This Week’s Endangered Species in Focus: Wavy-rayed Lampmussel (Lampsilis fasciola)

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Status: Endangered Provincially and Nationally
The Wavy-rayed Lampmussel is a medium-sized freshwater mussel. The shell of this lampmussel is yellow, or yellowish-green and has numerous thin wavy green lines (hence its name “wavy-rayed”). This species grows to a 100mm, has a lifespan of at least 10 years, but rarely more than 20 years. Spawning of the Wavy-rayed Lampmussel likely occurs in late summer and the larvae is released the following May-August.
Important Dates:

  • February 23, 2007: Recovery Strategy prepared by the Species at Risk Act – Recovery Strategy Series
  • April 2010: Species listed as a “special concern” via the Committee on the Status of Endangered Wildlife in Canada (COSEWIC)
  • February 18, 2011: Recovery Strategy back in place for the Wavy-rayed Lampmussel
  • November 18, 2011: Government Response Statement prepared (advises of actions being taken)
  • March 2013: Species listed as a “special concern” under the Species at Risk Act (SARA)


  • The Wavy-rayed Lampmussel can be found in 13 states and Ontario;
  • It can be found in much of the Ohio and Mississippi River drainages, as well as the lower great lakes and their tributaries;
  • Although this mussel was once prevalent in the rivers of southwestern Ontario, its range and abundance is now limited.


  • The Wavy-rayed Lampmussel lives mainly in gravel or sand bottoms of riffle areas in clear, medium-sized streams;
  • Typically the mussels are found in waters that have good current;
  • The presence of fish hosts such as large and small mouth bass is one of the key features that support the Wavy-rayed Mussels habitat.


  • Siltation is likely the most immediate threat to the Wavy-rayed Lampmussel;
  • The invasion of the zebra mussel may have been responsible for the decline of the Wavy-rayed Lampmussel from the Lake Erie, Lake St. Clair and Detroit Rivers;
  • Water clarity plays a particular role in the Wavy-rayed Lampmussel’s endangerment as it uses a visual lure to attach its larvae to the fish hosts;
  • Dams on the Grand and Thames Rivers have likely played a significant role in the decrease of the Wavy-rayed Lampmussel as well.


  • Protected under the Endangered Species Act, 2007;
  • Provided additional protection under the Fisheries and Planning Acts;
  • Currently it is listed as a species of “special concern” under SARA
  • An ecosystem-based, multi-species recovery plan is currently being prepared for the Wavy-rayed Lampmussel;

What YOU Can Do to Help:

  • Maintenance, or establishment of land adjacent to streams, rivers, lakes and wetlands can help protect mussel habitats from many of their threats;
  • Fence of streamside areas to keep cattle (and their manure) out of the water;
  • You may be eligible to receive funding assistance from Ontario Soil and Crop Improvement Association to help reduce soil erosion;
  • Report your sightings to the Natural Heritage Information Centre;
  • Volunteer with your local Nature Club or Provincial Park to learn how you can help in many ways


  • Wavy-rayed Lampmussels attach themselves to Bass gills and feed off their nutrients for the first few weeks of their existence. To attract the fish, the female produces a ‘lure’ that appears like a minnow to the fish, once attacked, the mussel ejects its larvae;
  • A single mussel can filter up to 40 litres of water per day;
  • As particularly sensitive creatures, the mussel is a great indication of the health of its surrounding ecosystem and will be one of the first species to disappear from their environment;
  • Aboriginal people harvested mussels for food and to create jewelry and tools; in the 1800s massive numbers of musseld were harvested from the Grand River to create buttons; millions were shipped out every year until the 1940s when plastic became more popular.

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