Abstract:The previous studies had indicated that the distant crossing between red crucian carp(Carassius auratus red var.)and common carp(Cyprinus carpio L.)results in chromosomal double in germ cells. In order to explore the potential ability of polyploidization in the goldfish from close crossing,by observing the chromosomal spreads of germ cells in testis,combining the flow cytometer examined DNA content of sperms,we studied the chromosomal characterization of spermiogenesis and the ploidy of sperms in goldfish.The results showed that the majority of spermatocytes in goldfish had normal chromosomal behavior in meiosisⅠ,like chromosome pairing with 50 bivalents.Furthermore,the bivalent number of a part of germ cells in goldfish doubled obviously among 17.0% of all examined chromosomal spreads,the doubling showed 100,150,200,250,300 and even more bivalents,which is similar to the chromosomal number doubling in distant crossing between red crucian carp and common carp. Unlike distant crossing species,the goldfish stably produced haploid sperms though.Taken together,it was concluded that both close crossing and distant crossing lead to chromosome doubling in germ cell.However,the production of functional gametes in process of chromosome doubling depends mainly on the genetic relationship between the parents.

Abstract:The study was conducted to investigate the difference of tissue structure and rheological properties between raw and heated Stomolophus meleagris by heating for 15,30,45 and 60 min,respectively.Histopathology difference for all samples were observed by Van Gieson stain and scanning electron microscopy,respectively.And the rheological parameters were determined by stressrelaxation and rupture experimentation.The results showed that weight and volume were decreased significantly with longer heating time,and histopathological structures were changed significantly as well.Besides,The rupture strength became smaller,while viscous modulus η₁,stressrelaxation time τ₁ increased with longer heating time.There was a correlation between rheological parameters and texture structure.These were caused by protein denaturation.Rheological parameters showed that the raw S. meleagris had lower hardness but higher elasticity and adhesiveness.

Abstract:The observations on the post embryonic development of larvae of tawny puffer(Takifugu flavidus)at each stage have been made.The photography and measurement were carried out on their growth,development and behavior ecology.The results showed that the post embryonic development of tawny puffer could be divided into 5 stages,i.e.early larva stage,late larva stage,early juvenile stage,mid juvenile stage and late juvenile stage.Each stage consists of several periods and there are 17 periods in total.The post embryo development lasted for 35 d from newly hatched larva to young fish under water temperature 20.5-26.0 ℃ and the salinity 10.0-13.5.There were 2 key periods of fry feeding habit changing,i.e.initial feeding and ingest artificial feed,and followed by the sequence of feed,yolk,rotifer,Artemia spp. larvae,mediumsized cladoceras,large copepods and cladoceras,benthic,shrimp larvae and artificial feed,etc.Habitat layers of fry are transferred from upper and middle layers into middle and under layers in the water,and their behavior underwent horizontal swimming,cruising and feeding cruising around the pond,three types of swimming behavior.The lowest of specific growth rates of fry were at late larva stage(3.18%/d)and the highest at mid juvenile stage(13.31%/d).The relationship between total length and day age or cumulative temperature could be fixed to the exponential function(y=ae^bx).The relationship of pre-anal length or body height and total length could be described by allometric growth model(y=ax^b).These growth showed two different stages indicated by inflexion points,which appeared at 16-17 d,total length 10.0 mm and 16-17 d,total length 10.5 mm,respectively.Before the inflection point,the growth of preanal length and body height were faster than total length(b＞1),after the inflection point it was slower(b＜1).It is recommended that the larvae of tawny puffer should be fed with Brachionus plicatilis(S-type)with 5-7 ind/mL at 4 days old,fry density should be reduced at 10-12 days old,fry should be transferred from indoor into pond outdoor at about 20 days old and divided to breed by sifting when fry can ingest artificial feed(35 days old)to improve the survival rate in tawny puffer fry rearing.

