The suitability assessment on site selection for bottom seeding scallop culture based on analytic hierarchy process

Scallop culture is an important way of bottom-seeding marine ranching,which is of great significance to improve the current situation of fishery resources.However,there are some problems in site-selection evaluation of marine ranching,such as imperfect criteria system,complex structure,untargeted criteria quantification,etc.In addition,no site-selection evaluation method of bottom-seeding culture areas for scallops is available.Therefore,we established a hierarchy structure model according to the analytic hierarchy process(AHP)theory,in which social,physical,chemical,and biological environments are used as main criteria,and marine functional zonation,water depth,current,water temperature,salinity,substrate type,water quality,sediment quality,red tide,phytoplankton,and zooplankton are used as sub-criteria,on which a multi-parameter evaluation system is set up.Meanwhile,the dualism method,assignment method,and membership function method were used to quantify sub-criteria,and a quantitative evaluation for the entire criteria was added,including the evaluation and analysis of two types of unsuitable environmental situations.By overall consideration in scallop yield,quality,and marine ranching construction objectives,the weight of the main criteria could be determined.Five grades in the suitability corresponding to the evaluation result were divided,and the Python language was used to create an evaluation system for efficient calculation and intuitive presentation of the evaluation outcome.Eight marine cases were simulated based on existing survey data,and the results prove that the method is feasible for evaluating and analyzing the site selection of bottom-seeding culture areas for scallops under various environmental situations.The proposed evaluation method can be promoted for the site selection of bottom-seeding marine ranching.This study provided theoretical and methodological references for the site selection evaluation of other types of marine ranching.

Characterization of Wnt genes in Argopecten scallops and their involvement in response to different temperature stresses in“Bohai Red”scallops

As“Bohai Red”scallops were originated from the hybrids between the Peruvian scallop(Argopecten purpuratus)and the bay scallop(Argopecten irradians)northern subspecies(Argopecten irradians irradians).Twelve Wnt members were identified from the two subspecies of bay scallop,and 13 Wnt genes were found in the genome of the Peruvian scallop.Protein structure analyses showed that most Wnt genes poses all 5 conserved motifs except Wnt1,Wnt2,Wnt6,and Wnt9 in the bay scallops and Wnt2 and Wnt9 in the Peruvian scallop.Unexpectedly,Wnt8 gene was present while Wnt3 was absent in both the bay scallops and the Peruvian scallop.Phylogenetic analysis revealed that Wnt3 might have disappeared in the early evolution of mollusks.The expression profile of Wnt genes in the“Bohai Red”exposed to different temperatures was examined by qRT-PCR.Results show that expression of Wnt genes responded differentially to temperature changes.The Wnt genes such as Wnt1,Wnt6,Wnt7,Wnt11,and WntA that responded slowly to low and high temperature stresses may be related to the maintenance of basic homeostasis.Other Wnt genes such as Wnt4,Wnt9,Wnt5,and Wnt2 that responded rapidly to low temperature may play an important role in organismal protection against low temperature stress.And yet some Wnt genes including Wnt10,Wnt16,and Wnt8 that responded quickly to high temperature stress may play key roles in response to high temperature stress.The results provide new insights into the evolution and function of Wnt genes in bivalves and eventually benefit culture of“Bohai Red”scallops.

ScanSAR的Scalloping辐射误差研究

由于在观测带内采用了多波束扫描的工作模式,使得ScanSAR产生了固有的周期性的scalloping效应,影响了ScanSAR的辐射特性。该文基于ScanSAR工作模式的特点,研究了scalloping产生的机理和性质,定量地分析了scalloping引起的辐射误差以及多普勒中心误差与scalloping的关系,并研究了对scalloping进行校正后的剩余误差问题。

Removal of biomass tar by steam reforming over calcined scallop shell supported Cu catalysts

In this study, the main purpose is to develop low-cost catalysts with high activity and stability for high quality syngas production via steam reforming of biomass tar in biomass gasification process. The calcined waste scallop shell（CS） supported copper（Cu） catalysts are prepared for steam reforming of biomass tar. The prepared Cu supported on CS catalysts exhibit higher catalytic activity than those on commercial CaO and Al;O;. Characterization results indicate that Cu/CS has a strong interaction between Cu and CaO in CS support, resulting in the formation of calcium copper oxide phase which could stabilize Cu species and provide new active sites for the tar reforming. In addition, the strong basicity of CS support and other inorganic elements contained in CS support could enhance the activity of Cu/CS. The addition of a small amount of Co is found to be able to stabilize the catalytic activity of Cu/CS catalysts,making them reusable after regeneration without any loss of their activities.

