Does the use of various population parameters affect fish assemblage structures?

While studying the fish populations in small streamlets and their responses to climate change and anthropogenic stress, the following parameters are used: present/absent species, relative number, and relative biomass recently. Although the image/structure of the population differ from these parameters, this problem has not been investigated by researchers in this topic. It is now known that the potential energy accumulated in animal tissues is the best indicator of his strength and importance in nature, but I have not encountered work assessing the image of population structure according to these population parameters. Consequently, most reliable parameter − the relative calorific value of biomass (in the wet weight), was used. Relative biomass is the parameter of the population, which was found to be the closest to the calorific value of the biomass, as demonstrated by the SOM (self-organizing map) artificial neural network algorithm used in this study. For this reason, attempts have been made to convince authors of future work that relative biomass studies are used in the studies of fish assemblages, as research has already been undertaken, and this paper provides evidence that this choice is justified.Regularly published works devoted to fish assemblage structures are constructed from three population parameters: species number, relative number or relative biomass. The last one is the most similar to the estimated by the relative caloric content of biomass (wet weight), i.e. the best indicator of the strength and importance of a population in nature