Abstract:Anguilla japonica is one of the most important commercial catadromous species in Asia.Yangtze River Estuary serves as the major production area of larval eels and the only fishery waters of adult eels in China.In this study,we analyzed biological information for 153 migrating silver eels collected at Jingjiang reach of Jiangsu Province(32?01′27″N,120?25′56″E)from Oct.to Nov. in 2007 and 2008.Based on the analysis of the morphological index system of Japanese eels with Principal Components and R-cluster Analysis the reults indicated that A. japonica could be classified by “body size and head feature”,"detail characteristics about the anterior part of snout” and “eye diameter and pectoral fin size”.On the basis of this analysis,17 characteristics were normalized and further used for stepwise discriminant.And then 5 characteristics were picked out:fatness,vertical eye diameter/head length,body depth/body length,horizontal eye diameter/head length,snout shape.Thus the discriminant equations were built for classifying 75 samples and the accuracy rate was 89.3%.Furthermore,the other Japanese silver eels were also classified by this model and the success rate was 88.5%.ANOVA analysis showed that,apart from snout shape,the other four standardized characteristics between male and female populations were significantly different(P<0.001).Therefore,we concluded that the female silver eels collected from Yangtze River estuary were superior to males in the respect of fatness and body depth but smaller in eye diameter.

Abstract:132 SSR and 63 EST markers were used to analyze the genotype of eightyfour individuals which crossed from barbless carp(Cyprinus pellegrini)and Hebao cold tolerance red carp(Cyprinus carpio var.wuyuanensis).The results showed that a total of 565 different alleles were found,and the number of alleles in each locus was 2 to 4.The DNA fragment length was 72 bp to 784 bp,and the average number of alleles per locus was 2.897 4.The mean polymorphism information content(PIC)was 0.584 9,and the average heterozygosity was 0.592 8.The GLM procedure was used to analyze the effects of these 195 microsatellites on body weight,length,head length and caudal peduncle length.Results revealed that HLJ133,HLJ346,HLJ360 were discovered very significantly related to carp’s body weight,HLJ133,HLJ368,HLJ390,HLJ673,HLJE96 had a significant impact on carp’s body length.Markers HLJ133,HLJ346,HLJ360 were discovered very significantly related to carp’s head length,and HLJ529,HLJE538,HLJE586 had a significant impact on carp’s head length.HLJ673,HLJE282 were discovered very significantly related to carp’s caudal peduncle length,and HLJ348,HLJ368,HLJ382,HLJ437,HLJ483,HLJ752,HLJE169,HLJE586 had a significant impact on carp’s caudal peduncle length.In addition,the correlation coefficient and the path coefficient were obtained between length,head length,caudal peduncle length and body weight.And the correlation between caudal peduncle length and body weight was insignificant.

Abstract:In order to understand and utilize heterosis and select the perfect one of numerous combination by multiple crosses,the present study attempts to analyse the utilization of heterosis by building the regression model,variance components,grey correlated degree,and comparing the prediction results through different methods based on the phenotype analysis of growth traits of 3?3 full diallel cross of common carp(Cyprinus carpio)(Jian carp,Huanghe carp and Heilongjiang carp).The results showed that:(1) The two formulas of functions were different by considering the tagging traits or not.Body length and tagging length had significant influence on body weight by creating multiple stepwise regression model together with grey correlated degree analysis;(2) Significant fixed effects of combination,combination(family)and initial weight(iw)?dam were observed;(3) combination Hyj,Hjy and JJh should be considered first in the compound breeding program.This illustrated that fixed effects of initial weight(iw)?dam,tagging length should be considered.The results also showed that utilization of heterosis can be increased by multiple crosses.

