Abstract:Olive flounder(Paralichthys olivaceus)is one of economically important fish in China.It is distributed widely over the Bohai Sea,the Yellow Sea and the South Sea in China,North Korea,Japan and along the east coastline of Russia.As its natural resource is exhausting gradually,olive flounder has become an important cultured fish in China.Polymorphic available DNA markers are needed for its genetic research.Microsatellites recently have become an extremely popular marker in a wide variety of genetic investigations.In this research,genomic DNA was extracted from fin of olive flounder collected from one locality along the Chinese coast.The genomic DNA was digested by using both RsaⅠ and Bst UI polymerase.And then a microsatellite-enriched genomic library was constructed.By using(GA)13 as probes,177 positive clones were identified from 269 clones,and 191 microsatellites were found.Among the 191 microsatellites,74.35% were perfect,14.66% were imperfect and 10.99% were compound type.50 markers were assessed using 32 individuals.Of the 50 loci 31 were found to be polymorphic.The result showed that the number of alleles ranged from 2 to 9,with an average of 3.939 4 alleles per locus.The number of effective alleles per locus is 3.052 2. The values of observed and expected heterozygosity per locus is 0.650 1 and 0.586 6, respectively.The values of Hardy-Weinberg equilibrium ranged from 0.012 587 to 0.984 917.These markers will be useful for population structure assessment,molecular marker-assisted selection and genetic linkage map construction for this species.

Abstract:EST-SSR marker development by screening and mining the SSR repeats in the EST database of Litopenaeus vannamei,161 075 EST sequences were downloaded from EST sequences in the database of GenBank.EST sequences were analyzed and the SSR was screened with SSIRT(http:∥www.gramene.org/db/markers.ssrtoo).As a result,12 600(7.8%)SSRs were identified from the EST resources,among which there were 10 104(80.2%)dinucleotide,2 036(16.1%)trinucleotide,336(2.7%)tetranucleotide,35(0.3%)pentanucleotide and 89(0.7%)hexanucleode SSRs.Among the dinucleotide sequences,AG/CT repeat motif accounted for 4 820(47.8%),3 584(35.4%)AC/GT repeat motif,AT/TA,CG/GC repeat motif was 1 673(6.6%),27(0.2%)respectively.77 pairs of primers were designed with Primer Premier 5.0.Fifty four primer pairs obtained expected product,with the success rate of 70.1%.And 28 of them showed polymorphism among 10 individuals,polymorphism rate was 51.9%.Number of alleles ranged from 2 to 5,and PCR product size was 140-600 bp.This implies that the polymorphism ESTSSR developed from NCBI could work in genetic mapping,gene clone and gene functional research.

Abstract:The genetic diversity of seven wild Scylla paramamosain populations,collected from Hangzhou Bay(HZ),Sanmen Bay(SM),Minjiang Estuary(MJ),Dongshan Bay(DS),Zhujiang Estuary(GD),Beibu Bay(GX),Qinglan Estuary(HN)in China were investigated using seventeen microsatellite markers.The number of alleles(A),number of effective alleles(N_e),polymorphism information content(PIC)and heterozygosity(H)were all determined.The Hardy-Weinberg Equilibrium was checked by χ² Test.The genetic distance was computed based on the allele frequency.A dendrogram was built on the unweighted pairgroup method with arithmetic means(UPGMA)results using PHYLIP software package(Ver 3.5).F-statistics analysis and the degree of population differentiation between the seven wild populations using analysis of molecular variance model (AMOVA) were computed by ARLEQUIN(Ver 3.1).A total of 253 alleles were obtained at the seventeen microsatellite markers in seven populations.Polymorphic information content (PIC) value per locus was greater than 0.5,indicating the seventeen loci were highly polymorphic.The mean number of alleles and effective alleles ranged from 9.41 to 10.94,5.42 to 6.87 respectively.The heterozygosity (H) ranged from 0.511 to 0.563.The data suggested that all the seven wild populations of Scylla paramamosain had little high genetic diversities.Analysis of molecular variance (AMOVA) revealed that the variation within populations was 94.13%,whereas the variation among populations explained 5.87% of the total variation.F-statistics analysis detected significant genetic differentiation among the seven wild populations,with the F_ST value ranged from 0.035 5 to 0.081 7.Genetic differentiation among populations was statistically significant.88.24% of the population loci showed significant deviation from the Hardy-Weinberg equilibrium.There was heterozygote deficiency at all loci.The genetic distances among populations ranged from 0.253 0 to 0.571 9.Cluster analysis indicated that HZ and SM populations,joining together for the closest relationship,were clustered with MJ and DS as one cluster.GD and HN populations were clustered together,while GX was an independent cluster.