Effects of hypoxia on survival,behavior,and metabolism of Zhikong scallop Chlamys farreri Jones et Preston 1904

Hypoxia,a frequent occurring threat in coastal regions,often results in mass mortalities of marine organisms and brings a serious ecological problem.The commercially important Zhikong scallop Chlamys farreri is being under such a threat as the risks of eutrophication and hypoxia have risen in their culture areas.However,little information has been known concerning their tolerance to hypoxia and their strategy for survival.In the present study,a 20-day experiment was conducted to determine the ef fects of hypoxia on the survival,behavior,and metabolism of Zhikong scallop.With the LC_(50)for dissolved oxygen(DO)being estimated as 1.8 mg/L,the survival of Zhikong scallop can be greatly challenged even under the moderate hypoxic condition of around 2.0 mg/L DO.The survival rate ranged from 69%to 59%when DO dropped from 3.0 to 2.0 mg/L,and it was further reduced to 47%at 1.5 mg/L DO.In hypoxic conditions,the scallops became significantly active,which may be explained as escape attempts to avoid hypoxic water.To save energy,Zhikong scallop would depress their respiration.However,when DO dropped from 3.0 to 2.0 mg/L,the oxygen consumption rate hardly changed.The upregulation of lactate dehydrogenase activity and the unrepressed phosphofructokinase activity,which often result in the unbalanced cellular homeostasis and energy budget,may account for the observed increase in the mortality rate of Zhikong scallops.In general,Zhikong scallop is sensitive to hypoxia events,though possible escape attempts,depressed respiration,and oxaloacetate-pathway may increase their survival chance.

POLYCULTURE OF SCALLOP CHLAMYS FARRERI AND KELP LAMINRIA JAPONICA IN SUNGO BAY

Several polyculture models of scallop Chlamys farreri and kelp Laminaria japonica currently employedin Sungo Bay and other parts of northern China are described in this paper. Economic benefits of differ-ent polyculture models are analysed based on the growth rate, culture density and market price. In addi-tion, site selection, critical environmental conditions and polyculture problems are discussed in detail.

Molecular identification of scallop planktonic larvae using species-specific microsatellites

The identification of scallop larvae is essential to understand the population structure and community dynamics and to assess the potential environmental impacts caused by scallop larvae released or escaped. However, the larvae identification by morphological characteristics is notoriously difficult, mainly due to the small size （usually being less than 150 μm） and vague morphological characteristics among different scallop species. A simple and accurate molecular method was developed to identify four economically farmed scallop species, the Zhikong scallop Chlamys farreri, the noble scallop C. nobilis, the bay scallop Argopecten irradians and the Yesso scallop Mizuhopecten yessoensis. The tests used the high degree of species-specific microsatellite markers, which was specified by transferability analyses, assessed by reference individuals and evaluated by BLAST searches. The sensitivity test indicated that the species-specific microsatellites were sensitive enough for the detection of 1% -2% larvae in mixed plankton samples. Larvae collected from scallop hatcheries and their effluents and from the artificially controlled crosses were well identified to the species/hybrid level. The results demonstrated that the one-step PCR-based assay was technically simple, inexpensive and robust in identification analyses, and also less sensitive to initial quality of template DNA extracted from the ethanol-preserved samples for several years.

