Biodiversity of Free-Living Marine Nematodes in the Southern Yellow Sea, China 免费阅读 下载全文 Biodiversity patterns of free-living marine nematodes were studied using specific,taxonomic and phylogenetic diversity measures in the southern Yellow Sea,China.The results showed that the average of Shannon-Wiener diversity index(H′) in the study area was 3.17.The higher values were distributed in the east part of Shandong coastal waters and north part of Jiangsu coastal waters,while the lower values were distributed in the southern Yellow Sea Cold Water Mass(YSCWM).The average of taxonomic diversity(Δ) was 62.09 in the study region.The higher values were distributed in the transitional areas between the coastal areas and the southern YSCWM,while the lower values were distributed near the north part of Jiangsu coastal waters and the YSCWM.Results of correlation analysis of species diversity and taxonomic diversity showed that some of the two kinds of diversity index were independent,which suggested that combining the two kinds of diversity indices can reflect the ecological characteristics better.A test for 95% probability funnels of average taxonomic distinctness and variation in taxonomic distinctness suggested that Station 8794(in the YSCWM) was outside of the 95% probability funnels,which may be due to the environmental stress.Results of correlation analysis between marine nematodes biodiversity and environmental variables showed that the sediment characteristics(Md? and Silt-clay fraction) and phaeophorbide a(Pha-a) were the most important factors to determine the biodiversity patterns of marine nematodes.
Two New Free-Living Marine Nematode Species of the Genus Anoplostoma （Anoplostomatidae） from the Mangrove Habitats of Xiamen Bay, East China Sea 免费阅读 下载全文 Two new species of free-living marine nematode from mangrove habitats in Xiamen Bay are identified.Anoplostoma tumidum sp.nov.is characterized by relatively short outer labial setae(0.86–1.00 h.d.),long tail(c 7.2–8.9,c’ 8.3–10.5),an instinct swollen distal portion of slender spicule(Sc 94–101 μm),and well developed copulatory bursae without bursal papillae.A.tumidum sp.nov.differs from all valid species of genus Anoplostoma in copulatory apparatus of males with a distinct swollen distal portion of spicule,and a relatively obvious constriction of head.A.paraviviparum sp.nov.is characterized by relatively long outer labial setae(1.11–1.22 h.d.),and tail(c 6.6–8.5,c’ 8.6–10.2);elongated spicules with distinct knob-like proximal and pointed distal ends(Sc 46–69 μm);distinct strip-like gubernaculum(length with 11–15μm);well developed copulatory bursae with precloacal papillae and post-cloacal papillae;and a distinct constriction of head.A.paraviviparum sp.nov.is similar to A.viviparum Bastian,1865,but differs in the reproductive mode of female and the constriction of head.
Meiofauna Distribution in Intertidal Sandy Beaches Along China Shoreline （18°-40°N） 免费阅读 下载全文
A New Species ofParodontophora （Nematoda： Axonolaimidae） from the Intertidal Zone of the East China Sea 免费阅读 下载全文 This study described a new species of free-living nematode discovered in the intertidal mudflat of Ximen Island,East China Sea.The new species,designated Parodontophora longiamphidata sp.nov.,was characterized by a cylindrical body with tapering extremeties;cuticle smooth without somatic setae;four short cephalic setae;cylindrical buccal cavity with six clawlike teeth at the top of stoma;pharynx cylindrical with widened base;amphidial fovea crook-shaped with elongated scalariform branch extending past level of base of pharynx and ventral gland;ventral gland cell long-oval shaped located posterior to pharyngo-intestinal junction;excretory pore at level of middle of buccal cavity;tail conico-cylindrical with enlarged tip;three caudal gland cells,male spicules arched with cephalic proximal end and tapered distal end;gubernaculum with dorso-caudal apophysis;female with two opposed outstretched ovaries;and vulva at slightly post-midpoint of body length.This new species was close to P.wuleidaowanensis Zhang,2005 and P.polita Gerlach,1955 in terms of long amphidial fovea branch.The newly found species was easily distinguishable from the two documented;its amphidial fovea branch(255–290 μm versus 72–106 and 125–150 μm) was obviously longer.Key to the Parodontophora species with a longer amphidial fovea branch was given.
