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Three tiny orange mussels with short pointy protruberances.
Information icon Tar River spinymussels. Photo by Chris Eads, NC State University.

Tar River spinymussel

Elliptio steinstansana

This freshwater mussel can only be found in North Carolina rivers and streams. It is now limited to a very small portion of its probable historical range and it could become extinct without significant intervention. Biologists from multiple organizations are working together to recover the species and conserve its habitat.

  • Taxon: Mollusk
  • Range: Edgecombe, Franklin, Halifax, Johnston, Nash, Pitt, Warren counties, North Carolina.
  • Status: Endangered, Listed July 29, 1985


Clean young shells are shiny, usually yellowish-brown, and often have greenish rays streaking outward from the hinge area. Older shells become brownish and tend to lack rays. One or two rows of spines can be present, with up to six spines on each valve. The spines rarely exceed 5mm in length. Shells rarely exceed 55mm in length.


The Tar River spinymussel lives in relatively silt-free unconsolidated beds of coarse sand and gravel in relatively in fast-flowing, well oxygenated stream reaches. It is found in association with other mussels, but it is never very numerous.


This mollusk feeds by siphoning and filtering small food particles that are suspended in the water.

Historical range

The Tar River spinymussel is endemic to only the Tar River and Neuse River systems in North Carolina. In the Tar River system, the species has been documented from the mainstem of the Tar River, Shocco Creek, Fishing Creek, Little Fishing Creek, Swift Creek, and Chicod Creek. In the Neuse River system, the species has been documented only from the Little River.

Current range

A map showing the presence of Tar River spinymussel in east-central North Carolina.
Tar River spinymussel distribution in North Carolina. Map by USFWS.

Conservation challenges

Based on available data, all surviving populations of the Tar River spinymussel are small to extremely small in size, highly fragmented and isolated from one another, and are in decline. The primary factors affecting the species and its habitat appear to be primarily stream impacts (sedimentation, bank instability, loss of instream habitat) associated with the loss of forest lands and forested riparian buffers, and poorly controlled stormwater runoff of silt and other pollutants from forestry and agricultural (livestock and row crop farming) activities, development activities, and road construction, operation, and maintenance. Pesticides were implicated in the largest known mortality event for Tar River spinymussel. In addition to the above, point source discharges continue to threaten habitat quality in both the Tar and Neuse River watersheds.

The genetic viability of the surviving populations remains a significant concern. All of the remaining populations of the Tar River spinymussel appear to be effectively isolated from one another by impoundments and long reaches of highly degraded habitat; and, the numbers of all of the surviving populations appear to be well below the level necessary to maintain a reproductively viable population. In addition, streams supporting populations of the Tar River spinymussel have been affected by severe - exceptional drought conditions which persisted from the fall of 2006 through the spring of 2009 – flow in reaches of several of the streams supporting the species was significantly reduced and in places completely dried up; the post-drought status of populations of the species is being assessed.

Recovery plan

Download the recovery plan (1992) and the five year review (2014).

Partnerships, research and projects

A collaborative effort to recover the Tar River spinymussel involves biologists from government agencies, a land conservancy, and academic institutions. Some of the actions the group pursues includes recovery planning, instream monitoring and research, captive propagation and population enhancement.

How you can help

  • Individuals can do a number of things to help protect freshwater species, including:
  • Conserving water to allow more water to remain in streams.
  • Using pesticides responsibly (especially around streams and lakes) to prevent runoff into mussel habitats.
  • Controlling soil erosion by planting trees and plants to avoid runoff of sediments into freshwater areas.
  • If you live near a stream, be careful not to disturb the stream bottom; you may be damaging a freshwater mussel’s home.
  • Don’t pick up any mussels that you may see in a stream. It may be one of the last few members of its species on the planet.
  • Help your family find ways to reduce the amount of chemicals that you pour down the drain in your home or use on your lawn or garden.
  • Check to see if the water draining off your roof or driveway flushes directly into a stream. Plant a garden to catch the water before it enters the stream. The garden will act like a filter and help purify the water.
  • Recycle as much as you can to reduce the amount of waste you place in the garbage.
  • Support conservation efforts that protect these unique animals and the habitats they live in.
  • Become a biologist and discover new ways to help protect freshwater mussels and other wildlife.
  • Learn more about how the destruction of habitat leads to loss of endangered and threatened species and our nation’s plant and animal diversity. Discuss with others what you have learned.
  • Support local and state initiatives for watershed and water quality protection and improvement.

Subject matter experts

Designated critical habitat

No critical habitat rules have been published for the Tar River spinymussel.

Federal Register notices

The following Federal Register documents were automatically gathered by searching the Federal Register Official API with this species’ scientific name ordered by relevance. You can conduct your own search on the Federal Register website.

  • We're sorry but an error occurred. Visit the Federal Register to conduct your own search.

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