Relationships of growth and mortality to enzymatic activity,and the relative mRNA expression of cultured scallops Patinopecten yessoensis in the Yellow Sea, China

The bottom aquaculture of yesso scallop (Patinopecten yessoensis) has developed rapidly in the north of Yellow Sea, China, but not without accompanying productivity problems. We, therefore, conducted field surveys to investigate factors related to growth and mortality rates of bottom-cultured scallops after release. Specifically, we focused on the effects of total antioxidant capacity (TAOC) and three key enzymes involved in antioxidant and metabolic function:glutamic pyruvic transaminase (GPT), lactic dehydrogenase (LDH), and superoxide dismutase (SOD). Across summer and winter, we also measured the relative mRNA expression of GPT and SOD to understand their seasonal variation in the scallops, along with how such variation correlated to growth and mortality. Results show that bottom cultured scallops experienced mass mortality during the first six months post-release. During winter (December), scallops grew more rapidly and suffered less mortality than in summer (August). The observed lower performance probably resulted from less advantageous environmental factors during the summer seasons, such as high temperature and low dissolved oxygen. These environmental stressors enhance protein consumption while decreasing energetic resources in scallops. Furthermore, scallops in summer exhibited high antioxidant levels that probably competed for energy with process integral to growth and survival. These negative factors combined to elevate mortality rates. In conclusion, we provided evidence suggesting correlations between metabolic/antioxidant activity and growth and mortality of bottom-cultured yesso scallops. These correlations implied us an accurate method to estimate the performance of bottom culture system. Suggestions about innovative aquaculture techniques were also discussed in the study. Our results might provide a possible guideline to the improvement of bottom culture techniques for this commercially valuable seafood species.

Genetic diversity and specific markers in four scallop species, Patinopecten yessoensis, Argopecten irradians, Chlamys nobilis and C.farreri

The AFLP （amplified fragrnent length polymorphism）technique was used to analyse the genetic diversity in four scallop species, Patinopecten yessoensis, A rgopecten irradians, Chlamys nobilis and C. farreri. The genetic similarity indexes of these four species are 0.8415, 0.7863, 0.7190 and 0.6731, while Shannon diversity indexes are 43.52, 58.87, 80.16 and 92.83, respectively. As analyzed, the genetic diversities in two native species, i.e., C, farreri and C. nobilis, are higher than those in other two introduced species, A. irradians and P. yessoensis. The results also showed that C. nobilis and C, farreri shared the most common loci. The genetic distance indicated that C. nobilis and C. farreri are closely related. Moreover, out of 510 AFLP markers, 21 specific bands are found to distinguish the four species scallops and these markers may be applied to the specific germplasm characterization and molecular assistant classification in scallops.

Effects of Temperature on Haemocyte and Granulocyte Counts and Expressions of Immunity-Related Genes in Haemocytes of Scallop Chlamys farreri After Vibrio anguillarum Infection

Bivalve live in aquatic environment and the water temperature can affect their immunity directly.In this research,the scallop Chlamys farreri was injected with 10^4 or 10^7 CFU mL^-1 Vibrio anguillarum and cultured at 11℃,17℃,23℃,and 28℃,respectively.For the control scallop,only phosphate-buffered saline(PBS)was injected.Then total haemocytes and granulocytes were measured by ELISA using monoclonal antibodies.In the meantime,expressions of six immunity-related genes,including lipopolysaccharide andβ-1,3-glucan binding protein(CfLGBP),C-type lectin(CfLec-2),Toll-like receptor(Cf TLR),Lysozyme(CfLYZ),superoxide dismutase(SOD),and phenoloxidase(CfPO)in haemocytes were measured using quantitative real-time PCR.The results showed that total haemocytes counts in 10^4 CFU mL^-1 injection groups showed no differences compared to the control group at all temperatures.However,they varied significantly in 10^7 CFU mL^-1 injection groups at 3 h at 11℃,6–12 h at 17℃,3–48 h at 23℃,and 12–48 h at 28℃.Granulocytes counts in 10^4 CFU mL^-1 injection groups showed no variance compared to the control group at all temperatures,except for 12 h at 23℃,and 24–36 h at 28℃.They were significantly decreased in 10^7 CFU mL^-1 injection groups during 6–48 h at 11℃,12–48 h at 17℃,3–48 h at 23℃,and 3–72 h at 28℃.The expression levels of six immunity-related genes in haemocytes of 10^7 CFU mL^-1 injection groups were significantly higher than those of control group and 10^4 CFU mL^-1 injection groups at all temperatures.The results indicated that infected with high concentration of vibrios,haemocyte counts,granulocyte counts and the expressions of immunity-related genes in scallop C.farreri were significantly affected by environmental temperature.

