Coregonus nilssoni is a putative species of whitefish, part of the Coregonus lavaretus complex (European whitefish). It is a pelagic fish feeding on zooplankton. Its distribution is in lakes of Sweden, southern Norway, Denmark and Poland.
In Sweden, the name C. nilssoni has referred to a form of whitefish known as the planktonsik. That is however no more considered a distinct species but an ecotype within Coregonus maraena ("Coregonus maraena morphotype nilssoni"), and not different from "Coregonus maraena morphotype megalops".Coregonus maraena morphotype nilssoni planktonsik Artfakta. Artdatabanken, SLUCoregonus maraena morphotype megalops blåsik Artfakta. Artdatabanken, SLU
References