Abstract:This paper aimed at comparing several commercially available extractives from brown algae and compound phosphate which are commonly used in aquatic product processing.So we weighed comprehensively waterholding capacity of different waterholding additives based on the yield of weight increasing after being soaked,drip loss,cooking loss and product yield and evaluated the quality of shrimp(Fenneropenaeus chinensis)by measuring the texture attributes and color value of cooked shrimps.The results indicated that shrimps were soaked in solution of 55 mPa·s 1%(W/W)alginate oligosaccharides whose weight increasing yield was up to 11.7% which was significantly higher than 3% compound phosphate whose yield was 6.2%(P<0.05),and after being frozen 10 days,drip loss was sharply lower than shrimps dealt with compound phosphate,cooking loss and product yield had no significant difference(P>0.05); after being frozen 20 days,drip loss would remain 7.2% of the increasing weight after being soaked,while compound phosphate was 5.1%,although the loss was higher than compound phosphate,it was lower than other groups,and there were no obvious differences between alginate oligosaccharides and compound phosphate.Additionally,the color of cooked shrimps was chromatic,while shrimps treated with compound phosphate were slightly pale.From all above,we can clearly come to the conclusion that alginate oligosaccharides’waterholding capacity is commensurate with compound phosphate,and to some degree is better than compound phosphate.Therefore 55 mPa·s alginate oligosaccharides is expected to be developed into a novel,safe and highly efficient nonphosphorus waterholding additive.

Abstract:Immunoglobulins(Igs),which bind antigens with high specificity,are important molecules in adaptive immune system of jawed vertebrates.This article summarizes all immunoglobulin isotypes reported in all vertebrate species,and focused on the current knowledge regarding isotypes and their loci in fish.Teleost fishes are found to express the isotypes of IgM,IgD,IgZ/IgT and a chimera IgMIgZ.In cartilaginous fish,three immunoglobulin isotypes,IgM,IgW and IgNAR have been identified,and IgW was reported also in lungfish.Furthermore,the genomic organization of IgH locus has been revealed in several species of teleost fish.The genome organization of IgH locus in channel catfish is a translocon arrangement,with three δ genes linked to a μ gene or pseudogene,and the loci in zebrafish,fugu and grass carp follow the pattern of genomic organization:Vn-Dn-Jn-Cζ-Dn-Jn-Cμ-Cδ.The organization of the IgH locus in rainbow trout is,in general,similar to that of zebrafish,fugu and grass carp,except that two VH genes are found downstream of the Cζ.The IgH loci organization in cartilaginous fishes are multiclusters,each consisting of a few gene segments(V_H-D-D-J_H-C_H)or(V_H-D-D-D-J_H-C_H).In different species of teleost fish,it is at least to some extent difficult or probably impossible to summarize a pattern in the expression of different Ig isotypes.Overall,these Ig isotypes are in general expressed in immune organs,such as thymus,head kidney and spleen.Despite the recent progress on the Ig genes and their loci in several species of teleost fish,many aspects such as the ontogeny of B lymphocytes,the pattern of antibody responses and the role of these different antibodies,and even the exact Ig gene composition and their loci may need to be further investigated either in different species or in greater detail.

Abstract:The effect of the medium of C/N ratio(1∶1,2∶1,3∶1,4∶1 and 5∶1,respectively)on the growth and total lipid content of Chaetoceros muelleri was evaluated in this study.The results showed that this algae had the highest growth rate of 1.98%/d at the C/N ratio of 2∶1 and lowest growth rate of 1.69%/d at ratio of 3∶1.The total lipid content of this algae was the highest(31.26%)at the C/N ratio of 5∶1,but lowest(28.39%)at 2∶1,and the daily lipid had the highest increment,which was 0.84 ag.The daily increment of lipid content was 0.64 ag at the C/N ratio of 3∶1.The unsaturated fatty acids were also different in accumulation during the cultivation with 5 different C/N ratio mediums in this finding.The total unsaturated fatty acids content was the highest when the C/N ratio was 5∶1.In conclusion,the growth rate and total lipid accumulation of C. muelleri was best at the C/N ratio of 2∶1 in this study.

Abstract:A 10week net pen experiment was carried out to examine the capacity of malabar grouper(Epinephelus malabaricus)in utilizing a blend of poultry byproduct meal,feather meal and blood meal at different dietary protein levels.A 2×4 experimental design,including two dietary protein levels(490 and 530 g/kg crude protein)and four fish meal level(500,350,200,50 g/kg),was established.At each dietary protein level,one feed was formulated to contain 500 g/kg herring meal as control,and in the remaining three feeds,the blend that was formulated to contain 65% poultry by product meal,20% feather meal and 15% blood meal was incorporated at 139,278 or 416 g/kg to replace 30%,60% or 90% of the fish meal.Initial body weight of the experimental fish was(33.4±0.1)g per fish.During the experiment,fish were fed to satiation twice daily except the days during which extremely high temperature or heavy waves occurred.The results of the experiment indicated that dietary protein level did not significantly affect feed intake(FI),weight gain(WG),feed conversion ratio(FCR),nitrogen retention efficiency(NRE),energy retention efficiency(ERE)and whole body composition,while dietary fish meal content had significant effect on WG,FCR,NRE and ERE.At the same dietary protein level,specific growth rate(SGR)decreased with the decrease of fish meal level.At the same dietary fish meal level,fish fed the feeds containing 530 g/kg crude protein had slightly high SGR relative to fish fed the feeds containing 490 g/kg crude protein.Results of the present study reveal fish meal level in diets for malabar grouper can be reduced to 200 g/kg by incorporating the blend of poultry by-product meal,feather meal and blood meal,and no benefit was found in reducing dietary fish meal level for malabar grouper by elevating dietary protein level from 490 to 530 g/kg crude protein.

