This paper deals mainly with etiology, pathology, sympotomatology, harmfulness, preventive measures and treatment of larval mycosis (caused by Lagenidium sp. ) and of ciliate disease (caused by Zoothamnium sp. ) of pe...This paper deals mainly with etiology, pathology, sympotomatology, harmfulness, preventive measures and treatment of larval mycosis (caused by Lagenidium sp. ) and of ciliate disease (caused by Zoothamnium sp. ) of penaeid shrimp larvae.展开更多
Closed polyculture of Chinese penaeid shrimp,Taiwan red tilapia ,and molluscans(constricted tagelus and bay scallop) was studied from 1995 to 1997 with the enclosure experiment method, on a shrimp farm in Haiyang Coun...Closed polyculture of Chinese penaeid shrimp,Taiwan red tilapia ,and molluscans(constricted tagelus and bay scallop) was studied from 1995 to 1997 with the enclosure experiment method, on a shrimp farm in Haiyang County,Shandong Province. Four structure optimized closed polyculture systems, i.e., the “shrimp tagelus" system, the “shrimp scallop" system,the “shrimp tilapia" system and the “shrimp tilapia tagelus" system,were worked out. All these polyculture systems were superior to shrimp monoculture system in economic and ecological efficiencies. The order of these polyculture systems in efficiencies was “shrimp tilapia tagelus">“shrimp tagelus">“shrimp tilapia">“shrimp scallop". The “shrimp tilapia tagelus" system raised the production by 28% and the utilization efficiency of input nitrogen by 85%.These closed polyculture systems reduced the nitrogen discharge ratio to 6%-8%, instead of 40%-90% in the usual open culture systems. The ecological features of the systems were also investigated and many meaningful results have been obtained. The mechanism enhancing the efficiencies of these systems, the ways to enhance the efficiencies further and those to reuse the sedimented materials are disscussed.展开更多
The morphology of larval and 1st postlarval stages of Penaeus penicillatus are described.Results from comparative studies on larval development of P.penicillatus,P.merguiensis and P.chinensis are as fol-lows: These t...The morphology of larval and 1st postlarval stages of Penaeus penicillatus are described.Results from comparative studies on larval development of P.penicillatus,P.merguiensis and P.chinensis are as fol-lows: These three species could not be identified during their naupliar stages. In the 1st protozoea,the antennule L1/L2 value is 1.7—2.0 in P.merguiensis,but lessthan 1.7 in P.chinensis and P.penicillatus;in the 2nd protozoea,the supra-orbital spine in P.chinensis isnot bifurcated,while those of P.merguiensis and P.penicillatus are bifurcated;in the 3rd protozoea,thereis a minute(or no)dorso-median spine on the posterior margin of the 1st and 2nd abdominal somite in P.chinensis,but they are prominent in P.merguiensis and P.penicillatus.In the mysis and 1st postlarvalstages,P.chinensis differs from P.merguiensis and P.penicillatus in having 9(8 in the other 2 species)longsetae on the exopod of pereopods 1—3;additionally,one dorsal tooth appears on the rostrum of P.chinensis in the 2nd mysis and that展开更多
An enzyme immunoassay technique is developed for detecting the baculoviral midgut gland necrosis virus (BMNV) in penaeid shrimp and beach anieds. An antiserum was obtained from rabbits immunized with a BMNV preparatio...An enzyme immunoassay technique is developed for detecting the baculoviral midgut gland necrosis virus (BMNV) in penaeid shrimp and beach anieds. An antiserum was obtained from rabbits immunized with a BMNV preparation Purified from Penaeus japonicus. γ-globulin was isolated and labelled with horseradish peroxidase (HRP). This reagent was used to detect the virus in penaeid shrimp experimentally infected with the BMNV preparation, in cultured penaeid shrimp and in several beach animals. The technique is specific, simple and sensitive and can be developed into a practical method for the detection of penaeid shrimp viruses. Among 128 tissue samples from 11beach animals, 77 samples gave positive reactions with the enzyme-labelled immunoglobulin against BMNV from P.japonicus. These animals could possibly constitute a horizontal transmission pathway for cultured penaeid shrimp viruses.展开更多
