Effects of different inoculation densities on growth and toxin production of Alexandrium minutum were studied.Experiments were conducted under conditions of varying inoculation densities(0.05×104,0.10×104,0.15×104,0.30×104 cells/mL).Higher inoculation densities always resulted in shorter lag phase of A.minutum,and an earlier setting in of the steady growth phase.However,the specific growth rate and maximum cell concentration of A.minutum decreased with increasing inoculation densities.The multiplication models developed correlated well with the observations,as the inoculation density increased,the initial-density dependent parameter a also deceased and the reduction of environmental capacity,instantaneous multiplication included.According to MBA analysis,toxicity of A.minutum is typically highest when cells are growing fast in early exponential phase and lowest as growth slows and eventually stops in plateau phase.The PSP-toxin congeners,GTX1(2.14 fmol/cell),GTX2(2.08 fmol/cell),GTX3(4.97 fmol/cell),GTX4(5.04 fmol/cell)were analysed by high-performance liquid chromatography with fluorescence diction(HPLC-FLD).Result of this study implied that toxin production of the dinoflagellate A.minutum is better in 0.10×104-0.15×104 cells/mL than other condition of inoculations densities.

Eighteen half-sib families and fifty-four full-sib families were constructed using methods of nest design and artificial insemination,in which each male mated three females.Sixty 5-month-old shrimp were measured for nine growth traits including the body weight(BW),the total length(TL),the body length(BL),the carapace length(CL),the carapace width(CW),the carapace depth(CD),the first abdominal segment depth(FASD),the third abdominal segment depth(TASD),and first abdominal segment width(FASW).According to quantitative genetics theory,the heritability of each growth trait,and the genetic and phenotypic correlation among the traits were statistically studied utilizing the method of variance and covariance analysis.The results showed that the heritability estimates in the narrow sense from intra-group correlation of paternal half-sib were precise and unbiased,and the heritability values for the above nine traits were 0.460,0.392,0.303,0.234,0.251,0.330,0.282,0.321 and 0.356,respectively.All of them belonged to moderate and high heritability,thus showed a high potential for selective breeding.The estimates of genetic correlation coefficients were 0.750-0.976,where the highest(0.976)was that between the BW and the TL,while the lowest(0.750)was seen between the TL and the TASD.The estimates of phenotypic correlation coefficients were 0.507-0.947,where the highest(0.947)was seen between the BW and the TL,while the lowest(0.507)was that between the FASD and the CD.Very significant difference was detected by t-test(P0.01)among the nine growth traits for both genetic and phenotypic correlation coefficients,which indicate all the nine traits may respond favorably to direct and indirect selection for growth.

Barbus capito is an endemic species in the Aral Sea of Uzbekistan.It is well-known for its salt tolerance and fast growth,and is a valuable food source in the region.The species was introduced to China in 2003 and F1 was obtained using artificial propagation in 2010.As an introduced species,B.capito has the relatively limited genetic resources due to the small founder population size.It is very important to effectively protect and utilize the existing gene resources in breeding practice.In this study,24 microsatellite markers were selected to analyze the genetic structure in cultured F1 population including 96 individuals.A total of 74 alleles were detected and the length of fragments ranged from 109 to 367 bp.The number of alleles per locus was from 2 to 5,and the mean was 3.0833.The effective number of alleles(Ne)ranged from 1.144 5 to 4.626 4 with an average of 2.265 6.The observed heterozygosity(Ho)and the expected heterzygosity(He)varied from 0.135 4 to 1.000 0(mean=0.538 4)and from 0.126 9 to 0.788 1(mean=0.487 2),respectively.The value of polymorphic information content(PIC)was between 0.118 3 and 0.749 0 with an average of 0.428 1,and this result indicated that the level of genetic diversity was moderate(0.25≤PIC0.50).The population accorded with Hardy-Weinberg equilibrium checking by χ2 test except 8 markers including B1,B20,B32,B37,B45,B51,B68,and BC43.In addition,the correlation was analyzed between 24 microsatellite markers and growth traits using the GLM procedure of SPSS 19.0.As a result,there were 8 markers that had a significant(P0.05)impact on growth traits.Six markers including B1,B20,B45,B51,B59,and BC38 had a significant(P0.05)impact on body weight,length,height,and thickness.B26 had a significant(P0.05)impact on body weight,height,and thickness.BC3 had a significant(P0.05)impact on body weight and length.Superior genotypes were obtained using Duncan's multiple comparison.

