In the United States this species occurs in Illinois, Indiana, Kentucky, Michigan, Missouri, Ohio, Tennessee and Wisconsin. NatureServe (2009) have classified it as Critically Imperilled in North Carolina, New York, Iowa, Arkansas, Alabama and Virginia and it is Presumed Extirpated in Kansas. In Canada, this species occurs in Ontario.

This species is widespread in the eastern United States and is distributed in the lower and middle sections of the St. Lawrence River Systems; Lake Huron, St. Clair and Erie; and the upper Mississippi River system, south to Ohio, Cumberland, and Tennessee River systems (Clarke 1981).

The slippershell is found in the upper Mississippi drainage, and in Ohio Cumberland and Tennessee Rivers. In the St. Lawrence system it is found from Lake Huron to the Ottawa River. In general its range extends from western Maine, south to northern Georgia, west to Arkansas and north to North Dakota.

In Michigan this species is found in smaller creeks and rivers in both the upper and lower peninsula.

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) Widespread in eastern U.S. and distributed from Lake Huron, St. Clair and Erie, and upper Mississippi River system, south to Ohio, Cumberland, and Tennessee River systems (Parmalee and Bogan, 1998). In Canada, this species is restricted to the Lake Erie drainage in Ontario (Metcalfe-Smith and Cadmore-Vokey, 2004).

The slippershell is up to 3.8 cm (1.5 inches) long , and is rhomboidal. Older individuals have fairly thick shells. The   anterior end is rounded, the posterior end square and truncated above and sharply rounded below. The dorsal margin is slightly rounded and the ventral margin is straight or slightly arched.

Umbos are raised slightly above the hinge line. The beak sculpture is three to six irregular loops.

The periostracum (outer shell layer) is smooth to rough, yellow-green to yellow-brown with wavy green rays.

On the inner shell, the   left valve has two triangular pseudocardinal teeth. The right valve has one single, serrated squarish pseudocardinal tooth. Usually lateral teeth are just thickened areas, but occasionally double teeth are in the left valve.

The beak cavity is shallow to moderately deep. The nacre is white, occasionally with a pink or salmon tint and is iridescent at the posterior end of the shell.

In Michigan, this species can be confused with the elktoe. The slippershell is smaller (therefore has closer growth lines) and lacks the dark blue dots found on the elktoe shell.

Range length: 3.8 (high) cm.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

Sexual Dimorphism: sexes alike

Habitat and Ecology

Systems

• Freshwater

This species is found in creeks and small rivers. Usually it needs fairly good quality water and is found buried in sand and gravel.

Habitat Regions: freshwater

Aquatic Biomes: rivers and streams

Habitat Type: Freshwater

Comments: This species is typically found in headwater streams but also may occur downstream. It is a small sized species that may burrow out of sight in sand or sandy mud so may be easily overlooked. It is not a species of impounements (Watters, 1995). Parmalee and Bogan (1998) claim the species exists in small creeks and shallow streams today but once inhabited the shoals and riffles of large rivers such as the French Broad and Holston before impounement. It may typically be found living in a substrate composed of sand and fine gravel, although in stretches where there is a continuious current it will thrive in a mud and sand bottom among roots of aquatic vegetation.

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

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

While freshwater mussels require a host fish for metamorphosis, the host for the slippershell is unknown.

Ecosystem Impact: parasite

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:

• muskrat, Ondatra zibethicus 
• mink, Neovison vison 
• raccoon Procyon lotor 
• otter, Lontra canadensis 
• turtles, Testudines 
• hellbenders, Cryptobranchus 
• freshwater drum, Aplodinotus grunniens 
• sheepshead, Archosargus probatocephalus 
• lake sturgeon, Acipenser fulvescens 
• shortnosed sturgeon, Acipenser brevirostrum 
• spotted suckers, Minytrema melanops 
• common red-horse, Moxostoma 
• catfish, Siluriformes 
• pumpkinseed, Lepomis gibbosus 