Abstract:Genetic diversity of 4 wild populations(Laizhou,Haizhou,Dalian,Qingdao)of Charybdis japonica was assessed by 10 microsatellite markers.Results showed that the number of averages allele of 10 loci was 13.600 0 and alleles obtained from different primers ranged from 11 to 17,the number of average effective alleles was 8.592 0;Observed heterozygosity value(H_o)was 0.318 2 to 0.858 4 and expected heterozygosity value(H_e)was 0.846 6 to 0.923 9;Average polymorphism information contents was 0.828 0 to 0.914 0,explained high level of genetic diversity in 4 wild stocks.Coefficient of gene differentiation F_ST ranged from 0.032 74 to 0.088 03,each group had larger genetic differentiation.Genetic identity(I),genetic distance (D) and cluster dengrogram between 4 stocks of C.japonica showed that Qingdao Bay was closest relative with Haizhou Bay stock,but Haizhou Bay was farthest relative with Laizhou Bay stock.

Abstract:Pepsinogens(PGs)are inactive precursors of pepsins,which convert to mature pepsins in gastric acidic environment.In this study,the complete cDNA sequence of PG A2 was obtained from the stomach of mandarin fish(Siniperca chuatsi)by Rapid Amplification of cDNA Ends(RACE).The full-length of PG A2 cDNA was 1 322 bp,which contained an open reading frame(ORF)of 1 131 bp encoding a peptide of 319 amino acids.Three regions were identified in PG A2 amino acid sequence:the signal peptide,the activation segment and the pepsin moiety.The pepsin moiety had two aspartates functioned as catalytic residues and three disulfide bonds.There were significant differences in sequence composition,physical and chemical properties,functional sites and spatial structure between pepsin A2 and pepsin A1 of mandarin fish,suggesting that they may have divergent functions.Gastric proton pump(gastric H⁺/K⁺-ATPase)is a key enzyme involved in the secretion of gastric acid.Both cDNAs of α and β subunits of the gastric proton pump were also isolated and cloned,with a length of 3 581 bp and 1 669 bp,respectively.High sequence conservation was revealed in α subunits which had multiple functional sites,while moderate variability was in β subunits.mRNA expressions of PG A1,PG A2 and α subunit of the gastric proton pump were detected in the same gastric gland cells of gastric mucosa using in situ hybridization,which implies these cells not only synthesized pepsinogens but also secreted hydrochloric acid,thus,they belonged to the oxynticopeptic cells.

Abstract:Okadaic acid(OA)is one kind of lipophilic marine biotoxins,and main pathogenic factor of diarrheic shellfish poisoning(DSP).In this paper,the artificial antigen was made by coupling hapten of OA with keyhole limpet hemocyanin(KLH)using active ester method,and the artificial antigen was tested by SDS-polyacrylamide gel electrophoresis and IR spectrum.After being obtained from rabbits,the antiserum was purified by Chromatography on Protein A Sepharose CL-4B gel column,and the purification efficiency was verified by ultraviolet scanning and ciELISA.The results showed the artificial antigen was prepared successfully and lots of interfering substances were removed.After being purified,the concentration of antiserum was 2.16 mg/mL,it had high titer(12 800)and sensitivity(the value of IC₁₅ was 3.41 ng/mL),which was tested by ciELISA.The success of obtaining polyclonal antibody against OA with high titer and affinity provides the solid foundation which is practical and theoretical for developing rapid and economical detections.