Nematode Community Structure and Diversity Pattern in Sandy Beaches of Qingdao, China 免费阅读 下载全文 We investigated the diversity and structure of free-living marine nematode communities at three sandy beaches representing typical intertidal environments of a temperate zone in Qingdao,Shandong Province,China.Average nematode abundance ranged from 1006 to 2170 ind.10 cm-2,and a total of 34 nematode genera were recorded,of which only 8 were common in all the studied beaches.Pielou’s evenness and Shannon-Wiener diversity index were the lowest at the second beach where nematode abundance was the highest.The highest species diversity index coincided with the lowest nematode abundance at Shilaoren beach.Sediment median grain size,sorting coefficient,and chlorophyll-a content were essential for differentiation in nematode abundance and species diversity,whereas taxonomic diversity of nematode was homogeneous across the three beaches.In 0–20 cm sediment profile,nematode abundance declined abruptly with depth,whereas nematode diversity changed gently with obvious difference in 16–20 cm layer.Sediment granulometry and chlorophyll-a content were the two foremost factors which influenced the vertical distribution pattern of nematode generic diversity.Non-selective deposit feeders constituted the most dominant trophic group,followed by epistratum feeders.Bathylaimus(family:Tripyloididae) dominated at the second and Yangkou beach,while Theristus(family:Xyalidae) prevailed at Shilaoren beach.Omnivores and predators became important at Shilaoren beach because of the high proportion of Enoplolaimus.Even though,nematode community of the studied beaches did not differ significantly from each other.
The Influence of Wave State and Sea Spray on Drag Coefficient from Low to High Wind Speeds 免费阅读 下载全文 Ocean waves alter the roughness of sea surface,and sea spray droplets redistribute the momentum flux at the air-sea interface.Hence,both wave state and sea spray influence sea surface drag coefficient.Based on the new sea spray generation function which depends on sea surface wave,a wave-dependent sea spray stress is obtained.According to the relationship between sea spray stress and the total wind stress on the sea surface,a new formula of drag coefficient at high wind speed is acquired.With the analysis of the new drag coefficient,it is shown that the drag coefficient reduces at high wind speed,indicating that the sea spray droplets can limit the increase of drag coefficient.However,the value of high wind speed corresponding to the initial reduced drag coefficient is not fixed,and it depends on the wave state,which means the influence of wave cannot be ignored.Comparisons between the theoretical and measured sea surface drag coefficients in field and laboratory show that under different wave ages,the theoretical result of drag coefficient could include the measured data,and it means that the new drag coefficient can be used properly from low to high wind speeds under any wave state condition.
Winter Meso-Scale Shear Front in the Yellow Sea and Its Sedimentary Effects 免费阅读 下载全文 In this paper,the authors explored the presence of shear fronts between the Yellow Sea Coastal Current(YSCC) and the monsoon-strengthened Yellow Sea Warm Current(YSWC) in winter and their sedimentary effects within the shear zone based on a fully validated numerical model.This work added the wind force to a tidal model during simulating the winter baroclinic circulation in the Yellow Sea.The results indicate that the YSWC is significantly strengthened by wind-driven compensation due to a northeast monsoon during winter time.When this warm current encounters the North Shandong-South Yellow Sea coastal current,there is a strong reverse shear action between the two current systems,forming a reverse-S-shaped shear front that begins near 34?N in the south and extends to approximately 38?N,with an overall length of over 600 km.The main driving force for the formation of this shear front derives from the circulation system with the reverse flow.In the shear zone,temperature and salinity gradients increase,flow velocities are relatively small and the flow direction on one side of the shear zone is opposite to that on the other side.The vertical circulation structure is complicated,consisting of a series of meso-and small-scale anti-clockwise eddies.Particularly,this shear effect significantly hinders the horizontal exchange of coastal sediments carried by warm currents,resulting in fine sediments deposition due to the weak hydrodynamic regime.
