[Reproductive strategy of the alien fishhook waterflea Cercopagis pengoi (Ostroumov, 1891) in the Baltic Sea (by example of the Vistula Lagoon)].

Early and prolonged bisexual reproduction has been registered in the population of Cercopagis pengoi within the Vistula Lagoon relative to its original habitat. Decrease in the role of parthenogenesis and increase in the frequency of gamogenesis have been registered in the population under study. It has been accompanied by reduction in the average number of parthenogenetic eggs per female and increase in the production ofgamogenetic eggs relative to the Caspian Sea.