Megan Baskerville, from Macon County Soil & Water Conservation District, emailed me about a “fun volunteer event coming up in Mohamet, Illinois” hosted by the Upper Sangamon River Conservancy.
And what was this event you may ask?
Jumping in the muddy Sangamon River and rooting for mussels.
Fun! Who doesn’t like live rocks? Sarah and I signed up. Upon arrival, many familiar faces were already in attendance. After a quick intro given by several field professionals, we were in the water. Freshwater mussels come in all shapes, sizes, and colors. Many prefer a sandy substrate, while others cobble or silt. They are filter feeders. Absorbing the environment makes them extremely sensitive to environmental stressors. This allows them to be a useful tool in monitoring water quality. These aquatic creatures lack exciting cub appeal, but they make up for it with a convoluted natural history – deception, parasitism, hitchhiking, bungee jumping…
Females of many mussels species have a modified extension of their mantle they extend. It’s called a lure. This ‘lure’ is indeed a lure, set to attract specific groups of fish. Each species has a slightly different lure. Some surprisingly look like small fish. Once a particular fish takes the bait, the mussel clamps down on the fish and forcibly expends its’ glochidia (larvae) into the mouth of the fish. These glochidia embed into the lungs of the host fish and drop off once developed into miniature mussels. The tiny mollusks set out an attachment thread, called a byssal thread, anchoring to something stable to hold themselves in place until developed further.
This all happens right here in our waters.
That afternoon, 15 different species of mussels were found by our group.