(FOX40.COM) — California officials took an extra step in mid-December to stop the spread of an invasive species detected for the first time on this continent this fall in the northern part of the state. According to the California Department of Fish and Wildlife, the California Fish and Game Commission took an "emergency action" to have the golden mussel listed as a restricted species. The golden mussel (Limnoperna fortunei) is now illegal to import, transport and possess in California. Golden mussels were first discovered on October 17 at the Port of Stockton, and since then, have been found as far south as a waterway connecting to the San Luis Reservoir forebay, in Merced County. Invasive Golden Mussels found in California Delta, first time in North America “Golden mussels are a bigger threat to California waters than quagga and zebra mussels because they can thrive in a wider range of water quality conditions,” said Jay Rowan, Chief of the CDFW’s Fisheries Branch. “Putting golden mussels on the restricted species list is an important first step toward containment and prevention of spread of this non-native species.” Golden Mussel shells collected in October 2024 at a water quality station at Rough and Ready Island near Stockton. The species poses a threat to ecosystems in the California Delta and all other state waterways, water conveyance systems, infrastructure and water quality, the CDFW said. Boat inspections stop Zebra Mussels entering Lake Tahoe The golden mussel is native to China and Southeast Asia and was likely brought across the ocean while attached to large ships, CDFW said. The mussels are typically under 1.5 inches with a shell color that is light golden to dark yellow or brown and can live in freshwater and brackish water. State wildlife officials ask anyone who spots the species to take clear, up-close photos with something next to them that shows their size, and to submit these at this link to help limit their spread.