Abstract:A 49day feeding experiment was conducted to evaluate the effects of replacement of fish meal by soybean meal in Siganus guttatus ［with the initial weight(104.64±2.76) g］diets on fish growth performance,body composition and biological indices and to determine the optimum soybean meal concentration in S.guttatus diets.Five isonitrogenous and isoenergetic diets were formulated containing 35% protein and 19.00 MJ/kg gross energy.The replacement ratio(soybean meal∶fish meal)was 0∶1(D₁),1∶2(D₂),1∶1(D₃),2∶1(D₄),1∶0(D₅). S.guttatus which were fed to satiate twice daily,were cultured in conical rearing tanks(0.5 m³)with 25 ind per tank and three replications per group.The results showed that the growth performance of S.guttatus was significantly affected by the concentration of soybean meal in the diets.Weight Gain(WG),Special Growth Rate(SGR)and Feed Intake(FI)had a negative correlation with diet soybean meal concentration.WG and SGR were maximized when fish were fed with pure fish meal, 24.42% and 0.44%/d,respectively.Significant differences were observed in SGR in each group.The value of FI in D₁ was significantly higher than that in D₅.Feed Conversion Rate(FCR)had a positive correlation with diet soybean meal concentration.The lowest value of FCR was found in D₁,but there was no significant difference between D₁ and D₂.There was also no obvious difference between D₂ and D₃.The replacement had no significant effects on muscle crude protein and moisture but had marked influence on whole body crude protein and fat.The lowest value of whole body crude protein was observed in D₅ (19.11%).Liver crude protein content tended to increase first and then decrease,with increasing soybean meal concentration in dietsi.Liver crude fat in higher soybean meal concentration diets is significantly lower than in lower soybean meal concentration diets.The replacement had no significant effect on biological indices except Viscerasomatic Index.The replacement ration should be less than 1∶2 in S.guttatus diets based on SGR,FCR,FI and some other parameters.However,considering the muscle quality of S.guttatus,it is indicated that the replacement ratio could amount to 2∶1.

Abstract:Three experiments were conducted to determine the lysine,methionine and arginine.requirements of juvenile Chinese mitten crab Eriocheir sinensis.The juvenile crab［average initial weight:Lys experiment(2.050±0.027)g;Methionine experiment(2.027±0.033)g;Arginine experiment(2.05±0.032)g］were fed amino acids test diets for 56 days with the protein source containing casein,white fishmeal,soybean meal and crystalline amino acids.The test diets contained 5 graded levels of lysine(1.58%,1.98%,2.38%,2.78% and 3.18%),methionine(0.50%,0.75%,1.00%,1.25% and 1.50%)and arginine(1.39%,2.09%,2.79%,3.49% and 4.19%)respectively.The triplicate feeding trials were conducted in fiberglass tanks indoor.Water temperature and pH were kept at (28±3.0) ℃ and 7.4,respectively.The results of the lysine experiment showed crab fed diet 3 containing 2.38% lysine had the best weight gain(WG)and specific growth ratio(SGR),but no significant difference was found between the levels of 1.98%(diet 2)to 2.78%(diet 4);the whole crab fed diet 3 had significantly low moisture and significantly high protein content(P<0.05).The results of methionine experiment showed crab fed diet 8 containing 1.00% methionine had significantly high WG and SGR(P<0.05),no significant difference was found in other test groups; the crab fed diet 10(1.5% methionine)had significant high moisture content and low protein content of whole body(P<0.05); no significant difference was found among the other test diets(diet 6 to diet 9).The results of arginine experiment showed crab fed diet 14 containing 3.49% arginine had significant high WG and SGR(P<0.05);but no significant difference for the body composition of crab was found.Based on the growth response and quadratic model regression analysis of the relationship of WG with dietary Lys,Met or Arg levels,the Lys,Met and Arg requirements of juvenile Chinese mitten crab were estimated to be 2.34%,1.12% and 3.62% respectively.

