Abstract:The purpose of this study is to accumulate the research data about artificial reproduction of Japanese eel and provide guidance on breaking through the key technology of successful larva survival.On the foundation of the studying on artificial reproduction in Japanese eel for many years,this experiment systematically studied the biological characteristics of embryo and the larva before 19 days incubation used by the methods of observing living body,computer-aided analysis,as well as tissue slice.The results indicated that the time needed 38 h 30 min from fertilized egg to the larva just leaving egg,and the total accumulated temperature was 885.50 ℃?h for this time.The development characteristic of embryo,similar to those of most other teleosts,is a classical meroblastic.The gastrulation is completed by cells wrapped downward and curled inward through yolk.The embryo development of Japanese eel can be divided into 14 stages.However,the development characteristic of larva was different from those of most other teleosts,such as transparent blood cell and Stransformer tubular heart,open oral cavity,3 pairs of genasauria that are developed and cannot close,about 6-9 pairs of neuromast which are located at both sides of body from the 3-day to 9-day of leaving egg,as well as the urohypophysis whose morphology continually changed during the development stages.Analyses for these results indicated that the environment of incubation for the larva of Japanese eel in nature may be very stable,and ingestion feed of larva may depend on the method of bite-after-touch.

Abstract:Because of the trait of denitrifying and phosphate-accumulating simultaneously,the requirement of carbon resources for denitrifying phosphate-accumulating organism(DPAO)will be minimized,which may provide a new routine to resolve the problem of lacking carbon resource.The discovery attracts many researchers’ attention.In this paper,a simple method of isolation for DPAO has been established.One pure denitrifying phosphate-accumulating organism(RC11)from pond sediment has been adopted,and the influences of external carbon resource and nitrate on the pure strain RC11 were studied.The results indicated that the strain RC11 could acquire energy from oxidizing external carbon resource using oxygen as electron accetpor directly to produce polyphosphate,but in anaerobic stage,the strain RC11 could not use nitrite as the electron acceptor to carry out denitrifying phosphorus uptake.With no external carbon resource,the strain RC11 could acquire energy from oxidizing PHB using nitrate as electron acceptor to produce polyphosphate,but phosphate will be released from cell in high concentration of nitrite because nitrite nitrogen could not be the electron acceptor to replace molecule oxygen; the strain RC11 could use nitrate as electron acceptor to produce polyphosphate in anaerobic stage.

Abstract:To survey antimicrobial resistance,plasmid fingerprinting and relationship between the size of plasmids and resistance in Aeromonas hydrophila strains which were isolated and collected from fish at different time and in different areas in China.Antimicrobial susceptibility of 40 strains to 29 different antimicrobials were tested by K-B;plasmids DNA were obtained by alkaline lysis and digested by EcoRⅠand HindⅢ,plasmids elimination were treated by EB,then analyzed by agarose gel electrophoresis.Results showed that Aeromonas hydrophila exhibited high antimicrobial resistance,almost was multi-drug resistance;Out of 40 strains,15 strains(37.5%)contained plasmids;The relationship between the antimicrobial resistance and plasmid fingerprinting showed that the number and size of plasmids the strain carried had no significant correlation with its antimicrobial resistance.Plasmid fingerprinting indicated that the strain with the same source and similar antimicrobial resistance would have similar plasmid profile and macrorestriction map.The rate of plasmid elimination for 15 isolates was 100%,but partially eliminated;meanwhile,the resistance phenotype of 12 isolates partially disappeared,suggesting that plasmid and chromosome encoding the resistance genes,2.01 kb plasmid was associated with the resistance to Nalidixie acid and Vancomycin.

