Most mussels sold in our supermarkets and fishmongers are cultivated rather than wild. There are several types of mussels, including European or blue mussels and larger green-lipped ones from New Zealand.
In the kitchen
They should be used as soon as possible, on the same day as you bring them home. If you have to keep mussels for a few hours - tip them in a deep bowl and cover with a couple of layers of damp newspaper. Don't soak them in water though - it ruins them.
Live mussels should have shiny shells and feel full when handled. Before cooking, they need to be cleaned under cold running water and any beards removed with a bristle brush.
When you buy mussels, they should all have closed shells. If any are open, give them a firm tap on the kitchen counter on their base and they should close after a few seconds. Discard any that don't close, as they run the risk of contamination.
Mussels are usually steamed in a little flavoured liquid until the shells have opened. They're often baked or grilled on the half-shell too.
Cooked mussels work well with pastas, and make tasteful additions to rice-based dishes such as paellas and risottos.