Abstract:In this paper,in comparison with their WSSVresistant characteristics,35 selective breeding families of the 4th generation and no selected shrimp of Litopenaeus vannamei were divided into three groups:relatively high resistant families,mid resistant families and susceptible families,with the average survival rates of 24.45%±6.56%,10.70%±1.41% and 2.72%±2.76%,respectively after 10³ copies WSSV/g(body weight)infection,which were significantly different among the three groups(P<0.01).Injected WSSV of 10²,10³,10⁴ and 10⁵ copies WSSV/g,the survival rate of the relative high resistant family 12 was 100%,23.3%±3.5%,7.8%±1.9% and 0 %,respectively; and the survival rate of the mid resistant family 7 was 87.7%±3.8%,12.2%±1.9%,0% and 0%,respectively; and the survival rate of the susceptible family 4 was 54.4%±3.8%,2.2%±1.9%,0% and 0%,respectively; and the survival rate of non-selected was 51.1%±5.1%,0%,0% and 0%,respectively.In comparison with mid-resistant family 7,susceptible family 3 and non-selected shrimp,the THC in relatively high resistant family 12 increased by 20.7%(P>0.05),36.7%(P<0.05)and 34.4%(P<0.05)compared with that of the abovementioned shrimps,respectively after 10³ copies WSSV/g(body weight)infection; the PO activities increased by 40.0%(P<0.05),76.3%(P<0.05)and 63.4%(P<0.05)compared with that of the abovementioned shrimps,respectively; the SOD activities compared with 31.1%(P>0.05),58.8%(P<0.05)and 32.0%(P>0.05)increased by that of the abovementioned shrimps,respectively; the POD activities compared with 29.64%(P>0.05),44.9%(P<0.05)and 43.3%(P<0.05)increased by that of the abovementioned shrimp s,respectively; the content of plasma protein compared with 31.2%(P>0.05),38.7%(P<0.05)and 39.3%(P<0.05)increased by that of the abovementioned shrimps,respectively.However,there were no significant differences of the THC,PO,SOD,POD and content of hemolymph protein among midresistant family,susceptible family and non-selected shrimp.After 4 generations of selection,the immune capability of the shrimp from relatively high resistant family was much higher than that of the other groups and nonselected shrimp,with apparent powerful capability of WSSV resistance.These findings would help to direct the future selective breeding of shrimp for WSSV resistance.

Abstract:Vibrio alginolyticus is the main Vibrio pathogen in aquaculture in the south of China,the number of which is the largest in marine Vibrio class.In the present study,the outer membrane protein K gene(OmpK)of V.alginolyticus strain ATCC17749 was amplified by PCR and cloned into high efficient expression vector pET28a.The results of sequencing and restriction enzyme analysis combined with agarose gel electrophoresis showed that the open reading frame sequence was correct and fully consistent with what had reported.The recombinant plasmid of pET-28a-OmpK was successfully constructed and transformed into E.coli BL21 pLys E.The fusion protein was expressed under the IPTG inducing condition,and the expression product was purified by an affinity chromatographic method.Mouse anti-OmpK poly-clonal antibodies(PAbs)were obtained via applying protein OmpK as antigen to immune mice.Western-blotting analysis proved the recombinant protein has a good reactive ability against OmpK positive serum.Then,an indirect Enzyme-Linked Immunosorbent Assay(ELISA)for the rapid diagnosis of V.alginolyticus has been developed using the PAbs.The lowest V.alginolyticus suspension was 10⁴ CFU/mL.Cross reactions of antisera with other bacteria were detected,and all results were negative.The results indicated the suitability and simplicity of the test as a rapid,field diagnostic tool for V.alginolyticus and it can be used for the rapid detection of V.alginolyticus. Further investigation will be focused on the development of an indirect ELISA Kit for the detection of V.alginolyticus.

