I would have thought someone imports them. If you can get the standrd rown ones in jars. then you may find them. "White anchovies" people often call them. They are a bit like herrings but sweeter and nicer.
Maybe and that's a big maybe in Buenos Aires but definitely not here out in the sticks.
The variety of fish and seafood is not only woeful it's also very expensive.....and what there is mostly comes frozen. Merluza (Hake) is the only fish readily available. Strange when you think of the massive coastline the country has.
Some decent frozen prawns can be got but they come already cooked. I nearly wet my pants when I saw smoked salmon (Scottish style) in the freezer cabinet at the supermarket. Pretty decent it is too.
I think hake might smoke well but I've still to get around to doing that....as I do miss my pale smoked haddock.