The Nature Conservancy / Florida Chapter

r Invasive Mussel Alert 8 Mytella charruana Found in Indian River Lagoon

History Identification pipes at industrial plants and power Mytella charruana, a tropical mussel Mytella charruana attaches to sub- utilities, decreasing efficiency and native to Mexico and South America, merged hard surfaces, including oyster increasing costs for these services. This first appeared in large numbers in the shells, driftwood and pilings. Speci- happened in Jacksonville in 1986. seawater intake pipes of a Jacksonville, mens are usually less than 2 cm in Florida power plant in 1986. It never length but may exceed 4 cm. At first What Are Invasive, became established as the population glance the shell is black or dark brown Non-Native Species? died off that winter. In August 2004, in color and has visible, semicircular Invasive, non-native species are organ- Mytella was discovered in the Mosqui- rings. Close inspection reveals a wavy isms that are introduced into new to Lagoon portion of the Indian River dark (brown, purple, dark green) and areas where they are not considered Lagoon. Since this discovery, Mytella light (cream) pattern. The shell’s in- native and have the ability to form numbers have increased, suggesting terior is iridescent purple. Mytella can self-sustaining, free-living popula- the mussels are reproducing. As of be distinguished from other common tions. These species have the ability April 2006, 578 individuals have been native mussels (Guekensia demissa to cause economic or environmental collected in Mosquito Lagoon. and Brachiodontes spp.) by the lack of damage or harm to human health. distinct ridges (ribs) on the exterior of They often go unnoticed until they What Is Being Done? the shells (see photos below). have spread extensively, making eradi- The Nature Conservancy has teamed cation difficult and costly. The zebra up with the University of Central Why We Are Concerned mussel in the Great Lakes and the Florida to determine the potential Mytella charruana has the potential green mussel in Tampa Bay, Florida, invasiveness of this species. Starting to greatly increase in numbers, which are examples of invasive mussels that in the summer of 2006, lagoon-wide may mean less food and space for have had devastating impacts. surveys will be conducted to deter- native organisms, including commer- mine Mytella charruana’s distribution, cially important native oysters. Mytella How You Can Help and genetic tests will be conducted to charruana can infest and clog intake Be on the look out for Mytella char- learn more about its make-up. ruana. Collect all specimens that you find; record the date and precise location (including the nearest land- mark, GPS coordinates if available, and substrate found on); and preserve specimens in rubbing alcohol. Please send this information to Dr. Linda Walters, Biology Department, UCF, Orlando, FL 32816, (407) 823-2148, Guekensia demissa [email protected].

The mission of The Nature Conservancy is to preserve the plants, animals and natural communities that represent the diversity of life on Earth by protecting the lands and waters they need to survive. Brachiodontes spp. Mytella charruana