And LEO as "coalfish; coley; pollack/pollock" -- not particularly helpful, either, at least not to me -- I've never seen any of those names before. See this discussion for a list of additional colloquial English names.

Apparently, the fish used to be called "Köhler" or "Kohlfisch" but was given the name "Seelachs" (roughly, "ocean salmon") later on as a euphemism, perhaps to make it seem more attractive. It's used as a cheaper salmon substitute.