Potamilus ohiensis was formerly known as Leptodea laevissima.
Three large, distinct ganglia make up the bilateral nervous system of a bivalve. Cerebropleural ganglia are anterior and give rise to the visceral (gut) ganglia and pedal (foot) ganglia.
The middle lobe of the mantle edge has most of a bivalve's sensory organs. Paired statocysts, which are fluid filled chambers with a solid granule or pellet (a statolity) are in the mussel's foot. The statocysts help the mussel with georeception, or orientation.
Unionids in general may have some form of chemical reception to recognize fish hosts. Mantle flaps in the lampsilines are modified to attract potential fish hosts. How the snuffbox attracts its main fish host, the logperch, is unknown. However, the mantle flaps are darkened and may resemble food for the logperch.
Glochidia respond to both touch, light and some chemical cues. In general, when touched or a fluid is introduced, they will respond by clamping shut.
Communication Channels: chemical
Perception Channels: visual ; tactile ; vibrations ; chemical
Potamilus ohiensis currently has no special conservation status.
US Federal List: no special status
CITES: no special status
Fertilized eggs are brooded in the marsupia (water tubes) up to 11 months, where they develop into larvae, called glochidia. The glochidia are then released into the water where they must attach to the gill filaments and/or general body surface of the host fish. After attachment, epithelial tissue from the host fish grows over and encapsulates the glochidium, usually within a few hours. The glochida then metamorphoses into a juvenile mussel within a few days or weeks. After metamorphosis, the juvenile is sloughed off as a free-living organism. Juveniles are found in the substrate where they develop into adults.
Development - Life Cycle: metamorphosis
Mussels are ecological indicators. Their presence in a water body usually indicates good water quality.
Glochidia were found to metamorphose on the freshwater drum in the lab. Natural infestations have also been observed.
Ecosystem Impact: parasite
Species Used as Host:
In general, unionids are filter feeders. The mussels use cilia to pump water into the incurrent siphon where food is caught in a mucus lining in the demibranchs. Particles are sorted by the labial palps and then directed to the mouth.
Mussels have been cultured on algae, but they may also ingest bacteria, protozoans and other organic particles.
Plant Foods: algae; phytoplankton
Other Foods: detritus ; microbes
Foraging Behavior: filter-feeding
Primary Diet: planktivore ; detritivore
The pink papershell is generally found in the Mississippi drainage, ranging from western New York to southern Michigan to eastern Texas.
In Michigan this species was recorded from the Grand River and Pentwater Lake.
Biogeographic Regions: nearctic (Native )
The pink papershell is usually found in rivers and large streams, and rarely small creeks. The current where it is found is fairly swift and substrates vary from silt, mud, or sand.
Habitat Regions: freshwater
Aquatic Biomes: rivers and streams
The pink papershell is up to 17.8 cm (7 inches) long , and is oblong and ovate in shape. The shell is usually fairly thin, fragile and compressed. The anterior end is sharply rounded, the posterior end also sharply rounded. The dorsal margin is straight and the ventral margin is uniformly curved. Behind the umbo and towards the posterior is a large wing. Aneriorly, there is also a wing, but it is smaller and usually missing in older individuals.
Umbos are flattened, not raised above the hinge line, and are slightly on the anterior end of the shell. The beak sculpture has three or four fine, small, nodulose, thickened ridges.
The periostracum (outer shell layer) is shiny, tan or olive-green to dark brown. Older specimens tend to be darker brown.
On the inner shell, the left valve has two pseudocardinal teeth, which are thin and divergent. The anterior tooth is anterior to the umbo. The two lateral teeth are curved and short. The right valve has one thin, long pseudocardinal tooth. Anterior to this tooth is a low, long, ridgelike denticle (nacreous swelling). The one lateral tooth is short and fairly high.
The beak cavity is shallow. The nacre is light purple to pink and iridescent at the posterior end.
In Michigan, this species can be confused with the fragile papershell and the pink heelsplitter. The fragile papershell is generally light yellow and darker toward the umbos. The fragile papershell is also a little more oval in shape and generally has less of a prominent wing. The pink heelsplitter is usually much darker, has a more prominent wing, and rays. The nacre is also uniformly purple.
Range length: 17.8 (high) cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
Unionids in general are preyed upon by muskrats, raccoons, minks, otters, and some birds. Juveniles are probably also fed upon by freshwater drum, sheepshead, lake sturgeon, spotted suckers, redhorses, and pumpkinseeds.
Unionid mortality and reproduction is affected by unionicolid mites and monogenic trematodes feeding on gill and mantle tissue. Parasitic chironomid larvae may destroy up to half the mussel gill.
Known Predators:
Age to sexual maturity for this species is unknown. In Michigan, reproduction of E. triquetra probably occurs from mid-July to August when water temperatures are from 21 to 27 degrees C. In general, gametogenesis in unionids is initiated by increasing water temperatures. The general life cycle of a unionid, includes open fertilization. Males release sperm into the water, which is taken in by the females through their respiratory current. The eggs are fertilized in the suprabranchial chambers, then pass into water tubes of the gills, where they develop into larvae, called glochidia.
Breeding interval: The snuffbox mussel breeds once in the warmer months of the year.
Breeding season: In Michigan, the breeding season is mid-July to August.
Average gestation period: 10 months.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); viviparous
Females brood fertilized eggs in their marsupial pouch. The fertilized eggs develop into glochidia. There is no parental investment after the female releases the glochidia.
Parental Investment: pre-fertilization (Provisioning); pre-hatching/birth (Provisioning: Female)
Potamilus ohiensis, the pink papershell, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae. It is also known as the papershell or fragile heelsplitter, and is similar to the Leptodea fragilis and Potamilus alatus species.[1]
The pink papershell has a thin, compressed, elongate shell, with rounded anterior and posterior ends. The surface is shiny, and brown or olive green in color. The nacre is pink or purple. These freshwater mussels grow as large as 7 inches (18 cm) in length. They generally live in large rivers, with mud, sand or silt bottoms.[1] Fish known as the freshwater drum and white crappie act as hosts for the glochidia larvae of P. ohiensis.[2]
Potamilus ohiensis, the pink papershell, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae. It is also known as the papershell or fragile heelsplitter, and is similar to the Leptodea fragilis and Potamilus alatus species.