Abstract:The technique of transmission electron microscopy combined with enzymatic methods was used to analyse the variations of the immune-related enzymes activity in hepatopancreas,gills and muscles,and to compare the morphological changes of the hepatopancreas and gills of redclaw crayfish, Cherax quadricarinatus, under different concentrations of nitrite stress.The results showed that the activity of ACP,AKP,SOD and GSH-PX in three tissues under the stress of nitrite were significantly lower(P<0.05)compared with control group; with the increase of the nitrite concentration,the activity of enzymes was decreased gradually substantially; the activity of Na ,K -ATPase and Ca² ,Mg² -ATPase in gills was also decreased with the increase of nitrite concentration.Ultrastructure analusis showed that the cuticle of gills was damaged or even disintegrated with the increase of nitrite concentration; epithelial cell was loosely arranged,and the phenomenon of vacuolization was emerged; morphological changes were also obviously found in organelles; the phenomenon of vacuolization was emerged in haemocoel,and hemocytes were deformed.Hepatopancreatic epithelial cells were arranged in haphazard,or even with cell lysis and severe vacolation phenomenon; microvilli were structural damaged,some broken,the distance between the hepatopancreatic tubules was expanded,connective tissues became thin,and hemocytes deformations were found; in high concentration,the lipid droplets of R cells were reduced,nuclear membrane was disintegrated,cell membrane was ruptured and vacolation was increased; in F cells,the rough endoplasmic reticulum was reduced,smooth endoplasmic reticulum was increased,ribosomes was decreased,vacolation was increased and endoplasmic reticulum edema was emerged.In summary,the activity of immunerelated enzymes was influenced by the nitrite stress,and the morphological structures of the hepatopancreas and gills were also affected,as well as their biological functions.

Abstract:An 8-week feeding experiment was conducted to evaluate the effects of different proportion of rapeseed meal(RSM):cottonseed meal(CSM)on growth performance,hematological index and gossypol residues of Carassius auratus gibelio.Six diets were fed to fish with average weight of 5.6 g.The ratios of RSM∶CSM in diets(the total inclusion of RSM and CSM was 60%)were designed as 5∶0,4∶1,3∶2,2∶3, 1∶4 and 0∶5.The results showed that weight gain(WG),feed efficiency ratio(FER)and specific growth rate(SGR)of Carassius auratus gibelio first increased,then decreased with the ratio of RSM∶CSM changing from 5∶0 to 0∶5.Fish fed with diet of RSM∶CSM=3∶2,had the highest weight gain(WG,505.6%),condition factor and lowest feed conversion ratio(FCR,1.33),hepatosomatic index.However,fish fed with diet of RSM∶CSM=5∶0,had the lowest weight gain(WG,430.1%),condition factor,and highest feed conversion ratio(FCR,1.52),hepatosomatic index.No significant differences among treatments were observed in survival rate and muscle moisture,crude protein,crude lipid,crude ash content(P>0.05).Serum ALT and AST activities of RSM∶CSM=5∶0 group were significantly higher than that of group of RSM∶CSM=3∶2,or 2∶3(P<0.05); AKP activities of fish of RSM∶CSM=3∶2 group had the highest value in all groups.There was no significant difference in serum TP in all groups(P>0.05).Free gossypol content in muscle and liver increased with the rise of cottonseed meal content in diet(P<0.05).This study showed that the ratio of RSM and CSM for 3∶2 was the optimal ratio for growth of Carassius auratus gibelio. High inclusion of rapeseed meal or cottonseed meal in diet would reduce growth performance and increase serum ALT and AST activity.

Abstract:Charybdis japonica is an important marine crab widely distributed in China sea area.The main purpose of the study was to provide a theory basic for the research of reproduction biology and promote the progress of artificial breeding technolagy of C.japonica.The morphological changes of sperm during the acrosome reaction in C.japonica were studied in detail with light and transmission electron microscope, and the optimal induced conditions of acrosome reaction in vitro was obtained by orthogonal experiments.Then the induced effect of ionophore A23187 and egg-water was investigated by contrast experiment,and the acrosome reaction rate of the sperm collected from male seminal receptacle has been analysed induced by treatment with ionophore A23187.The process of acrosome reaction consists of four consecutive stages:(1) swelling of the apical cap,(2) the apical cap ruptures to form an aperture which acrosomal vesical can evert through it and radial arms contract,(3) elongation forward of perforator and aggregation of acrosomal granule in the posterior segment of acrosomal tubule,(4) rupture of perforator and shedding of the acrosomal vesicle outer layer result in formation of the acrosomal filament,then acrosomal granules release out and nuclear size reduce.Most of the acrosome reaction of C.japonica sperm were complete in 50 minutes.Three factors with five levels including a series of pH(6.0,7.0,8.0,9.0 and 10.0),a series of different concentrations in Ca² (0.10%,0.15%,0.20%,0.25% and 0.30%)and A23187(30,40,50,60 and 70 μg/mL)were chosen to assay the optimal induced conditions for the acrosome reaction in sperm of with an orthogonal experiment.The highest rate(80.41%)of the acrosome reaction in sperm collected from female spermatheca can be achieved when sperm exposed to 60 μg/mL A23187,0.30% CaCl₂ at pH=8.0 in Ca² free artificial seawater for 50 minutes,but the acrosome reaction rate of the sperm is 73.87% induced by egg-water.64.37% of acrosome reaction rate can be achieved by treating the sperm taken from male seminal receptacle with the optimal induced conditions.

