Open earthen pond-based larviculture is the main method for rearing Chinese mitten crab(Eriocheir sinensis)larvae in China.Bacterioplankton play a vital role in aquaculture ecosystems,but their community succession th...Open earthen pond-based larviculture is the main method for rearing Chinese mitten crab(Eriocheir sinensis)larvae in China.Bacterioplankton play a vital role in aquaculture ecosystems,but their community succession throughout the larval nursery stages of E.sinensis in such systems is still poorly understood.Using 16S rRNA gene amplicon sequencing,this study characterized the dynamics of bacterioplankton communities during a complete E.sinensis larval rearing cycle in open earthen ponds.Results presented a distinct,unidirectional succession in bacterioplankton composition,characterized by a decrease in Alphaproteobacteria and an increase in Actinobacteria.Live feeds(Brachionus plicatilis and Artemia salina)significantly affected bacterioplankton communities directly through their biological activities and indirectly by modifying the structure of phytoplankton composition.In addition to live feeds,water temperature and dissolved oxygen were key environmental factors affecting the structure of bacterioplankton communities.Biotic interactions,specifically with phytoplankton and copepods,were key drivers of bacterioplankton succession.Routine feeding practices during larval cultivation decreased bacterioplankton network complexity and strengthened community stability.Keystone taxa,specifically OTU783(Rhodobacteraceae)and OTU1235(Microbacteriaceae),played an essential role in maintaining the community stability through recruiting more rare species during the later stages despite their low abundances.These outcomes advance our understanding of the mechanisms central to bacterioplankton community succession and stability in E.sinensis larviculture systems,offering critical insights for developing sustainable aquaculture management strategies.展开更多
The freshwater species,Euplotes mazeii n.sp.,and the marine species,E.balteatus(Dujardin,1841)Diesing,1850 were collected from China and investigated based on their living morphology,ciliary pattern,and small subunit ...The freshwater species,Euplotes mazeii n.sp.,and the marine species,E.balteatus(Dujardin,1841)Diesing,1850 were collected from China and investigated based on their living morphology,ciliary pattern,and small subunit ribosomal RNA(SSU rRNA)gene sequence data.Euplotes mazeii n.sp.was characterized by its small cell size((40-55)μm×(25-35)μm),nine frontoventral cirri,one marginal and two caudal cirri,seven dorsal kineties,and a double-eurystomus type of dorsal silverline system.Phylogenetic analyses based on molecular data confirmed the branching position of this new taxa within the genus Euplotes,with 5.01%(84 nucleotides)sequence variation,supporting the identification of a new species.We re-examined all described and supposedly conspecific populations and give a review of Euplotes balteatus.E.balteatus has been reported frequently;however,E.balteatus sensu Agamaliev,1968 is different from other populations in the number of marginal cirri or the type of silverline system,which suggests there might be a misidentification.The SSU rRNA gene sequences of two populations of E.balteatus from the studies of Chen et al.(2013)and Pan et al.(2012)differ from each other by more than 135 nucleotides,implying that the identity of the species currently associated with the SSU rRNA gene sequence in molecular databases requires further confirmation.展开更多
基金supported by the National Key R&D Program(No.2022YFD2400700)from the Ministry of Science and Technology of Chinathe Open Competition Project(No.JBGS[2021]127)from the Department of Agriculture and Rural Affairs of Jiangsu Provincepartially supported by the platform project of Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-culture of Aquaculture Animals(No.2021-KJ-02-12)。
文摘Open earthen pond-based larviculture is the main method for rearing Chinese mitten crab(Eriocheir sinensis)larvae in China.Bacterioplankton play a vital role in aquaculture ecosystems,but their community succession throughout the larval nursery stages of E.sinensis in such systems is still poorly understood.Using 16S rRNA gene amplicon sequencing,this study characterized the dynamics of bacterioplankton communities during a complete E.sinensis larval rearing cycle in open earthen ponds.Results presented a distinct,unidirectional succession in bacterioplankton composition,characterized by a decrease in Alphaproteobacteria and an increase in Actinobacteria.Live feeds(Brachionus plicatilis and Artemia salina)significantly affected bacterioplankton communities directly through their biological activities and indirectly by modifying the structure of phytoplankton composition.In addition to live feeds,water temperature and dissolved oxygen were key environmental factors affecting the structure of bacterioplankton communities.Biotic interactions,specifically with phytoplankton and copepods,were key drivers of bacterioplankton succession.Routine feeding practices during larval cultivation decreased bacterioplankton network complexity and strengthened community stability.Keystone taxa,specifically OTU783(Rhodobacteraceae)and OTU1235(Microbacteriaceae),played an essential role in maintaining the community stability through recruiting more rare species during the later stages despite their low abundances.These outcomes advance our understanding of the mechanisms central to bacterioplankton community succession and stability in E.sinensis larviculture systems,offering critical insights for developing sustainable aquaculture management strategies.
基金supported by the National Natural Science Foundation of China(Nos.32030015,32111530116)the China Postdoctoral Science Foundation Grant(No.2021M701993)the Fundamental Research Funds for the Central Universities(No.GK202207019)。
文摘The freshwater species,Euplotes mazeii n.sp.,and the marine species,E.balteatus(Dujardin,1841)Diesing,1850 were collected from China and investigated based on their living morphology,ciliary pattern,and small subunit ribosomal RNA(SSU rRNA)gene sequence data.Euplotes mazeii n.sp.was characterized by its small cell size((40-55)μm×(25-35)μm),nine frontoventral cirri,one marginal and two caudal cirri,seven dorsal kineties,and a double-eurystomus type of dorsal silverline system.Phylogenetic analyses based on molecular data confirmed the branching position of this new taxa within the genus Euplotes,with 5.01%(84 nucleotides)sequence variation,supporting the identification of a new species.We re-examined all described and supposedly conspecific populations and give a review of Euplotes balteatus.E.balteatus has been reported frequently;however,E.balteatus sensu Agamaliev,1968 is different from other populations in the number of marginal cirri or the type of silverline system,which suggests there might be a misidentification.The SSU rRNA gene sequences of two populations of E.balteatus from the studies of Chen et al.(2013)and Pan et al.(2012)differ from each other by more than 135 nucleotides,implying that the identity of the species currently associated with the SSU rRNA gene sequence in molecular databases requires further confirmation.
