الخلاصة:
The cyanobacteria or blue green algae are a morphologically distinct group of oxygenic,
photosynthetic organisms that inhabit terrestrial and aquatic ecosystem. The term diversity is
used here to describe the number, variety and variability of living organisms in the ecosystem.
This study was carried out at H. Boughrara dam located in the northwestern of Algeria, from
January 2016 to December 2016, at 3 stations, between 8.00 and 13.00 GMT + 1. All samples
were preserved in bottles plastic containing 4% neutralized formaldehyde solution (final
concentration), before being transported to the laboratory immediately for the identification.
A small quantity of the concentrated samples were analyzed for the dominant cyanobacterial
group. The cells were counted on a ZEISS-WINKEL inverted microscope. During this study,
16 species of cyanobacteria were collected Oscillatoria limnetica, Oscillatoria agardhii
Oscillatoria sp, Merismopedia glauca Merismopedia elegans, Anabaena circinalis Anabaena
variabilis, Anabaena planctonica, Pseudoanabaena sp Aphanizomenon flos-aquae
Aphanizomenon sp Chroococcus turgidus Chroococcus minutus Chroococcus sp Microcystis
aeruginosa and Microcystis sp. The species Oscillatoria limnetica is the most dominant by
37%, followed by Oscillatoria agardhii with 23%, Microcystis sp by 15%, while the rest of
the species were recorded with low percentages. The abundance of these species is due to the
fact that these species proliferate in the eutrophic environments which is the case of Hammam
Boughrara dam