A Theoretical Analysis of the Bearing Performance of Vertically Loaded Large-Diameter Pipe Pile Groups 免费阅读 下载全文 This paper aims to present a theoretical method to study the bearing performance of vertically loaded large-diameter pipe pile groups.The interactions between group piles result in different bearing performance of both a single pile and pile groups.Considering the pile group effect and the skin friction from both outer and inner soils,an analytical solution is developed to calculate the settlement and axial force in large-diameter pipe pile groups.The analytical solution was verified by centrifuge and field testing results.An extensive parametric analysis was performed to study the bearing performance of the pipe pile groups.The results reveal that the axial forces in group piles are not the same.The larger the distance from central pile,the larger the axial force.The axial force in the central pile is the smallest,while that in corner piles is the largest.The axial force on the top of the corner piles decreases while that in the central pile increases with increasing of pile spacing and decreasing of pile length.The axial force in side piles varies little with the variations of pile spacing,pile length,and shear modulus of the soil and is approximately equal to the average load shared by one pile.For a pile group,the larger the pile length is,the larger the influence radius is.As a result,the pile group effect is more apparent for a larger pile length.The settlement of pile groups decreases with increasing of the pile number in the group and the shear modulus of the underlying soil.
Dynamics of Anchor Last Deployment of Submersible Buoy System 免费阅读 下载全文 Submersible buoy systems are widely used for oceanographic research,ocean engineering and coastal defense.Severe sea environment has obvious effects on the dynamics of submersible buoy systems.Huge tension can occur and may cause the snap of cables,especially during the deployment period.This paper studies the deployment dynamics of submersible buoy systems with numerical and experimental methods.By applying the lumped mass approach,a three-dimensional multi-body model of submersible buoy system is developed considering the hydrodynamic force,tension force and impact force between components of submersible buoy system and seabed.Numerical integration method is used to solve the differential equations.The simulation output includes tension force,trajectory,profile and dropping location and impact force of submersible buoys.In addition,the deployment experiment of a simplified submersible buoy model was carried out.The profile and different nodes’ velocities of the submersible buoy are obtained.By comparing the results of the two methods,it is found that the numerical model well simulates the actual process and conditions of the experiment.The simulation results agree well with the results of the experiment such as gravity anchor’s location and velocities of different nodes of the submersible buoy.The study results will help to understand the conditions of submersible buoy’s deployment,operation and recovery,and can be used to guide the design and optimization of the system.
Experimental Study of Dissolved Oxygen Transport by Regular Waves Through a Perforated Breakwater 免费阅读 下载全文 The perforated breakwater is an environmentally friendly coastal structure,and dissolved oxygen concentration levels are an important index to denote water quality.In this paper,oxygen transport experiments with regular waves through a vertical perforated breakwater were conducted.The oxygen scavenger method was used to reduce the dissolved oxygen concentration of inner water body with the chemicals Na2SO3 and Co Cl2.The dissolved oxygen concentration and wave parameters of 36 experimental scenarios were measured with different perforated arrangements and wave conditions.It was found that the oxygen transfer coefficient through wave surface,K1a1,is much lower than the oxygen transport coefficient through the perforated breakwater,K2a2.If the effect of K1a1 is not considered,the dissolved oxygen concentration computation for inner water body will not be greatly affected.Considering the effect of a permeable area ratio α,relative location parameter of perforations δ and wave period T,the aforementioned data of 30 experimental scenarios,the dimensional analysis and the least squares method were used to derive an equation of K2a2(K2a2=0.0042α0.5δ0.2T-1).It was validated with 6 other experimental scenarios data,which indicates an approximate agreement.Therefore,this equation can be used to compute the DO concentration caused by the water transport through perforated breakwater.
Effects of Uncertainties in the Position and Orientation of Both the Transmitter and Receivers on Marine Controlled-Source Electromagnetic Data 免费阅读 下载全文 Simulation and interpretation of marine controlled-source electromagnetic(CSEM) data often approximate the transmitter source as an ideal horizontal electric dipole(HED) and assume that the receivers are located on a flat seabed.Actually,however,the transmitter dipole source will be rotated,tilted and deviated from the survey profile due to ocean currents.And free-fall receivers may be also rotated to some arbitrary horizontal orientation and located on sloping seafloor.In this paper,we investigate the effects of uncertainties in the transmitter tilt,transmitter rotation and transmitter deviation from the survey profile as well as in the receiver’s location and orientation on marine CSEM data.The model study shows that the uncertainties of all position and orientation parameters of both the transmitter and receivers can propagate into observed data uncertainties,but to a different extent.In interpreting marine data,field data uncertainties caused by the position and orientation uncertainties of both the transmitter and receivers need to be taken into account.