Effects of scallop shell extract on scopolamine-induced memory impairment and MK801-induced locomotor activity

Objective:To evaluate the neuroprotective effects of the organic components of scallop shells(scallop shell extract) on memory impairment and locomotor activity induced by scopolamine or 5-methyl-10,11-dihydro-5H-dibenzo(a,d) cyclohepten-5,10-imine(MK801).Methods:Effect of the scallop shell extract on memory impairment and locomotor activity was investigated using the Y-maze test,the Morris water maze test,and the open field test.Results:Scallop shell extract significantly reduced scopolamine-induced short-term memory impairment and partially reduced scopolamine-induced spatial memory impairment in the Morris water maze test.Scallop shell extract suppressed scopolamine-induced elevation of acetylcholine esterase activity in the cerebral cortex.Treatment with scallop shell extract reversed the increase in locomotor activity induced by scopolamine.Scallop shell extract also suppressed the increase in locomotor activity induced by MK801.Conclusions:Our results provide initial evidence that scallop shell extract reduces scopolamine-induced memory impairment and suppresses MK-801-induced hyperlocomotion.

Purification and Identification of Antioxidant Peptides from the Scallop Skirts of Mimachlamys Nobilis

The processes of scallop meats can produce a large amount of by-products like scallop skirts,which are rich in nutrients. This work aimed to obtain the information about antioxidant peptides derived from scallop skirts of Mimachlamys nobilis. The hydro-lysates obtained by trypsin exhibited the highest antioxidant activity( 75.6%,79.5% and 76.7% using DPPH,hydroxyl and superoxide anion radical scavenging activity assays,respectively). The antioxidant peptides( MNAP) were separated and purified using UF membranes,GFC processes and RP-HPLC,and the antioxidant activity of MNAP was identified to be 85.7% using DPPH radical scavenging activity assay. The peptides( MNAP) were composed of two peptides with their molecular weights2 855.6 Da and 3 007.2 Da using MALDI-TOF-MS,respectively. The results suggested that the scallop skirts of Mimachlamys nobilis could be explored as a source of antioxidant peptides.

TETRAPLOID INDUCTION BY INHIBITING MITOSIS I IN SCALLOP CHLAMYS FARRERI

Tetraploid induction was carried out by inhibiting mitosis I in fertilized eggs of Chlamys farreri . Mitosis I was blocked with cold shock (5 7℃), Cytochalasin B (0.75 mg/L) and 6 dimethylaminopurine (6 DMAP) (60 75 mg/L) when 60% fertilized eggs released polar body II at 20℃. At 4 cells embryo stage, the ploidy was determined by counting chromosome number. In control groups, most embryos were diploids (72.22%) and aneuploids (24.78%). In Cytochalasin B, cold shock and 6 DMAP treated groups, tetraploids were respectively 10.51%, 4.08%, and 13.34%; aneuploids were 43.10%, 35.93% and 29.16%,and triploids were 7.84%, 8.52% and 18.33%. At D larva stage, ploidy was determined by flow cytometry (FCM). The ploidy analysis of day 2 larvae showed diploids in control group and also in three treated groups. Juvenile scallops (0.2 0.3cm) which were harvested in two control groups and two CB treated groups were all diploids through checking ploidy individually by FCM.

Application of the first internal transcribed spacer(ITS-1)of ribosomal DNA as a molecular marker to population analysis in farrer's scallop Chlamys farreri

Sequence variation of the first internal transcribed spacer of ribosomal DNA （ ITS - 1 ） was examined and its application to the study of genetic variation was explored in four populations of farter＇ s scallop Chlamys farreri. ITS - 1 fragments, with a length of about 300 bp,of 78 individuals collected from Dalian, Qingdao, Yantai in China and Korea respectively were amplified via PCR, cloned and sequenced. Intra-genomic variation was examined by sequencing several clones of single individuals. Alignment and polymorphism analysis detected 44 haplotypes and 50 polymorphic sites which consist of 30 substitutions and 20 indels, indicating a high level of polymorphisms. Sequence analysis also showed a very low level of intra-individual variation. All these features validated the feasibility of application of ITS - 1 fragment to population analysis. Polymorphism analysis showed that the Korea sample has the richest genetic variation, followed by Yantai and Qingdao samples. AMOVA （analysis of molecular variance） showed that the majority （96.26%） of genetic variation was distributed within populations and 3.74% resulted from among populations, but with P 〈 0.05 （ = 0.042）, indicating that the populations in this study have significant divergence. This output was basically concordant with the result arising from RAPD data and different from that from mitochondrial 16S rDNA sequence data. Discussion on this inconsistency was made accordingly.