Abstract:Genomic DNA prepared from the Nile tilapia testis was used for Fosmid library construction.It was randomly sheared to -40 kb fragments.End-repair and recovery of the size-fractionated DNA were manipulated according to the manufacturer’s protocols.Ligation of the end-repaired fragments into the Fosmid vector pCC2FOS(Epicentre,USA)was performed by using T4 DNA ligase for 16 h at 4 ℃.Fosmid clones were packaged using MaxPlaxi Lambda packaging extract provided by the kit.Infected EPI300^TM-T1^R cells were grown at 37 ℃ in solid medium overnight. Well-separated colonies were picked out and transferred into individual wells of 384-well plates,each well with 300 L culture medium.After overnight incubation at 37 ℃,100 L medium was transferred from each of the 24 wells of every row of the 384-well plates into one well of the 96-well plate to construct rowpools.Totally 16 row-pools were constructed for each 384-well plate.Similarly,100 L medium was transferred from each of the 16 wells of every column of the 384 well plates into one well of the 96-well plate to construct column-pools.Totally 24 column-pools were constructed for each 384-well plate.Plate-pools were constructed by pooling the 16 column-pools and 24 row-pools(200 L from each column and rowpool)from the same 384-well plate.Totally 4 800 column-pools,7 200 row-pools and 300 plate-pools were constructed and arrayed.The library was further arranged into 25 super-pools,each including a mixture of culture medium from 12 plate-pools(500 L from each plate-pool).Finally,All 384-well plates and constructed pools were replicated,one copy was kept at -80 ℃ for longterm storage,another copy was kept at -20 ℃ for routine use.The constructed tilapia Fosmid library encompasses 115200 clones.Any gene of interest can be screened only by 3 rounds of minimally 77(25 12 40)colony PCR due to the array of super-,plate-,row- and columnpools.Fosmid stability assays were performed for the constructed library with 9 randomly picked clones by serial culture for 100 generations over a period of 6 days.The electrophoretic patterns of each clone digested with Hind Ⅲ and EcoRⅠ were identical from day 1 to day 6.No loss or rearrangement of the inserted DNA fragment was found during the continuous passage.Ten clones were randomly selected from the library and plasmids of these clones were prepared, digested with NotⅠ and visualized by electrophoresis.All the 10 clones contained insert with an average size of around 40 kb,ranging from 38 to 42 kb.Therefore,the coverage rate of this library is about 3 genome equivalents,leading to a 98.7% probability of recovery of any specific sequences of interest.Eighteen genes related to tilapia sex differentiation and growth were screened to test the quality of the library.All of them were successfully isolated from this library,with each having 2-5 positive clones,confirming the 3 genome equivalents coverage rate and the availability of the library.In summary,a high-quality Fosmid library of the Nile tilapia with large insert(40 kb)was successfully constructed,microarrayed and characterized using the vector pCC2FOS.

Abstract:The method of magnetic bead hybridization enrichment was used to screen the microsatellite molecular markers of Charybdis japonica. Genomic DNA of Charybdis japonica was extracted and digested with restriction enzyme Sau3 A I.The fragments of 400-1 200 bp were recycled and purified.DNA fragments which containing microsatellite sequence were screened with(AC)₁₅ oligonucleotide probe and connected to pMD18-T vector.Genomic library contained the microsatellite sequence was constructed.Positive clones were isolated with PCR method and sequencing.After sequence analysis on 369 positive clones randomly picked from 970 colonies,321(86.99%)of the colonies were found to contain microsatellite sequences.Among the 321 microsatellites,80.54% were perfect,15.95% were imperfect and 4.28% turned out to be compound.From the primers designed for the 102 microsatellite loci,65 could amplify expected PCR products and 27 were found to be polymorphic.The results of this work may contribute to future studies of Charybdis japonica molecular genetic breeding.