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

Comments: In Wisconsin, this species is known from eastern Wisconsin in the Mississippi and Lake Michigan drainages (Mathiak, 1979). It is widespread in the streams of the southern half of Missouri but has only been found in those streams flowing off the two plateaus (Oesch, 1995). In Kansas, it is extirpated and only known from relic or subfossil specimens primarily in Tequa Creek (Marais des Cygnes drainage) in Osage County and just over the border in Missouri in the Spring River basin (Couch, 1997). In Kentucky it is generally distributed to occasional in the lower Cumberland River and eastward (Cicerello and Schuster, 2003; Clark, 1988). In the Alabama and Mobile Basin, it is limited to the Tennessee River drainage and only recently from Fowler Creek, Madison Co., Alabama, and Paint Rock River tributaries (Ahlstedt, 1996; Williams et al., 2008). In Tennessee, it inhabits headwater creeks and small streams primarily east and, to a lesser extent, middle Tennessee (Parmalee and Bogan, 1998). Only relic shells were found in the upper Clinch River in Virginia (Jones et al., 2001) exc. Copper Creek where extant (Hanlon et al., 2009); upper South Fork Holston (Stansbery and Clench, 1978). In North Carolina, it is known from the Little Tennessee, Mills, and French Broad Rivers (Bogan, 2002) in Henderson, Macon, and Swain Cos. (LeGrand et al., 2006). In Illinois, it is sporadically found in tributaries to the Fox, Kankakee, Mackinaw, Sangamon, and Vermillion Rivers (Cummings and Mayer, 1997; Schanzle and Cummings, 1991). It was recently documented in the Fox River basin in Illinois and Wisconsin where it appears to be widespread though only in small numbers (Schanzle et al., 2004). It was recently collected in the Middle Fork North Branch Vermillion River and Jordan Creek in Illinois (Szafoni et al., 2000) and Kyte River (Lower Rock basin) as relict (Tiemann et al., 2005). In Indiana, it is in the lower East Fork White (Harmon, 1992) and Tippecanoe (Cummings and Berlocher, 1990). In Arkansas, this species is known from the Buffalo and White Rivers only where it is nearly extirpated (Harris et al., 1997). In Ohio, it is widespread (but sporadic) and often common in all sizes of streams (absent from unglaciated and NE Ohio) but often overlooked because of its small size and burrowing habit (Watters, 1995; Watters et al., 2009); including Ohio Brush Creek (Watters, 1992), Black River (Lyons et al., 1997), Swan Creek (Lower Maumee) (Grabarkiewicz, 2008). This species was recently collected from 5 of 38 sites (all as weathered or dead shells) surveyed in the Tonawanda Creek basin (Niagara River drainage) in western New York (Marangelo and Strayer, 2000). It occurs in the St. Clair/Detroit drainage and lower Michigan (Strayer, 1980) and southern upper peninsula (Goodrich and Van der Schalie, 1939) in Lake Michigan and St. Clair-Detroit (Badra and Goforth, 2003). Specimens from the Black River (St. Clair drainage), Michigan, were relocated to the Detroit River in 1992 (Trdan and Hoeh, 1993). In Canada, this species is restricted to the Lake Erie drainage in Ontario (Metcalfe-Smith and Cadmore-Vokey, 2004) including the Sydenham (Metcalfe-Smith et al., 2003).

>1,000,000 individuals

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 slippershell attracts or if it recognizes its fish host is unknown.

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

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

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.

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.

Alasmidonta viridis is a long-term brooder. In the Huron River in Michigan, it was gravid from early August through late April of the following spring. It probably breeds in early May to July in Michigan.

Breeding interval: The slippershell breeds once in the warmer months of the year.

Breeding season: In Michigan, the breeding season is probably May 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)

Host fish include Johnny darter (Etheostoma nigrum) and mottled sculpin (Cottus bairdi) (Clark and Berg, 1959); as well as banded sculpin (Cottus carolinae) (Zale and Neves, 1982).

Alasmidonta viridis is on endangered lists in Alabama, Iowa, North Carolina, and Virginia. In Illinois and Wisconsin it is considered threatened, and in Michigan it is a species of special concern.

US Federal List: no special status

CITES: no special status

State of Michigan List: special concern

IUCN Red List of Threatened Species: no special status

Canada

Rounded National Status Rank: N3 - Vulnerable

United States

Rounded National Status Rank: N4 - Apparently Secure

Rounded Global Status Rank: G4 - Apparently Secure

Reasons: This species is widespread in the eastern U.S. and distributed from Lake Huron, St. Clair and Erie, and upper Mississippi River system, south to Ohio, Cumberland, and Tennessee River systems. Although intolerant of impoundment, it is considered stable throughout most of its range.

Intrinsic Vulnerability: Not intrinsically vulnerable

Environmental Specificity: Moderate. Generalist or community with some key requirements scarce.

Comments: This species is typically found in headwater streams but also may occur downstream. It is a small sized species that may burrow out of sight in sand or sandy mud so may be easily overlooked. It is not a species of impounements (Watters, 1995). Parmalee and Bogan (1998) claim the species exists in small creeks and shallow streams today but once inhabited the shoals and riffles of large rivers such as the French Broad and Holston before impounement. It may typically be found living in a substrate composed of sand and fine gravel, although in stretches where there is a continuious current it will thrive in a mud and sand bottom among roots of aquatic vegetation.

Population

Population Trend

Global Short Term Trend: Relatively stable (=10% change)

Comments: Only relic shells were found in the upper Clinch River in Virginia (Jones et al., 2001).

Global Long Term Trend: Increase of 10-25% to decline of 50%

Comments: It is extirpated from the Tennessee River proper (pre-impoundment) and upper Elk River in Tennessee (Williams et al., 2008). In Alabama it was limited to the Tennessee River drainage with a few museum records from the Tennessee River proper (pre-impoundment) and several tributaries plus the lower reaches of the Elk River but is only known recently from fowler Creek in Madison Co. and Paint Rock River tributaries (Williams et al., 2008).

Major Threats

Conservation Actions

Global Protection: Unknown whether any occurrences are appropriately protected and managed

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.