Description:

The Round Pigtoe is one of Canada’s 54 freshwater mussel species, it is a medium to large-sized freshwater mussel that may reach 13 centimetres in length. Adults have a thick, solid, mahogany-coloured shell with dark bands. Juvenile shells are tan with green lines. This species develops growth rings as it ages, which resemble those of a tree stump.

 

Status: Endangered Provincially and Nationally

 

Important Dates:

June 30, 2008: Species listed at Risk

June 30, 2013: Species granted Habitat Protection

 

Range:

• In Ontario, it is found in the Grand, Thames and Sydenham rivers, found around Walpole Island in Lake St. Clair, and shallow areas along the shorelines of Lake Erie.

 

Habitat:

• Lives in a wide range of habitats, from small rivers in area of moderate flow with gravel, cobble and boulder bottoms, to larger rivers in mud, sand and gravel at varying depths;
• Its breeding season lasts from early May to late July and the larvae are released before winter;
• Like all freshwater mussels, this species feeds on algae and bacteria that it filters out of the water;
• Mussel larvae are parasitic (an animal or plant that lives in or on another (the host) from which it obtains nourishment) and must attach to a fish host – some known hosts are Bluegill, Spotfin Shiner and Bluntnose Minnow

 

Threats:

• Introduction and spread of the Zebra Mussel throughout the Great Lakes severely reduced or eliminated the Round Pigtoe in Lake St. Clair, Lake Erie and the Detroit and Niagara rivers;
• Decreased water quality from pollution continue to threaten the round pigtoe

 

Protection:

• Under the Ontario Endangered Species Act, the Round Pigtoe is protected against threat of being killed, collected, possessed, sold or traded;
• Under SARA (Species at Risk Act), a recovery strategy and an action plan have been developed to prevent the loss and maintain/return healthy self-sustaining populations of the Round Pigtoe

 

What You Can Do To Help:

• Help improve mussel habitat by maintaining natural vegetation next to creeks and rivers. The roots of the 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;
• Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk

 

FUN FACTS:

• Round Pigtoe eggs hatch inside a special pouch in the mother’s gills called a marsupium, where the larvae are supported before being ejected into the water;
• Mussel larvae have a very low survival rate, so mussels will produce a lot of larvae – often over a million;
• Mussels rely on a lot of good luck in order to reproduce. Males release sperm into the water, and if there happens to be a female nearby, she will capture the sperm as she filters water for food;
• Mussels are indicators of environmental health. Since they have a complex life cycle, are long-lived species (some 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.