Seafood Idioms. The sea covers two thirds of our planet.

The sea has always been an important source of food.

Any food that we take from the sea is called seafood.

There are various types of seafood.

The main type of seafood is fish.

Fish have gills which let them absorb oxygen from the water.

They use fins to move through the water.

Fish include the bony fish like cod and haddock.

These are the most popular fish in Britain.

I went off them when I got a bone stuck in my throat once.

It hurt a lot and I had to go to hospital.

I was looking a bit blue around the gills, I can tell you.