Zebra mussel

The zebra mussel is a small freshwater mollusk with a striped shell, originally from lakes in Russia and Europe. It hitches rides on boats and has spread to new places, often causing problems by clogging pipes and outcompeting local wildlife. These hardy bivalves filter huge amounts of water, changing entire ecosystems wherever they settle.

• Originally lived only in Russian and European lakes.
• Spread to North America's Great Lakes in the 1980s.
• Considered one of the most troublesome invasive water species.