Microeukaryotes play a vital role in shaping marine ecosystems,especially in marine productivity,the microbial food web,and carbon cycle.The Indian Ocean is one of the largest oligotrophic areas in the world,but littl...Microeukaryotes play a vital role in shaping marine ecosystems,especially in marine productivity,the microbial food web,and carbon cycle.The Indian Ocean is one of the largest oligotrophic areas in the world,but little is known about the biodiversity of microeukaryotes in the area.The community composition and geographical distribution of microeukaryotes collected from the surface(SUR)and deep chlorophyll maximum(DCM)layers in the southwestern Indian Ocean were studied using high-throughput sequencing of the 18S rRNA gene.The metagenomic data helped quantify the impact of environmental factors on microeukaryotic communities.The relative abundance of different taxa groups exhibited distinct patterns between SUR and DCM layers,except for the most dominant Dinoflagellata that accounted for more than 40.6%abundance in each sample.Radiolaria was much more abundant in the nutrient-rich DCM layer than the SUR layer.The community similarity of microeukaryotes decreased with increasing of geographic distance,whereas the temperature and inorganic nitrogen were the most important environmental parameters to community structure.Abundant communities were more influenced by dispersal limitations and rare communities were more responsive to environmental factors.Correlation network analyses revealed strong biotic interactions indicative of parasitism,predation and competition,and their contribution to microeukaryotic population in diverse environments.Overall,this study provided insights into the biodiversity of microeukaryotes by characterizing the differences between water layers and identifying the driving factors in the ocean.展开更多
Three species of dinophysoid planktonic dinoflagellates are described from the eastern Mediterranean Sea.Amphisolenia sp.aff.brevicauda was collected at 70-m depth in the Ionian Sea.This small species showed a more as...Three species of dinophysoid planktonic dinoflagellates are described from the eastern Mediterranean Sea.Amphisolenia sp.aff.brevicauda was collected at 70-m depth in the Ionian Sea.This small species showed a more asymmetric midbody and a proportionally longer neck when compared to the closer relative A.brevicauda.Three individuals of Dinofurcula tricornuta sp.nov.collected at 154-m depth in the Marmara Sea are characterized by three posterior-oriented processes when compared to its congeneric species.This is the first record of the genus Dinofurcula beyond the eastern tropical Pacific Ocean.Dinophysis profunda sp.nov.collected at 500-m depth in the Ionian Sea is characterized by ovate hypotheca and a serrate crest-like left sulcal list when compared to its close relative D.alata.These findings evidence an undescribed biodiversity in the under-sampled subphotic depths.展开更多
From the stratotype section of the Bazhukeng Formation, Dengshan Group (formerly assigned to the late Proterozoic), situated at Dengshan Village, Zhujia, Yiyang County, Jiangxi Province, three dinoflagellate-bearing h...From the stratotype section of the Bazhukeng Formation, Dengshan Group (formerly assigned to the late Proterozoic), situated at Dengshan Village, Zhujia, Yiyang County, Jiangxi Province, three dinoflagellate-bearing horizons have been found, in which the lower two contain ?Conochitina sp. and Cyathochitina sp., while the upper yields ?Conochitina sp.展开更多
基金Supported by the China Ocean Mineral Resources R&D Association(Nos.DY135-E2-4-04,DY135-E2-4-06)the Global Change and AirSea Interaction Program(Nos.GASI-03-01-03-03,GASI-02-IND-STSspr)。
文摘Microeukaryotes play a vital role in shaping marine ecosystems,especially in marine productivity,the microbial food web,and carbon cycle.The Indian Ocean is one of the largest oligotrophic areas in the world,but little is known about the biodiversity of microeukaryotes in the area.The community composition and geographical distribution of microeukaryotes collected from the surface(SUR)and deep chlorophyll maximum(DCM)layers in the southwestern Indian Ocean were studied using high-throughput sequencing of the 18S rRNA gene.The metagenomic data helped quantify the impact of environmental factors on microeukaryotic communities.The relative abundance of different taxa groups exhibited distinct patterns between SUR and DCM layers,except for the most dominant Dinoflagellata that accounted for more than 40.6%abundance in each sample.Radiolaria was much more abundant in the nutrient-rich DCM layer than the SUR layer.The community similarity of microeukaryotes decreased with increasing of geographic distance,whereas the temperature and inorganic nitrogen were the most important environmental parameters to community structure.Abundant communities were more influenced by dispersal limitations and rare communities were more responsive to environmental factors.Correlation network analyses revealed strong biotic interactions indicative of parasitism,predation and competition,and their contribution to microeukaryotic population in diverse environments.Overall,this study provided insights into the biodiversity of microeukaryotes by characterizing the differences between water layers and identifying the driving factors in the ocean.
基金Supported by the Spanish Ministry of Science and Technology(No.MEC2007#0213)the French CNRS ANR Biodiversity program‘Aquaparadox’(No.ANR-07-BDIV-004)the Spanish Ministry of Science and Technology(No.JCI-2010-08492)。
文摘Three species of dinophysoid planktonic dinoflagellates are described from the eastern Mediterranean Sea.Amphisolenia sp.aff.brevicauda was collected at 70-m depth in the Ionian Sea.This small species showed a more asymmetric midbody and a proportionally longer neck when compared to the closer relative A.brevicauda.Three individuals of Dinofurcula tricornuta sp.nov.collected at 154-m depth in the Marmara Sea are characterized by three posterior-oriented processes when compared to its congeneric species.This is the first record of the genus Dinofurcula beyond the eastern tropical Pacific Ocean.Dinophysis profunda sp.nov.collected at 500-m depth in the Ionian Sea is characterized by ovate hypotheca and a serrate crest-like left sulcal list when compared to its close relative D.alata.These findings evidence an undescribed biodiversity in the under-sampled subphotic depths.
文摘From the stratotype section of the Bazhukeng Formation, Dengshan Group (formerly assigned to the late Proterozoic), situated at Dengshan Village, Zhujia, Yiyang County, Jiangxi Province, three dinoflagellate-bearing horizons have been found, in which the lower two contain ?Conochitina sp. and Cyathochitina sp., while the upper yields ?Conochitina sp.
