The paper pondshell occurs statewide, in quiet water of ponds, lakes, reservoirs, sloughs, and streams. It is found in rivers as large as the Mississippi and as small as the Maries. In rivers, it favors quiet backwaters and eddies in silt or a mix of silt and fine sand.
Externally, the paper pondshell's shell is very thin and elongated; it is oblong and inflated in adults. The umbo (beak) is not raised above the very flat hinge line. The periostracum (thin outer layer) is shiny, yellow to green, with faint yellow to green rays; young individuals are beautiful bright green, with thin glossy shells.
Inside the shell, the beak cavity is shallow to absent; teeth are absent; the nacre (mother-of-pearl layer) is iridescent white to bluish white.
For a fuller introduction to Missouri’s native freshwater mussels, and to learn the terms for their anatomy, see their group page.
Similar species: Small giant floaters are distinguished by having the umbo distinctly raised above the hinge line. The pondmussel, cylindrical papershell (Anodontoides ferussacianus), and scaleshell are also similar.
Adult length: 1–4 inches.
Statewide but sporadic; sometimes locally abundant.
Habitat and Conservation
Quiet water in ponds, lakes, reservoirs, sloughs, and streams. Found in rivers as large as the Mississippi and as small as the Maries. In rivers, it favors quiet backwaters and eddies in silt or a mix of silt and fine sand.
Food
Freshwater mussels consume algae, bacteria, and fine particles of decaying organic matter. They extract nutrients and oxygen from water drawn into the body cavity through a specialized structure called the incurrent siphon; sediment, undigested food, and waste (called pseudofeces) are expelled through the excurrent siphon.
Status
Fairly common, although degrading water quality and watershed destabilization interfere with the survival of this and all freshwater mussels.
Life Cycle
As with most mussels, males release sperm into water, and females downstream siphon sperm into the gill chamber, where eggs are fertilized. Eggs mature into larvae and discharge into the water and attach to host fish. The growing mussel later breaks away and floats to the stream bottom, and the cycle repeats.
This species, unlike most other freshwater mussels, is hermaphrodic: An individual can produce both eggs and sperm, and can also fertilize itself.
For its larval hosts, the paper pondshell a wide variety of species, but apparently the principal hosts are green sunfish, largemouth bass, and bluegill.
Human Connections
Mussels play important roles in maintaining the health of Missouri’s water resources:
- As food for fish, they are important for Missouri’s fisheries. Small mammals and some birds eat them, as well.
- They filter algae, bacteria, and other particles from the water, improving water quality and cycling nutrients and energy in streams and lakes. Clean water is necessary for people and nature.
- Because mussels are sensitive to habitat disturbance and pollution, they are good indicators of the overall health of aquatic ecosystems and water quality.
The shells of several types of mussels were an important resource historically for button manufacture. Some species are still commercially important in the cultured pearl and jewelry industries.
Ecosystem Connections
Mussels play important roles in maintaining the health of Missouri’s water resources:
- As food for fish, they are important for Missouri’s fisheries. Small mammals and some birds eat them, as well.
- They filter algae, bacteria, and other particles from the water, improving water quality and cycling nutrients and energy in streams and lakes. Clean water is necessary for people and nature.
- Because mussels are sensitive to habitat disturbance and pollution, they are good indicators of the overall health of aquatic ecosystems and water quality.
The shells of several types of mussels were an important resource historically for button manufacture. This species is one that was used to make buttons. Some species are still commercially important in the cultured pearl and jewelry industries.