The protein expression of tilapia liver in different periods was studied after Streptococcus agalactiae infection. Tw o-dimensional electrophoresis w as employed to analyze the proteome from liver of GIFT tilapia at 0 h,24 h,48- 144 h and 12 days after Streptococcus agalactiae infection. The differential expressing proteins w ere identified by mass spectrometry. The results show that there w ere significant differences betw een experimental groups and control group in the proteomic map. Among the 30 differentially expressed proteins,13 show an up- regulated expression and 15 show s dow n- regulated expression. Tw o proteins disappeared in the infection group 12 days later. The function classification of these proteins w as analyzed by MALDI-TOF / TOF 4800 and mascot soft w are. They included association w ith energy metabolism proteins,cell defense and stress proteins,digestive immune proteins,immune and detoxification and other proteins. It is likely that they play an important role in the resistance responses to Streptococcus agalactiae. The discovery and identification of these proteins can offer a valuable insight into Tilapia Streptococcus lactis vaccine development and disease resistance breeding.

In each spring during 1989—1993 and 2003—2012,oyster samples(Crassotrea rivularis Gould)were collected from 16 sites along Guangdong coast,China.The contents of DDTs(including o,p'-DDT,p,p'-DDT,p,p'-DDD,p,p'-DDE)were detected by gas chromatography with electron capture detector.Based upon the detected data of DDTs in oysters along Guangdong coast and the data taken from the pollution investigations of Guangdong coastal zone,China during 1980—1985,the residues levels,spatial and temporal trends and compositions of DDTs in oysters were analyzed and discussed.Also,food safety and biological quality of DDTs in oysters were assessed.The results indicated that DDTs was detected in 95.9% of the samples,and in the detectable samples,DDTs contents ranged from 0.11 to 76.3 ng/g with an average of 3.87 ng/g on wet weight basis.DDTs contents decreased obviously during the early period after DDTs was banned from 1980s to early 1990s,but presented a gentle increase owing to possible inputs of new DDTs in 2003—2007,and with the national implementation measures for the Stockholm Convention,DDTs contents maintained steady finally between in 2008—2012.In early 1980s,DDTs contents in Pearl River Estuary were much higher than East Guangdong coast and West Guangdong coast,but the difference of DDTs contents from these three coasts narrowed gradually with time and became not significant statistically since 1989(P0.05).The composition analysis of DDTs in the oyster samples showed that DDTs residues were sourced mainly from the historical usage,but the higher ratios of DDT/(DDD+DDE)and o,p'-DDT/p,p'-DDT(1)indicated that there was probably new input of DDTs which might come from dicofol in periods of 1989—1993 and 2003—2007.The DDTs residues levels of all oyster samples were below the national residual limit standards,during the period of 1980s—1990s and 2003—2007,there was only 4.6% of oyster samples exceeded US EPA reference limits(14.4 ng/g),and 6.7% of samples exceeded the requirement of the first grade of the National Marine Biological Quality Standard of China(10 ng/g).The biological quality of DDTs in oysters was good and the food safety has been acceptable in recent years.

The Pampus fishes are important commercial species and widely distributed in the coastal waters of China. Due to the similarities and complexities of morphological characters used in traditional taxonomy,taxonomic confusion has arisen in Pampus concerning the nomenclature. Among the genus,perhaps none is more confusing in the taxonomic studies than Pampus argenteus. Up to date,no reports about neotype of P.argenteus can be found. In the present study,redescription of morphological characters and redefinition of DNA barcoding of P. argenteus are conducted based on sixteen specimens collected from Kuw ait( northern w aters of Kuw ait),Pakistan( Sonmiani Bay,Ormara,Pasni),Beibu Bay and Taiw an during October 2010 to September 2012. The diagnostic characters of P. argenteus: dorsal fin Ⅶ- Ⅷ-39- 43,pectoral fin 21- 29,anal fin Ⅴ- Ⅵ-35- 41,caudal fin 26- 28. First gill arch w ith 10- 12[( 2- 3) +( 8- 9) ]small and sparse gill rakers. Vertebrae 37- 38. In the occipital region,the area of the w avy branches above lateral line is developed and plume-like,w ith a little obtuse edge. Ventral w avy branches below lateral line are curvy and shorter than that above lateral line,and not reaching the base of dorsal fin. Combining all COⅠ sequences of P. argenteus from GenBank w ith those of this study,four absolute groups can be found in all specimens based on the genetic differences in amino acids and distance betw een groups. From the NJ tree,w e can find that only one sequence( FJ384702) is similar to our DNA barcoding of P. argenteus. Therefore,it is urgent to guarantee the correctness of all sequences from GenBank. Redescription of morphological characters and the right DNA barcoding of P. argenteus are given,w hich provide a guarantee for efficient and accurate study,and theoretic basis for classification of Pampus in future.

