Species from the viewpoint of biocoenology

Some questions of the use of the “species” concept in biocoenology and hydrobiology are considered. The existence of certain difficulties and ambiguities in the use of this concept is shown. It is proposed to clarify the goals and objectives of identifying the species structure of biocoenoses. The examples show that ecomorphs and coeno-ecomorphs are not less important elements of a biocenotic system and require thorough research. The question of the possibility and feasibility of definitions "to species level" of all members of the community is considered. The ecological niche concept is associated with species, although there is also the guild concept that unites species according to the principle of convergent similarity of trophic, topical, or other preferences. Various systems of bioindication have become widespread, which are based on the principle of compliance of a particular species population to certain conditions. First of all, we are talking about disturbed conditions, including various impacts by pollution. It was shown that not only species, but also more easily identifiable higher taxa could be used as bioindicators of certain conditions.