Abstract:To understand the response of fish antioxidant defense and neural system to mercury exposure,studies were conducted in laboratory between 26 and 29 ℃ on the acute toxicity and exposed effects on antioxidant enzymes and AChE activities in the young crimson snapper,Lutjanus erythropterus Bloch,of an average weight of(4.57?2.02) g and body length(4.95?0.79) cm.Using static renewal method,the results showed that the safe concentration of mercury chloride for the young crimson snapper was 0.040 mg/L.The enzymes activities were evaluated under four sublethal concentrations(0.000 5 mg/L,0.002 5 mg/L, 0.005 mg/L and 0.025 mg/L Hg² ).The tissues(gill and liver)were tested for SOD,MDA activity and the brain for AChE after 6 h,12 h,24 h,48 h and 96 h exposure,respectively.The results showed that hepatic SOD activities had significant increase on 6 h exposure(P<0.05).With the increase of mercury concentration,the hepatic SOD activities were inhibited or induced,which showed the disturbance of fish metabolism.And the branchial SOD activities were also significantly elevated.The variation of MDA content exhibited that the gill was impaired on 6 h exposure,while the hepatic tissue was detected to be impaired on 12 h.The AChE activities in the brain had no significant decrease(P>0.05)on 6 h exposure.However,it decreased with the induction rate of 36% on 12 h exposure.When the fish were exposed longer time,the inhibition rates were 28%-38%,14%-24% and 12%-17% on 24 h,48 h and 96 h exposure in concentrations respectively.

Abstract:Small abalone Haliotis diversicolor is an economically important shellfish speices in southern China.The new variety “Dongyou No.1” was crossbred by Japan selective strain as male and Taiwan selective strain as female.Morphological characteristics and grow-out performance in “Dongyou No.1”and its parental populations of small abalone were studied recently.The results for morphological characteristics showed that parameter of W/L was significantly different among three groups.The W/L for Japan population was significantly larger than Taiwan population(P<0.05)and the value for “Dongyou No.1” was between them.These three groups were cultured in the coast of Fujian with suspended long-line cages farming model,Guangdong and Hainan with land-based intensive farming model for one year.The survival rate and shell length for three groups were calculated each three months.The results showed that Taiwan population experienced high mortality during grow-out period in the whole three areas.Japan population showed high disease-resistant ability with high survival rate.But the growth rate for Japan population was significantly slower than Taiwan population(P<0.05).“Dongyou No.1” showed excellent grow-out performance in all three areas.The results indicated that “Dongyou No.1” was the suitable new variety of small abalone for farming in the subtropical and tropical areas.

Abstract:The 90ku heat shock proteins(HSP90s)are a group of evolutionarily highly conservative molecular chaperones and essential for viability in eukaryotes.The basic functions of HSP90s are of assisting protein folding,protein degradation and protein trafficking,and they also play an important role in signal transduction networks,cell cycle control and morphological evolution.Although HSP90s are constitutively expressed in most organisms,their expression is upregulated in response to stresses such as cold,heat,salt stress,heavy metals,phytohormones,light and dark transitions. Porphyra yezoensis Ueda,one of intertidal macroalgae,periodically experiences immersion and emersion due to the tidal cycles.When P.yezoensis thalli are exposed to air,they experience a variety of abiotic stresses such as nutrient limitation,high light,ultraviolet ray,high and low temperature,desiccation and osmotic stress.In order to investigate the contribution of HSP90 to abiotic stresses tolerance in P.yezoensis thalli,molecular cloning and expression analysis of HSP90 gene(designated as PyHSP90)from P.yezoensis were performed. PyHSP90 gene was obtained with computer assisted cloning,and characterized using multiple bioinformatic programs.The relative mRNA expression levels of PyHSP90 gene under stresses were investigated in P.yezoensis thalli using real-time RT-PCR.The PyHSP90 cDNA contained a 2 274 nt of continuous complete open reading frame encoding a polypeptide of 757 amino acids with a calculated molecular mass of 86 ku.Analytic results of PSORT,TargetP and phylogenetic tree showed that PyHSP90 localized to cytoplasm.PyHSP90 contained conserved signature motifs and domains of HSP90 family.PyHSP90 shared high amino acid sequence identity with HSP90s from other organisms.Sequence comparison of PyHSP90 revealed 26.0%-39.4% and 61.4%-71.8% identity with prokaryotic and eukaryotic HSP90s respectively.In the phylogenetic tree red algae HSP90s,including PyHSP90,clustered with Cryptophyta HSP90s firstly,and then clustered with HSP90s of green algae and land plants,and at last all cytoplasmic HSP90s of algae,plants and animals were clustered together.Low and high temperature stresses significantly induced the expression of PyHSP90 gene in P.yezoensis thalli,and there was a clear dose-dependent expression pattern of PyHSP90 gene after different temperature exposure.The expression of PyHSP90 gene was up-regulated under low salinity stress,and downregulated under desiccation stress.The results indicated that PyHSP90 is essential to hold configuration of proteins under temperature and salinity stresses,and dispensable under desiccation stress.Investigation of PyHSP90 gene can contribute to its molecular mechanism of tolerance to abiotic stresses,and lay a foundation for further enhancing resilience of P.yezoensis through genetic improvement.