In two penaeid shrimp (Penaeus monodon and Penaeus penicillatus)postlarvae exposed to 10, 50, 500μg/L Cu, Cd and CuLCd(1:1) mixture respectively,the total carbohydrate(CHO), ash, lipid and moisturegradually decreased...In two penaeid shrimp (Penaeus monodon and Penaeus penicillatus)postlarvae exposed to 10, 50, 500μg/L Cu, Cd and CuLCd(1:1) mixture respectively,the total carbohydrate(CHO), ash, lipid and moisturegradually decreased to a little less than that in the controls without exposure to the twe metals asconcentration increased; but the protein amount gradually increased to a little above that in the controls.Cu caused more reduction in CHO, ash, and lipid as compared to Cd. In contrast, reduction in total constituents was not notable in the case of exposure. to 1:1 mixture of both metals.There were negligiblechanges in all components at 10 μg/L exposure of each metal. Cu, like Zn, probably induced synthesis of specific metal binding proteins (metallothionine) causing increase in synthesis of proteins.In mixture,Cd had antagonistic effects on total composition of constituents in postlarvae.展开更多
Genomic selection(GS)can be used to accelerate genetic improvement by shortening the selection interval.The successful application of GS depends largely on the accuracy of the prediction of genomic estimated breeding ...Genomic selection(GS)can be used to accelerate genetic improvement by shortening the selection interval.The successful application of GS depends largely on the accuracy of the prediction of genomic estimated breeding value(GEBV).This study is a fi rst attempt to understand the practicality of GS in Litopenaeus vannamei and aims to evaluate models for GS on growth traits.The performance of GS models in L.vannamei was evaluated in a population consisting of 205 individuals,which were genotyped for 6 359 single nucleotide polymorphism(SNP)markers by specifi c length amplifi ed fragment sequencing(SLAF-seq)and phenotyped for body length and body weight.Three GS models(RR-BLUP,Bayes A,and Bayesian LASSO)were used to obtain the GEBV,and their predictive ability was assessed by the reliability of the GEBV and the bias of the predicted phenotypes.The mean reliability of the GEBVs for body length and body weight predicted by the dif ferent models was 0.296 and 0.411,respectively.For each trait,the performances of the three models were very similar to each other with respect to predictability.The regression coeffi cients estimated by the three models were close to one,suggesting near to zero bias for the predictions.Therefore,when GS was applied in a L.vannamei population for the studied scenarios,all three models appeared practicable.Further analyses suggested that improved estimation of the genomic prediction could be realized by increasing the size of the training population as well as the density of SNPs.展开更多
文摘This paper deals mainly with etiology, pathology, sympotomatology, harmfulness, preventive measures and treatment of larval mycosis (caused by Lagenidium sp. ) and of ciliate disease (caused by Zoothamnium sp. ) of penaeid shrimp larvae.
基金Project3 94 3 0 1 50supportedbyNSFC .WorkalsosupportedbytheNationalKeyProgramfortheNinth Five Year PlanunderGrantNo.96 92 2
文摘Closed polyculture of Chinese penaeid shrimp,Taiwan red tilapia ,and molluscans(constricted tagelus and bay scallop) was studied from 1995 to 1997 with the enclosure experiment method, on a shrimp farm in Haiyang County,Shandong Province. Four structure optimized closed polyculture systems, i.e., the “shrimp tagelus" system, the “shrimp scallop" system,the “shrimp tilapia" system and the “shrimp tilapia tagelus" system,were worked out. All these polyculture systems were superior to shrimp monoculture system in economic and ecological efficiencies. The order of these polyculture systems in efficiencies was “shrimp tilapia tagelus">“shrimp tagelus">“shrimp tilapia">“shrimp scallop". The “shrimp tilapia tagelus" system raised the production by 28% and the utilization efficiency of input nitrogen by 85%.These closed polyculture systems reduced the nitrogen discharge ratio to 6%-8%, instead of 40%-90% in the usual open culture systems. The ecological features of the systems were also investigated and many meaningful results have been obtained. The mechanism enhancing the efficiencies of these systems, the ways to enhance the efficiencies further and those to reuse the sedimented materials are disscussed.