Spatial diff erence in net growth rate of Yesso scallop Patinopecten yessoensis revealed by an aquaculture ecosystem model

Identifying the main factors on spatial diff erences in net growth rate of Yesso scallop(Patinopecten yessoensis)in culture system is the key to eff ective aquaculture management and development.Coupling a 3D ecosystem model(ROMS-CoSiNE)with a dynamic energy budget model for scallops,a Yesso scallop culture ecosystem(YeSCE)model was established with which scallop growth was simulated with real seeding density and juvenile size from local aquaculture experiments from December 1,2012 to November 30,2013.Results show that the YeSCE model has reasonably simulated the environmental variation and scallop net growth rate in the Changhai sea area.The growth of scallops was slow in winter and midsummer and was limited mainly by temperature.Food availability was a key factor that contributed to the fast growth of the scallops during spring to early summer and in autumn.Generally,the scallops cultured in the north part of the Changhai sea area grew faster than those in the south;and the net growth rate for scallops cultured near the island was signifi cantly higher compare to the others,which is probably correlated to the spatial distribution of food availability.Based on the correlation analysis,the spatial diff erences of the net growth rate were largely aff ected by the length of the match timing of temperatures and food availability.The results of this study provide a scientifi c support for optimizing bottom culture planning and adjusting bottom culture methods.

Depuration of paralytic shellfish toxins in Japanese scallop(Patinopecten yessoensis) in natural environment

To study the paralytic shellfish toxins（PSTs） depuration in Japanese scallop Patinopecten yessoensis in natural environment, Japanese scallops naturally contaminated with paralytic shellfish poisoning（PSP） toxins in the Dayao Bay in the northern Huanghai Sea are transited to Qipanmo waters in the Bohai Sea of no reported PSTs incidents. The levels and profile of PSTs during 30-day depuration are detected by the high performance liquid chromatography with fluorescence detection（HPLC-FLD）. The results show that the toxicity of the PSTs in soft tissues decreases to a relatively low level at Day 9. Moreover, the depurated ratio at the early stage of the PSTs depuration is higher than that at the later stage. The toxicity analysis of dissected organs reveals that the digestive gland is the most contaminated PSTs part, which is of important implication for the human health and scallop aquiculture. The mortality of Japanese scallops during PSTs depuration experiment is relevant to PSTs level in the soft tissue.

Fossil Scallops from the Cenozoic Duho Formation of the Pohang Basin,Korea

A great number of fossil scallops were found from the Duho Formation of the Pohang Basin,Korea.Most of the specimens are preserved as slightly altered original carbonate shells,and internal and external molds were also observed in the specimens whose calcareous materials were washed out.In particular, external and internal molds are more frequently observed from the thin and small(less than 1 cm

STUDIES ON INTERCROPPING OF PORPHYRA HAITANENSIS T.J.CHANG ET B.F.ZHENG WITH BAY SCALLOP ARGOPECTEN IRRADIANS LAMARCK

Results of the experiment of northward transplantation of Porphyra haitanensis showed thatintercrop of P. haitanensis with Bay Scallop is feasible because the growth duration of both of them is about the same in August - December.Full use of cultivating area, lowering its cost and increasing its product per unit area as well as improving the ecological envronment are realized during intercrop.

A new iso-scallop height tool path planning method in three-dimensional space

This paper presents a new approach for designing the tool paths in the machining of sculptured surfaces for computer nu- merical controlled end milling. In the proposed method, the tool paths are determined so that the scallop height formed by two adja- cent machining paths is maintained constant across the machined surface. Unlike previous work on iso-scallop height milling, the present work considers the true 3D configuration of the milling procedure and can be used to generate better results, which is shown by examoles.

Application of purple nonsulphur bacterium Rhodopseudomonas sp．in spat rearing of Bay Scallop Argopecten irradians irradians

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