Abstract:Based on the epidemic features,etiology and pathologic characteristics of the disease,the causative agent was identified as Cryptocaryon irritans.Upon the isolation of the parasites,efforts were made to inactivate the ciliate by using several disinfectants and herbal compound.The results showed that H₂O₂ and herbal compound were both effective to kill the parasite.In clinical treatment,the combined use of “HD-2” and 100-200 mL/m³H₂O₂ was proved to control the disease effectively.The present study represents the first report to use H₂O₂ and herbal compound instead of formaldehyde for the disease treatment.The treatment established in this study is highly effective,and contains no poisonous substance,with no residues in fishery products,which provides insight into the fish disease prevention and treatment,as well as into the quality maintenance of aquatic products,with the protection of ecological environment.

Abstract:To investigate the influence on channel catfish(Ictalurus punctatus)liver toxicity and liver proteome change by the use of selenium-enriched yeast,Se-concentration in channel catfish liver was determined and the pathological change was monitored after selenium-enriched yeast feeding for 56 days.Proteins extracted from the liver of seleniumenriched yeast feeding channel catfishes and nonfeeding controls were separated by two-dimensional gel electrophoresis(2-DE),differentially expressed proteins between the two groups were analyzed using ImageMaster software and identified by online reversedphase nanoflow liquid chromatography coupled with ion trap mass spectrometry(LC-MS/MS).The average Se-concentration of liver form the non-feeding controls and the seleniumenriched yeast feeding ones were 0.15 mg/kg and 0.81 mg/kg.Significant difference was detected between these two groups(P<0.05).H.E staining of pathology from channel catfish liver showed that the seleniumenriched yeast group has obvious cell loose and cell fatty degeneration.15 differetial protein were found by 2-DE separation and ImageMaster software analysis.Of them,8 overexpressed proteins in seleniumenriched yeast were selected for MS analysis and identified successfully,including 3 uregulated proteins and 5 uniquely expressed proteins in selenium-enriched yeast group compared with the controls.These differential proteins correspond to chaperonin TCP1 subunit 8 and glyceraldehyde-3-phosphate dehydrogenase,4SNc-Tudor domain protein,adenosine kinase a,transketolase and alanyl-tRNA synthetaselike et al.Obvious toxicity was detected in the channel catfish liver after feeding with selenium-enriched yeast.Organic selenium might strengthen immune through 4SNc-Tudor protein involved signal transmission pathway.Differential proteins identified in our work could be specific biomarkers related to toxicity of organic Se to channel catfish.

Abstract:Crucian carp(Carassius auratus)is a main freshwater fish species and has been widely used as a raw material for food productions.The output of crucian carp reached 1 955 500 tons in 2009 in China,but a considerable number of them spoiled because of lacking good preservation.Therefore,it is necessary to develop an efficient method of preservation of fish.During the last decade,there has been a developing interest in edible or biodegradable films based on biopolymers,which can be used to cover the body of fish to prolong the shelf life of fish products.Fish scale is easier to obtain compared to other materials and is always abandoned.It is economical to make a kind of fishscale film obtained from fish scales by hydrolysis and the film itself can be antibacterial and antioxidant.There is a growing interest to identify antioxidative properties in many natural sources of polyphenolic compounds for food preservation,such as murta ecotypes extracts and borage extracts.Recently,as a source of antioxidant polyphenols and physiological benefits,there has been an increasing interest towards the commercial use of rosemary extracts as application for foods.The antioxidation and bacterinertness of rosemary extracts have already been verified by many reports.This paper aims to study the effects of fishscale protein hydrolysates with addition of rosemary extracts on quality changes of crucian carp during 4 ℃ storage.After being gutted and washed,the crucian carps were immersed in 4 ℃ fishscale protein hydrolysates solution and fish-scale protein hydrolysates with addition of rosemary extracts solution respectively for 1.5 min,and then packed in plastic trays after being drained.All the packed fishes were put into refrigerator maintained at 4 ℃.In order to investigate the quality changes of crucian carp during 4 ℃ storage,total bacterial counts,2-Thiobarbituric acid value,total volatile base nitrogen value,Kvalue,weight loss and sensory assessment were observed every two days.The results showed that:fishscale protein hydrolysates can significantly(P＜0.05)inhibit bacteria growth and restrain the increase of total volatile base nitrogen value,2-Thiobarbituric acid value,K value,sensory scores and weight loss for quite a long time(10 d)in contrast with the control and extent the shelf life of crucian carp during 4 ℃ storage for about 8 days; fish-scale protein hydrolysates with addition of rosemary extracts,however,can only restrain the increase of total volatile base nitrogen value,K value,weight loss and sensory scores for a short time(4-6 d)and failed to prolong the shelf life of crucian carp during 4 ℃ storage.