On the Tectonic Problems of the Southern East China Sea and Adjacent Regions： Evidence from Gravity and Magnetic Data 免费阅读 下载全文 In this paper,two sets of gravity and magnetic data were used to study the tectonics of the southern East China Sea and Ryukyu trench-arc system:one data set was from the ‘Geological-geophysical map series of China Seas and adjacent areas’ database and the other was newly collected by R/V Kexue III in 2011.Magnetic and gravity data were reorganized and processed using the software MMDP,MGDP and RGIS.In addition to the description of the anomaly patterns in different areas,deep and shallow structure studies were performed by using several kinds of calculation,including a spectrum analysis,upward-continuation of the Bouguer anomaly and horizontal derivatives of the total-field magnetic anomaly.The depth of the Moho and magnetic basement were calculated.Based on the above work,several controversial tectonic problems were discussed.Compared to the shelf area and Ryukyu Arc,the Okinawa Trough has an obviously thinned crust,with the thinnest area having thickness less than 14 km in the southern part.The Taiwan-Sinzi belt,which terminates to the south by the NW-SE trending Miyako fault belt,contains the relic volcanic arc formed by the splitting of the paleo Ryukyu volcanic arc as a result of the opening of the Okinawa Trough.As an important tectonic boundary,the strike-slip type Miyako fault belt extends northwestward into the shelf area and consists of several discontinuous segments.A forearc terrace composed of an exotic terrane collided with the Ryukyu Arc following the subduction of the Philippine Sea Plate.Mesozoic strata of varying thicknesses exist beneath the Cenozoic strata in the shelf basin and significantly influence the magnetic pattern of this area.The gravity and magnetic data support the existence of a Great East China Sea,which suggests that the entire southern East China Sea shelf area was a basin in the Mesozoic without alternatively arranged uplifts and depressions,and might have extended southwestward and connected with the northern South China Sea...Molecular Characterization of Sulfate-Reducing Bacteria Community in Surface Sediments from the Adjacent Area of Changjiang Estuary 免费阅读 下载全文 Sulfate-reducing bacteria(SRB),which obtain energy from dissimilatory sulfate reduction,play a vital role in the carbon and sulfur cycles.The dissimilatory sulfite reductase(Dsr),catalyzing the last step in the sulfate reduction pathway,has been found in all known SRB that have been tested so far.In this study,the diversity of SRB was investigated in the surface sediments from the adjacent area of Changjiang Estuary by PCR amplification,cloning and sequencing of the dissimilatory sulfite reductase beta subunit gene(dsr B).Based on dsr B clone libraries constructed in this study,diversified SRB were found,represented by 173 unique OTUs.Certain cloned sequences were associated with Desulfobacteraceae,Desulfobulbaceae,and a large fraction(60%) of novel sequences that have deeply branched groups in the dsr B tree,indicating that novel SRB inhabit the surface sediments.In addition,correlations of the SRB assemblages with environmental factors were analyzed by the linear model-based redundancy analysis(RDA).The result revealed that temperature,salinity and the content of TOC were most closely correlated with the SRB communities.More information on SRB community was obtained by applying the utility of Uni Frac to published dsr B gene sequences from this study and other 9 different kinds of marine environments.The results demonstrated that there were highly similar SRB genotypes in the marine and estuarine sediments,and that geographic positions and environmental factors influenced the SRB community distribution.
Research on Strategy Marine Noise Map Based on i4Ocean Platform： Constructing Flow and Key Approach 免费阅读 下载全文 Noise level in a marine environment has raised extensive concern in the scientific community.The research is carried out on i4 Ocean platform following the process of ocean noise model integrating,noise data extracting,processing,visualizing,and interpreting,ocean noise map constructing and publishing.For the convenience of numerical computation,based on the characteristics of ocean noise field,a hybrid model related to spatial locations is suggested in the propagation model.The normal mode method K/I model is used for far field and ray method CANARY model is used for near field.Visualizing marine ambient noise data is critical to understanding and predicting marine noise for relevant decision making.Marine noise map can be constructed on virtual ocean scene.The systematic marine noise visualization framework includes preprocessing,coordinate transformation interpolation,and rendering.The simulation of ocean noise depends on realistic surface.Then the dynamic water simulation gird was improved with GPU fusion to achieve seamless combination with the visualization result of ocean noise.At the same time,the profile and spherical visualization include space,and time dimensionality were also provided for the vertical field characteristics of ocean ambient noise.Finally,marine noise map can be published with grid pre-processing and multistage cache technology to better serve the public.
