Abstract:Transcription of turbot Mx protein confirmed to be an antivirus factor was induced by PolyI∶C with intraperitoneal injection, immersion and oral administration. Mx mRNA was tested by semi-quantitative RT-PCR to validate the effect of PolyI∶C’s induction. The results illustrated that all the three induction ways could effectively induce the transcription of Mx gene and the peak of Mx mRNA quantity appeared at 48h after PolyI∶C application. The immersion method seemed to be the most effective way to induce Mx mRNA, as Mx mRNA could last more than 120 h at a high level. This experiment proved that the homemade PolyI∶C could effectively induce Mx mRNA transcription in different applications, which provided a reference to use PolyI∶C in aquaculture practice.

Abstract:Ovary histology of anchovy Engraulis japonicus in the Yellow Sea was studied using macroscopic and microscopic observation with olefin slices. Macroscopic characteristics of the ovary at different development stages were described; oocyte development phase composition, oocyte size distribution and the developmental differences between the two lobes of the ovary and that among the anterior, middle and posterior part of each lobe were statistically analyzed. The results showed that oocytes of different development phases were present simultaneously in the same ovary. Stage Ⅱ ovary is comprised of phase 1-3 oocytes, with phase 2 oocytes being the dominant in number (66.3%). Stage Ⅲ, stage Ⅳ and stage Ⅵ ovaries were comprised of phase 1-4 oocytes; the distinction among the ovaries at these three stages lied in the number percentage of phase 4 oocytes, which was the highest in stage Ⅳ (34.8%), second in stage Ⅲ (28.6%) and the lowest in stage Ⅵ (17.8%) ovary. Stage Ⅴ ovary was comprised of phase 1-5 oocytes, of which the quantity of mature phase 5 oocytes was the highest (29.8%). During the ovary development from stage Ⅲ to Ⅴ, it was mainly the phase 3-4 oocytes that developing towards phase 4-5, while the percentages of phase 1 and 2 oocytes remained roughly unchanged. The oocyte size distributions were characterized by distinct crests and troughs, which was contrary to the previous “shallow saw like distribution” understanding of the issue. The size (major axis) of the oocytes in stage Ⅲ and Ⅵ ovaries was of unimodal distribution, with a mode at 0.5-0.6 mm class for both stages. The oocyte size distribution was of bimodal for stage Ⅳ and Ⅴ ovaries, with the two modes at 0.2-0.3 mm and 0.7-0.8 mm, 0.5-0.6 mm and 1.1-1.2 mm, respectively. The two dominant size groups of oocytes in the stage Ⅴ ovary were well separated with a clear hiatus, and the oocytes in the larger size group were all hydrated, which were in accordance with the characteristics of batch spawners. The two lobes of the ovary were significantly different in size, with the right one being the smaller. The mean of the right/left lobe weight ratio was 0.71, with a 95% confidence interval of (0.67, 0.75). Statistical test showed that the development status of the oocytes was not significantly different (P>0.05) either within or between the two lobes.

Abstract:Muscle of cultured starry flounder Platichthys stellatus were analyzed for the content of protein, lipids, ash, amino acid, fatty acid, and other biochemical components. The results showed that starry flounder is a kind of fish with high protein and low lipid contents. And the total amino acid content was of medium level. However, the essential amino acid contents were of high level. The ratio of branched-chain and aromatic amino acids was 2.33 for juvenile starry flounder. Oleic acid (18∶1n) content was the highest of all fatty acids, and the contents of linoleic acid (18∶2n6) and palmitic acid (16∶0) were lower than oleic but higher than the other fatty acids. The fish was also rich in the EPA (20∶5n3) and DHA (22∶6n3), and had enriched and balanced nutrients, indicating that it is an excellent candidate for farming and is a nutritious seafood.