Pollution biology indices on zooplankton and benthos were used to analyze the pollution state of different areas of Dalianhu water source,in order to study the pollution characteristics of Dalianhu water source.The evaluation effects of different biological indices on water pollution were considered with its water quality indices,and principal component analysis was used to analyze its pollution characteristics comprehensively.The results showed,during summer and autumn,the range of Shannon-Wiener index(H1)and Margalef diversity index(D)of zooplankton in different areas of Dalianhu water source was 0.3-1.8 and 1.0-10.4,respectively;and the range of Shannon-Wiener index(H2)and Goodnight index of benthos(G)was 0.81-1.26 and 0.30-0.88,respectively,which all showed it were in pollution.Correlation analysis results was in comparison with the water quality indices,showing the Margalef diversity index(D)of zooplankton and Goodnight index(G)of benthos can reflect the water pollution state preferably.Combined with the results through principal component analysis,the rank order of pollution state of different areas of Dalianhu water source was water-forestinner riverpondsexternal riverlake area.The results showed the lake area of Dalianhu water source had certain ability to purify and protect water,and the pollution was mainly from interior sedimentation of organic matter and pond aquaculture.The ecological restoration measures for Dalianhu water source should include reshaping the terrain,sediment dredging,communicating water network,controlling pond aquaculture,and so on.

Porphyra haitanensis is one of the most important economic marine crops of China.For any cultivar,the correct identification of species or forma of the cultivated strains is necessary to ensure a well-bred cultivation and good production quality.However,because the gametophytic blade of Porphyra is morphologically simple and marked variations can occur as environmental conditions change,it is very difficult to precisely identify the species or forma of cultivated strains based only on their morphological characteristics.With new advances in molecular biology,molecular markers and DNA fingerprinting techniques have become routine for the identification and classification of many crops,including seaweeds.The strain of Z-26 of P.haitanensis was selected by the laboratory of germplasm improvement and the application of P.haitanensis in Jimei University which has the characters of high-temperature tolerance and high yield,and it has been widely cultivated in south China.In order to construct the technology of variety identification for Z-26,firstly,300 primers of RAPD were used to scan the specific markers of 6 new strains of P.haitanensis and 9 specific RAPD markers of Z-26 were selected.After cloning and sequencing,two specific RAPD markers of Z-26 were transformed into the SCAR markers successfully,the length of the 2 SCAR markers was 540 and 242 bp,respectively.Secondly,after verification by 4 different experiments,we can affirm that the 2 SCAR markers were the specific and stable markers of Z-26.At last,based on the 2 SCAR markers,after optimization of experimental conditions,the technology of multiplex PCR which was used to identify the variety of Z-26 was constructed.The result supplied a simple,fast and reliable technigue for variety identification of Z-26.

Grass carp reovirus(GCRV)has been considered as the most pathogenic agent and poses a significant threat to grass carp culture.A virulent reovirus strain,HZ08,was isolated from diseased grass carp in Zhejiang Province,and has been proven to be epidemic strain in China.To development serological methods for detecting prevalent GCRV,the gene encoded for major outer capsid VP4 was selected clone to plasmid pET32a(+)and the purified recombinant VP4 protein was injected into BALB/c mice through subcutaneous route.The spleen cells from immuned BALB/c mice were fused with SP2/0 myeloma cells,and three hybridoma cell lines,designated as 2C2,2F3 and 5E5 respectively,were screened out to be able to secrete monoclonal antibody(MAb)against VP4 protein using indirect ELISA.All the MAb were IgG1 subtype with κlight chain and could not react with GSRV,ISKNV,IHNV except GCRV-HZ08.The hybridoma cell line 2C2 was selected for MAb preparation,and the titers in cell culture medium of the ascetic fluids were up to 1∶ 720 000.The results of Western-blotting and IFA showed that the MAb could recognize the authenticVP4 protein of GCRV HZ08 particles.In present study,the MAb against VP4 of GCRV HZ08 was successfully prepared,which laid a foundation of developing a rapid determination method for GCRV and further study of structures and functions of VP4 protein.