Species At Risk

Wavy-rayed Lampmussel

(Lampsilis fasciola)


Wavy-rayed Lampmussel
Wavy-rayed Lampmussel occurrences map


The Wavy-rayed Lampmussel is a medium-sized freshwater mussel. It can reach ten centimetres in length and can live up to 20 years. This species is characterized by its yellow or yellowish-green, rounded shell that has numerous thin wavy green lines.


In Canada, the Wavy-rayed Lampmussel is found only in Ontario in the Grand, upper Thames, Maitland, and Ausable rivers, and the St. Clair River delta in Lake St. Clair. It has disappeared from Lake Erie, the Detroit River and most of Lake St. Clair, and may also be gone from the Sydenham River.


The Wavy-rayed Lampmussel is usually found in small to medium rivers with clear water. It lives in shallow riffle areas with clean gravel or sand bottoms. Like all mussels, this species filters water to find food, such as bacteria and algae. Mussel larvae are parasitic and must attach to a fish host, where they consume nutrients from the fish body until they transform into juvenile mussels and drop off. The Wavy-rayed Lampmussel’s fish hosts are the Largemouth Bass and Smallmouth Bass. The presence of fish hosts is one of the key features for an area to support a healthy mussel population.


The main threats to the Wavy-rayed Lampmussel are pollution and siltation, which occurs when too much soil washes into the river from nearby agricultural and urban areas. The Zebra Mussel, an invasive species from Europe, has caused the loss of populations in the Great Lakes and connecting channels and could threaten river populations if they invade reservoirs on these systems. Conditions that threaten the fish host species also threaten the Wavy-rayed Lampmussel. Predation by muskrats may also be a problem for small populations.


The Wavy-rayed Lampmussel and its habitat are protected under Ontario’s Endangered Species Act.

What You Can Do to Help the Wavy-rayed Lampmussel

  • The Ministry of Natural Resources tracks species at risk such as the Wavy-rayed Lampmussel. You can use a handy online form to report your sightings to the Natural Heritage Information Centre. Photographs with specific locations or mapping coordinates are always helpful. nhic.mnr.gov.on.ca
  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).
  • You can help improve mussel habitat and keep Ontario’s water safe and clean by maintaining natural vegetation next to creeks and rivers. The roots of plants reduce erosion and can stop soil from washing into the river. Fence off streamside areas to keep cattle (and their manure) out of the water. There are many other things that you can do to help reduce soil erosion and you might be eligible for funding assistance. For more information, visit the Ontario Soil and Crop Improvement Association: www.ontariosoilcrop.org.
  • Private land owners have a very important role to play in species at risk recovery. If you find Wavy-rayed Lampmussel in a watercourse on or adjacent to your property,you may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.
  • Invasive species seriously threaten many of Ontario’s species at risk. To learn what you can do to help reduce the threat of invasive species, visit: ontario.ca/invasivespecies ; www.invadingspecies.com ; www.ontarioinvasiveplants.ca ; and, www.invasivespecies.gc.ca .
  • Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.

Did you know?

The Wavy-rayed Lampmussel can fish. To attract a fish host that its parasitic larvae can attach to, the female produces a lure that looks like a wriggling minnow. When a fooled fish attacks the lure, the mussel ejects its larvae, which have a better chance of attaching to the host at such a close distance.

Did you know?

The Wavy-rayed Lampmussel is known to produce four different fishing lures. The lure can be bright red, black, or even resemble a minnow, complete with eye spots!

Did you know?

Mussels are good indicators of environmental health. Since they have a complex life cycle, are long-lived (some species can live up to 100 years!) and eat by filtering water and its pollutants, mussels can provide a snapshot of how healthy our waterways are.

Did you know?

Aboriginal people harvested mussels for food and to create jewelry and tools. In the 1800s, massive numbers of mussels were harvested from the Grand River to create buttons. Millions were shipped out every year until the 1940s when plastic became more popular.

The Endangered Species Act

Contact your local ministry office

Often the best source of local information on species at risk is your nearest ministry office. Call with your questions or concerns.