Theorie:

To speak about seafood, you need the appropriate vocabulary.
 
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Jellied - jellied meat or fish is cooked and then served in its own juices that become firm when cold;

Plaice - a sea fish with a flat, circular body, or its flesh eaten as food;

Crab - a sea creature with ten legs and a round, flat body covered by a shell, or the meat from this animal;

Shrimp - a small, pink, sea animal that you can eat, with a curved body and a shell;

Salmon - a large, silver fish, or the pink meat of this fish;

Grouper - a large fish with a big head and a wide mouth that lives in warm seas;

Lobster - a sea creature that has two claws (= sharp, curved parts) and eight legs, or the meat of this animal;

Sturgeon - a type of fish that lives in northern parts of the world and is usually caught for its eggs, which are eaten as caviar;

Sardines - a small sea fish that you can eat;

Herring - a small, silver-coloured fish which lives in the sea and is eaten as food;

Pike - a large river fish with sharp teeth, or the meat of this fish;

Oyster - a sea creature that lives in a flat shell and is eaten as food;

Trout - a type of river fish, or the meat from this fish.

Examples.

In this café you can try shrimps and oysters.

Lobster is very expensive to buy.

I like eating salmon once a week.