88 of fish clustered together, while the MyD88 of mammalians and amphibians formed two separate clusters.qRT-PCR revealed the expression of AaMyD88 could be detected in all adult tissues examined.The highest expression level was observed in the liver, followed by the heart, intestine, and spleen, and the lowest expression level was found in muscle and gills.After injection with goat IgG, the AaMyD88 expression level was obviously up-regulated in the kidney at 7 d and returned to the normal level after 14 d.The obvious up-regulation of the AaMyD88 expression level was observed in the spleen from 7 d to 21 d, peaking at 7 d with a value 1.7 times higher than that of the kidney.After stimulation with poly I:C, AaMyD88 transcripts in fin cell line were down-regulated significantly at 3 h, increased strongly from 6 h to 48 h, and peaked at 12 h.After treatment with LPS, the expression level of AaMyD88 in fin cell line was sharply down-regulated at 3 h and began to significantly increase at 6 h and peaked at 12 h.As the time progressed past this time point, the expression level rapidly decreased to the control levels at 24 h post-treatment.Compared with the group of LPS treatment, the expression level of AaMyD88 in the poly I:C group was observed continuously higher from 12 h to 48 h.Our results suggested that AaMyD88 might play important roles during the immune response of Anguilla anguilla against the different pathogen microbes.

Abstract:A feeding trial was conducted to investigate the effects of dietary arginine on growth performance, immune responses and digestive enzyme activities of juvenile sea cucumber Apostichopus japonicus Selenka with initial body weight 9.10 g.Five experimental diets were formulated with the graded arginine levels(0, 1.00%, 2.00%, 3.00% and 4.00% dry diet, respectively).The five trial diets were determined to contain arginine of 0.32%, 0.73%, 1.16%, 1.61%, and 1.99% dry diet, respectively.Each diet was randomly assigned to triplicate groups of 30 sea cucumbers and fed once a day(16:00)for 60 days.The results showed that the weight gain rate(WGR), specific growth rate(SGR)and protein efficiency ratio(PER)were all increased by dietary arginine, and reaced maximum at D4 group;Ratio of visceral weight to body wall weight(VBR), ratio of intestine weight to body wall weight(IBR)and ratio of intestine length to body length(IBL)of D3, D4 and D5 groups were significantly lower than those of D1 and D2 groups, but there were no differences among them;Crude protein deposition of body wall was increased by dietary arginine, but there were no effects on moisture and crude lipid contents;Dietary arginine increased Glu, Arg, Leu, His, Hyp, essential amino acids(EAA)and total amino acids(TAA)contents of body wall, but decreased lysine content;Total superoxide dismutase(T-SOD), total antioxidant capacity(T-AOC), nitric oxide(NO), nitric oxide synthase(NOS), alkaline phosphataes(AKP), alanine aminotranferase(ALT)and asparate aminotransferase(AST)in coelomic fluid all increased with the increasing of dietary arginine levels(P < 0.05);There was a negative correlation between protease and dietary arginine levels(Yenzyme activity=-3.228X²Arg+2.865XArg+26.24, R²=0.934);Activities of cellulose of D3, D4 and D5 groups were significantly higher than those of D1 and D2 groups;meanwhile, activities of amylase and lipase were not affected by dietary arginine.With WGR as evaluation indicator, quadratic regression analysis showed that the optimum dietary arginine of sea cucumber with body weight 9.10 g was 1.55% of diet or 7.10% dietary crude protein.

Abstract:The full length DNA and cDNA of IgZ gene from swordtail fish Xiphophorus hellri were cloned.The obtained DNA of IgZ is 5 420 bp in length, which is composed of four exons and three introns.The length of cDNA is 1 527 bp, containing a 1 299 bp open reading frame(ORF)which encoded a protein of 432 amino acids with deduced protein molecular weight 47.48 ku.Alignment based on amino acid sequence indicates that swordtail fish IgZ shared similarities of 28%-54% with other fishes.IgZ mRNA expression of swordtail fish was predominantly detected in head kidney, spleen and intestines.The expression levels of IgZ in the head kidney and spleen both demonstrated peaks at 4 days post immunization, increasing of approximately 2 fold and 4 fold in comparison with control group, respectively.Moreover, the expression level of IgZ in intestines varied more sensitively with increasing about 11 fold in comparison with control in the second day after immunization.The results further reveal the IgZ gene plays an important role in the intestinal mucosal immunity.Furthermore, this study also indicates that the swordtail fish could be utilized as a useful fish model for the research of fish diseases and vaccine evaluation.

