Corvina = croaker, grunt, or drum: used for ceviche and almost everything else.
Mero = grouper: also commonly used here.
Chita = grunt: usually deep fried whole so you can eat it with your hands.
Lenguado = Dover sole: delicate fish often used to stuff with crab meat.
Cabrilla = rock sea bass: like corvina
Ojo de uva (grape eye) = sea bass: used like corvina
Charela/Cherela = weakfish (probably in the croaker family): also used like corvina
Espada (and espadilla) = swordfish (and scabbard fish): firm dry fish
Pejerrey = smelt/silverfish: Young fish or “small fry” hence why it’s usually fried.
Lisa (mujol) = mullet: But not “business in the front; party in the back” kind of mullet.
Rodaballo = turbot: A flatfish.
Trucha – trout (This name is used for smaller river fish and for the larger, orange-fleshed salmon-like fish). Keep in mind that salmon in Lima is imported from Chile.
Atun – tuna
Most of these fish names change depending on where you are fishing, and on fashion. For example, corvina sounds better than croaker. I imagine that many restaurants in English speaking places will start using corvina rather than croaker on their menus.