Expand search form
In the News

As we build awareness of the incredible tall-grass prairie in southeast Manitoba, the story is being shared through various channels.

Species at Risk Spotlight: Mapleleaf Mussel

Dawson Trail Dispatch, written by Norm Gregoire, March 2024
Page 14 https://issuu.com/dispatch222/docs/dawson_trail_dispatch_march_2024

Throughout Manitoba, we are fortunate to have an abundance of waterways. Whether we enjoy them for recreation or rely on them for day-to-day living, waterways are essential for life. Waterways are also often at the forefront of discussions with regard to the health of a natural area. When we have healthy waterways, it usually coincides with the surrounding ecosystem being healthy. That being said, it is important to monitor our waterways to ensure a healthy future, not just for human residents but also for the many species that rely on them as habitat. By monitoring species like the mapleleaf mussel, we can keep track of how our local waterways are faring.

At first glance, many of Manitoba’s mussel species may look alike. The main identifying feature of mapleleaf mussels is the nodules on the shell. No other mussel in Manitoba has them. The mapleleaf mussel was named due to its similarity in shape to the maple leaf and the dark ridges on the shell that can be compared to the growth rings of a tree. They are usually brown to yellowish green in colour and have a light-coloured inside shell. This species is considered a large mussel in Manitoba, measuring twelve centimetres across.

The main reason why monitoring the health of mapleleaf mussels is so important regarding the health of a waterway is because they are filter feeders. The mapleleaf mussels spend most of their lives in slow-moving rivers with clay or hard-packed bottoms, like the Roseau River in the tall-grass prairie natural area. It is here that they are filtering the water for essential nutrients that they rely on. In turn, they also filter the water from harmful particulates such as algae and bacteria.

When living in a healthy water system, the mapleleaf mussel has a lifespan that can reach over sixty years! The life cycle of a mussel is more complex and interesting than you may think. Spawning begins in late spring; the male will release sperm into the water, and the female will siphon it in. The brood will develop inside the mother’s shell. When leaving the mother, the young mussels are known as glochidia. The glochidia are a form of parasite, as when they are ready to leave the mother, they need a host species to survive. In the case of the mapleleaf mussel, in Manitoba, they rely on channel catfish as hosts. When the time comes for release from the mother, she will attract the host by protruding a piece of her body called the mantle. Think of this almost as bait for the channel catfish. As the host is attracted to investigate the mantle, the mother mussel will release her brood. The hope is that they are able to attach themselves to the gills of the host and absorb nutrients for approximately two months before they drop off. It should be noted that, besides a polluted waterway, another big factor that contributes to the success rate of mapleleaf mussels is the presence of non-native mussels such as zebra or quagga that can outcompete them for habitat.

I find it interesting that a seldom-seen species with such a complex lifecycle can still be a big part of environmental health here in the tall-grass prairie natural area. Mapleleaf mussels play a key role in the health of our waterways, and in doing so, they truly deserve a spot in this shared ecosystem.

If you have any questions or comments, please reach out to me at info@sharedlegacymb.ca.