Phenomenon of splenimegaly in cyclimorphic rodents populations: display, ecological risk factors, the reasons

Natural populations of seven cyclomorphic rodents of three genera have been used for ecological analysis of splenomegaly (SM) phenomenon. The variation of spleen index and a portion of SM individuals are shown for each species. A clear connection of SM with two types of ontogenesis is revealed on the level of physiological functional groups. The evaluation of risk factors, influences the development of SM, has been carried out for the dominating species - the bank vole. The relation of SM to the infestation by a number of transmissive infections is shown.