This study was to evaluate the effect of stocking densities on the nitrogen and phosphorus budgets for a polyculture of the crab Portunus trituberculatus and the Pacific white shrimp Litopenaeus vannamei.The shrimps(i...This study was to evaluate the effect of stocking densities on the nitrogen and phosphorus budgets for a polyculture of the crab Portunus trituberculatus and the Pacific white shrimp Litopenaeus vannamei.The shrimps(initial weight,0.012 g)were cultured at a density of 45 shrimp m^(-2),and juvenile crabs(initial weight,0.024 g)were cultured at five densities of 0,3,6,9,and 12 crabs m^(-2).The treatments were grouped as C0S45,C3S45,C6S45,C9S45,and C12S45,respectively.Water quality parameters,growth of shrimp and crabs,and nitrogen and phosphorus budget were measured.The results indicated that the shrimp performances in polyculture treatments C3S45 and C6S45 were superior to those in the crab-free treatment(C0S45).The crab in treatments C3S45 and C6S45 exhibited a significantly higher final mean weight and carapace width/length than those in treatments C9S45 and C12S45.The final size and survival of crabs had a negative correlation with the increasing crab stocking density.The contents of total phos-phorus and total nitrogen and the comprehensive contamination index values were higher in the C9S45 and C12S45 treatments than in the other treatments.The conversion ratios of nitrogen for crab and shrimp growth in treatment C3S45 were significantly higher than those in the crab-free treatment.These findings indicate that polyculturing shrimp with crabs at suitable densities can improve productivity,profitability,nutrient utilization,and the environmental quality.From the 60-day treatments,the optimal culture densi-ties were 3-6 crabs m^(-2) and 45 shrimps m^(-2).展开更多
Along with the sequencing technology development and continual enthusiasm of researchers on the mitochondrial genomes, the number of metazoan mitochondrial genomes reported has a tremendous growth in the past decades....Along with the sequencing technology development and continual enthusiasm of researchers on the mitochondrial genomes, the number of metazoan mitochondrial genomes reported has a tremendous growth in the past decades. Phylomitogenomics—reconstruction of phylogenetic relationships based on mitochondrial genomic data—is now possible across large animal groups. Crustaceans in the class Malacostraca display a high diversity of body forms and include large number of ecologically and commercially important species. In this study, comprehensive and systematic analyses of the phylogenetic relationships within Malacostraca were conducted based on 86 mitochondrial genomes available from Gen Bank. Among 86 malacostracan mitochondrial genomes, 54 species have identical major gene arrangement（excluding t RNAs） to pancrustacean ground pattern,including six species from Stomatopoda, three species from Amphipoda, two krill, seven species from Dendrobranchiata（Decapoda）, and 36 species from Pleocyemata（Decapoda）. However, the other 32 mitochondrial genomes reported exhibit major gene rearrangements. Phylogenies based on Bayesian analyses of nucleotide sequences of the protein-coding genes produced a robust tree with 100% posterior probability at almost all nodes. The results indicate that Amphipoda and Isopoda cluster together（Edriophthalma）（BPP=100）.Phylomitogenomic analyses strong support that Euphausiacea is nested within Decapoda, and closely related to Dendrobranchiata, which is also consistent with the evidence from developmental biology. Yet the taxonomic sampling of mitochondrial genome from Malacostraca is very biased to the order Decapoda, with no complete mitochondrial genomes reported from 11 of the 16 orders. Future researches on sequencing the mitochondrial genomes from a wide variety of malacostracans are necessary to further elucidate the phylogeny of this important group of animals. With the increase in mitochondrial genomes available, phylomitogenomics will emerge as an important component in the Tree of Life researches.展开更多
The complete sequence of the mitochondrial genome of the Japanese snapping shrimp Alpheus japonicus Miers(Crustacea:Decapoda:Caridea) is presented here.A comparative analysis based on the currently available mitochond...The complete sequence of the mitochondrial genome of the Japanese snapping shrimp Alpheus japonicus Miers(Crustacea:Decapoda:Caridea) is presented here.A comparative analysis based on the currently available mitochondrial genomic data revealed many previously unknown characteristics of the mitochondrial genomes of caridean shrimps.The A.japonicus mitochondrial genome is 16487 bp long and contains the typical set of 37 metazoan genes.The gene arrangements in the mitochondrial genomes of four previously studied carideans(Macrobrachium rosenbergii,M.nipponense,M.lanchesteri and Halocaridina rubra) were found to be identical to the pancrustacean ground pattern;thus,it was considered that gene rearrangements probably did not occur in the suborder Caridea.In the present study,a translocation of the trnE gene involving inversion was found in Alpheus mitochondrial genomes.This phenomenon has not been reported in any other crustacean mitochondrial genome that has been studied so far;however,the translocation of one transfer RNA gene(trnP or trnT) was reported in the mitochondrial genome of Exopalaemon carinicauda.When the ratios of the nonsynonymous and synonymous substitutions rates(Ka/Ks) for the 13 protein coding genes from two Alpheus species(A.japonicus and A.distinguendus) and three Macrobrachium species(M.rosenbergii,M.nipponense,M.lanchesteri) were calculated,the Ka/Ks values for all the protein coding genes in Alpheus and Macrobrachium mitochondrial genomes were found to be less than 1(between 0.0048 and 0.2057),indicating that a strong purification selection had occurred.The phylogenetic tree that was constructed based on the mitochondrial protein coding genes in the genomes of nine related species indicated that Palaemonidae and Alpheidae formed a monophyly and shared a statistically significant relationship,(Palaemonidae+Alpheidae)+Atyidae,at the family level.展开更多
基金supported by the National Key Technology Research and Development Program of Chi-na for the Eleventh Five-Year Plan(No.2006BAD09A01).
