The first data on the fauna and biology of amphipods of ice-free creek in the Uda river basin (Western Transbaikalia)

The paper is devoted to the fauna, biology and significance of amphipods in benthos communities of ice-free creek located in Ulan-Ude City (Russia, Buryatia). It was found that macrobenthic invertebrates in the creek in February and March of 2017 were presented by turbellarian worms, bivalvia and gastropods snails, amphipods, larvae of chironomids midges, Trichoptera and Plecoptera. The rate of amphipods in total abundance of all organisms reached 59 %. The next amphipods species were found in the creek: the Holarctic Gammarus lacustris Sars and the alien species of Baikalian origin Gmelinoides fasciatus (Stebb.) and Micruropus wohlii (Dyb.). The rate of G. lacustris in amphipods community on biomass reached 80 %. There are data in the paper on the sizes of amphipods of all species, the sex structure of their populations, the rate of ovigerous females in the populations of M. wohlii и G. lacustris, as well as dependence of fecundity from the body length of specimens. We consider the influence of temperature of the creek on the biology of these species in the light of the Transbaikalian winter season.