The effect of the ctenophore Mnemiopsis leidyi A. Agassiz, 1865 (Ctenophora: Lobata) on the population density and species composition of mesoplankton in inshore waters of the Crimea

This paper studies the qualitative and quantitative food composition of the ctenophore Mnemiopsis leidyi A. Agassiz, 1865, as well as its feeding intensity and predatory impact on selected species of mesoplankton in the inshore waters of the northwestern Black Sea in 2008–2010. Interannual and interspecies differences in the intensity of the predatory impact on zooplankton were found. Copepod nauplii, the cladocerans Penilia avirostris and Pleopis polyphemoides , and bivalve veligers experienced the highest predation pressure. The daily consumption rate for adult copepods did not exceed several percent of their total abundance. The mass development of M. leidyi defines the qualitative and quantitative composition of the zooplankton community through the control of the abundance of copepod nauplii and cladocerans, which, in turn, can result in changes in the trophic structure of the entire food chain.