文摘This study was to evaluate the effect of stocking densities on the nitrogen and phosphorus budgets for a polyculture of the crab Portunus trituberculatus and the Pacific white shrimp Litopenaeus vannamei.The shrimps(initial weight,0.012 g)were cultured at a density of 45 shrimp m^(-2),and juvenile crabs(initial weight,0.024 g)were cultured at five densities of 0,3,6,9,and 12 crabs m^(-2).The treatments were grouped as C0S45,C3S45,C6S45,C9S45,and C12S45,respectively.Water quality parameters,growth of shrimp and crabs,and nitrogen and phosphorus budget were measured.The results indicated that the shrimp performances in polyculture treatments C3S45 and C6S45 were superior to those in the crab-free treatment(C0S45).The crab in treatments C3S45 and C6S45 exhibited a significantly higher final mean weight and carapace width/length than those in treatments C9S45 and C12S45.The final size and survival of crabs had a negative correlation with the increasing crab stocking density.The contents of total phos-phorus and total nitrogen and the comprehensive contamination index values were higher in the C9S45 and C12S45 treatments than in the other treatments.The conversion ratios of nitrogen for crab and shrimp growth in treatment C3S45 were significantly higher than those in the crab-free treatment.These findings indicate that polyculturing shrimp with crabs at suitable densities can improve productivity,profitability,nutrient utilization,and the environmental quality.From the 60-day treatments,the optimal culture densi-ties were 3-6 crabs m^(-2) and 45 shrimps m^(-2).
基金The National Natural Science Foundation of China under contract Nos 41476146 and 40906067Hong Kong Scholars Program under contract No.XJ2012056+1 种基金China Postdoctoral Science Foundation under contract Nos 2012M510054 and 2012T50218a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Along with the sequencing technology development and continual enthusiasm of researchers on the mitochondrial genomes, the number of metazoan mitochondrial genomes reported has a tremendous growth in the past decades. Phylomitogenomics—reconstruction of phylogenetic relationships based on mitochondrial genomic data—is now possible across large animal groups. Crustaceans in the class Malacostraca display a high diversity of body forms and include large number of ecologically and commercially important species. In this study, comprehensive and systematic analyses of the phylogenetic relationships within Malacostraca were conducted based on 86 mitochondrial genomes available from Gen Bank. Among 86 malacostracan mitochondrial genomes, 54 species have identical major gene arrangement（excluding t RNAs） to pancrustacean ground pattern,including six species from Stomatopoda, three species from Amphipoda, two krill, seven species from Dendrobranchiata（Decapoda）, and 36 species from Pleocyemata（Decapoda）. However, the other 32 mitochondrial genomes reported exhibit major gene rearrangements. Phylogenies based on Bayesian analyses of nucleotide sequences of the protein-coding genes produced a robust tree with 100% posterior probability at almost all nodes. The results indicate that Amphipoda and Isopoda cluster together（Edriophthalma）（BPP=100）.Phylomitogenomic analyses strong support that Euphausiacea is nested within Decapoda, and closely related to Dendrobranchiata, which is also consistent with the evidence from developmental biology. Yet the taxonomic sampling of mitochondrial genome from Malacostraca is very biased to the order Decapoda, with no complete mitochondrial genomes reported from 11 of the 16 orders. Future researches on sequencing the mitochondrial genomes from a wide variety of malacostracans are necessary to further elucidate the phylogeny of this important group of animals. With the increase in mitochondrial genomes available, phylomitogenomics will emerge as an important component in the Tree of Life researches.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40906067 and 31172054)Special Funds From the Central Finance to Support the Development of Local Universities(Grant No. CXTD04)+1 种基金the China Postdoctoral Science Foundation Funded Project (Grant No. 2012M510054)the Jiangsu Key Laboratory of Marine Biotechnology (Grant Nos. 2009HS12 and 2009HS13)
文摘The complete sequence of the mitochondrial genome of the Japanese snapping shrimp Alpheus japonicus Miers(Crustacea:Decapoda:Caridea) is presented here.A comparative analysis based on the currently available mitochondrial genomic data revealed many previously unknown characteristics of the mitochondrial genomes of caridean shrimps.The A.japonicus mitochondrial genome is 16487 bp long and contains the typical set of 37 metazoan genes.The gene arrangements in the mitochondrial genomes of four previously studied carideans(Macrobrachium rosenbergii,M.nipponense,M.lanchesteri and Halocaridina rubra) were found to be identical to the pancrustacean ground pattern;thus,it was considered that gene rearrangements probably did not occur in the suborder Caridea.In the present study,a translocation of the trnE gene involving inversion was found in Alpheus mitochondrial genomes.This phenomenon has not been reported in any other crustacean mitochondrial genome that has been studied so far;however,the translocation of one transfer RNA gene(trnP or trnT) was reported in the mitochondrial genome of Exopalaemon carinicauda.When the ratios of the nonsynonymous and synonymous substitutions rates(Ka/Ks) for the 13 protein coding genes from two Alpheus species(A.japonicus and A.distinguendus) and three Macrobrachium species(M.rosenbergii,M.nipponense,M.lanchesteri) were calculated,the Ka/Ks values for all the protein coding genes in Alpheus and Macrobrachium mitochondrial genomes were found to be less than 1(between 0.0048 and 0.2057),indicating that a strong purification selection had occurred.The phylogenetic tree that was constructed based on the mitochondrial protein coding genes in the genomes of nine related species indicated that Palaemonidae and Alpheidae formed a monophyly and shared a statistically significant relationship,(Palaemonidae+Alpheidae)+Atyidae,at the family level.
