A mussel is a bivalve mollusk that can be found in lakes, rivers, creeks, intertidal areas, and throughout the ocean. The saltwater mussels and freshwater mussels are not thought to be closely related and are grouped in different subclasses. All freshwater mussels belong to the mollusk order Unionoida, a solely freshwater group. These animals are large (up to 150 mm) possessing a hinge which is most developed posterior of the beaks or umbos. The shells are typically covered by a thick skin or periostracum that is variously colored and sometimes rayed on the disk depending upon the species. Internally, the shell has a "pearly" appearance due to the nacreous lining of the inner shell surfaces. These features have made freshwater mussels popular among collectors since the early 19th century. The hard, calcium-based shells consist of two halves joined by a hinge. Unique names like "monkeyface," "threehorn wartyback," and "pink heelsplitter" refer to the wide range of shell size, color, shape, and texture found among mussel shells. Mussels usually don't move much, but a muscular "foot" helps them burrow and allows limited travel if disturbed by floods or drought. The foot also helps anchor them against strong currents and may prevent a hungry muskrat from tugging them out for its dinner! A mussel's shell, however, provides its main protection from predators. Unlike most animals, which must travel in search of food, freshwater mussels' food drifts to them, mainly tiny plants and animals called plankton suspended in the water. By drawing water inside their shells through a siphon, their gills filter out food and take in oxygen. Freshwater mussels need a lot of luck to successfully reproduce. Their unusual life cycle begins when eggs held inside the female are fertilized by sperm drawn inside her while siphoning water. For most species, if a male of her kind isn't nearby upstream, she can't reproduce. For a few, this is not a problem because they seem able to fertilize themselves. Freshwater mussels are used as the host animal for the cultivation of freshwater pearls.
No other country in the world equals the United States in freshwater mussel variety. While all of Europe supports only 12 species, nearly 300 kinds live here, mostly within the vast watershed of the Mississippi River. Unfortunately, it's estimated that 70% of the freshwater mussels are extinct, endangered, or in need of special protection.
Mussels are a popular seafood item. Mussels can be prepared boiled or steamed. As for all shellfish, mussels should be alive just before they are cooked. A simple criterion is that live mussels, when in the air, are tightly shut; open mussels are dead and should be discarded. The mussel shells open by themselves when cooked.
It's not hard to find a good mussels recipe. Mussels with garlic, onions, and lemon is a succulent dish. You'll need: 8 to 10 quarts mussels in shell; 3 ribs celery, chopped; 2 medium onions, sliced; 1/4 cup chopped fresh parsley; 1 large clove garlic; 1 large lemon, sliced; 2/3 cup water. Scrub mussels. Wash mussels in lukewarm water, changing water 3 to 4 times; set aside. Put celery, chopped onions, parsley, garlic, lemon and water to a large kettle. Cover kettle and cook for about 15 minutes, or until vegetables are tender; add mussels. Cover and cook for about 15 minutes, or until mussels are open. Shake kettle a few times to prevent sticking. Remove and discard unopened mussels. Serve in broth.