A New Trophic Relationship in the Baikal Ecosystem: The Pelagic Amphipod Macrohectopus branickii (Crustacea, Amphipoda) and the Bat Myotis petax (Mammalia, Chiroptera)

— The phenomenon of the trawling insectivorous eastern bat Myotis petax Hollister 1912 feeding on the Baikal pelagic amphipod Macrohectopus branickii (Dybowsky 1874), which migrate to the water surface at night, is reported. The accumulation of large numbers of M. branickii was observed in the upper water layer near a steep underwater slope. The bats touched the water surface and captured the amphipods at the moment of their contact with the water–air interface. These trophic relationships between pelagic organisms and terrestrial vertebrates complement the food net in the ecosystem of Lake Baikal, an ancient deep lake.