We studied for the first time the Ecology and biodiversity of underground water in a semi-arid region of the hauts plateaux of Eastern Algeria. The results obtained from the investigations of 24 dug wells and 01 source from September 2014 to May 2016 at the regions of 'Ain Beida and Ksar Sbihi' in Oum El Bouaghi city eastern Algeria showed that this aquatic fauna is composed of 21 taxa (families) and 7582 individuals, and is dominated by 56% insects and 25% crustaceans. Only a stygobitic species was harvested in these regions 'Pseudoniphargus sp'. The maximum of diversity is present in wells when the water is of good quality, but it decreases in case of pollution. Stygobitic species are generally more sensitive to pollution than other aquatic sow species, they contain the indicator species of the water quality. The knowledge and comparative review of the diversity of the fauna of wells located in the same region can be used for purposes of monitoring and environmental management.
