Welcome to the
Wonderful World of Freshwater Mussels
You might wonder why you should care about freshwater mussels. Well our answer, “Why shouldn’t you care about freshwater mussels?!”
Mussels are Mother Nature’s water filters.
Freshwater mussels are filter-feeders that can filter up to 15-20 gallons of water per day. They naturally remove bacteria, algae and fine organic particles from the water just by eating and being themselves. By their feeding processes, they can even remove things like suspended inorganic sediment and even sequester chemical pollutants. This is a talent we love to show off when we give tours of our facility.
Mussels serve as indicators of healthy streams.
As long-lived filter feeders that are exposed to all of the things we do to our lakes and streams, their presence (or absence) tells us a LOT about how water quality. A diverse mussel population means a healthy stream. A healthy stream means healthy water for all the organisms that depend on it – including us. How are the mussel populations doing in the streams that your city or town gets their water from?
They are our unique natural treasures… and they are disappearing
Historically home to about 300 different species, North America is the global hotspot for freshwater mussel biodiversity. Unfortunately, about 10% of those are already extinct with another 60% or more being imperiled to varying degrees. North Carolina, where we live, is home to about 50 species with some of those only being found within our state. To have animals as beautiful and important as these in our collective care is a tremendous gift and tremendous responsibility.
They have a unique and absolutely fascinating life cycle.
The larvae of our native freshwater mussels have to attach to a specific host fish where they metamorphose to the next life stage. We guarantee it will blow your mind! Learn more about the various ways a female mussel that can’t really move can get her babies on to a highly mobile fish.
They are a critical part of our aquatic ecosystems.
Not only is the filtration that mussels perform vital for clean water, they are also participating in nutrient cycling, making nutrients available to other invertebrates. They help stabilize substrate, and their shells serve as habitat for certain aquatic insects and cover for small fish. They serve as food to certain fish as well as mammals like muskrats, otters, and raccoons.
Imperiled Freshwater Mussels
Meet the three flagship species at the heart of our conservation efforts: the Dwarf Wedgemussel, Yellow Lance, and Atlantic Pigtoe.
Federally endangered
Dwarf Wedgemussel
Alasmidonta heterodon
One of North America’s rarest freshwater mussels, this tiny species plays an outsized role in healthy river ecosystems.
Learn more about the Dwarf Wedgemussel
Range
This species is distributed in Atlantic coast drainages from North Carolina, USA to New Brunswick, Canada (historically).
Habitat
The Dwarf Wedgemussel prefers quick running water on cobble, fine gravel, or firm sandy substrate.
Did you know?
In North Carolina, the Dwarf Wedgemussel appears to be restricted to a few isolated headwater streams. They can metamorphose on several darter species, but the Tessellated Darter (Etheostoma olmstedi), pictured above, is the most efficient host in NC. This mussel attracts their host fish with a very subtle luring display by manipulating their mantle tissue.
Fun fact!
The Dwarf Wedgemussel larvae are about 0.3 mm long and have hooks that allow them to attach to either gills or fins or their hosts. The scientific name heterodon, meaning different teeth, refers to their highly unique and reversed hinge-tooth pattern.
Federally threatened
Yellow Lance
Elliptio lanceolata
Known for its distinctive golden shell, the Yellow Lance is a symbol of both the beauty and vulnerability of our freshwater rivers.
Learn more about the Yellow Lance
Range
This species range extent is decreasing and is restricted to the Atlantic slope of Maryland south to North Carolina.
Habitat
The Yellow Lance prefers sand at the downstream end of stable sand/gravel bars and are often found buried deep.
Check it out!
The Yellow Lance has an elongate shell with a waxy yellow color. It ranges from the Neuse River Basin in North Carolina north to the Patuxent Basin in Maryland. Unfortunately, they have been extirpated from much of their historical habitat. Yellow Lance prefer clean, coarse sand or very fine gravel with moderate flow. They may be found on certain sand bars or in small pockets of clean, stable sand adjacent to areas of high flow. They are often completely buried and can be found up to a foot below the substrate surface.
Take a closer look
Larvae are released with small bits of mucus that are near neutrally buoyant and would be attractive for their fish hosts to nibble on. The larvae (called glochidia) are around 170-180 microns in size and are sub-circular in shape. Depending on the size of the mussel, one female might release approximately 5,000-40,000 individual glochidia.
Bonus!
The Yellow Lance uses White Shiners (Luxilus albeolus) and Pinewoods shiners (Lythrurus matutinus) as hosts. Both fish species are dependent on mounds constructed by Bluehead Chubs (Nocomis leptocephalus) or Bull Chubs (N. raneyi) for their spawning grounds. This makes Nocomis chubs very important for the rare Yellow Lance mussel.
federally threatened
Atlantic Pigtoe
Fusconaia masoni
An important natural water filter, the Atlantic Pigtoe helps keep rivers healthy while facing an uncertain future.
Learn more about the Atlantic Pigtoe
Range
This species is found in increasingly limited headwater areas throughout the southern Atlantic slope.
Habitat
The Atlantic Pigtoe prefers quick running water on sand and gravel at the downstream edge of riffles.
Host attraction
The Atlantic Pigtoe uses a variety of minnows as their host fish.
In order to attract these fish, this mussel packages their glochidia (larvae) into worm-like strands called conglutinates.
Many are tinted red due to the color of unfertilized eggs. However, some conglutinates can also be white.
Take Action Now
Help us protect what can’t speak for itself. Your support directly supports conservation, research, and the protection of vulnerable species.