If you don't mind eating with the workers so aren't looking for anything fancy, after almost 20 years on the island I have yet to find better tasting fish dishes at better value here in the south than at Bar El Boya located in El Pajar in Arguineguin. What makles dining here even more unique is the restaurant is located on a pebble beach just a few dozen meters from a huge cement factory. Dinner is only Friday and Saturday nights until 23:30 otherwise it's open daily from 08:00 until 17:30 and closed on Thursday. You can get their seafood rice for around 5 euros which other tourist restaurants might serve as paella only with less seafood and charge 20 euros. Also, if you're self catering and have a microwave they do food to take away so grab something during the day to take away for dinner?
If you do want something fancy though then a short drive from the fishing harbour is the highly recommended sea-front restaurant in Patalavaca - the La Aquarela restaurant. Haute cuisine though you're paying for it. Check their website for a look at the menu. In Puerto Rico try the Grill Costa Mar down near the beach, in Meloneras try Las Rias in the Varadero center, El Senador on the beach at Maspalomas and in Playa del Ingles try Rias Bajas next to the Yumbo center. In Puerto de Mogan all the restaurants around the marina serve fresh fish dishes with some having their own boats to go out and bring in fish and seafood for them.
So what dishes to try? My favourite and perhaps the most traditional here on Gran Canaria is of course seafood Paella. As mentioned above, head to Arguineguin on a Friday or Saturday evening for the best deal. Another traditional option is to grill fish over an open flame. Sardines are cooked this way with rock salt, as is sea bass (lubina). "Cherne" is on just about every menu; It’s actually Wreckfish which is also known as Stone Bass or Bass Grouper - not to be confused with Sea Bass which it isn't. As with all restaurants, if it's full of locals or you need a reservation to get a table then it's good.
Fish Translations :-
Anchoa – Anchovies
Anguila – Small eels, often served with scrambled eggs.
Atún Rojo – Red Tuna, better known as Bluefin Tuna which is actually an endangered species in the Atlantic
Bacalao – Cod
Bocinegro – Sea Bream
Bonito – Skip-jack Tuna
Boquerones – Anchovies - this time marinated ones.
Burro – Grunt
Caballa – Mackerel
Cherne – Wreckfish / Stone Bass or Bass Grouper
Chicharro – Blue Jack Mackerel.
Chopa – Black Sea Bream
Congrio – Conger Eel
Corvina – Brown Meagre
Dorada – Gilthead Sea Bream.
Gallo – Megrin
Lenguado – Sole
Lubina – Sea Bass.
Merluza – Hake
Mero – Dusky Grouper
Morena – Moray Eel
Pez Espada – Swordfish
Pampano – Blue Butterfish
Panga – Vietnamese Cobbler
Pargo – Common Sea Bream
Rabil – Yellowfin Tuna
Rape – Monkfish
Raya – Ray
Rodaballo – Turbot
Rubio – Tub Gurnard
Salmón – Salmon, an easy one.
Salmonete – Red Mullet
Sama – Red Sea Bream
Sardina – Sardines
Sargo – White Sea Bream
Tollos – shark.
Trucha – Trout
Vieja – Parrot Fish
Seafood :-
Calamares - Squid
Cangrejo - Crab
Gambas - Prawns
Langosta - Lobster
Langostina - Crayfish
Mejillones - Muscles
Ostras - Oysters
Pulpo - Octupus