Abstract:To research the sensory physiology functions of peculiar sense organs on the abocular side of Cynoglossus semilaevis, both mechanical and chemical stimulations of the peculiar sense organs were investigated by using electrophysiological techniques.The mechanical stimulations can be demonstrated by evoking discharges from the nerves of peculiar sense organs after being touched with glass hooks lightly,which were recorded by Biomedical Multichannels Data Acquisition System.The results of small and big mechanical stimulations showed that stimulatory effects were significantly affected by the strength of mechanical stimulations; While using six kinds of L-amino acids,dimethyl sulphoxide and clam worm as chemical subjects,chemical stimulations of the dermal surface structures were also checked by the evoking discharges recorded by Biomedical Multichannels Data Acquisition System,and the frequencies and scopes of evoking discharges from the nerves of peculiar sense organs were raised as the concentrations of chemical subjects increasing.In comparison with the relations about natural responses and concentrations of chemical subjects,we knew that the order of the strength of chemical subjects was:clam worm >L-Arg>L-Met>L-Lys>L-His>dimethyl sulphoxide>L-Gly>L-Ala.The results indicated that peculiar sense organs on the abocular side have dual sensory function to both mechanical and chemical sensitivity.Since C.semilaevis depend on sensory organs to find food,it is probable that the dermal surface structures may be relative to feeding activities,and have an active effect on feeding of tongue sole.This study develops a research about peculiar sense organs on the abocular side of C.semilaevis using electrophysiological techniques,which may serve as a valuable resource for further ultrastructure and behavioral science research of C.semilaevis.

Abstract:Chinese shrimp Fenneropenaeus chinensis is one of the most economically valuable and widely cultured species in China.The hemolymph is the source of its immunity to disease and environmental factors,which invariably involves protein components.To better understand the physiology of F.chinensis and the major protein components expressed during its life cycle,two proteomics approaches,two-dimensional gel electrophoresis(2-DE)in conjunction with MALDI-TOF/TOF MS,were employed to analyze its hemolymph proteins.The proteins of F.chinensis plasma were separated using immobilized pH gradient 2-DE after desalting.By optimizing loading amount,and separation scope of IPG strip,the proteins were successfully extracted from Chinese shrimp plasma and were separated by 2-DE.After silver staining or colloidal brilliant blue staining,PDQuest image analysis software was applied to analyze the 2-DE images and a total of 11 proteins highly expressed in shrimp plasma were identified by MALDI-TOF/TOF MS,which are all hemocyanins.The results revealed that when a 150 μg sample,with 18 cm IPG(pH 4-7),after silver staining,2-DE analysis patterns were obtained；and when a 1 000 μg sample,with 18 cm IPG(pH 4-7),after colloidal brilliant blue staining,2-DE prepared patterns were obtained.We have successfully established a 2-DE technique for shrimp plasma proteome,which can lay the foundation for the further study of plasma proteomics of shrimp and other crustaceans.

