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.
Mussels are heterothermic, and therefore are sensitive and responsive to temperature.
Unionids in general may have some form of chemical reception to recognize fish hosts. How the fluted shell attracts and recognizes its fish host is unknown.
Glochidia respond to 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
Lasmigona costata is listed as Endangered in Vermont, Threatened in Kansas and Special Concern in Minnesota.
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 a glochidium, usually within a few hours. The glochidia 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
There are no significant negative impacts of mussels on humans.
Mussels are ecological indicators. Their presence in a water body usually indicates good water quality.
Fish hosts are determined by looking at both lab transformations and natural infestations. Looking at both is necessary, as lab transformations from glochidia to juvenile may occur, but the mussel may not actually infect a particular species in a natural situation. Natural infestations may also be found, but glochidia will attach to almost any fish, including those that are not suitable hosts. Lab transformations involve isolating one particular fish species and introducing glochidia either into the fish tank or directly inoculating the fish gills with glochidia. Tanks are monitored and if juveniles are later found the fish species is considered a suitable host.
In lab trials, Lasmigona costata metamorphosed on the banded darter, longnose dace, and northern hogsucker.
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.
The parasitic glochidial stage absorbs blood and nutrients from hosts after attachment. Mantle cells within the glochidia feed off of the host’s tissue through phagocytocis.
Plant Foods: algae; phytoplankton
Other Foods: detritus ; microbes
Foraging Behavior: filter-feeding
Primary Diet: planktivore ; detritivore
The fluted-shell is generally in the Mississippi River drainage, including the Tombigbee River system. To the north it occurs in the St. Lawrence system from north of Lake Superior to Lake Champlain and the Ottawa River. In the Hudson Bay drainage it is found in the Red and Winnipeg systems.
In general, L. costata is sporadically distributed where it is found. In Michigan the fluted shell generally occurs in small to medium sized rivers in both the upper and lower peninsulas.
Biogeographic Regions: nearctic (Native )
The fluted shell is found in medium to large rivers, often in riffles and runs. Substrates it inhabits includes sand, mud, or fine gravel in areas with slow to moderate flow.
In the Huron it was found mainly in areas with noticeable current, with sand and gravel substrates.
Habitat Regions: freshwater
Aquatic Biomes: rivers and streams
The age of mussels can be determined by looking at annual rings on the shell. However, no demographic data on this species has been recorded.
The fluted-shell is up to 17.8 cm (7 inches) long , and is ovate and elongate in shape. The shell is moderately thick, compressed to moderately inflated. The anterior end is uniformly rounded, the posterior end is truncated above and angular where the posterior ridge meets the margin of the shell. The dorsal and ventral margins are straight to slightly curved.
Umbos are low, and not raised above the hinge line. The beak sculpture has three or four concentric and sometimes sinuate ridges.
The periostracum (outer shell layer) is smooth, and younger individuals often has green and brown rays. Older specimens tend to be more brown.
On the inner shell, the left valve has two fused pseudocardinal teeth, which are smooth. The lateral teeth is just a thickened area on the hinge line. The right valve has one (occastionally two) triangular and smooth pseudocardinal tooth.
The beak cavity is shallow. The nacre is blue-white, tinged with cream or salmon-colored at the beak cavity, and iridescent at the posterior end.
In Michigan, this species can be confused with the creek heelsplitter, which is usually smaller and lacks flutings on the wing.
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. Unionids are gonochoristic (sexes are separate) and viviparous. The glochidia, which are the larval stage of the mussels, are released live from the female after they are fully developed.
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 internally fertilized in the suprabranchial chambers, then pass into water tubes of the gills, where they develop into glochidia.
Lasmigona compressa is a long-term brooder. In the Huron River in Michigan, it was gravid from early August to late May. It probably spawns from June to July in Michigan.
Breeding interval: The fluted shell breeds once in the warmer months of the year.
Breeding season: In Michigan, the breeding season is probably June to July.
Range gestation period: 10 (high) months.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); 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)
Lasmigona costata, the flutedshell, is a species of freshwater mussel.[1] It is an aquatic bivalve mollusk in the family Unionidae.