Abstract:The temporal dynamics of oocyte growth and ovary development were examined during a 12-month ovarian maturation cycle in captive Cynoglossus semilaevis Günther using light microscopy method. Results showed that the oocyte growth could be divided into 6 phases and ovary development consisted of 6 periods accordingly. Two or three distinct batches of vitellogenic oocytes were found in Cynoglossus semilaevis Günther ovaries at one development stage, indicating that this species are a non-synchronized multiple batch spawners. The ovaries are in stage I when the fish are less than 6 month old, which only appears once in their whole life．As fish grew, the ovaries enter into stage Ⅱ when they are 9 to 12 months old. The stage Ⅲ which were characterized by cortical alveoli accumulation was attained when the fish were 12-month old and maintained until 24-month old. Deposition of lipids and vitellogenesis began to happen in ovaries of stage Ⅳ when the fish were over 3 years old. The ovaries could be matured (stage Ⅴ) under artificial photothermal control from May to August and fish spawned between September and November. Hydration observed in oocytes indicates that the fish were completely matured for ovulation. After spawning period, the ovaries retrogressed to stage Ⅲ via stage Ⅵ, then continued regressing to stage Ⅱ and was maintained until the next reproductive season. Gonadosomatic index (GSI), hepatosomatic index (HSI) and condition factor (CF) were all found to increase prior to, or during the peak phase of vitellogenic growth corresponding to the gonad development, which are important indices for evaluating the reproductive condition of the parental fish. Cynoglossus semilaevis Günther appear to strategically utilize episodes of high feeding activity to accrue energy reserves early in the reproductive cycle prior to its deployment during periods of rapid ovarian growth. In the developing ovaries (mainly after stage Ⅳ), some post-vitellogenic follicles failed to undergo final maturation, resulting in widespread preovulatory atresia, which may depress the fecundity or be an indicator of capacity of multiple spawns.

Abstract:The distribution of the chyme in the digestive tract of flounder Paralichthys olivaceus was studied by adding green fluorescent protein (GFP) to the bait. The protease activity in the mucus of different part of the digestive tract was studied by the Folin-phenol reagent method post ingestion. The results showed that the protease activity changed with chyme distribution in the digestive tract after feedion. The chyme reached the midgut 1 h after ingestion, and the protease activity of stomach and midgut increased rapidly. The chyme was distributed in the whole digestive tract 5 h after ingestion, and the stomachic protease activity reduced to near null.The protease activity in the midgut kept at the highest level until 8 h.The protease activity in the hindgut kept at the high level until 12 h after feeding. The results showed that the intestines might be more significant in protein digestion than the stomach for the fish with short digestive tract. 

Abstract:The pharmacokinetics, tissue metabolism and elimination of sulfamethoxazole (SMZ) was investigated in turbot Scophthalmus maximus following a single oral dose of 100mg/kg at (11±1)℃. Plasma and tissue concentration of SMZ was determined by HPLC. The concentration-time curves of SMZ in the muscle, liver and plasma fitted well to a one-compartment open model with first-order absorption. After the oral administration, the time to reach maximum SMZ concentration in the muscle, liver and plasma was 11.89 h, 10.53 h and 4.87 h, and the maximum concentration of SMZ was 21.52 mg/kg, 5.35 mg/kg and 44.07 mg/kg, respectively. 5 d, 6 d and 72 h after the administration, the SMZ content in the muscle, liver and plasma were less than the MRL (0.1 mg/kg); and it was undetectable at 18d, 24d and 10d in these tissues, respectively.

