The invertebrate and vertebrate bioindicators are known as biomonitors which are used to indicate the negative effects caused in time by different pollutants from water, air and soil. These species are living in natural environments and are not the same model species/organisms which are used in toxicological studies conducted in laboratory conditions. A certain species can be classified as a bioindicator of the environmental health after the analysis of several specific criteria: is it common in many ecosystems? Can it tolerate a large group of toxicants, those which cannot be tolerated creating disturbances of the populations by decreasing the number of the individuals and triggering migrations in order to avoid the pollution sources? One possibility to measure the pollutant effect upon the bioindicator is the population density or the absence of the species from an area where it was previously present in high abundance. Many studies proposed data bases with bioindicator species and many of them were focused on water quality analysis. For instance, Neumann et al., 2003 presented in their study the data base of lIMPACT with 39 bioindicators that were observed in the studied stream (Taxa: Turbellaria, Oligochaeta, Gastropoda, Amphipoda, Isopoda, Plecoptera, Coleoptera, Diptera, Ephemeroptera, Megaloptera and Trichoptera). The results were based on the interpretation of the abundances and rule syntax. These showed the level of contamination with pesticides correlated with nine water-quality and morphological parameters. Other authors proposed benthic larvae of insects for pesticides and heavy metals after complex chemical analyses. The freshwater mollusks are considered to be the best bioindicators for the contamination with pesticides and heavy metals in freshwater environments but the interactions with environmental conditions release questions about the bioindicator. Can the bioindicators species adapt to the negative effects of the pollutants? Each aquatic environment is unique and each species on this planet has the capacity to adaptitself to the environmental conditions. For the terrestrial environment there are several groups of bioindicators for the level of contamination with heavy metals and pesticides, e.g.: spiders, grasshoppers, birds, wild mice and humans. The aim of present study was to investigate species bioindicators of aquatic and terrestrial environments contaminated with pesticides and heavy metals, in order to be used in future studies.acknowledgements This study was supported by the project Resources pilot center for cross-border preservation of the aquatic biodiversity of Prut Rive MIS-ETC 1150 Romania-Ukraine-Republica Modova