Effects of Retention Time on Biomass and Species Composition of Blue-Green Algae in Lake Suwa

Species diversity of epilithic cyanobacteria was studied in a 90 m deep prehistoric el-Wad cave eroded in Cenomanian limestones of Mount Carmel, Israel. The degree of illumination is the most variable index throughout the cave, whereas humidity and temperature vary moderately. In a number of sites inside the cave dripping water occurs due to filtration of rain water. In el-Wad cave 42 species from 20 genera of blue-green algae were found. The share of coccoid forms decreased and filamentous (especially oscillatorial) ones increased from the entrance to the end of the cave. Intensity of light was the governing factor for distribution of cyanobacteria in el-Wad cave; the availability of dripping affected it to a lesser extent due to the constantly high humidity of the air. Diversity of species composition and taxonomic spectrum of cyanophytes was reduced from the entrance to the end of the cave, covarying positively with darkness stress.

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Species Composition, Seasonal Dynamics and Distribution of Phytoplankton of the Zaporizke Reservoir

International Letters of Natural Sciences ◽

10.18052/www.scipress.com/ilns.62.1 ◽

2017 ◽

Vol 62 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Vladimir Yakovenko ◽

Svetlana Melnik ◽

Elena Fedonenko

Keyword(s):

Surface Layer ◽

Species Composition ◽

Microcystis Aeruginosa ◽

Green Algae ◽

Seasonal Dynamics ◽

Temporal Dynamics ◽

Ecological Status ◽

Ecological State ◽

Algae Biomass ◽

Blue Green Algae

Species composition, seasonal dynamics and distribution of phytoplankton were researched to characterize temporal dynamics and horizontal distribution of phytoplankton and to indicate the ecological status of the sites in the Zaporizke reservoir. During 2015 - 2016 a seasonal dynamics of species composition and quantitative characteristics of phytoplankton have been studied near Monastyrsky island in upper part of the reservoir both in surface and bottom layers in conjunction with water temperature measurement. At early September 2016 phytoplankton sampling was performed at different sites of the Zaporizke reservoir including the sites undergone to sewage impact. During phytoplankton seasonal dynamics diatom bloom was reported in March and early April and algae biomass was higher in the bottom layer with a gradual decrease in the direction of the surface layer. From July to October the apparent dominance of blue-green algae took place with a clear concentration in the surface layer. Domination of the speciesMicrocystis aeruginosadetermined phytoplankton distribution along the reservoir at the beginning of September. Despite the high resistance to the effects of toxic substances the level ofMicrocystis aeruginosa (Kützing) Kützing 1846development decreased at the sites of direct sewage impact. At 100m below the sewages sites degree of phytoplankton development increased mainly due to increase of blue-green algae abundance. Indexes of phytoplankton showed the best ecological state at the site «near Kodaki water draw-off» and the worst ecological state at the sites of direct sewage impact. The results obtained are important to indicate ecological state of the sites in the Zaporizke reservoir.

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Freeze-Fracture Replication in the Ultrastructure of Blue-Green Algae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100060386 ◽

1967 ◽

Vol 25 ◽

pp. 74-75

Author(s):

L. V. Leak

Keyword(s):

Cell Wall ◽

Electron Microscope ◽

Green Algae ◽

Three Dimensional ◽

Freeze Fracture ◽

Electron Microscopic ◽

Photosynthetic Membranes ◽

Blue Green Algae ◽

Cell Biol ◽

Cellular Components

Electron microscopic observations of freeze-fracture replicas of Anabaena cells obtained by the procedures described by Bullivant and Ames (J. Cell Biol., 1966) indicate that the frozen cells are fractured in many different planes. This fracturing or cleaving along various planes allows one to gain a three dimensional relation of the cellular components as a result of such a manipulation. When replicas that are obtained by the freeze-fracture method are observed in the electron microscope, cross fractures of the cell wall and membranes that comprise the photosynthetic lamellae are apparent as demonstrated in Figures 1 & 2.A large portion of the Anabaena cell is composed of undulating layers of cytoplasm that are bounded by unit membranes that comprise the photosynthetic membranes. The adjoining layers of cytoplasm are closely apposed to each other to form the photosynthetic lamellae. Occassionally the adjacent layers of cytoplasm are separated by an interspace that may vary in widths of up to several 100 mu to form intralamellar vesicles.

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