Abstract:Sinonovacula rivularis sp. nov., found in Minjiang Estuary Waters of Fujian Province,was identified as a new species after study,and it belonged to Sinonovacula,Pharellidae,Bivalvia.The outer shape for the shell of S. rivularis sp. nov. was similar to that of S.constricta (Lamarck,1818), and it was likely that S. rivularis sp. nov. and S. constricta had a relatively closer affinity.Because the morphological structure of spermatozoon had the specificity of species,the differences between the species could be shown by studying and comparing the ultrastructure of spermatozoa with relatively closer affinity and could be used as the auxiliary evidence for related classification.This article observed the ultrastructure of mature sperms of S.rivularis sp. nov. and S.constricta respectively by scanning electron microscope and transmission electron microscopy aiming at providing a certain basic data and related figures for the reproductive biology research of S.rivularis sp.nov. and also providing strong evidences for differentiating S.rivularis sp.nov. and S.constricta. The samples of S.rivularis sp.nov. and S.constricta were collected in mating season(in November).Samples of S.rivularis sp. nov. were collected from coastal waters of Meihua town,Changle city,Fujian,while samples of S.constricta were collected from Xiamen Seafood Market.The sample preparation method of scanning electron microscope:dissecting the mature brood stock,extracting the sperms by suction tube and fixating by glutaric dialdehyde of 2.5%(V/V);taking 1-5 mL of the fixated and concentrated sample,and filtering it into the nuclear porous filter membrane at the size of 1.8 μm;then washing them three times with sterilized sea water and distilled water respectively,each time 10 minutes,dehydrate it once using 0%,50%,70%,90% and 95% graded ethanol respectively; and then dehydrate it twice using absolute ethyl alcohol,10 minutes for each grade.The sample is to be dried in CO₂ Critical Point Dryer; the sample after being dried is to be sprayed with metal for 25 s;and using LEO1530 field emission scanning electron microscope to observe and take photographs.The sample preparation method of transmission electron microscopy:selecting male S.rivularis sp. nov. with full and well-developed gonad,absorbing spermary by the suction tube,and quickly placing it into the fixative solution(2% paraformaldehyde 2.5% glutaraldehyde 0.05% CaCl₂,pH 7.6,0.1 MPBS),and then fixating it in an environment of 4 ℃,after dehydration and embedding,and then cutting it into slices by NOVA ultramicrotome; dyeing it with 3% uranyl acetate-lead citrate; using JEM-2100HC High contrast TEM to observe and take photographs.The ultrastructures of spermatozoa of Sinonovacula rivularis sp. nov. and Sinonovacula constricta were examined by transmission electron microscopy(TEM)and scanning electron microscopy(SEM).The results showed that there were a great deal of differences between S.rivularis sp. nov. and S.constricta. The mature sperm of S.rivularis sp. nov. was a typical primitive type,consisting of head,middle piece and tail. S.rivularis sp. nov. and S.constricta both have ellipse-shaped acrosome,but the length of acrosome for S.rivularis sp. nov. was shorter than S.constricta. The nucleus of S.rivularis sp. nov. was oblate with 8-9 arc-tubes in outer margin,whereas the nucleus of S.constricta was spherical.The middle piece of S.rivularis sp. nov. contained five mitochondria,and typically a proximal and a distal centriole.Few mature sperm of S.rivularis sp. nov. contained 4 or 6 mitochondria.There were 5 or 6 mitochondria of S.constricta based on published information.The flagellum exhibited the typical 9 2 microtubule structure in both species.

Abstract:Rabbit fish(Siganus guttatus)(67.76?26.12)g were reared under different salinities(fresh water,salinity 5,10,20 and control group(the local seawater))to study the response of survival,growth and antioxidant defense system to salinity.The rabbit fish which were fed twice everyday were held in 500 L conical plastic tank with 95 cm in height and 95 cm in diameter for 40 days and three parallels each group.After 40 d,six fish each group were taken randomly to collect the samples of the gill,liver,kidney and muscle.The results showed that the abnormal phenomenon was not found.The survival rate of salinity 5,10,20 and the control group during the experimental period was 100%.However,the abnormal phenomenon of the rabbit fish in fresh water was found(the food consumption was reduced)on the sixth day.They fasted from the 7th day and began to die from 9thd.Feed was recovered from the 13th day.However,death continued.The fish in fresh water died out after 27 d.Specific growth rate(SGR)in different salinities did not show significant differences.The body weight in salinity 10 was significantly higher than that in salinity 5 and 20.However,no significant difference was observed between salinity 10 and the control group.The total length in salinity 5 was significantly lower than other groups.In order to study the response of antioxidant defense system to salinity,the activity of superoxide dismutase(SOD),catalase(CAT),superoxide anion radical,hydroxyl radical of rabbit fish were measured.The activities of SOD,CAT,superoxide anion radical and hydroxyl radical in gill,liver,kidney,muscle of rabbit fish,reared under salinity 10,20,returned to normal levels(the level of control group)after 48 d.No significant differences were observed among each group of each index.However,the activities of SOD and superoxide anion radical in gill of rabbit fish under salinity 5 were significantly higher than that under salinity 10,20 and the control group.The activity of SOD in liver of rabbit fish was the highest among all groups,and followed by kidney and gill,muscle was the lowest and significantly lower than that in other tissues(P<0.05);the activity of CAT in liver of rabbit fish among all groups was the highest and significantly higher than that in other tissues(P<0.01),and followed by gill and kidney,muscle was the lowest;the activity of superoxide anion in liver of rabbit fish among all groups was the highest,and significantly higher than that in other tissues(P<0.01),and followed by muscle,kidney and gill were the lowest;the activity of hydroxyl radical in kidney of rabbit fish among all groups was the highest and significantly higher than that in other tissues(P<0.05);and followed by gill,liver and muscle were the lowest.The results showed that salinity can affect the activity of antioxidative enzymes,but did not affect the distribution.