Abstract:Portunus trituberculatus is one of the most important fishery resources in China because of its high commercial value. In recent years, it has suffered from overfishing and various diseases, and the total resource of wild populations has decreased year by year. Considering for this situation, it is necessary to study the genetic diversity and genetic linkage map of P. trituberculatus. In this study, maternal broodstock and paternal broodstock were sampled from Laizhou Bay and Zhoushan Island wild population, respectively. Through directional mating (1♂×3♀), they generated F1 family. 63 individuals of F2 family came from sisterhood intercross between F1 family and these broodstock were used as experiment materials. The AFLP analyses showed that a total of 1 742 loci were produced,of which 417 loci were polymorphic, accounting for 23.9%. In these polymorphic loci, there were 226 (accounting for 54.2% of total segregating loci) loci segregating as 1∶1 Mendelian model while 31 (7.4%) loci segregating as distorted model.128 loci (30.7%) segregated as 3∶1 model and the numbers of 32 (7.7%) loci were distortion bands. Additionally, several AFLP bands which segregated neither as 1∶1 nor as 3∶1 were named with odd segregating loci. They were treated as non-segregating loci in order to reduce the influence of statistical error. Genetic diversity index of the F2 was 0.130, and Shannon genetic diversity index was 0.193. Analysis of distances showed that Nei’s genetic distance of family with male parent and female parent were between 0.064~0.111, 0.065~0.107 respectively. In the mean time, No63 individual was most distant from its male parent and No48 individual was most distant from its female parent. The main purpose of the study was to provide the technical support for genetic diversity analysis of wild populations or families and construction of high density genetic linkage map of P. trituberculatus.

Abstract:The optical density (OD) was measured by Enzyme-Linked Immunosorbent Assay (ELISA) with the combination of different dilutions of white spot syndrome virus (WSSV) and monoclonal antibodies (MAbs) specific to WSSV envelope protein. As the model animal, crayfishes Cambarus proclarkii were intramuscular injected of 50μl WSSV at different dilutions pre-incubated with MAbs, then their cumulative mortalities were recorded. Results of ELISA showed that both MAb1D6 (VP28) and MAb2E9 (VP19) were sufficient at 1×10-3 virus dilution. In vivo neutralization assay showed mortalities in the MAb1D6 (VP28) group were 100%, 90%, 167% and 6.7%, at a dilution of 1×10-3, 1×10-4, 1×10-5 and 1×10-6, respectively; while mortalities in the MAb2E9 (VP19) group were 100%, 100%, 100% and 93.3%, respectively. These results demonstrated that the neutralization effect of MAb1D6 was concentration dependent. MAb2E9 has no obvious neutralization effect.

Abstract:A feeding trial was carried out to evaluate the effects of dietary fatty acids on growth and proximate composition of juvenile sea cucumber Apostichopus japonicus. Juvenile sea cucumber weighing 1.45g in body weight was stocked into 42 plastic tanks of each 45 cm×31 cm×30 cm for 80 days and fed the commercial 12.70% crude protein and 5.48% crude fat diets containing various proportions of olive oil, linoleic acid (LA), linolenic acid (LNA), docosahexaenic acid (DHA), and eicosapentaenic acid (EPA) with a ratio of LA to LNA=20∶0 （S1）；20∶1（S2）；1∶2（S3）and 2∶1（S4）and with LA∶LNA∶DHA∶EPA=6∶1∶5∶0（S5）；10∶1∶30∶5（S6）and 10∶5∶6∶1（S7）at water temperature of 13.0~23.0 ℃. The sea cucumber fed the diets containing supplement of only olive oil (S1), both olive oil and LNA (S2) and LA and LNA (S3) was found to have the minimal special growth rate (SGR), significantly lower than the animals fed other diets(P < 0.05). There were significantly lower visceral-somatic ratio, and higher intestinal amylase and protease activities, and higher apparent digestibility in the juveniles fed the diet with a ratio of LA∶LNA∶DHA∶EPA= 10∶5∶6∶1（S7）(P < 0.05). Much higher total levels (85.79%) of protein, fat and ash were observed in the juveniles fed the experimental diets than in the initial juveniles(7970%), descendantly ranged as S2（90.57%）> S1（87.97%）> S3（85.78%）> S4（85.29%） > S7（84.19%） > S5（83.79%）> S6（82.97%）.While there was degrowth in LA+LNA levels in the juveniles fed the experimental diets, there was increase in EPA level, varying from 4.36%to 6.83% in the juveniles fed the experimental diets without supplementation of EPA, indicating that dietary 18-C fatty acids were to some extent converted into EPA in the juveniles. The catalase activity was significantly higher in groups S4, S5, S6 and S7 than that in other groups in the juveniles (P < 0.05). High catalase activity appeared in the sea cucumber juveniles when they grew fast, and superoxide dismutase had no apparent variations under different conditions.