Abstract:In order to obtain the useful information on the role of different bacterial strains isolated from middle wettability surface on the plantigrade settlement of the mussel Mytilus coruscus, the interaction between bacterial biofilms and plantigrade settlement was studied.The marine bacteria were isolated from the biofilms developed on the middle wettability surface and identification by 16S rDNA gene sequences was conducted.The effects of monospecific bacterial biofilms on settlement of M.coruscus plantigrades were investigated in the laboratory.The phylogenetic tree derived from the elected 16S rDNA sequence was constructed and the genetic distance was calculated.Of 6 different isolates, all bacterial biofilm showed significant inducing activity on settlement of M.coruscus plantigrades.Among the 6 bacterial species, Cobetia sp.3 biofilm induced the highest percentage of plantigrade settlement and the settlement rate was 70%±3%;Other 5 species of bacteria including Nautella sp.2, Pseudoalteromonas sp.9, Pseudoalteromonas sp.10, Bacillus sp.5 and Pseudoalteromonas sp.11 showed moderate inducing activity, and the percentages of of plantigrade settlement ranged from 51% to 60%.Bacterial density was significantly correlated with the inducing activity for each test strain.The density of monospecific bacterial biofilms increased with the initial incubation density.The inducing activity of individual bacterial isolates was not correlated with their phylogenetic relationship.Thus, marine bacteria derived from biofilms developed on moderate wettability surface can promote the settlement of plantigrades of the mussel M.coruscus. This finding is important to understand the mechanism of settlement of M.coruscus plantigrades.

Abstract:Siglecs, sialic acid-binding immunoglobulin-like lectins is a class of membrane receptors which could specifically recognize sialic acid polysaccharide of self or some pathogens.In order to prepare Nile tilapia(Oreochromis niloticus)Siglecs-like fusion proteins and study their functions in the interaction of host-pathogen, we prepared O.niloticus Siglecs like fusion proteins using eukaryotic expression system.In this research, the extracellular domain of the three O.niloticus Siglecs like were respectively amplified from the cloned vectors containing the ORF of Siglec-1/-4b/-14 like and then inserted into the expression vector of pcDNA3.1(+)hIgG1 Fc.After double digestion and sequencing, they were transfected into the COS-7 cells in vitro.The expressions of target genes was detected by qPCR and Western-blot analysis.The fusion proteins were purified by affinity chromatography, and their purity was detected by SDS-PAGE electrophoresis.To study the biological activities of these Siglecs like fusion proteins, binding activities of the fusion proteins to Group B Streptococcus(GBS)were detected by ELISA.The results showed that these three recombinant plasmids containing extracellular domains of tilapia Siglecs like with human IgG1 Fc fragment were constructed successfully.These three genes were highly expressed in COS-7 cells both in mRNA and protein levels.Three Siglecs/Ex-Fc fusion proteins were proved to be of high purity.The binding activities between fusion proteins and control were significantly different(P < 0.05).This research showed we successfully obtained purified fusion proteins by COS-7 cells expression system.A preliminary study proved they could bind GBS.

