granchio

Many different species and sizes. Besides just eaten plain, they find their way into ravioli and onto fettuccine. In Venice it's granzio.

Crab claws are called chele.

The kind of crab making the headline in Italy at the moment, however, is the Chesapeake blue crab, the Granchio blu, an invasive species brought over from North America in ships’ ballast, and safe from their usual predators in the Po delta are decimating the native fauna, especially the clams. They taste delicious so the government is trying to encourage chefs to prepare them, although the locals say that isn’t enough.