The mouthparts of two species of adult planktonic calanoid copepods (Epischura baikalensis and E. chankensis), in particular the distance between setae and setules of the second maxillae (M2), were compared using electron (SEM) and light microscopy. The mesh-sizes of the food-collection grid formed by these setae and setules ranged between 3,2 µm for E. chankensis and 9,1 µm for E. baikalensis. With such a density of the mesh and low speeds of a movement of the limbs, these species do not have the ability to filter food particles, and the capture occurs under the action of the hydrodynamic forces. The area, presumably covered by the first maxillae, was 13,215 μm² and 66,470 μm², respectively. A large area for capturing food from E. baikalensis can be advantageous at low concentrations of food objects.