Abstract:The distribution characteristics of dominant phytoplankton species and their cell abundance and cell volume conversion biomass off the Changjiang Estuary were analyzed based on a comprehensive survey conducted at 67 stations during July,2006.The cell abundance of Diatom was dominant,which mostly consists of Thalassionema nitzschioides and Skeletonema costatum.The cell abundance ranged from 1.42?10⁶ to 448.25?10⁶ cell/m³ and the average value was 90.47?10⁶ cell/m³ for all of the stations.Phytoplankton conversion biomass of Chlorophyll-a was calculated by cell volume measurement.The average Chlorophyll-a biomass was 4.41 mg Chl.a/m³,with a range from 0.02 to 34.08 mg Chl.a/m³.Based on conversion biomass,dominant diatoms were Coscinodiscus jonesianus, Coscinodiscus radiatus Ehrenberg and Thalassionema nitzschioides, and dominant dinoflagellates were Peridinium conicum, Ceratium fusus, Ceratium tripos and Ceratium furca. The trend and magnitude of the conversion biomass distribution were similar to those of the Chlorophyll-a distribution of SeaWiFS monthly ocean color data.This area could be divided into 4 parts according to phytoplankton conversion biomass:the dilute plume area is the highest biomass area; the estuary area and Taiwan Warm Current area are the lowest biomass areas;and the area off Jiangsu Coast current area is the middle biomass area.The area of conversion biomass more than 4.0 mg Chl.a/m³ corresponded well to the salinity contour 28.0 adjacent to the area of Changjiang river plume and areas with low NH₃-N and P.

Abstract:Rapid development of mariculture supplied the demand of quality protein for human,meanwhile,also resulted in environmental degradation and ecological imbalance.For this reason,lots of maricultureecological models for improving cultured environment were suggested.Among them,seaweeds/macroalgae were introduced into the system and produced environmental effects.However,macroalgal effect was only restricted in water column,with no effect to improve quality of sediment.This article investigated three-dimensional effects of improving environmental quality by introducing benthos and seaweed into the system.Different stocking densities of benthos(Perinereis aibuhitensis)were introduced into the cultured systems that only had fish(F)or fish seaweed(Gracilaria lichenoides)to investigate the effect of benthos on removing POM of sediment and the most optimal density of benthos to build an integrated mariculture system(IMCS).The results showed that the benthos made remarkable effect of reducing POM in sediments.Compared with the system that only has fish(F model),the contents of nitrogen(N)and phosphorus(P)in sediments decreased by 9.59%-10.47% and 7.11%-8.18%,respectively in the models of FP(fish benthos)and FGP(fish seaweed benthos).And the stocking density of benthos had a significant impact on the removal of POM in the sediment.The models with the densities of 22.5 kg/hm² and 30 kg/hm² had better environmental benefits than the one with 15 kg/hm²,and there were no differences between the two high densities models.Considering this two treatments’ remediation effects and culture benefits,22.5 kg/hm² of benthos’ density can promote the culture benefit and improve the sediment environment.

