Something for St. Patrick’s Day! (I get to celebrate, because my grandmother’s original name was Murphy, which is about as Irish as you get.)
This green crab (Carcinas maenas) can be found in the waters around Ireland. Unfortunately,it’s been distributed around the world, and is no one of the world’s worst invasive species.
However, Ireland also has its own problems with unwelcome visitors. My most recent paper looks at this.
If St. Patrick were alive today, his job should be casting out alien crayfish, not snakes.