Characterization of the Growth, Chlorophyll Content and Lipid Accumulation in a Marine Microalgae Dunaliella tertiolecta under Different Nitrogen to Phosphorus Ratios 免费阅读 下载全文 Microalgal lipids are regarded as main future feedstock of biofuels for its higher efficiency of accumulation and sustainable production.In order to investigate the effect of various nitrogen to phosphorus ratios on cells growth,chlorophyll content and accumulation of lipids in Dunaliella tertiolecta,experiments were carried out in modified microalgal medium with inorganic nitrogen(nitrate-nitrogen) or organic nitrogen(urea-nitrogen) as the sole nitrogen source at initial N:P ratios ranging from 1:1 to 32:1.The favorable N:P of 16:1 in the nitrate-N or urea-N medium yielded the maximum cell density and specific growth rate.Decrease in chlorophyll content were observed at the N:P of 4:1 in both nitrate-N and urea-N cultures.It was also observed that the maximum lipids concentration was obtained at the N:P of 4:1 in both nitrate and urea nutrient medium.The lipid productivity and lipid content of cultures in the urea-N medium at the N:P of 4:1were markedly higher than those from cultures with other N:P ratios(p < 0.05).The results of this work illustrate the possibility that higher ratios of nitrogen to phosphorus have enhancing effect on cells growth of D.tertiolecta.Conversely,higher lipid accumulation is associated with a decrease in chlorophyll content under lower ratios of nitrogen to phosphorus.The results confirm the hypothesis of this study that a larger metabolic flux has been channeled to lipid accumulation in D.tertiolecta cells when the ratios of nitrogen to phosphorus drop below a critical level.
Last 150-Year Variability in Japanese Anchovy （Engraulisjaponicus） Abundance Based on the Anaerobic Sediments of the Yellow Sea Basin in the Western North Pacific 免费阅读 下载全文 Relatively short historical catch records show that anchovy populations have exhibited large variability over multi-decadal timescales.In order to understand the driving factors(anthropogenic and/or natural) of such variability,it is essential to develop long-term time series of the population prior to the occurrence of notable anthropogenic impact.Well-preserved fish scales in the sediments are regarded as useful indicators reflecting the fluctuations of fish populations over the last centuries.This study aims to validate the anchovy scale deposition rate as a proxy of local anchovy biomass in the Yellow Sea adjoining the western North Pacific.Our reconstructed results indicated that over the last 150 years,the population size of anchovy in the Yellow Sea has exhibited great fluctuations with periodicity of around 50 years,and the pattern of current recovery and collapse is similar to that of historical records.The pattern of large-scale population synchrony with remote ocean basins provides further evidence proving that fish population dynamics are strongly affected by global and basin-scale oceanic/climatic variability.
Determination of Internal Controls for Quantitative Gene Expression ofIsochrysis zhangjiangensis at Nitrogen Stress Condition 免费阅读 下载全文 Isochrysis zhangjiangensis is a potential marine microalga for biodiesel production,which accumulates lipid under nitrogen limitation conditions,but the mechanism on molecular level is veiled.Quantitative real-time polymerase chain reaction(q PCR) provides the possibility to investigate the gene expression levels,and a valid reference for data normalization is an essential prerequisite for firing up the analysis.In this study,five housekeeping genes,actin(ACT),α-tubulin(TUA),β-tubulin(TUB),ubiquitin(UBI),18 S r RNA(18S) and one target gene,diacylglycerol acyltransferase(DGAT),were used for determining the reference.By analyzing the stabilities based on calculation of the stability index and on operating the two types of software,ge Norm and bestkeeper,it showed that the reference genes widely used in higher plant and microalgae,such as UBI,TUA and 18 S,were not the most stable ones in nitrogen-stressed I.zhangjiangensis,and thus are not suitable for exploring the m RNA expression levels under these experimental conditions.Our results show that ACT together with TUB is the most feasible internal control for investigating gene expression under nitrogen-stressed conditions.Our findings will contribute not only to future q PCR studies of I.zhangjiangensis,but also to verification of comparative transcriptomics studies of the microalgae under similar conditions.