Abstract:The effects of various seawater temperature and salinity on clearance rate,filtration rate and absorption efficiency of Pteria penguin were investigated by adopting the measures of experimental ecology,which would provide both insight into culturing capacity and physiology of cultivating pearl of Pteria penguin and reference for marine ecosystem restoration.The results were as follows:(1) the temperature had distinct effect on the clearance rate,filtration rate and absorption efficiency of Pteria penguin(P<0.01).The clearance rate,filtration rate and absorption efficiency of Pteria penguin increased with increasing water temperature under test temperature(14-32 ℃),which reached the peak at 29 ℃ and were 0.87 L/h,4.17 mg POM/h and 84.01%,respectively.Contrasting to 29 ℃,the clearance rate,filtration rate and absorption efficiency of Pteria penguin began to decrease at 32 ℃,however,these three physiological indicators remain at higher level,suggesting that Pteria penguin is typical of the tropical and subtropical species and possesses good adaptability to high temperature.The more suitable sea water temperature for the feeding of Pteria penguin was 23-32 ℃,and the optimum sea water temperature was about 29 ℃.(2) the salinity had distinct effect on the clearance rate,filtration rate and absorption efficiency of Pteria penguin (P<0.01).The clearance rate,filtration rate and absorption efficiency of Pteria penguin increased with increasing water salinity under test salinity(19-37),which reached the maximum value with 0.36 L/h,1.87 mg POM/h and 76.95% at 31,respectively.The clearance rate,filtration rate and absorption efficiency of Pteria penguin began to decrease at 34 and 37,however,these three physiological indicators remain at higher level when salinity was at 34,suggesting that Pteria penguin is typical of narrow salinity shellfish and possesses good adaptability to high salinity.The more suitable sea water salinity for the feeding of Pteria penguin was 25-34,and the optimum sea water salinity was about 31.

Abstract:An enhanced bioreactor was designed according to the highly effective interception principle of biofilm in recirculating aquaculture systems(RAS)by inoculating nitrifying and denitrifying bacteria to the elastic fiber carriers on which biofilms could be observed in situ 6 weeks after inoculating.The impact of hydraulic retention time(HRT)and water temperature(WT)on the purifying effects of enhanced bioreactor on wastewater of RAS was investigated.The result showed that HRT and WT significantly impacted the purifying effect of the bioreactor on wastewater(P<0.05).After analysis of significant differences between HRT and WT within removal rate of COD_Mn,TN and NH ₄-N,and considering run-time,cost and operational easiness of bioreactor,it was concluded that 18 h of HRT and 30 ℃ were the best operating conditions.The bioreactor was operated stably for 25 days under these conditions,the average removal rate of COD_Mn,TN and NH ₄-N reached 44.18%,51.31% and 82.08%,respectively.In addition,the cultivable microorganisms in the biofilm of the enhanced bioreactor were detected regularly throughout the 25 days of experimental time.As the biofilm developed,the biomass of all kinds of cultivable microorganisms rose,average levels of nitrifying bacteria grew from 35.91?10⁴ CFU/mg to 89.43?10⁴ CFU/mg,nitroso-bacteria from 25.75?10⁴ CFU/mg to 61.65?10⁴ CFU/mg and denitrifying bacteria from 14.23?10⁴ CFU/mg to 100.95?10⁴ CFU/mg.Nitrifying and nitroso-bacteria dominated among cultivable microorganisms(59.95%-81.25%).Denitrifying bacteria were constantly adsorbed,colonized and successfully reproduced on the surface of elastic fiber carriers,which made biofilms more mature and stable(the removal rate of TN and NH ₄-N reached respectively 51.31% and 82.08%).The results of present study revealed that the enhanced bioreactor plays an important role in the removal of COD_Mn,TN and NH ₄-N in wastewater of RAS.