文摘The morphology of larval and 1st postlarval stages of Penaeus penicillatus are described.Results from comparative studies on larval development of P.penicillatus,P.merguiensis and P.chinensis are as fol-lows: These three species could not be identified during their naupliar stages. In the 1st protozoea,the antennule L1/L2 value is 1.7—2.0 in P.merguiensis,but lessthan 1.7 in P.chinensis and P.penicillatus;in the 2nd protozoea,the supra-orbital spine in P.chinensis isnot bifurcated,while those of P.merguiensis and P.penicillatus are bifurcated;in the 3rd protozoea,thereis a minute(or no)dorso-median spine on the posterior margin of the 1st and 2nd abdominal somite in P.chinensis,but they are prominent in P.merguiensis and P.penicillatus.In the mysis and 1st postlarvalstages,P.chinensis differs from P.merguiensis and P.penicillatus in having 9(8 in the other 2 species)longsetae on the exopod of pereopods 1—3;additionally,one dorsal tooth appears on the rostrum of P.chinensis in the 2nd mysis and that
文摘An enzyme immunoassay technique is developed for detecting the baculoviral midgut gland necrosis virus (BMNV) in penaeid shrimp and beach anieds. An antiserum was obtained from rabbits immunized with a BMNV preparation Purified from Penaeus japonicus. γ-globulin was isolated and labelled with horseradish peroxidase (HRP). This reagent was used to detect the virus in penaeid shrimp experimentally infected with the BMNV preparation, in cultured penaeid shrimp and in several beach animals. The technique is specific, simple and sensitive and can be developed into a practical method for the detection of penaeid shrimp viruses. Among 128 tissue samples from 11beach animals, 77 samples gave positive reactions with the enzyme-labelled immunoglobulin against BMNV from P.japonicus. These animals could possibly constitute a horizontal transmission pathway for cultured penaeid shrimp viruses.
文摘In two penaeid shrimp (Penaeus monodon and Penaeus penicillatus)postlarvae exposed to 10, 50, 500μg/L Cu, Cd and CuLCd(1:1) mixture respectively,the total carbohydrate(CHO), ash, lipid and moisturegradually decreased to a little less than that in the controls without exposure to the twe metals asconcentration increased; but the protein amount gradually increased to a little above that in the controls.Cu caused more reduction in CHO, ash, and lipid as compared to Cd. In contrast, reduction in total constituents was not notable in the case of exposure. to 1:1 mixture of both metals.There were negligiblechanges in all components at 10 μg/L exposure of each metal. Cu, like Zn, probably induced synthesis of specific metal binding proteins (metallothionine) causing increase in synthesis of proteins.In mixture,Cd had antagonistic effects on total composition of constituents in postlarvae.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A404)the National Natural Science Foundation of China(No.31502161)Financially Supported by Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02)
文摘Genomic selection(GS)can be used to accelerate genetic improvement by shortening the selection interval.The successful application of GS depends largely on the accuracy of the prediction of genomic estimated breeding value(GEBV).This study is a fi rst attempt to understand the practicality of GS in Litopenaeus vannamei and aims to evaluate models for GS on growth traits.The performance of GS models in L.vannamei was evaluated in a population consisting of 205 individuals,which were genotyped for 6 359 single nucleotide polymorphism(SNP)markers by specifi c length amplifi ed fragment sequencing(SLAF-seq)and phenotyped for body length and body weight.Three GS models(RR-BLUP,Bayes A,and Bayesian LASSO)were used to obtain the GEBV,and their predictive ability was assessed by the reliability of the GEBV and the bias of the predicted phenotypes.The mean reliability of the GEBVs for body length and body weight predicted by the dif ferent models was 0.296 and 0.411,respectively.For each trait,the performances of the three models were very similar to each other with respect to predictability.The regression coeffi cients estimated by the three models were close to one,suggesting near to zero bias for the predictions.Therefore,when GS was applied in a L.vannamei population for the studied scenarios,all three models appeared practicable.Further analyses suggested that improved estimation of the genomic prediction could be realized by increasing the size of the training population as well as the density of SNPs.
