Arkansas Freshwater Mussel (Mollusca: Unionoidae) Checklist
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Contact Info - kentaro.inoue@smail.astate.edu
*1 Taxonomic status in AR not certain
*2 Introduced species
Arkansas State Heritage Program Ranking Codes (2004)
State Ranks |
Narrative |
|---|---|
S1 |
Extremely rare. Typically 5 or few estimated occurrences in the state, or only a few remaining individuals; may be vulnerable to extirpation. |
S2 |
Vary rare. Typically between 5 and 20 estimated occurrences or with many individuals in few occurrences, often susceptible to becoming extirpated. |
S3 |
Rare to uncommon. Typically between 20 - 100 estimated occurrences, may have fewer occurrences, but with large number of individuals in some populations; may be susceptible to large-scale disturbances. |
S4 |
Common, apparently secure under present conditions. Typically between 100 or more estimated occurrences, but may have fewer with many large populations; may be restricted to only a portion of the state; usually not susceptible to immediate threats. |
S5 |
Demonstrably widespread, common, and secure in the state and essentially ineradicable under present conditions. |
SA |
Accidental |
SH |
Historically known from the state, but not verified for an extended period of time, usually 15 years. |
SU |
Possibly in peril in state, but status not certain; more information is needed. |
SX |
Apparently extirpated from state. |
SZ |
Zero occurrences. Not of practical conservation concern in the state because there are no definable occurrences, although the taxon is native and appears regularly in the state. |
Global Ranks |
Narrative |
|---|---|
G1 |
Critically imperiled globally because of extreme rarity (≤5 occurrences or very few remaining individuals or acres); or because of some factor(s) making it especially vulnerable to extinction. |
G2 |
Imperiled globally because of rarity (6-20 occurrences or few remaining individuals or acres); or because of some factor(s) making it especially vulnerable to extinction. |
G3 |
Either very rare (in the range of 21-100) and local throughout its range or found locally (even abundantly as some of its locations) in a restricted range (e.g. a single western state; a physiographic region in the East); or because of other factor(s) making it vulnerable to extinction throughout its range. |
G4 |
Apparently secure globally, though it may be quite rare in parts of its range, especially at the periphery. |
G5 |
Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery. |
GH |
Of historical occurrence throughout its range( i.e. formally part of the established biota with the expectation that it may be rediscovered (e.g. Bachman's Warbler)). |
GU |
Possibly in peril range wide, but status uncertain; more information is needed. |
GX |
Believed to be extinct throughout range (e.g. Passenger Pigeon) with virtually no likelihood that it will be rediscovered. |
Federal Status Codes
Federal Status |
Narrative |
|---|---|
E |
Endangered |
T |
Threatened |
SC |
Special concern |
CS |
Currently stable |
Latest State and North American Mussel Status Papers
(Downloadable adobe PDF files via permission of John L. Harris)
Harris, J. L., P. J. Rust, A. D. Christian, W. R. Posey, II., C. L. Davidson, and G. L. Harp. 1997. Revised status of rare and endangered Unionacea (Mollusca: Margaritiferidae, Unionidae) in Arkansas. Journal of the Arkansas Academy of Science 51:66-89.
Williams, J. D., M. L. Warren, K. S. Cummings, J. L. Harris, and R. J. Neves. 1993. Conservation status of freshwater mussels of the United States and Canada. Fisheries 18:6-22.
(Last updated: 12 June 2007)
