What are the physical characteristics of the zebra mussel?

Zebra mussels are small, freshwater bivalves typically measuring about 1 to 2 inches in length, though they can grow up to 2.5 inches. They are characterized by their distinctive dark brown or black shells adorned with light yellow or white zigzag stripes, which give them their name. Their shells are D-shaped and have a smooth texture. Zebra mussels also possess a byssal threads that allow them to attach firmly to surfaces, aiding in their ability to colonize various habitats.