Abstract:The micro organism communities which colonized on fresh blade,decomposing blade and detritus of kelp Laminaria japonica were analyzed using fatty acid biomarkers.Results showed that the total crude lipid contents of decomposing blade and kelp detritus were significantly higher than those in fresh kelp blade,whereas monounsaturated and polyunsaturated fatty acids contents were less than those in fresh blade.Bacterial biomarkers 18∶1(n-7)and odd/branched fatty acids were more abundant in decomposing tissue and detritus than fresh kelp,indicating the colonization of bacteria in the kelp decomposing process.The diatom biomarker 16∶1(n-7)/16∶0 ratio exhibited the highest in kelp detritus,and it was also higher in decomposing tissue than in fresh blade,indicating the adherence of large amount of diatoms.No protozoa fatty acid biomarker(DHA)was detected in fresh kelp blade; however,it existed in decomposing tissue and detritus at a relative concentration of 0.65% and 1.57% respectively,indicating the colonization of protozoa.Due to the colonization of complex micro organism community,decomposing kelp blade and kelp detritus showed different carbon and nitrogen components.Fresh kelp blade had a high C/N ratio of 17.32,but in decomposing tissue and detritus,the organic nitrogen content increased remarkably,which resulted in the decline of the C/N ratio to 6.61 and 6.48.Results confirmed that kelp detritus is a mixture of decomposing kelp debris,diatoms,bacteria and protozoa.Through the colonization of different kinds of micro organisms and biodegradation,kelp debris became organic nitrogen abundant and more nutritious,hence much more suitable as the food source of other consumers in a kelp-based polyculture area.

Abstract:In order to assess the effects of UV radiation(UVR,280-400 nm)on the relative sensitivity,attachment,germination success and seedling growth of the zoospores of the green tide macroalga, Ulva prolifera,we exposed the cells to three different radiation treatments(PAB:280-700 nm,PA:320-700 nm,P:400-700 nm)under solar or artificial radiation.The experimental units were covered with three different cut-off filters to obtain three treatments:PAB,PA and P under solar simulator,respectively.The light intensity was set at 900 μmol photons/(m²?s),while the irradiances of ultraviolet radiation were UV-A:19.9 W/m²,UV-B:0.68 W/m²,respectively.Optimum photosynthetic efficiency(Fv/Fm)of zoospores was measured as variable fluorescence of PSII by using a water pulse amplitude modulation(PAM)fluorometer.After being exposed to light treatments,the samples were then placed in the dark so that the zoospores could be attached to the cover glass slices randomly.After 24 h the settled zoospores were counted by microscope.The randomly settled zoospores on the cover glass slices were placed under different light treatments with cut-off filters.The germination success and growth were measured punctually.The results showed that:1)PA and PAB treatments could significantly inhibit the zoospores optimum photosynthetic efficiency(Fv/Fm)under 900 μmol photons/(m²?s),and the extension of inhibition increased with exposure time.Moreover,the inhibition of PAB treatment was more obvious than those of P and PA treatments.(2)The hysteresis effects of zoospore settlement were observed under shortterm ultraviolet radiation,and the results showed that 24 h settlement rate of PA and PAB treatments after short-term exposure to ultraviolet radiations of 5,10 and 15 min were not significant from control(P).(3)The significant differences among the groups of germination success of settled zoospores were found when the samples were placed under different solar radiations.The relative germination rates to P treatment at 3^rd-day and 6^th-day were:PA:57.0% and 58.5%,PAB:39.1% and 34.6%,respectively.There was no significant difference of germination rate between first 3 d and 6 d,which implied zoospore survival depends on the initial 3 d.(4)The seedling growth were significantly inhibited by PA and PAB treatments.The rates of seedlings that contained more than 4 cells at 5^th-day were P:72.9%; PA:14.3%; PAB:10.1% respectively.The growth inhibition rates were 46.2% and 68.1% by PA and PAB treatments.Overall the data showed that optimum photosynthetic efficiency,adhesion time,germination success and seedling growth of zoospore were significantly inhibited by UVR,and the inhibition of PAB was stronger than that of PA.The results suggested that UVR could play the negative roles on the early development and survival,and might have a major impact on the occurrence and recruitment of U.prolifera populations.