Abstract:Residues and withdrawal periods of oxytetracycline (OTC) was evaluated by HPLC in globefish Fugu rubripes following multi-oral administration of 100 mg/kg weight body per day for 5 days at 14±2℃. The result showed that the highest concentrations of OTC in blood and muscle were found in 2 days after the last administration, which were 1.092μg/ml and 0.806μg/g, respectively. While the highest level found in liver was 1.229μg/g, 3 days post-administration. It was revealed that the elimination half lives of OTC in blood, muscle and liver were 23.8, 22.4 and 26.8 days respectively, indicating that the elimination rate of OTC in globefish was very low. OTC concentrations in the muscle of globefish fell below the 0.1μg/g and 0.05μg/g residue limits at day 58 and day 81 post-administration, respectively.

Abstract:Twenty-three morphological parameters were analyzed using ANOVA, cluster analysis and discriminant analysis to study the morphological variations between Clupea pallasii and Clupea harengus. ANOVA results showed that there were extremely significant differences (P<0.001) in the means of 14 morphological parameters, greater variance between populations than within populations. Cluster analysis suggested that all of the 82 samples were divided into two clusters. Discriminant analysis based on 23 parameters showed that there were extremely significant differences between the two species (P<0.001); discriminant analysis with 11 selected parameters gave a discriminant formula with accuracy of 100%. However, the coefficients of difference of 23 parameters suggested that the differentiations between the two species were still under the level of different geographic populations within species according to Mayr’s 75% Rule. We postulated that the small scale divergence in morphology between the two species might be caused by a recent separation and similar ecology environment.

Abstract:The distribution and composition of dissolved nutrients in Zhangzi Island maricultural areas were discussed based on the data collected in March,May,July and October,2005．The results showed that because of large current velocity,the horizontal distribution of nitrogen and phosphorous were symmetrical and there were no obvious stratification between surface and bottom water(except in July).The nutrient level of DIN and PO3-4 in the surveyed areas belong to oligothrophic state.Nutrient limitations were assessed according to the ratio of Nitrogen/Phosphorus(N/P) and the concentration threshold,results showed that the limiting nutrients may change with seasons.There was high potential for phosphorous limitation of the photosynthesis of phytoplankton in July and nitrogen limitation in March and May.Though this survey revealed that there was little effect or impact of mariculture on the environment,the nutrients structure had change somewhat.For example, in March, May and July, DIN were the major component of ammonia the bottom water,and the relatively low concentrations of chlorophyll usually found at the extensive bottom culture areas may all reflect the activity of mariculture,which needs further study in the future.

Abstract:Cryopreservation of tongue sole Cynoglossus semilaevis sperm offers benefits for artificial propagation, hybridization, gynogenesis and sex control.In order to develop a protocol to freeze tongue sole sperm,the effects of cryoprotectants, extenders and dilution ratio on motility,fertilization rate and hatching rate of frozen-thawed sperm were evaluated. Dimethylsulfoxide(DMSO)provided higher protection than glycerol and 1,2 propylene glycol during freezing and thawing.Motion time and life of sperm in A(MPRS +28 mol/L DMSO)and B(TS-2+2.8 mol/L DMSO)before freezing were 37.75±6.45 sec and 145.00±78.98 sec,which was not different from that of fresh sperm(P>0.05).The motility and life of frozen thawed sperm in A were 5350±669% and 98.00±13.51 sec,which was significantly higher than that of frozen thawed sperm in B.When sperm were diluted with A at a ratio of 1∶05,1∶1,1∶15 and 1∶2, the highest motility(82.5±3.54%, 1∶1 dilution ratio)of frozen-thawed sperm was obtained and which was significantly higher than that of other dilution ratio treatment.According to the results above, tongue sole sperm were cryopreserved successfully with MPRS+2.8 mol/L DMSO at a dilution ratio of 1∶1.As a result,the fertilization rate(55.0±5.0%) and hatching rate(35±13.23%) of frozen-thawed sperm were obtained,which was not significantly different from that of fresh sperm(P>0.05).