Abstract:With the rapid development of aquaculture industry, bacterial diseases in fish are breaking out frequently.Antibiotics are the main methods to prevent and control the bacterial diseasesof fish, but this has been bringing some problems, such as bacterial resistance, drug residues, food safety and environmental pollution.Vaccines to control fish disease outbreaks are the most effective way.Currently, the use of natural polymer materials for carrier preparation of oral microsphere vaccine has become a hot topic.Oral microsphere vaccine can not only prevent gastrointestinal environmental damage to the vaccine, but also achieve all the growth stages of immunization of fish, and reduce the immune costs.In order to optimize the condition of preparation in microsphere vaccine.Pathogenic bacteria Edwardsiella ictaluri were killed by formalin and sodium alginate was used, and then the oral microsphere vaccine of E.ictaluri was prepared by emulsification ionic crosslinking method.Single factors including sodium alginate concentration, water-oil ratio, emulsifier concentration and emulsification time were investigated separately.On the basis of single-factor experiments, the relationships among main preparation conditions were modeled using a 4-factor, 3-level Box-Behnken experimental design.The established model was analyzed by response surface methodology to obtain the optimal preparation conditions.All results showed that the optimal preparation conditions were as follows:sodium alginate concentration was 3.5%, water-oil ratio was 2.4:7.6, emulsifier concentration was 5.4%, and emulsification time was 13 min.Under these conditions, the encapsulation efficiency of microspheres was 96.37%.It matched with the predicted encapsulation efficiency.The microspheres had good form, diameter of particles was homogeneous distribution, diameter(8.88±1.26)μm, span 0.38, remarkable acid resistance, enteric and high security.By response surface methodology, preparation of the oral microsphere vaccine of E.ictaluri.For the development of aquaculture, this vaccine provides a theoretical basis, and the effectiveness of the vaccine will be further studied in subsequent trials.

Abstract:On the basis of cDNA library of Tegillarca granosa, Tg-TIMP-3 cDNA was cloned by SMART RACE(Rapid Amplification of cDNA Ends)techniques and then the bioinformatics, expression and immune defense analysis of Tg-TIMP-3 were carried out.The full length cDNA of Tg-TIMP-3 gene was 804 bp, containing a complete ORF(Open Reading Frame)of 570 bp encoding 189 amino acids.The deduced amino acid sequence of Tg-TIMP-3 did not share high similarity with others, only shared 35.8% similarity with TIMP-3 from Crassostrea gigas, but the two functional domains of TIMPs were relatively conservative.The results of tissue-specific expression by real time PCR showed that the mRNA transcript level of Tg-TIMP-3 in gill was higher than those in other tissues including haemocytes, adductor muscle, foot, hepatopancreas and mantle.After being challenged by different concentration of Cd, the level of relative expression in gill of Tg-TIMP-3 mRNA was first slightly reduced and then significantly increased the highest.Those challenged by the concentrations of 25 μg/L and 250 μg/L of Cd reached the highest at 6 h(P<0.01), 500 μg/L reached the highest at 9 h, but finally inhibited to different degrees after 48 h.The results indicated that Tg-TIMP-3 played a vital role in the immune defense responses to Cd.However, the temporal sequence and sensitivity of mRNA expression were different in different challenge groups.

Abstract:To research the characteristics and structural features of ORF3 gene from infections hypodermal and hematopoietic necrosis virus NJ strain(IHHNV-NJ)isolated in the laboratory, the primers were designed upon ORF3 gene sequence.Then we used PCR method to clone the ORF3 gene sequence and inserted it into the prokaryotic expression vector pET-32a(+).The successfully constructed vector pET32a-ORF3 was transformed into BL21(DE3)competent cells for prokaryotic expression.ORF3 gene sequence was studied by means of bioinformatics software.As the results showed, the length of ORF3 gene sequence was 990 bp, encoding 329 amino acids.The theoretical molecular mass of the protein was 37 385.2 u and the isoelectric point was 7.22.The grand average hydrophobicity was -0.619 and the hydrophilic zone(score<0)was evenly and widely distributed, which revealed a good hydrophile.The ORF3 sequence did not have transmembrane regions and signal peptide.The secondary structure of the protein contained 55.9% of α-helix, 52.0% of β-fold and 13.4% of β-corner.Epitopes were located in multiple sequence intervals, and the protein showed a strong antigenicity.There were 13 potential O-glycosylation sites and 17 potential phosphorylation sites, but with no potential N-glycosylation sites.Phylogenetic analysis showed that the highest homology was between NJ strain and Ecuador strain.Comparing NJ strain with Ecuador strain, Hawaii strain, Taiwan strain, Fujian strain, California strain and Thai strain, the homology was 99.7%, 99.1%, 99.1%, 98.8%, 98.2% and 96.6%.The recombinant expression vector pET32a-ORF3 successfully expressed a 49 ku fusion protein, which conformed to the expected size.Research shows, ORF3 gene may encode IHHNV capsid protein.O-glycosylation sites can participate in the assembly of capsid proteins and cellular infection process.Phosphorylation sites can participate in the reproduction process of the virus inside the shrimp's cells.ORF3 gene sequence has a strong conservative property that won't impact the viral toxicity and infection ability among individuals.The study provided the guidance and laid the foundation for those researches such as the IHHNV ORF3 gene's genetic information, gene functions and establishment of IHHNV molecular epidemiology methods.