Abstract:AVNV(acute viral necrosis virus)is the pathogen leading to mass mortality of cultured Chlamys farreri,but the transmission of the virus is unknown.In order to clarify the relationship between the plankton and transmission of AVNV,and to afford proof for tracing transmission track,the sea water samples were fetched from 50 cm and 300 cm depths in the sea area for culturing Chlamys farreri at Shazikou of Qingdao and Sanggouwan of Rongcheng regularly from May to November in 2009,and the plankton was collected by 25 μm,3μm,0.22μm pore size filter,respectively.The AVNV carried by the plankton was identified by FQ-PCR.The results showed that the virus could be carried by the plankton,and the virus number in the plankton from both sea areas arrived at the peak in August.The highest number of AVNV identified for the samples from Shazikou sea area was 8.21×10⁶ copies per litre sea water,and that was 2.98×10⁵ copies for the samples from Sanggouwan sea area.Based on the number of AVNV carried,the plankton group with different particle sizes was 3-0.22 μm,25-3 μm and >25 μm from high to low in turn.The number of AVNV carried by the plankton from 50 cm and 300 cm depths was not different significantly.This is the first report about AVNV carried by the plankton from the sea area for cultured scallop.These results implied that the scallop could be infected by taking the plankton that carried AVNV as food,and the plankton was crucial carrier of AVNV.

Abstract:Insulinlike growth factors(IGFs)system,including IGFs and IGFbinding proteins,plays a central role in growth and reproduction of fish and higher vertebrates.In serum and extracellular fluids,most circulating IGFs are bound to specific high affinity IGFbinding proteins(IGFBPs)that can protect them from degradation and modulate their actions.Common carp(Cyprinus carpio)is one of the most economically important fish in China.To improve the yield of common carp and get more economic benefits,the study of mechanism of growth and reproduction is very important.In the previous study,the cDNAs of common carp Igfbp-2 and -3 had been cloned,and the expression profiles and hormonal regulation were studied.The results showed that common carp Igfbp-2 and -3 mRNAs were expressed in many various tissues and different embryonic developmental stages,but the abundances were different significantly.To further understand the regulation mechanism of Igfbp-2 and -3,the study of their promoters is necessary.So,in this paper,the sequences of Igfbp-2 and -3 promoters were firstly cloned,and then the putative transcription binding sites were analyzed.The length of Igfbp-2 and -3 promoters we obtained was 1 142 bp and 1 067 bp,respectively.There was a consensus TATA box 22 bp 5′ to the start site of transcription in Igfbp-3 promoter,while in the upstream there was a SP1 binding site instead of CAAT box.Neither TATA box nor CAAT box was found in the promoter of Igfbp-2,only a SP1 binding site and rich G/C motif in this region.These results showed that the promoters of common carp Igfbp-2 and -3 did not contain the characteristics of classic promoter.Furthermore,some other transcription binding sites were observed in the two promoters,such as CREB,HNF,Pit-1,Oct-1,RXR,GR,ER,PR,SRY and so on,while the STAT(signal transducer and activator of transcription)was only found in Igfbp-3.These results suggested that there were basic and hormone inducible expression patterns of Igfbp-2 and -3 genes.However,the regulation mechanisms were not consistent between the two genes.

Abstract:An in situ experiment was performed at a Chlamys farreri culture zone of Yantai SiShili Bay to learn more about the heavy metal concentration in the tissues and the food organisms of C.farreri at different growth stages and to carry out food safety evaluation on C.farreri for human consumption.C.farreri samples were monthly collected from June to December in 2009.At the same time,the heavy metals were monitored in sea water,sediments and suspended solids(SS).The method for monitoring heavy metals in sea water and sediments complied with The Specification for Marine Monitoring(GB 17378—2007).By filtering 2-3 L seawater with microfiltration membrane,the samples of SS were obtained,which would be digested together with filtration membrane after desiccation,while doing a blank determination.The monitoring method complied with The Specification for Marine Monitoring(GB 17378—2007).The C.farreri were tested in conformity to Methods of Food Hygienic Analysis(GB/T 5009—2003),and 200g samples were respectively obtained as whole soft form,adductor,visceral mass and lamellibranch.The results showed that there is significant variation and selectivity of heavy metal concentration in different tissues of C.farreri,of which the enrichment coefficient of Cd is as high as 25 495,the content of Cd in adductor muscle being 1/5 of that in visceral mass,while the enrichment coefficient of Cu and Pb are 1 453 and 258,respectively.The results indicated that the enrichment process of Cd was positively correlated with the growth cycle of C.farreri,while the enrichment of Cu and Pb is in a faintcorrelation with its growth cycle,which may be elucidated by the comparatively higher enrichment coefficient of Cd than those of Pb and Cu in phytoplankton,the main feeding source of C.farreri.The results from quality appraisal of C.farreri showed that the content of Cu and Pb conforms to the evaluation criteria,while the content of Cd exceeded in whole soft form,visceral mass,adductor and lamellibranch.The value of Cd content in visceral mass is 7.50 times greater than the normal,and in the whole soft form it is 3.33 times greater than the normal.In addition,a preliminary study on human body consumption standard was performed in the paper,and reference intake of C.farreri for humans was put forward.If it is eaten wholly,the weekly reference intake of the fresh will be 0.75 kg,i.e.3.0 k g including the weight of shell;if just adductor muscle is eaten,its weekly reference intake will be 1.86 kg,i.e.18.6 kg including the weight of shell.