Abstract:A comparison study of the muscle nutritive composition and quality between the new selected strain of Macrobrachium rosenbergii,“South Tailake No.2” and the non-selected population was carried out.The results showed that there was no significant difference of the crude ash content between the “South Tailake No.2” and the non-selected population(P>0.05).The muscle crude protein of the “South Tailake No.2” was significantly higher than that of the non-selected population(P＜0.05),and muscle crude fat and moisture were significantly lower(P＜0.05); Muscle amino acid profiles were basically similar between the “South Tailake No.2” and non-selected population by analyzing 17 amino acids,which were in accordance with the FAO/ WHO Standard.Significantly higher levels of total amino acids,total essential amino acids(EAA)and total amino acids relating to taste in the muscle of the “South Tailake No.2” were observed compared with those of the nonselected population(P＜0.05).Based on the nutritional evaluation by amino acids score(AAS)and chemical score(CS),isoleucine was identified as it first limiting amino acid; Of muscle fatty acids profile,the percentages of total polyunsatured fatty acids(PUFA)and EPA DHA of the “South Tailake No.2”were 41.34%?0.54% and 28.09%?0.45% respectively.The percentages of total PUFA,EPA DHA and total ω₃PUFA of the “South Tailake No.2” were significantly higher than those of the non-selected population(P＜0.05),while the percentage of total ω₆PUFA was not of significant difference between the two groups(P>0.05).In conclusion,the nutritive quality of the “South Tailake No.2” is more favorable,which is intrinsic to genetic factors.Thus muscle quality improvement of Macrobrachium rosenbergii by family selection seems feasible.

Abstract:Deep-water net-cages made from HDPE,are the most widely used aquaculture facility among all kinds of anti-wave net-cages.They can be divided into cylinder netcage and truncated-cone net-cage according to different net shapes.Comparing and analyzing the similarities and differences in the aspects of the forces and deformation between cylinder net-cage and truncated-cone net-cage,could help to provide a strong reference for the selection of cage style.Using lumped mass method and the rigid body kinematics principle,this paper described a numerical model including floating circular model as well as net model for simulating the force and deformation of net-cages in current,and the accuracy of simulation was validated by the data of marine in-situ measurements.By comparing,the numerical results of the mooring line forces on the cage were in good agreement with the in-situ test data,only 7% of maximum relative error and 4.6% of average relative error between them.The results indicated the numerical model and computational method adopted could meet the need of calculation accuracy for practical study.On the basis of that,under the conditions of two weight sizes(GW₁=350 kg,GW₂=600 kg)and five kinds of current velocities(U=0.3-0.9 m/s),the drag forces and the volume reduction rate for cylinder net-cage and truncated-cone net-cage were calculated.In the process of simulating net,the mesh grouping method that 28?28 meshes have been combined into an equivalent large mesh,was applied to decrease computational time and improve efficiency.The results showed that after cages getting equilibrium in current,the two different cages in both drag force and cage volume kept the similar varying tendency with weight size or current velocity,only had little difference between them.The volume reduction rate of cylinder net-cage was much greater than that of truncated-cone net-cage.The cylinder net-cage had an obvious initial deformation when cage was only impacted by sinkers,the volume reduction rate of which was about 28% in relatively small velocity U=0.3 m/s,but the truncated-cone net-cage had better anti-current and anti-deformation performances,with about 5% of volume reduction rate.Therefore,to decrease the loss of net volume in current as well as manufacturing cost,selecting truncated-cone net-cages with sinkers weight mode has more advantages than cylinder net-cages with that for aquaculture.

Abstract:The dielectric constant and loss factor of silver carp(Hypophthalmichthys molitrix)surimi paste and surimi-soybean compound added by different proportions of soy protein isolate emulsion were measured by the open-ended coaxial probe method at 915 MHz and 2 450 MHz from 10 ℃ to 80 ℃.The results suggested that dielectric constant of silver carp surimi paste and surimi-soybean compound decreased with increasing temperature,however,loss factor increased.The dielectric constant and loss factor of silver carp surimi paste and surimi-soybean compound decreased with increasing frequency.With the addition of soy protein isolate emulsion ranging from 6.5% to 28%,the dielectric constant and loss factor increased.Penetration depth of silver carp surimi paste and surimi-soybean compound decreased both with increasing temperature,and with the soy protein isolates emulsion addition.Frequency,temperature,and soy protein isolate emulsion had a significant effect on the dielectric properties and penetration depth of silver carp surimi paste.The application of SPSS software to regression analysis and prediction of dielectric constant,loss factor and penetration depth was effective.