Abstract:A 3×3 diallel crosses of three different shell color families of Pacific oyster(Crassostrea gigas)(white/W, black/B, purple/P)were conducted.Three parental groups and six reciprocal hybrid crosses were established.The growth, survival rate and heterosis of hybrid crosses at larval and grow-out stages were compared among all experimental groups.The results showed that at the larval stage, hybrid cross PB presented significant growth superiority than other experimental groups.The larval survival rates of all the hybrid crosses were higher than that of parental crosses.All the hybrid crosses showed obvious larval survival heterosis.At the grow-out stage, the shell height of parental group PP was significantly greater than that of WW and BB.The grow of hybrid PB was the fastest among the six hybrid crosses, followed by hybrid BP, then hybrid WP and PW were the slowest.The survival rates were not different significantly among all the hybrid crosses and parental crosses during the grow-out stage.The heterosis of shell height, shell length, total weight and survival rate of hybrid cross BP and its reciprocal cross PB were between 3.71%-15.27%, -2.00%-13.10%, 11.23%-41.56% and -2.77%-9.83%, respectively.The other four hybrid groups had no heterosis during the grow-out stage.

Abstract:Tilapia scraps were hydrolyzed by neutral protease and flavourzyme, and the hydrolysate was fractionated through ultrafiltration membranes with a range of molecular weight cutoffs(MWCO)of 10 ku, to yield the fraction EH10K with MW distribution<10 ku.The zinc chelating salts(CH-0)was produced by EH10K chelating with ZnSO₄.CH-Ⅰ and CH-Ⅱ were the purified components from CH-0 by using 95% ethanol and dialysis(FW=500 u)respectively.The formation of Zn²⁺ chelating salts of hydrolysate was confirmed by the UV-VIS spectra.The physicochemical properties of CH-0, CH-Ⅰ and CH-Ⅱ were analysed and their free radical scavenging activities were evaluated also.The results showed that CH-0 contained 71.86% of protein(on dry basis), 16.08% of Zn, CH-Ⅰ and CH-Ⅱ were 75.94% and 14.49%, 78.83% and 12.20% respectively.The gel chromatography results showed that CH-Ⅰand CH-Ⅱ had three same main absorption peaks compared to CH-0 but had little impurity peaks.The contents of Asp, Glu, Gly, Lys, Arg and His in CH-Ⅱ were high than those of CH-Ⅰ, and all were high than those of CH-0.The content of essential amino acid and branched chain amino acid in CH-Ⅱ were high than that in CH-Ⅰ.CH-0, CH-Ⅰ and CH-Ⅱ showed evident radical scavenging activity in a dose-dependent manner with the IC₅₀ values for hydroxyl radical and 1, 1-diphenyl-2-pycrylhydrazyl(DPPH)radical being 9.08 and 6.07, 8.27 and 3.76, 6.90 and 3.27 mg/mL respectively.The superoxide radical scavenging activity of EH10K was 69.27% at 10.00 mg/mL, CH-0, CH-Ⅰ and CH-Ⅱ showed no effect on superoxide radical scavenging but to promote the oxidation.

