To Save a Mussel, Find Its Fish
The Altamaha Spinymussel
(Elliptio spinosa) Up Close
Description: Palm-sized mussel usually sporting one to five spikes, or “spines,” no longer than one inch. Seemingly limited to swift-flowing water.
- Distribution: First described near the Altamaha River’s mouth near Darien in 1836. Spinies once ranged across the coastal-plain portion of the Altamaha and into the lower Ocmulgee, Oconee, and Ohoopee rivers. None have been found in the Oconee since the 1960s, the Ohoopee since 1993, and the Ocmulgee since 2001. Recent finds have been on the Altamaha.
- Conservation status: First proposed for federal protection in 2001. Pending candidate for listing as endangered. Spinies are classified as endangered on Georgia’s state list.
- Look-alikes: North America’s other two spinymussel species are found in North Carolina, Virginia, and West Virginia. The Tar River spinymussel (Elliptio steinstansana) and James spinymussel (Pleurobema collina) are listed as endangered by the federal government. Preliminary research shows that these species are not closely related to the Altamaha spiny.
- Natural role: These filter feeders improve water clarity; siphon out pollutants, nutrients, and sediment; help stabilize riverbeds; and provide a food source for animals such as raccoons. Mussels are also sensitive to contaminants, serving as indicators of stream health.
- Why the spines? Some speculate they serve as predator protection or as anchors in the river substrate.
- Dire straits: More than 70 percent of the 300 or more freshwater pearly mussels native to North America are at risk of extinction in the near future. Eleven are found in Georgia, which has about 127 different species.
Sources include U.S. Fish and Wildlife Service