Association of myostatin Variants with Growth Traits of Zhikong Scallop （Chlamysfarren＇） 免费阅读 下载全文 Scallop is a popular sea food and an important aquaculture shellfish.Identification of genes and genetic variants relating to scallop growth could benefit high-yielding scallop breeding.Myostatin(MSTN) is a conservative regulator of muscle growth,and has become one of the most important target genes for genetic improvement of the production of farmed animals.In this study,four single nucleotide polymorphisms(SNPs) were identified in the 5’ flanking region of MSTN gene(Cf MSTN) in Zhikong scallop(Chlamys farreri).The association of these SNPs with scallop growth traits,including shell length,shell height,body weight and striated muscle weight was analyzed.The SNP g-1162G>T was found to associate with shell length,shell height,and striated muscle weight.The TT type scallops showed significantly higher trait values than those of GT type,and the GG type individuals exhibited median values.On the contrary,significantly more Cf MSTN transcripts were detected in the striated muscle of GT type scallops than in those of TT and GG type ones.Our results suggested that Cf MSTN might regulate the scallop muscle growth negatively,and SNP g-1162G>T can be used as a candidate marker for the selective breeding of high-yielding scallop.
Identification of Light-Harvesting Chlorophyll a/b-Binding Protein Genes of Zostera marina L. and Their Expression Under Different Environmental Conditions 免费阅读 下载全文 Photosynthesis includes the collection of light and the transfer of solar energy using light-harvesting chlorophyll a/b-binding(LHC) proteins.In high plants,the LHC gene family includes LHCA and LHCB sub-families,which encode proteins constituting the light-harvesting complex of photosystems I and II.Zostera marina L.is a monocotyledonous angiosperm and inhabits submerged marine environments rather than land environments.We characterized the Lhca and Lhcb gene families of Z.marina from the expressed sequence tags(EST) database.In total,13 unigenes were annotated as Zm Lhc,6 in Lhca family and 7 in Zm Lhcb family.Zm LHCA and Zm LHCB contained the conservative LHC motifs and amino acid residues binding chlorophyll.The average similarity among mature Zm LHCA and Zm LHCB was 48.91% and 48.66%,respectively,which indicated a high degree of divergence within Zm LHChc gene family.The reconstructed phylogenetic tree showed that the tree topology and phylogenetic relationship were similar to those reported in other high plants,suggesting that the Lhc genes were highly conservative and the classification of Zm Lhc genes was consistent with the evolutionary position of Z.marina.Real-time reverse transcription(RT) PCR analysis showed that different members of Zm Lhca and Zm Lhcb responded to a stress in different expression patterns.Salinity,temperature,light intensity and light quality may affect the expression of most Zm Lhca and Zm Lhcb genes.Inorganic carbon concentration and acidity had no obvious effect on Zm Lhca and Zm Lhcb gene expression,except for Zm Lhca6.
