Morphofunctional Specialization of the Digestive Tract in Lemmings (Lemmus lemmus and Myopus schisticolor)

Functionally important structural and morphometric features of the digestive tract (DT) of representatives of two genera of lemmings, Lemmus and Myopus, as well as the kinetics of dietary fiber in their DT, are considered. In lemmings, the DT is adapted to the rapid assimilation of easily digestible components of plant objects and the most complete elimination of indigestible components. This digestive strategy is due to the lower capacity of the DT of lemmings (10–14% of body mass versus 18–30% in voles), the absence of isolating structures in the stomach, and the disproportionately developed colonic spiral, which performs a separator function. The predominance of small-sized food particles in the stomach as a result of chewing promotes rapid assimilation of the contents of plant cells.