Abstract:Polyodon spathula cartilage as the cartilage tissue mainly contains two kinds of functional components:protein and polysaccharide,which possess antitumor,anti-aging effects and so on.The extraction,structure as well as activities of polysaccharides from the cartilage were investigated extensively and deeply.However,the extract technology for protein-polysaccharide complex has less been reported compared with polysaccharides.Therefore,the present work uses Polyodon spathula cartilage as material,and focuses on the process of protein-polysaccharide complex extracted by microwave-assisted alkali.The effects of alkali concentration,microwave power,microwave time and the ratio of liquid to material on the extract yield of protein-polysaccharide complex were studied by single factor analysis.On the basis of single factor analysis,the orthogonal test was performed to optimize the extract technology of microwave-assisted alkali.The results indicated that the optimum conditions of protein-polysaccharide complex from Polyodon spathula cartilage were cartilage with the ratio of liquid to material(15∶1, V/W),was extracted by 0.9% alkali solution,and was synchronously treated with 360 W microwave power for 6 min to obtain extract yield of 15.72%.The extraction technology of the microwave-assisted alkali can reduce the consumption of alkali,shorten the extraction time,and enhance the extract yield of cartilage.This work is favorable to further purification of proteins and polysaccharide component from Polyodon spathula cartilage,as well as to development of new health food and medicinal function products by providing the technical basis.

Abstract:This paper firstly summarized the experimental methods on marine fish feeding ecology and food web,mainly including stomach contents analysis,stable isotope analysis,compound-specific stable isotope analysis and behavior methods,their development and current applications.Secondly,the progress and achievement of fish diet composition,foraging types,food consumption and distribution in body were introduced.The strategies of marine food web research based on traditional stomach contents analysis,focusing on simplified food web,developing in stable isotope analysis techniques and ecosystem modeling were also presented.Finally,the trends of marine fish feeding ecology and food web research were predicted; furthermore,the problems and deficiency of the development and research in this field in China were discussed.

Abstract:This article makes a summary on crossstrait Economic Cooperation Framework Agreement(ECFA)and its contents of some annexes.It analyses the influence of the product lists of Early Harvest of cargo trade on imports of the animal products in fisheries after ECFA becomes effective.The author considers that the lower tax on aquatic animal products imported from Taiwan,even tending to zero,will undoubtedly enhance the competitiveness of Taiwan’s aquatic animal products in Mainland China.After the implementation of the program of Early Harvest,the aquatic animal products quantities imported from Taiwan into Mainland is going to be increased substantially.Certainly,this situation is a challenge and impact for the mainland fisheries enterprises.Only continuously improve products quality and safety,and reduce production costs,the fisheries enterprises in Mainland can meet the challenge and endure the trial.With respect to service trade,it must promote the rapid increase on fisheries technology in Mainland China,and boost the healthy and rapid development of fishery economy,if Taiwan can set up these enterprises in Mainland,provide scientific research and development services on pelagic fishery,aquiculture and fish processing.In respect of investment and economic cooperation,if under the framework of ECFA,by means of progressive reducing the limit of bilateral investment,expanding from the current investment focusing on the primary and secondary industry to a comprehensive investment which contains aquatic seed breeding,fish processing,aquafeed,pelagic fishery,recreational fisheries and science and technology cooperation,it must promote the overall development of fisheries industry in Mainland,and improve the effectiveness of fishery economy.Under the framework of ECFA,the author puts forward some proposals on fisheries economic cooperation from several aspects about conservation and management of fisheries resources,recreational fisheries and so on.