Abstract:To evaluate the gamete compatibility and zygote fertility between Crassostrea angulata and C.sikamea, the fertilization rate and hatching rate of two oysters at different temperature(18, 21, 24, 27 and 30 ℃)and salinity(16, 20, 24, 28 and 32)were studied, and then the F₅₀ critical values were determined under the different sperm concentration.Results clearly demonstrate that hybridization between C.angulata and C.sikamea is achievable in one direction due to asymmetric gamete compatibility.Fertilization and hatching level of SS, AA and SA was raised with temperature increasing, while these max values were severally 99.1?Dd#177;0.3%, 98.4?Dd#177;1.2% and 81.3?Dd#177;2.8% for fertilization rate, and 99.1%±0.5%, 96.8%±2.8% and 67.1%±5.5% for hatching rate at 27 ℃, respectively.Fertilization rate and hatching rate of SS, AA and SA at a salinity of 24 were severally 98.8%±1.3%, 94.8%±4.5%, 81.1%±7.4% and 75.9%±3.7%, 86.4%±4.2%, 66.1%±4.5%, respectively.Fertilization rate and hatching rate of SS, AA and SA at sperm concentration of 10³ ind./μL were severally 92.5%±2.2%, 87.2%±5.7%, 92.4%±1.2%, and 79.8%±4.3%, 78.9%±7.8%, 82.2%±7.0% at temperature of 27 ℃ and a salinity of 24, respectively.The F₅₀ critical values of gamete compatibility and zygote fertility were calculated, and were 58.88 ind./μL and 208.93 ind./μL, respectively.This study provided the theory and practice for reproductive isolation mechanism and interspecific hybridization between C.angulata and C.sikamea.

Abstract:LED lamp is a new type of light source which was introduced to light fishing, and its reasonable arrangement on boat will directly relate to the effect of luring fish.The article analyzes the Fresnel Phenomenon.The formula of relationship between each component of transmittivity and refractive indexs and angle of incidence when light goes through two different interfaces of medium can be get through the Fresnel's formula that is deduced from the principle of optical critical condition and the definition formula of transmittivity and refraction.And then, we can get the functional images that the transmittivity and refraction changed because of the variation of incidence angle when light passes through the sea surface by making use of MATLAB.The incidence when intensity of transmission beam reaches the maximum is 53.6°.This incidence angle can guide the installation of LED fish aggregation lamp in fishing boat.But the incidence angle could be changed to 36.4° for flat plate type LED fish aggregation lamp and could be changed to 23.6° for the three columns type of LED fish aggregation lamp.The included angle between two columns of LED fish aggregation lamps is 160°.

Abstract:In order to research the application of microstructures of statolith and beak to age validation of jumbo flying squid, the samples of the jumbo flying squid were collected by the Chinese squid jigger fleet during July to October in 2013.The statolith, upper beak and lower beak were extracted from 39 samples.Their microstructures were analysed and the growth increments were counted.Meanwhile, the differences between the numbers of statolith, upper beak and lower beak increments were analysed by variance analysis.Results showed that the increments in the dorsal region of the beak's hood were more complete.And to avoid the tip erosion effects, the first increments could be counted in the dorsal area of the rostral sections.This study found that the microstructures of the upper and lower beaks were very similar, and both of them contained longitudinal increments and internal rostral axis.However, in terms of the morphology and the pigmentation process, there are differences between the microstructures of upper and lower beaks.Results indicated that the growth increments of the upper and lower beaks obtained were lineally related with that of the statolith.Values of r² and slope close to 1 were obtained(P < 0.01).Results indicated that both of the microstructures of the upper and lower beaks can better estimate the age of the jumbo flying squid.And the beak should be widely used in the research of age and growth of cephalopod.

