Marimo moss balls sold at pet stores have been found to be contaminated with Zebra mussels.

Invasive zebra mussels found in aquarium moss products (some in Kalamazoo) prompt national response

Here are 5 things to know about invasive zebra mussels in moss balls

Invasive zebra mussels found hiding in aquarium plants for sale at pet stores - Natural Resources

Update: Pet store chains remove product infested with invasive zebra mussels, new how-to video on cleaning your aquarium, Local News Stories

Invasive zebra mussels found in aquarium products, Indiana DNR says

Zebra mussels found in Wyoming pet stores

Invasive mussel contaminated moss balls seized

DNR warning: Check your aquariums for a potentially invasive species

Moss Balls Carrying Zebra Mussels

Lethbridge Northern Irrigation District -- Invasive Species

Invasive zebra mussels found in aquarium moss products (some in Kalamazoo) prompt national response

Zebra mussels found in moss balls shipped to pet stores in several states, including North Dakota

INVASIVE ZEBRA MUSSELS on MARIMO MOSS Balls: What's the Latest? — Ep. 235

Aquatic Invasive Species Found In Moss Balls - RMA