Abstract:A pathogenic bacterium(WT01)was isolated from diseased clam Meretrix meretrix Linnaeu,and was confirmed to be the pathogen of the epidemic by artificial infection experiment.The morphological,physiological and biochemical characteristics and 16S rRNA sequence were analyzed for this bacterium,and the relationship between reproduction of the bacterium and NaCl concentrations,pH and temperature were also determined.The results showed that the strain was gram negative,glucose fermented without gas production,oxidase positive,requiring sodium ions for growth,no pigment,non luminescence; It grew well on TCBS plate as yellow colonies and was sensitive to Vibrio inhibitor O/129.Therefore,it was confirmed that the strain belonged to the genus of Vibrio. The sequence analysis of 16S rRNA gene of WT01 and comparison with that of other related Vibrios showed that WT01 was very close to Vibrio natriegen,with a similarity of 99％.In conclusion,strain WT01 belonged to Vibrio natriege ,and the LD50 of the bacterium to M.meretrix was 5.5×106CFU/g(tested by Reed-Muench method).The sensitive test showed that the pathogen was sensitive to drugs such as norfloxacin(NOR), bactrim(SXT),ceftriaxone(CRO), cefobid(CFP),streptomycin(STR), chloromycetin(CMP) and cidomycin(GEN).Biochemical analysis was also done for its extracellular products.

Abstract:RAPD analysis of genetic diversity of Patinopecten yessoensis with different shell colours

Abstract:Based on the beam trawl surveys in Yellow River estuary which were conducted in May and July, 2007, benthic fisheries resources in this area were analyzed and calculated using species richness R, Shannon-Wiener diversity index H′, evenness index J ′ and biology index b, respectively. In our study, the average catch biomass per net was 0.927 and 2.12 kg/h, R, H′ and J′ were 12.08, 2.277, 0.64 and 10.91, 2.743, 0.76 in spring and summer, respectively. The results showed that the benthic biological resources were richer in summer than in spring, and the diversity indices of the community were also higher in summer. Moreover, dominant species were Nassarius variciferus, Chaeturichthys hexanema, and Oratosquilla oratoria etc. The data provided a scientific basis for protection of fishery biology diversities and resources restoration in Yellow River estuary.

Abstract:Based on the data of four seasons fishery resources investigations in the continental shelf of northern South China Sea from 2006 to 2007, the composition and distribution of Squilla species were analyzed. The results showed there were 15 species belonging to 4 families and 7 genuses in the area. Based on their adaptability habitats, all species of Squilla were categorized into three ecological groups: tropical group, tropical semitropical group and eurythermic group, and most of them belonged to tropical semitropical group. The dominant species were Oratosquilla oratoria, O. kempi，Harpiosquilla harpax，O. nepa and H. raphideaccording to Pinkas IRI deternination. These species belonged to Squillidae and Harpiosquillidae, and their catch rate (1.86 kg/h) was around 98.17% of total catch rate (1.90 kg/h). The economic Squilla species were O. oratoria, O. kempi, H. harpax, O. nepa and O. ornata, which also belonged to Squillidae and Harpiosquillidae, and their catch rate (1.84 kg/h) was around 96.85% of total catch rate (1.90 kg/h). The average biomass of Squilla species was 42.18 kg/km2, while the average biomass of economic Squilla was 40.85 kg/km2.The temporal distributions of Squilla showed a highest biomass in transect B (76.27 kg/km2)and a lowest biomass in transect A (25.13 kg/km2); while the seasonal distribution of Squilla biomass showed a highest value in the autumn (49.24 kg/km2) and a lowest value in the winter (32.29 kg/km2). The distribution trends of Squilla biomass showed an approximately negative correlation with water depths, and they were mostly found at depths of 10~40 m and the highest value (173.40 kg/km2)was found at a depth of around 10 m; all species of Squilla belonged to economic species in the water area at about 10 m depth.

