scholarly journals Effects of Daphnia carinata grazing on the phytoplankton of Lake Xuanwu, Nanjing

2009 ◽  
Vol 21 (3) ◽  
pp. 415-419
Author(s):  
ZHANG Zhen ◽  
◽  
CHEN Feizhou ◽  
ZHOU Wanping ◽  
LIU Zhengwen
Keyword(s):  
Daphnia Carinata ◽  
Lake Xuanwu

Studies on the ecology of some temporary freshwater pools in Victoria with special reference to microcrustaceans

1977 ◽  
Vol 28 (4) ◽  
pp. 439 ◽  
Author(s):  
DW Morton ◽  
IAE Bayly
Keyword(s):  
High Probability ◽  
Calanoid Copepod ◽  
Shallow Waters ◽  
New Combinations ◽  
Common Occurrence ◽  
Chemical Parameters ◽  
Daphnia Carinata ◽  
Large Numbers ◽  
Three New Species ◽  
Ph Range

Fifty-three temporary freshwater pools (mean depth 23 cm) located mainly in eastern Victoria were studied from February to September 1973. Chemical parameters determined were pH (range 5.7-8.2, mean 6.9), conductivity (K18, range 55-5500, mean 340 �S/cm), dissolved oxygen (range 23-170, mean 72% saturation) and turbidity (range 2-310, mean 50 Formazin turbidity units). A total of 60 microcrustacean species was recorded. The Australasian endemic cladoceran, Saycia cooki (King), was of common occurrence from June through to August. The fact that it tends to reach peak numbers early in the life of a pool is probably related to the production of large numbers of ephippial eggs. In contrast, cladocera which produce only one or two ephippial eggs, such as Chydorus, Moina and Simocephalus, tend to appear later in succession. Simocephalus expinosus (benthic) and Daphnia carinata, s.l. (planktonic) had mutually exclusive distributions and are apparently unable to coexist in shallow waters. Endemic cyclopoid copepods encountered included three new species of Microcyclops, M. arnaudi (Sars), Acanthocyclops australis Sars, and Acanthocyclops, sp. nov. Like Saycia, Microcyclops varicans and Acanthocyclops bisetosus exhibited maximal numbers early in succession. Several new combinations of coexisting calanoid copepod species belonging to the genera Boeckella and Hemiboeckella are reported. Computer analysis showed that the following four groups of species had a high probability of co-occurrence: (1) Cypretta sp., Attheyella australica, Ilyodromus sp., Saycia cooki; (2) Cyprinotus leanus, Acanthocyclops bisetosus, Moina tenuicornis; (3) Boeckella major, B. pseudochelae, Cypris sp., Daphnia carinata, s.l. ; (4) Simocephalus exspinosus, Microcyclops varicans.

Toxicity of chlorpyrifos and TCP alone and in combination to Daphnia carinata: The influence of microbial degradation in natural water

2007 ◽  
Vol 41 (19) ◽  
pp. 4497-4503 ◽  
Author(s):  
Tanya Cáceres ◽  
Wenxiang He ◽  
Ravi Naidu ◽  
Mallavarapu Megharaj
Keyword(s):  
Microbial Degradation ◽  
Natural Water ◽  
Daphnia Carinata

Genetic diversity of picoeukaryotes in eight lakes differing in trophic status

2011 ◽  
Vol 57 (2) ◽  
pp. 115-126 ◽  
Author(s):  
Biying Zhao ◽  
Meijun Chen ◽  
Ying Sun ◽  
Jiaxin Yang ◽  
Feizhou Chen
Keyword(s):  
Genetic Diversity ◽  
Community Composition ◽  
Trophic Status ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Oligotrophic Lake ◽  
Rrna Genes ◽  
Multivariate Statistical ◽  
Mesotrophic Lake ◽  
Gradient Gel Electrophoresis ◽  
Lake Xuanwu

The genetic diversity of picoeukaryotes (0.2–5.0 µm) was investigated in 8 lakes differing in trophic status in Nanjing, China. Denaturing gradient gel electrophoresis (DGGE) and cloning and sequencing of 18S rRNA genes were applied to analyze the picoeukaryotic communities. DGGE analysis showed that among the 8 lakes, the diversity of picoeukaryotes was greatest in the mesotrophic Lake Nan (24 bands) and least in the oligotrophic Lake Qian (12 bands). Cluster analysis of DGGE profiles revealed that the 8 lakes were grouped into 2 distinct clusters. Cluster 1 contained lakes Mochou, Zixia, Huashen, Nan, Pipa, and Qian, while cluster 2 contained lakes Xuanwu and Baijia. Clone libraries were constructed from the mesotrophic Lake Xuanwu and the oligotrophic Lake Zixia, and the 2 libraries were compared using the program LIBSHUFF. This analysis indicated that the picoeukaryotic community composition differed significantly between the 2 lakes (p = 0.001). A total of 25 operational taxonomic units were detected; 18 (62 clones) were related to known eukaryotic groups, while 7 (30 clones) were not affiliated with any known eukaryotic group. Alveolates and stramenopiles were the dominant groups in Lake Xuanwu, while alveolates and chlorophyta predominated in Lake Zixia. Multivariate statistical analysis indicated that the differences in the picoeukaryotic community composition of the 8 lakes might be related to trophic status and top-down regulation by metazooplankton.

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