There's actually a sizeable Brazilian community in Zürich, many of them living in Kreis 4. There are quite a few shops and other businesses (such as hairdressers) catering to them. There are also several restaurants but I can't give any recommendations.
If you guys keep making posts out of topic, I'm going to start slapping you with a fresh sole! *joking*
There is a restaurant in Stäfa " Gasthof zur Sonne " that makes some really nice fish. It has a little bit more than the usual 2 fishy options, and it's served in very nice ambient. It has a gorgeous view to the lake.
My favourite place for fish in Zürich is the Primitivo, by Letten. Nothing beats the feeling of eating a freshly caught trout while sitting on cushions in an open tent. Caesar himself can't have had such good trout, at least not in Zurich.
I went to Atlantico Marisqueira in Altstetten on Friday night and really enjoyed it overall. The wait for our first course was a little long, but to be fair, we arrived just after a table of about 15 or so was seated. Otherwise service was very good. I had grilled dorado and the texture and flavour was wonderful.
I tried calling Esquina but their phone line was dead and their website no longer exists. Not a good sign.