Abstract:The brown macroalga Sargassum naozhouense is a native species of Guangdong Province,which has edible value,medicinal value and prospect to be exploited into a new cultivation species.Based on reproductive biology study from July 2009 to June 2010 in Xuwen,Zhanjiang,the seasonal variation of biomass and mean thallus length of S.naozhouense were investigated.S.naozhouense is a pseudopermanent,dioecious species with dimorphism receptacles.The growth pattern of S.naozhouense may be divided into inactivity period(from August to October),growth period(from November to midApril of next year),reproductive period(from mid-April to early-June)and senescence period(from early-June to late-July).The propagation and maintenance of field population was mainly based on regeneration seedlings of rhizoids that occurred every month in a year round,and the seedlings produced by sexual reproduction accounted for a quite low proportion.Removing holdfast suggested reducing population,but the same species’ standing stock of the same area and same time increased markedly next year if it is harvested by cut method.The wild population is located on rock within 2 m depth,5-10 m width of intertidal zone.After the earlyNovember,thalli grew faster and faster and reached the largest length to early-May.Seasonal variations of length and biomass were very obvious and shared the same pattern.The highest biomass of a permanent quadrat is 1 280 g/m²,the length of the maximum single plant can achieve 1.73 m,and the weight of the maximum single plant can be up to 250 g.

Abstract:Gracilaria lemaneiformis (Bory)Webervan Bosse is an economically important red seaweed that is cultivated on a large scale in China due to the quantity and quality of agar in its cell walls.This alga is also considered an excellent species for alleviating coastal eutrophication,which has become ever more serious in China.To aim at such a function of bioremediation,in this study,the characteristics of inorganic phosphorus(Pi)uptake in G.lemaneiformis were investigated.Thalli were incubated in artificial seawater with f/2 enrichment and different Pi concentrations under different conditions of temperature(15,23,31 ℃),irradiance levels［0,30,200 μmol photons/(m²·s)］and nitrate concentrations(0,30,200 μmol/L),and the uptake dynamics of Pi were determined.The results showed that the uptake dynamic curve of Pi was always accordant with Michaelis-Menten equation under various conditions.The maximal uptake rate of Pi increased with the enhancements of temperature and nitrate concentration.However,the ratio of maximal uptake rate and halfsaturation constant(V_m/K_s),which represented the efficiency of Pi uptake,was the highest at the lowest temperature(15 ℃)and the level of nitrate concentration close to natural seawater(30 μmol/L).Both the maximal uptake rate and efficiency were higher at lower irradiance level［30 μmol photons/(m²·s)］than at higher level［200 μmol photons/(m²·s)］or dark［0 μmol photons/(m²·s)］.It is concluded that environmental factors such as temperature,irradiance level and nitrate concentration,could significanty affect the Pi uptake in G.lemaneiformis,and the mechanisms should be further studied in detail.

Abstract:To assess the effects of cooling water from power plant on eutrophication in Xiangshan Bay Harbor,a dynamic model for nitrogen and phosphorus transport and transformation in mesocosm was established,in which 7 state variables(DIN,PO^3-₄-P,DON,DOP,phytoplankton,zooplankton and detritus)were included.Logically it had 5 modules—phytoplankton,zooplankton,dissolved inorganic nutrients,dissolved organic nutrient s and detritus.Not only the results showed that this model could simulate the variations of nitrogen and phosphorus nutrients in the pelagic ecosystem in mesocosm properly,based on the experiment data from one temperature section in Xiangshan Bay in October 2010,but also the conclusion was drawn that the effect of temperature elevation on Nitrogen and Phosphorus Transport and Transformation from simulation of mesocosms that belong to three different temperature sections.The results show that the cooling waters increased eutrophication of the receiving water in Xiangshan Bay.