Isolation of Immune-Relating 185/333-1 Gene from Sea Urchin （Strongylocentrotus intermedius） and Its Expression Analysis 免费阅读 下载全文 The 185/333 gene family involved in the immune response of sea urchin.One 185/333 c DNA was isolated from Strongylocentrotus intermedius,and named as Si185/333-1.Its full-length c DNA was 1246 bp in length with a 906 bp open reading frame encoding a protein of 301 aa.The molecular weight of the deduced protein was approximately 33.1 k D with an estimated PI of p H 6.26.Si185/333-1 had high identities(70%–86%) to most of Sp185/333.An extraordinary identity of 92% was found between Si185/333-1 and Sp185/333 C5 alpha(ABR22474).Moderate identities(63%–64%) were displayed between Si185/333-1 and He185/333.Si185/333-1 had similar structure to Sp185/333.A signal-peptide,a gly-rich region and a his-rich region were found in its secondary structure.RGD motif was found in gly-rich region at position 116–118aa.There was no transmembrane region in Si185/333-1.The element pattern of Si185/333-1 is different from any available pattern that identified in Sp185/333.Si185/333-1 clustered together with pattern C Sp185/333 in phylogenetic tree.The Si185/333-1 m RNA could be detected in tissues including peristomial membrane,coelomocytes,muscle of Aristotles lantern,gut and tube feet,with the highest expression level detected in peristomial membrane and a relatively low expression in ovary and testis.The temporal expression of Si185/333-1 in peristomial membrane and coelomocytes were up-regulated after bacterial,β-D-glucan and ds RNA challenges,reaching the maximum at 12 h post-stimulation.The up-regulation was more obvious in coelomocytes,and bacterial challenge triggered the highest response.These results proved that 185/333-1 gene was involved in the immune defense of S.intermedius,while more studies were necessary for its function in S.intermedius immunity.
Composition and Distribution of Planktonic Ciliates in the Southern South China Sea During Late Summer： Comparison Between Surface and 75 m Deep Layer 免费阅读 下载全文 Ciliates are very important components in most marine ecosystem.They are trophic link between the microbial food web and grazing food chain.In this study,ciliates were collected from 11 sites in the southern South China Sea（SCS） during August 25 to September 28,2011.Their composition and distribution at the surface and 75 m deep depth of the ocean were studied.A total of 30 species belonging to 22 genera were identified,and 22 species of 15 genera were Tintinnids.Eutintinnus fraknoii and E.stramentus were the most common species.The other dominants were strombidiids ciliates including Strombidium conicum and S.globosaneum,which were followed by the tide form,Mesodinium pulex.Ciliates abundance ranged from 46 ind L-1 to 368 ind L-1 in the open sites,46–368 ind L-1 at surface and 73–198 ind L-1 at 75 m deep layer.In the Yongshu reef,ciliates abundance ranged from 167 ind L-1 to 365 ind L-1 in the water column,similar to that in Sanya coral reef waters.Ciliates composition showed obvious difference between surface and 75 m deep layer at station S2（P < 0.05）,while no similar result was observed at other sites.At 75 m deep layer,salinity was negatively related to mixed layer depth（P < 0.05）,but positively to chlorophyll a concentration（P < 0.05）,indicating that the change of vertical mixing in water column influenced vertical distribution of ciliates in the southern SCS.
Development of Fatty Acid Biomarkers for the Identification of Wild and Aquacultured Sea Cucumber （Apostichopus japonicus） 免费阅读 下载全文
RNA/DNA Ratio and LPL and MyoD mRNA Expressions in Muscle of Oreochromis niloticus Fed with Elevated Levels of Palm Oil 免费阅读 下载全文 Palm oil is of great potential as one of the sustainable alternatives to fish oil(FO) in aquafeeds.In this present study,five isonitrogenous diets(32% crude protein) with elevated palm oil levels of 0%,2%,4%,6% and 8% were used during an 8-week feeding trial to evaluate its effects on RNA/DNA ratio and lipoprotein lipase(LPL) and Myo D m RNA expressions in muscle of Oreochromis niloticus.The results showed that RNA,DNA content as well as ratio of RNA to DNA were significantly affected(P < 0.05),in each case the highest was recorded in fish group subjected to 6% palm oil level.There was a strong positive correlation between nucleic acid concentration(RNA concentration and RNA:DNA ratio) and specific growth rate(SGR),protein efficiency ratio(PER),while a negative correlation existed between nucleic acid concentration(RNA concentration and RNA:DNA ratio) and feed conversion ratio(FCR).The m RNA expressions of LPL and Myo D in muscle were not significantly affected by the different palm oil levels,although the highest expression was observed in fish fed with 6% palm oil level.There also existed a strong positive correlation between the m RNA expression of LPL,Myo D and SGR,PER,while their correlation with FCR was negative.In conclusion,elevated palm oil affected the RNA,DNA concentration as well as RNA/DNA ratio significantly,although the m RNA expression of LPL and Myo D were not affected significantly by elevated palm oil levels.