Abstract:HSP90 proteins are major chaperones that play pivotal roles in controlling multiple regulatory pathways such as hormone signaling,cell differentiation,cell proliferation and apoptosis,morphogenesis and morphological evolution,metamorphosis and stress defense.Using realtime fluorescent quantitative RT-PCR approach,expression profiles of HSP90 genes were examined during larval development and in adult tissues in Japanese flounder,Paralichthys olivaceus.In adult tissues,HSP90α was mainly expressed with higher transcript levels in skeletal muscle,intestine and stomach; but HSP90β exhibited higher mRNA levels in brain,spleen and kidney.During metamorphosis,HSP90α transcript increased distinctly with the highest mRNA levels at the metamorphosis climax; whereas HSP90β mRNA levels did not change.Due to the important role of thyroid hormone(TH)for the flounder metamorphosis,the transcriptional regulation of HSP90 genes by TH was evaluated using exogenous TH and thiourea(TU)treatment.Compared with untreated control,HSP90α transcript increased significantly in larvae sampled 8 and 13 days after TH treatment,and TU-treated larvae exhibited lower HSP90α mRNA levels.In contrast,the transcript levels of HSP90β did not vary after TH and TU treatment.Overall,these results demonstrate that HSP90α transcription is upregulated by thyroid hormone and plays an important role during metamorphosis in Japanese flounder.

Abstract:Based on data collected by quarterly otter trawl surveys in the Beibu Gulf in 2007,fish species compositions and community pattern were analyzed.A total number of 323 fish species belonging to 101 families and 18 orders were collected during the surveys.The largest number of species was recorded in winter (231 species),followed by those in autumn and summer (217 and 214 species,respectively),and the number of fish species was the smallest in spring(186 species).The spatial pattern of fish community was analyzed using hierarchical clustering and nonmetric multidimensional scaling.Five station groups based on fish assemblages were indentified.The Group Ⅰ was located in the coastal waters of northeast Beibu Gulf and showed less seasonal variation in distribution.The Group Ⅱ was located in the coastal waters west off Hainan Island.The Group Ⅲ covered a large area of the central and southern waters of the Beibu Gulf,while the Group Ⅳ located near the Bailongwei Island covered the least stations,and the Group Ⅴ can only be identified in spring season to the west Qiongzhou Strait.The ANOSIN tests showed highly significant differences (R=0.896-0.956,P<0.001) in fish assemblages between the station groups.The relationships between changes in fish community pattern and environmental factors (depth,bottom temperature and bottom salinity) were examined.The correlation analysis showed that the water depth was the major environmental factor dominating the fish community pattern,while bottom temperature and salinity contributed less to determining the community pattern.

Abstract:In order to clone full-length myostatin gene and characterize its tissue expression profile in E. bambusa,RT-PCR and rapidamplification of cDNA ends(RACE)were used to acquire full-length cDNA.A full-length of 2 177 bp myostatin cDNA sequence in E. bambusa was cloned,which included a 1 125 bp complete ORF encoding a 375 amino acids peptide,a 89 bp long 5′-untranslated region,and a 1 052 bp long 3′-untranslated region.The 375 amino acids long putative peptide contains a 22 amino acids long signal peptide,a conserved RIRR proteolytic processing site,and 9 conserved cysteine residues in the C terminal of the protein.The E. bambusa MSTN had high similarity to the Megalobrama pellegrini,Ctenopharyngodon idella,Cyprinus carpio myostatin while had low similarity to the M. perciformfishes myostatin and lower similarity to the mammalian and bird myostatin.The phylogenetic analyses showed that the E. bambusa myostatin had closest relationship with the M. pellegrini myostatin.Furthermore,myostatin mRNA tissue expression profile was assessed by semi-quantitative RT-PCR.In the seven examined tissues,the myostatin gene was expressed strongly in muscle and brain,weakly in heart but not expressed in kidney,intestine,gill,heart and liver.These results suggested that the fish myostatin gene might not only play roles in muscle development but also contribute to other biological functions.