Abstract:In order to study the fine morphologyand ultrastructure of telencephalon in zebrafish(Danio rerio)deeply, light microscope and electron microscope were adopted to observe the telencephalon of zebrafish brain.The telencephalon consists of olfactory bulbs and the cerebral hemispheres.A pair of olfactory nerves lie anterior to olfactory bulbs, and olfactory bulb connects with the cerebral hemisphere through olfactory stalk.The olfactory bulbs were composed of epithelium layer, nerve fiber layer, glomerular layer and internal cellular layer from external to internal under light microscope.Cerebral cortex covers on the cerebral hemispheres and striatum is located in the base of cerebral hemispheres.And public ventricle emerges between the cerebral cortex and the striatum.The striatum comprised nerve nuclei and nerve fibers.Nerve nuclei including dorsal olfactory nucleus, lateral olfactory nucleus, preoptic nucleus and entopeduncular nucleus, which are located in the periphery of the striatum.Nerve fibers include commissure anterior, longitudinal central olfactory tract and lateral olfactory tract.Mitral cells and synapses can be observed in the nerve fiber layer and glomerular layer of olfactory bulb under electron microscope.Besides, the astrocytes, synapses and blood-brain barrier system also arise in the cerebral hemispheres through TEM.The morphological structure of telencephalon in zebrafish is similar to those in other teleosts, but still exist individual differences in some nuclei.Thus, the results of this study can provide a theoretical reference for the establishment and application of zebrafish's neurobiological model.

Abstract:Analysis of functional feeding groups is increasingly used to monitor the change in benthic macroinvertebrates community of marine ecosystems compared to traditional biodiversity analysis(Shannon-Wiener index and Pielou index).The present study examined species composition, abundance and spatial distribution of the functional feeding groups of macroinvertebrates in the seaweed beds of Gouqi Island in the summer of 2012.The results showed that carnivores and filter feeders dominated the macroinvertebrate communities in the macroalgae beds.The dominant species of carnivores were Mitrella burchardi, Paguridae sp., Siphopatella walshi, Cantharus cecillei and Pugettia quadridens.Septifer virgatus, Modiolus comptus, Lithophaga curta and Arca boucardi were the dominant species of filtering feeders.The dominant species of herbivores were Gammaridea sp., Calliostoma unicum and Chlorostoma rustica.The vertical distribution of the functional feeding groups were correlated with water depth and prey food.It was concluded that the ecological status of benthic community was at good level, but the benthic community was slightly disturbed.

Abstract:In order to better understand the feeding characteristics of Alosa sapidissima at the early development stage, the effects of starvation on growth and morphology, the point of no return(PNR)of A.sapidissima larvae, and the feeding rhythm of A.sapidissima larvae and juveniles were researched by experimental ecology approach at the water temperature of (20.5±1.0)℃.It has been clearly described that newly-hatched larvae were(7.45±0.15)mm in total length(TL), (2.01±0.06)mg in body weight(BW)and the yolk sac was(5.99±0.13)mm³ in volume.5 days after hatch(DAH), the yolk sac of A.sapidissima larvae was absorbed completely.Both TL and BW of control group increased gradually with the consumption of yolk sac and the establishment of exogenous nutrient.In contrast, the TL and BW of the starved larvae started to decrease from 6 DAH, and all the starved larvae died at 10 DAH;The first feeding time of A.sapidissima larvae was 3 DAH, the feeding rate reached 46.67%, the higtest feeding rate was 89.29% in 5 DAH, and the PNR was 7-8 DAH.According to the yolk sac absorption and PNR, the the optimal time of initial feeding should be 2-3 DAH.The feeding rhythm of A.sapidissima larvae and juveniles exhibited that the feeding peak of early stage larvae(4 DAH)appeared at 14:00, and the feeding amount reached 0.14 mg;the feeding peak of late stage larvae(17 DAH)was at 10:00 and 14:00, and the feeding amount was 0.92 mg and 1.36 mg, respectively;the juvenile at 28 DAH reached three feeding peaks at 10:00, 14:00 and 18:00, and the feeding amount was 1.77, 2.45 and 1.55 mg, respectively.Therefore, A.sapidissima was typically feeding only in daytime, and the feeing peak period was gradually prolonged with fish growth.The result of daily feeding situation of A.sapidissima showed the feeding rate in daytime was 20.08%(4 DAH), 29.48%(17 DAH)and 12.41%(28 DAH), which could be a reference for A.sapidissima daily feeding.