Abstract:This paper presents the methods for exploring fish schooling behavior by means of mathematical modeling and computer simulation,to explore and find out the major factors which have speculated influence on the space distribution of individuals in fish school.Preliminary findings indicated that among the factors of visibility and swimming ability etc.,the visual ability of fish,including sighting distance and perspective is the factor having stronger influence on the school structure,which provides some revelations or indications to the fish behaviour experiments design and observation.The comparison between the simulation and video records of Hemigrammus bleheri shows that the model based on IBMs theory is feasible,and the simulation results are similar to the actual movement of fish school,which indicates that the visual simulation technology helps better exploration and understanding on fish group motion.

Abstract:Based on the biological data(n=271)collected in the southern Atlantic Ocean off Argentina during December 2009 to January 2010,the present study analyzed the biological characteristics of rockcod(Patagonotothen ramsayi),including total length(TL),standard length(SL),the relationship between TL and body weight(BW),sex ratio,sexual maturity and size at 50% sexual maturity.The results showed that:(1) The TL ranged from 145 to 302 mm with dominating TL of 200 to 260 mm,the SL ranged from 135 to 265 mm with dominating SL of 160 to 220 mm.The TL(F=1.930,P=0.167＞0.05)and SL(F=1.965,P=0.163＞0.05)distribution between female and male individuals had no significant differences.The relationship between TL and SL was TL=0.875 5SL 0.007 6(R²=0.984 6).(2) The relationship between TL and BW was BW=1.084 5?10^-6 TL^{3.396 8}(R²=0.981 8)and the relationship between TL and BW for female and male individuals had no significant differences(ANCOVA,F=1.755,P>0.05).(3) The ratio of female to male was 1∶0.17.(4) The sexual maturity was dominating of stage Ⅱ,the percentage of stages Ⅲ to Ⅵ was low during December to January.Significant difference can be found for the sexual maturity among TL classes(χ²=569.59,P<0.05).(5)Total length at 50% sexual maturity was 275 mm and the maturation rate was 0.026 3/mm.

Abstract:As the largest producer and consumer of freshwater fish in the world,many people suffer from allergy for consuming freshwater fish in China.However,the allergen profiles of freshwater fish are rarely known.Parvalbumin(PV)and collagen represent the major allergens involved in IgE-mediated food hypersensitivity to fish and fish products.A variety of clinical symptoms,such as urticaria,angioedema,respiratory symptoms(asthma and rhinoconjunctivitis),gastrointestinal symptoms(diarrhea and vomiting)and,in severe cases,fatal anaphylaxis can be caused after ingestion of fish.In this paper,collagen was isolated from Japanese eel(Anguilla japonica)via alkali dissolving,acid dissolution,salt precipitation,freeze-drying; and two subtypes of parvalbumin(PV-Ⅰ,PV-Ⅱ)were purified from Japanese eel with the methods of boiling,fractionation with ammonium sulphate,and DEAE-Sepharose anion-exchange chromatography.Then collagen and parvalbumin were identified by Western-blot with rabbit anti-collagen polyclonal antibody and by Dot-blot with mouse anti-parvalbumin monoclonal antibody respectively.After that,collagen and PV-Ⅰ,PV-Ⅱ were detected the cross immunoreaction of IgE binding to the fish-allergenic sera with enzyme linked immunosorbent assay(ELISA)and Dot-blot,and there is no cross immunoreaction to the fish-allergenic sera among collagen and PV-Ⅰ,PV-Ⅱ.Finally,the digestibility of collagen and parvalbumin was analyzed in simulated gastric fluid(SGF)digestion system.And the results showed that collagen and parvalbumin have high digestive stability.In conclusion,our present results indicated that collagen and parvalbumin from Japanese eel have high digestive stability and immunogenicity,and they can induce the IgE-mediated food hypersensitivity of different patients.

