Missouri’s 65 species of freshwater mussels live all around us, sitting quietly in the bottoms of rivers and streams, often unnoticed despite their bright pearls and colorful names.
Discover Nature this week, as the “Pocketbook” mussel begins breeding.
Pocketbook mussels have large, thick, oval shells, with a smooth, yellow or tan to yellowish-green epidermis, with dark green rays.
They feed on fine particles of decaying organic matter by pulling water through their body cavity, extracting nutrients and oxygen, and expelling sediment and other undigested waste.
Males release sperm directly into water. Females downstream siphon sperm into the gill chamber, where eggs are fertilized. Eggs mature into larvae, discharge into the water, and attach to host fish such as white crappie, sauger, bluegill, or yellow perch. The tiny mussel eventually breaks away and floats to the bottom of the stream where the cycle begins again.
Mussels are excellent indicators of water quality, and are an important food source for other species in the aquatic environment.
Damming, and sand and gravel mining pose the largest threat to mussel habitat. Pollution from pesticides, herbicides, fertilizers, mining waste and residential and livestock sewage also kills mussels.
Learn more about Missouri’s mussels with the Missouri Department of Conservation and their online Field Guide.