Теория:
To speak about seafood, you need the appropriate vocabulary.

Plaice – камбала
Crab – краб
Shrimp – мелкая креветка
Salmon – лосось, семга
Grouper – морской окунь
Lobster – омар
Sturgeon – осетр
Sardine – сардина
Herring – сельдь
Pike – щука
Oyster – устрица
Trout – форель
Examples:
I would like to try a lobster.
She dislikes sardines.
Источники:
http://www.loligos.co.za/?lightbox=image_7t3