Abstract:Half-smooth tongue sole(Cynoglossus semilaevis G?nther)is distributed along the coast to the Yellow Sea,and Bohai Sea.It is a cultured marine fish species which is highly valued because of its delicious,tender meat and nutrition.However,diseases of the farmed fish have taken place constantly and yield losses due to epidemic diseases restrict earnings and progress of fishery.To develop new strain with enhanced disease-resistance and fast growth is an important task in tongue sole aquaculture.In the present study,wild population from Bohai sea and cultured population were used as basic populations.18 families of half smooth tongue sole were established.Growth comparison indicated that significant differences were observed in growth rate among the 18 families.Among these 2 fastgrowth families(family 15 and 16),4 secondly fast-growth families(family 6,7,16 and 27),and 12 common growth families(family 1,3,4,10,12,14,19,24,27,28,33 and 34)were obtained.12 families were chosed for pathogenic bacteria, Vibrio anguillarum,challenge experiments which showed that one family(family 2)had strong disease resistance with the survival rate of 79%;2 families(family 12 and 14)had secondly strong disease resistance with the survival rate of 50%-60%;6 families(family 3,6,7,10,16 and 19)had common disease resistance with the survival rate of 35%-50%;and 3 families(family 15,27,and 30)had low disease resistance with the survival rate of less than 35%.

Abstract:The cDNA and genomic sequences of IgZ-2 and IgM-IgZ were characterized in grass carp Ctenopharyngodon idellus in the present study.The secretory IgZ-2(sIgZ-2)cDNA sequence of grass carp is 1 889 bp,encoding 539 amino acides,and it contains a 267 bp 3′ untranslated region(UTR),but lacking 5′ UTR and partial variable region(V).The secretory IgM-IgZ(sIgM-IgZ)cDNA sequence of grass carp is 1 316 bp,encoding 361 amino acids,and contains a 3 bp 5′ UTR and a 227 bp 3′ UTR.The cDNA sequence of membrane-bound form IgM-IgZ(mIgM-IgZ)possesses two transmembrane exons,which are also spliced to a site within the CH2 exon.Amino acid alignment based on heavy chain constant regions of Igs showed that IgZ-2 and IgM-IgZ contain conserved cysteines.Phylogenetic analysis indicates that the grass carp IgZ-2 was clustered closely with the reported zebrafish IgZ, and then with IgZ in grass carp,which then was clustered well with grass carp IgM-IgZ and chimeric IgM-IgZ in common carp.There was apparent discrepancy in mRNA expression of sIgM-IgZ,mIgM-IgZ and sIgZ-2 in the four fish.In general,IgM-IgZ and IgZ-2 were expressed mainly in lymphoid organs.

Abstract:Germplasm degradation caused by inbred is an important problem that should be avoided during fish fry production in aquaculture.The inbred risk may be more severe in fry production of Amur sturgeon Asipenser schrenckii and Kaluga Huso dauricus because of their late maturation,rare mature fish resource and the ability to reproduce a large amount of eggs at one time.The present work examined the genetic diversity of 4 Amur sturgeon and 2 Kaluga reserved parent fish boodstocks from two hatcheries,using mitochondrial control region(D-loop)fragment sequence(Amur sturgeon 425 bp;Kaluga 434 bp(as the molecular marker.A total of 5 haplotypes were detected among 34 individuals from 4 Amur sturgeon stocks.There were 11 polymorphic sites,accounted for 2.6% of the total sites,no parsimonyinformative sites.There were 1-10 variable size among different haplotypes,accounted for 0.2%-2.4% of the total sites.Genetic distance among these haplotypes varied from 0.002-0.024.The haplotype divergence,average number of nucleotide differences and nucleotide divergence were 0.768,4.367 and 0.011,respectively.There was only one haplotype for each Kaluga stock from the two different hatcheries.Genetic difference between the two Kaluga haplotypes was 0.005,indicating a marked low genetic difference in Kaluga reserved parent fish broodstocks.These results show that much attention should be paid to avoid the inbred risk in sturgeon fry production,especially for Kaluga.