That's a hell of a thing to drop with no further explanation. I thought eukaryotes were supposed to have evolved from basically archaea, or at least very archaea-like ancestors. How do eukaryotes end up sharing chemistry with bacteria but not archaea?
"On the other hand, in the late 1980s the Western Atlantic ctenophore Mnemiopsis leidyi was accidentally introduced into the Black Sea and Sea of Azov via the ballast tanks of ships, and has been blamed for causing sharp drops in fish catches by eating both fish larvae and small crustaceans that would otherwise feed the adult fish."
https://en.wikipedia.org/wiki/Ctenophora