Abstract:Macroalgae covering on the rocky reef around coast of Gouqi Island were surveyed and sampled through diving during 2005 to 2006 and May to June 2010,in order to find out the distribution,constitution and life history of macroalgae.Two composing patterns of macroalgae were shown in the subtidal zone of rocky reef:one was dominated by standing macroalgae Sargassum horneri;another was dominated by smaller macroalgaes,such as Ulva pertusa,which is widely distributed both in intertidal and subtidal zone.The life history of S.horneri showed the four stages of the larger kelp bed:young seedling development period(August to September),slow growth period of seeding(October to February in next year),fast growth and reproduction period(March to May),decomposing and declining period(June to July).The smaller kelp bed exists the whole year,without much difference to outside of the kelp bed.To estimate the composition of fish assemblages in three habitats around Gouqi Island nearshore,i.e.rocky reef,sandy beach and mussel cultivation rafts,we sampled the fish assemblages in three habitats by combined gill nets every month from February 2009 to January 2010.The indexes of Jaccard similarity,Margalef richness and Shannon-wiener diversity were used to compare the variety of fish community structures among habitats,combined with statistical analysis of variance,UPGMA and nMDS.It showed that the differences of fish community structures among above three habitats were significant.The dominant fish species in rocky reef habitat were Sebastiscus marmoratus,Agrammus agrammus and N.albiflora. Fish community was mainly based on the demersal omnivorous rocky fishes,which prey mainly on benthic invertebrates living on macroalgaes.The dominant fish species in sandy beach habitat were Paraplagusia japonica and Nibea albiflora. Fish community was mainly based on the mid-lower migration fishes.For fish assemblages in mussel cultivation raft habitat,which were mainly bigger-size fishes, Mugil cephalusand Decapterus maruadsi were dominant species.The diversity of fish assemblages in rocky reef habitat was higher than that in the other two habitats,due to the relative complex habitat structure.The dominant fish species in both kinds of kelp beds were the same,i.e.S.marmoratus,A.agrammus and N.albiflora.But the structures of fish community were different,due to the species composition of macroalgae covering on rocky reefs.Fish communities in rocky reef habitat dominated by standing larger macroalgae were more stable than those in areas with smaller macroalgae,varied following the life history of S.horneri.The biomass of fishes showed a similar trend to the abundance.But the biomass and abundance of fishes in rocky reef habitat dominated by smaller macroalgaes were quite different.Fish assemblages in areas controlled by smaller macroalgae were affected greatly by the external migration fish assemblages.The species diversity based on abundance of the former was smaller than the latter,but the species diversity based on biomass of the former was larger than the latter.The abundance and biomass have a significant monthly variation in rocky reef habitat with smaller macroalgae.This can be due to the fish assemblages,in which fish species were with larger size,which migrated to rocky reef habitat from open sea area during February to May.Rocky areas covered by standing macroalgae provided a more diversified food selection for local dominant fish species.They possessed an attraction for partial group larvae and smallsize individuals.Meanwhile,they offered diversified food choices for upper class of fish,which contribute to the stability of fish community.