Abstract:The flow changing around the artificial reef is the fundament of its physical effect.So far,using 3D numerical calculation to study the flow around the artificial reef is a tentative research,so this paper compared the water channel experiment with the numerical calculation to prove its accuracy.Using the Large Eddy Simulation(LES),a method of Computational Fluid Dynamics,this paper simulated the flow around a Mizi type artificial reef(dimension compared with actual reef is 1∶10)under a steady initial coming flow.Also,the water channel experiment with the same size as the numerical model is set to prove the feasibility of the numerical simulation.This paper compared the flow from x,y and z,three directions,under six different velocities of the coming flow,0.2 m/s,0.4 m/s,0.6 m/s,0.8 m/s,1.0 m/s and 1.2 m/s.The result showed,about 80% of the velocity on the measured points by numerical simulation are consistent with the results measured by water channel experiment.Also,the discrepant points mainly located on the hatch of the top of the reef.And this position was difficult to measure because of the strong flow changing so that it was allowed to be variant.Therefore,under the overall comparison of results,this threedimensional numerical simulation can replace the water channel experiment and be applied in the simulation of the same size as the actual artificial reef in the sea area to do the further research of the flow around the artificial reefs more clearly.At the same time,we can use this method to build the artificial reef models to study the flow around the artificial reef with different structures or a set of some artificial reefs,then we can optimize the construction of artificial reefs.

Abstract:Vasa gene is specifically expressed in gonads and plays an important role in the germline formation and differentiation in most animals.In this study,a full open reading frame of vasa gene was amplified from the testis cDNA pool of the prawn Macrobrachium nipponense,and ligated with expression plasmid pET32a with 6×histine tag.After the recombinant plasmid was transferred into host bacteria Escherichia coli (BL21),the recombinant VASA protein was expressed under the induction of IPTG.The optimum concentration of IPTG was 0.2 mmol/L with a duration of 6 h at 30 ℃.SDSPAGE analysis showed that the fusion protein was highly expressed as inclusion body and the yield accounted for 48.7% of the total bacterial protein.Westernblotting analysis demonstrated the target protein with the molecular weight of 85 ku.The recombinant protein was subsequently purified by Ni²⁺-NTA affinity chromatography.To further prepare the prawn VASA antibody,New Zealand white rabbits were immuned by the purified protein.The highest titer of the antiserums was up to1∶160 000as revealed by ELISA assay.The specificity of the antibodies against VASA protein was verified by Westernblotting.Immunohistochemical analyses indicated that,in oocyte VASA protein was mainly concentrated at the perinuclear region at vitellogenic oocyte; in testis,VASA protein was mainly distributed in spermatogonia.These data suggest that the VASA could play a key role in the development and differentiation of the germ cells in the prawn.

Abstract:In this paper,a computing model of underwater irradiance of fish aggregation lamps was developed based on Monte Carlo method by using chlorophyll concentration and wind speed with characteristic parameters of the lamps.The absorption and scatter character of chlorophyll concentration and pure sea water in class I waters were used to compute beam attenuation coefficient including absorption coefficient and scatter coefficient,and scattering cumulative distribution function.Wind speed was used to construct windblown capillary wave surface which would have a great influence on light fields for large airincident angles.Compared with the traditional computing model,this model has the following advantages:(1) the model took the difference of beam attenuation coefficient over wavelength into account without a constant assumption or using guessing value;(2) the model can provide the spectral distribution of fishing lights for different depths which was important for design of fishhook and researches of fish behavior to light;(3) the scattering of the light was calculated,so the model can provide downward irradiance under the shadow area of fishing vessels;(4) the influence of the windblown capillary wave surface on the reflectance for large airincident angle was taken into account,so that the model was more reasonable in computing underwater light field of fish aggregation lamps;(5) the chlorophyll and wind speed can be drawn from remote sensing data,which make the model easy to use.Comparing with the in situ measure data,the value computed by model was larger,the relative root mean error was 37.6%,but the correlation between the two data was significant(P<0.001).Finally,the difference between the two data was discussed.