检索结果-南通市图书馆

A potential source of recruitment of Acartia pacifica nauplii: viable benthic resting eggs

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2005年第2期24卷 151-158页

作者： WANGGulzhong JIANGXiaodong LIShaojing WULisheng WUDingxun DepartmentofOceanography InstituteofSubtropicalOceanographyKeyLaboratoryforMarineEnvironmentalScienceoftheMinistryofEducationXiamenUniversityXiamen361005China

Many estuarine and coastal planktonic copepods depend on the hatching of benthic resting eggs for recruitment of nauplii to the water column population. The distribution and abundance of viable resting eggs of Acartia pacifica in the Xiamen Bay were determined by the presence of nauplii in the laboratory. The number of viable eggs var/ed temporally and spatially. The maximum number (9.2×10^4m^-2) of viable eggs was in summer. In spring the average abundance of viable eggs was 5.6×10^4 m^-2. The abundances of viable eggs in fall and winter were similar, respectively 2.7×10^4 and 3.3×10^4m^-2, which were the lowest in the year. The numbers of viable eggs inside the stations of the Xiamen Bay were higher than those outside the stations. The viable eggs were found at all depths (0-10 cm),although not in every station. The maximum number did not necessarily occur in the uppermost centimeter of the sediments but often occurred several centimeters below the water-sediment interface. The accumulation of viable eggs in the seabed of a subtropical bay constitutes a potential source of recruitment of nauplii into the pelagic population.

关键词： recruitment resting eggs Acartia pacifica

STUDY ON MIXIS POTENTIAL OF ROTIFER resting eggs ( BRACHIONUS PLICATILIS ) WITH DIFFERENT COLLECTION TIMES AND DIFFERENT PRESERVATION PERIODS

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Oceanology and Limnology 2001年第3期19卷 222-227页

作者：周利郑严相建海 lnstituteofOceanology ChineseAcademyofSciencesQingdao266071China InstituteofMolecularAgrobiology anAffiliateoftheNationalUniversityofSingapore117604Singapore

The present study investigated the possible changes in the mixis potential of rotifer resting eggs produced by a single stock of Brachionus plicatilis and collected and preserved annually from 1985-1998. Several clones derived from each batch of resting eggs were cultured under the same conditions for 21 days. The percentage of clones appearing resting eggs and the average yield of resting eggs produced from each clone were recorded and statistically analyzed to find the differences between the mixis potential of those resting egg batches. Results showed that different batches of resting eggs had different mictic levels among their descendent clones; but no regular relationship was found between the mixis potential of resting eggs and their collection times/preservation periods. Several internal and external factors that might affect the mixis potential of resting eggs were discussed.

关键词： Brachionus plicatilis resting eggs mixis potential collection times preservation periods

Cambrian Fossil Embryos from Western Hunan,South China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2009年第3期83卷 429-439页

作者： DONG Xiping Department of Geology Peking University Beijing 100871 State Key Laboratory of Paleobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjin 210008 China

The exquisitely preserved fossil embryos of Markuelia recovered from the limestones of the Middle Cambrian Haoqiao Formation and Upper Cambrian Bitiao formation in western Hunan, South China are described and illustrated in detail for the first time. A new species Markuelia elegans sp. nov. is established based mainly on embryos from the Upper Cambrian. A few of animal＇s resting eggs, which are comparable with those of the Ediacaran Doushantuo Formation, have been also found in the Upper Cambrian of western Hunan. The membrane of one egg from the uppermost Cambrian has been replaced by pyrite and the overgrowth of the pyrite crystals exhibits a unique inorganic pattern termed herein ＇Pseudoembryo＇. The taphonomic setting in deeper water with possible strong reducing conditions promoted the excellent preservation for the Markuelia specimens. The study of Markuelia provides not only constraint on the anatomy, affinity, embryonic development and phylogenetic significance of this wormlike animal and but also opens a new window onto the evolution and development of the earliest animals.

关键词： Markuelia fossil embryos resting eggs pseudoembryo taxonomy taphonomy Cambrian,Hunan China

Discovery of the budding phosphatized globular fossils from the Neoproterozoic Doushantuo Formation at Weng'an, Guizhou Province, China

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第10期16卷 1079-1083页

作者： LIU Pengju , YIN Chongyu and TANG Feng (Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China) [a]Institute of Geology Chinese Academy of Geological Sciences Beijing China

There is much debate on biological affinities of the phosphatized globular fossils from the Neoproterozoic Doushantuo phosphorites at Weng’an, Guizhou Province. Here we report for the first time the budding structures of some of these globular fossils, which have previously been interpreted as the resting eggs and early cleavage embryos of metazoans. The budding structures are similar to the germinating tubes of the spore and zygote of living algae, suggesting that some globular fossils from the Doushantuo phosphorites bear affinity with algae. The present new information indicated various biological affinity of the phosphatized globular fossils from the Doushantuo phosphorites.

关键词： Neoproterozoic Donshantuo Formation globular fossil budding structure algae resting eggs embryos.

resting Stages of Crustaceans in the Crimean Hypersaline Lakes(Ukraine) and Their Ecological Role

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2014年第S1期88卷 46-49页

作者： Elena ANUFRIIEVA Nickolai SHADRIN Institute of Biology of the Southern Seas Department of Marine Animal Physiology and Biochemistry MLR Key Laboratory of Saline Lake Resources and Environments Institute of Mineral ResourcesCAGS

1 Introduction A presence of resting stages in various aquatic organisms is a long-known phenomenon as a mechanism of species adaptation to exist in unstable aquatic habitats,surviving adverse conditions in the"sleeping"state(Radzikowski,2013).Bank of resting stages of planktonic organisms is an important component of the plankton community,without which we cannot understand community dynamics(Brendonck and De Meester,2003).

关键词： saline lakes resting eggs Crustacea Crimea