Abstract:The Japanese eel, Anguilla japonica, is one of the most important cultured species,widely distributed in rivers of the northeastern Asian countries’ Taiwan,China,Korea and Japan.The spawning grounds were recently discovered in the North Equatorial Current west of the Mariana Islands,15°N,140°E.From January to March 2008,there were 538 Japanese eel elvers collected from nine estuaries along Guangdong Province to Jiangsu Province which were measured on total length and long radius of sagitta otolith.Furthermore,observations were based on growth increments in sagittal otoliths of elvers collected at 9 sites.These results indicated that total length of elvers were 47.40 mm to 62.43 mm,the average value was(54.77±2.21) mm and the mean total length of each site was significantly different(ANOVA, P<0.001).As for long radius of sagitta otolith,it was from 133.22 μm to 175.95 μm,the average value was(154.55±9.09) μm and there was no significant difference among each site(ANOVA,P>0.05).Daily age of elvers ranged from 124 d to 158 d and the average value was(135.78±6.84) d,indicating that migration of eel larvae from their oceanic spawning ground to the estuary requires 4 to 5 months.An obvious trend of daily age was increasing from southern to northern areas and the maximum difference was 15.9 d.Elver hatching dates,backcalculated from estimated daily ages,indicated that the spawning season lasted 2 months(from Sep.6 to Oct.20),mainly concentrated in middle of October and approximately 85.98% samples accorded with New Moon Hypothesis.Finally,the inverse correlation between daily age and mean daily growth rates of fish length and otolith radius indicated that the time taken on migration from oceanic spawning ground to the estuary was shorter for fastgrowing larvae than fast-growing elvers which arrived at the estuary earlier than slowgrowing ones.

Abstract:Carrying out artificial breeding of Octopus tankahkeei is imperative,because of decline of fishery resources and the increasing of market demand.So far,the structure and function of the reproductive system of O.tankahkeei is lack systematic and in-depth understanding.In this study,the reproductive system of O.tankahkeei was observed using anatomical and histological methods,in order to enrich the content of its reproductive biology and provide a theoretical basis for breeding protection.The male reproductive system is composed of spermary,spermaduct,vesicular seminalis,prostate gland,blind sac,spermatophore sac and penis.The lobular type of spermary consists of spermary wall and parenchyma.The vesicular seminalis is classified into three parts artificially:the forepart of vesicular seminalis,the middle of vesicular seminalis and the rear of vesicular seminalis.The forepart of vesicular seminalis is connected with the spermaduct,and the rear of vesicular seminalis is connected with the prostate gland.The spermaduct doesn’t import vesicular seminalis directly,but moves side by side,and then the lumens merge gradually.The wall of the vesicular seminalis is very complex,with two lingulate processes fingering out into the cavity.From the middle of vesicular seminalis to the rear of vesicular seminalis,a lingulate process is getting bigger and bigger while the other one becomes smaller and smaller.A lot of glandular cells are located in the wall of vesicular seminalis and tonguelet.Spermatophore and colloid tail are both formed in the prostate gland,concentrated in the spermatophore sac,and are stored there.The female reproductive system is composed of ovary,oviduct and oviducal gland.Oviduct is long,opening at the funnel mouth.The structure of oviducal gland located on the oviduct is complicated,with a thelycum in it.The discovery of thelycum reveals the mechanism of fertilization which provides practical evidence for artificial breeding of O.tankahkeei.

Abstract:In this paper,the hybridization between Fugu rubripes and Fugu flavidus was carried out,and the early morphological characteristics and growth rate of hybrid progenies(F.flavidus ♀×F.rubripes ♂)were compared with the nonhybrids of the parents.The 5 cm length and 10 cmlength fingerling were collected for the comparison of morphological characteristics.The main differences are described as follows:(1) The color of tail fin which is light yellow in F.flavidus and black in F.rubripes’s,the hybrid is yellow with a little bit black,similar to F.flavidus.(2) The distribution of aculeus on the dorsum usually is not out of the lateral line,and never intersects with black spots even if it spreads in F.flavidus; in the case of F.rubripes,the aculeus spread over the lateral line and down to the abdomen,intersecting with the black spots; the acules in hybrid progenies were similar to those of F.rubripes,but did not spread to the abdomen.(3) The dorsal aculeus which extend to the line between two eyes in F.flavidus and to the line between two nostrils in F.rubripes,reach the place that between the eyes and nostrils in hybrid progenies.The discriminate function was established by two and four morphological variables at 5 cmlength and 10 cmlength respectively.The integrative identification is 96.8% and 100%.Thus,we could distinguish them by the color of tail fin and the distribution of aculeus in the stage of juvenile.After 110 days,the average body lengths of F.rubripes,the hybrid progeny and F.flavidus were(110.24±3.78) mm,(101.16±6.56) mm,and(82.92±4.29) mm,with the average body weights of(35.68±5.04) g,(33.00±6.24) g,and(20.99±3.00) g,respectively.The results revealed that the order of the three in both body length and weight is F.rubripes>hybrid progeny>F.flavidus,of which the hybrid progeny are 31.00%,57.22% higher than F.flavidus in the end of the experiment,There were significant differences between any two of them(P<0.01)based on analysis of variance and multiple comparison.The hybrid progeny exhibit significantly higher growth rate than that of F.flavidu and similar early morphology toF.rubripes, indicating a great deal of economic value and market potential.

