Abstract: | The productivity of the combined use of the method of morphophysiological indicators (MMPI) and functional-ontogenetic approach in population studies is shown based on the example of analysis of the phenomenon of splenomegaly (SM) in rodents. A solution of the problem of analysis of spleen with a giant variation range is proposed, namely, to analyze the spleen index separately for normal spleen and spleen with SM. It is shown that there is no morphophysiological peculiarity in individuals with different functional statuses in the studied states. It is established that SM does not significantly influence the processes of animal vital activity. The maximum proportion of animals with SM was recorded in reproducing groups, which is due to a high intensity of metabolic processes. It is proved that SM is infectious in the study area. Feral herd infection agents are identified and the mechanism of SM development is considered. The criteria for the correspondence of organs to morphophysiological indicators, as well as the use of spleen as an ecological indicator, are substantiated. All the obtained materials suggest the adaptation of the studied bank vole population to a long-term effect of the infectious factor, which was historically formed in the process of the long-term coevolution of the parasite-host system. |