Abstract:The quantity of fouling organism on scallop shell and the effects of the mass of artificial fouling on growth and survival of C.farreri was studied.Sixty scallops were randomly sampled from September to November, 2007, at monthly intervals.Artificial fouling (cement) weighing 0.5, 1, 2 and 3 times the mass of the upper valve were fixed to the upper valve of C.farreri Scallops with no artificial fouling served as the controls.Survival and specific growth rate (SGR) of shell length,dry mass of muscle and remaining soft tissue were examined after 60 d longline cultivation in Sanggou Bay.From September to November,the amount of shell fouling decreased from 1.47 g to 0.49 g,and again increased to 2.09 g in November.There were no significant differences in growth parameters and survival between the treatment and control groups,indicating that artificial fouling did not detrimentally affects the growth and survival of C.farreri. In Sanggou Bay, even in summer season when the natural fouling was heaviest,the mass that developed on scallop shells was much lower than the experimental levels. Thus, it is unlikely that the mass of natural occurred fouling organisms on the shell would negatively affect the growth and survival of C.farreri.

Abstract:By taking the monitoring data of Xiangshan Bay from the year of 2000 to 2006 as the training data and referring to the prior knowledge, a Bayesian network was constructed through the incremental learning based on the immune heredity algorithm. The model can effectively express the causal relationship among the various indicators in the net-cage aquaculture environment, and the shift cycle of the net-cage aquaculture at Xiangshan can be predicted. The result showed that the appraisal accuracy reached 91.7%, which meant that this method is feasible.

Abstract:By means of the common rotation composite design of quadratic regression, four mathematical models were established to analyze the impact of light intensity (x1), temperature (x2) and salinity (x3) on cell division rate (k) of each microalgal species seperated from shrimp ponds in mixed culture. The suitable conditions for the microalgae growth and the weightiness of each factor to the cell division rate were obtained. The suitable light intensity for Cryptomonas erosa ranged from 5 750 lx to 7 944 lx, the suitable temperatures ranged from 21.3 ℃ to 28.3 ℃ and the suitable salinity ranged from 13.3 to 23.0. The weightiness of the impact of each factor on cell division rate was x3>x2>x1. The suitable light intensity for Nitzschia closterium ranged from 5 761 lx to 8 697 lx, the suitable temperatures ranged from 23.4 ℃ to 29.6 ℃ and the suitable salinity ranged from 11.9 to 25.7. The weightiness of the impact of each factor on cell division rate was x3>x1>x2. The suitable light intensity for Nannochloropsis oculata ranged from 6754lx to 8775lx, the suitable temperatures ranged from 17.1 ℃ to 20.7 ℃ and the suitable salinity ranged from 19.6 to 26.4. The weightiness of the impact of each factor on cell division rate was x2>x3>x1.The suitable light intensity conditions for Chlorella pyrenoidosa ranged from 7 128 lx to 9 012 lx, the suitable temperatures ranged from 18.7 ℃ to 26.7 ℃ and the suitable salinity ranged from 17.9 to 24.3. The weightiness of the impact of each factor on cell division rate was x1>x2>x3. The k of Cryptomonas erosa and Nitzschia closterium was significantly affected by salinity acting synergistically with light intensity and temperature.