Abstract:An 8-week feeding trial was conducted to estimate the effects of dietary arginine(Arg)and lysine(Lys)on growth and non-specific immune responses of juvenile darkbarbel catfish.Nine diets(42% crude protein and 10% crude lipid)were formulated to contain three Arg levels(2.41%,4.86% and 6.81% of dietary protein),and each with three Lys levels(1.95%,5.84% and 8.27% of dietary protein).Each diet was randomly fed to triplicate groups of darkbarbel catfish［initial body weight:(2.12±0.01) g］to apparent satiation and each group was stocked with 30 fish.At the termination of the feeding trial,growth and nonspecific immune parameters were monitored.The results showed dietary arginine and lysine had significant effects on the specific growth rate(SGR)and the respiratory burst activity of head kidney macrophages of juvenile darkbarbel catfish(P<0.05).The appropriate content of diet arginine/lysine was 6.81/5.84 dietary protein based on the growth,but the respiratory burst activity of headkidney macrophages was the highest when arginine/lysine was 4.86/8.27 dietary protein.Dietary Arg had significant effects on the serum nitricoxide synthase(NOS)activity of juvenile darkbarbel catfish(P<0.05).The activity of NOS was higher in fish fed appropriate or high Arg levels than low Ary levels.No significant differences were found in the serum arginase(ARG)and catalase(CAT)(P>0.05)among dietary treatments.In the present study,significant interactions of dietary arginine and lysine were found on growth of juvenile darkbarbel catfish,but not on the body composition,hepatosomatic index(HSI),and serum NOS,ARG and CAT activity.

Abstract:Experiments were conducted to study the effects of dietary zinc supplementation on the immune gene expression and immunity and disease-resistant ability of white shrimp(Litopenaeus vannamei).The shrimp were fed with 3 zinc methionine diets(supplemented at 0,50,150 mg Zn/kg diet respectively)respectively for 14 days.Then the expressions of Toll Receptor mRNA and lysozyme mRNA in gill and superoxide dismutase(SOD)activity and lysozyme(LSZ)activity in hepatopancreas,muscle and haemolymph were assayed respectively.The shrimp treated with different zinc diets were also challenged with Vibrio alginolyticus.The results showed that the zinc levels in hepatopancreas and muscle of shrimp significantly increased(P<0.05)as the dietary zinc increased.While the hepatopancreas accumulated more zinc than muscle.Compared to those of the shrimp in 0 mg Zn/kg and 150 mg Zn/kg treatments,the expressions of Toll receptor mRNA and lysozyme mRNA in gill of the shrimp in 50 mg Zn/kg treatment were significantly up-regulated.The lysozyme activities in muscle,hepatopancreas and haemolymph of the shrimp in 50 mg Zn/kg treatment were significantly higher than those in 0 mg Zn/kg treatment(P<0.05).The SOD activities in hepatopancreas and haemolymph of the shrimp in 50 mg Zn/kg and 150 mg Zn/kg treatments were also higher than those in 0 mg Zn/kg treatments(P<0.05).While the SOD activity in muscle of the shrimp treated with 150 mg Zn/kg was significantly higher than those treated with 0 mg Zn/kg and 50 mg Zn/kg respectively.The half lethal time and complete lethal time for the shrimp in 50 mg Zn/kg treatment were longer than those in 0 mg Zn/kg and 150 mg Zn/kg treatments after being challenged with V.alginolyticus.It is therefore suggested that compared to those in 0 mg Zn/kg and 150 mg Zn/kg treatments,the shrimp fed the diets added 50 mg Zn/kg(the content of zinc in diet was 73.25 mg Zn/kg)had improved immunity and Vibrio resistant ability.

Abstract:Compensatory,or catch-up,growth is a period of unusually fast growth that follows a period of reduced growth resulting from restricted food availability,or some other unfavorable environmental conditions,including low temperatures,hypoxic conditions,density alternation,etc..The compensatory phenomenon has been found in a wide range of aquatic animals including fish.For some fish species,the magnitude and duration of compensatory growth depended on the length of food deprivation.In the wild,fish often suffer starvation because of unstable food supply.And the underlying physiological mechanism for increased growth potential during compensatory growth is still inconsistent and poorly understood.In the present study,the juvenile tongue sole(Cynoglossus semilaevis),an important cultured fish in China,was selected to research the effects of repetitive periods of fasting and satiation feeding on the growth,body composition,metabolism and energy budget.There were five groups:the control fed ad libitum throughout the experiment(C),and other four groups which were subjected to repetitive periods of fasting and satiation feeding(2∶4,4∶8,8∶16 and 12∶24 days for group S2F4,S4F8,S8F16 and S12F24).Feces and uneaten food were collected twice a day by pipetting during the experiment.All samples were measured at the end of the experiment.The specific growth(SGR including SGR_w,in terms of weight,and SGR_e,in terms of energy)in group C were significantly higher than those in other groups(P<0.05).There was no significant difference in body weight between S2F4 and C fish(P>0.05),and both of them were significantly higher than those in other groups.The apparent digestion rate in C fish was significantly lower than those in other three groups(P<0.05).The energy digestion rate in C fish was not significantly different from that in S12F24 fish(P>0.05),but was significantly lower than those in the other three groups(P<0.05).The food conversion efficiency in S4F8 fish was significantly lower than that in S12F24 fish(P<0.05).The feeding rate in C fish was the lowest(P<0.05).The protein content in fish decreased with increasing starvation period.There was no significant difference in protein content between S2F4 and C fish(P>0.05).The oxygen consumption and ammonia excretion were lower in S2F4 fish than those in other groups.The food energy of the control group was the highest(P<0.05).The food energy assimilated to metabolism in S2F4 fish was higher than that in C fish(P<0.05).The data indicated that the juvenile tongue sole of S2F4 showed complete compensatory growth.The complete compensatory growth in juvenile tongue sole could be attributed to hyperphagia and an improved digestion rate.During the repetitive periods of fasting and satiation feeding,the protein content in juvenile tongue sole was significantly affected.The results provided useful evidence to understand the feeding biology of tongue sole,and were conducive to the best management in largescale aquaculture,especially indoor intensive culture.

Abstract:Muscles components of Hypophthalmichthys molitrix and Aristichthys mobilis in Jinshahe Reservoir and Taoyuanhe Reservoir were analyzed and compared by the national standard(GB)test method according to FAO and WHO evaluation criteria.The results showed that crude protein(P<0.05)and crude ash(P>0.05)contents in Jinshahe Reservoir were higher than those in Taoyuanhe Reservoir.The crude fat content of A.mobilis in Jinshahe Reservoir was significantly higher than that in Taoyuanhe Reservoir(P<0.05).Amino acid composition of H.molitrix and A.mobilis in two reservoirs were identical in category hut different in content.The contents of total amino acids and flavor amino acid of H.molitrix in Jinshahe Reservoir were significantly higher than that in Taoyuanhe Reservoir(P<0.05),and not significant among other amino acids.EAAI of H.molitrix and A.mobilis in Jinshahe Reservior were both higher than that in Taoyuanhe Reservior.By evaluation of these indicators,we know that muscle quality of H.molitrix and A.mobilis in Jinshahe Reservoir is both better than that in Taoyuanhe Reservoir.