Taxonomy
Common Name: SCALESHELL
Phylum: MOLLUSCA
Class: BIVALVIA
Order: UNIONOIDA
Family: UNIONIDAE
Genus: POTAMILUS
Species: LEPTODON
Taxonomic Authority: (RAFINESQUE)
Taxonomy References: 013 , 001
Status
FEDERAL ENDANGERED
STATE ENDANGERED
STATE RANK S1
GLOBAL RANK G1
Habitat Summary
"Occurs in clear, nonpolluted riffles with moderate current and firm gravel, cobble or sand substrates."
Primary Habitat: "Aquatic - river/stream"
References: 008 , 009 , 010 , 003
Distribution
General Occurrence in State:
"Is found in the Gasconade and Meramec river basins."
County Occurance
| Known | Likely | Unknown | Not Likely | Historic | Extirpated |
|---|---|---|---|---|---|
| CALLAWAY | ADAIR | TANEY | |||
| COLE | ANDREW | ||||
| CRAWFORD | ATCHISON | ||||
| FRANKLIN | AUDRAIN | ||||
| GASCONADE | BARRY | ||||
| JEFFERSON | BARTON | ||||
| LACLEDE | BATES | ||||
| MARIES | BENTON | ||||
| OSAGE | BOLLINGER | ||||
| PULASKI | BOONE | ||||
| ST. LOUIS | BUCHANAN | ||||
| STONE | BUTLER | ||||
| WRIGHT | CALDWELL | ||||
| CAMDEN | |||||
| CAPE GIRARDEAU | |||||
| CARROLL | |||||
| CARTER | |||||
| CASS | |||||
| CEDAR | |||||
| CHARITON | |||||
| CHRISTIAN | |||||
| CLARK | |||||
| CLAY | |||||
| CLINTON | |||||
| COOPER | |||||
| DADE | |||||
| DALLAS | |||||
| DAVIESS | |||||
| DEKALB | |||||
| DENT | |||||
| DOUGLAS | |||||
| DUNKLIN | |||||
| GENTRY | |||||
| GREENE | |||||
| GRUNDY | |||||
| HARRISON | |||||
| HENRY | |||||
| HICKORY | |||||
| HOLT | |||||
| HOWARD | |||||
| HOWELL | |||||
| IRON | |||||
| JACKSON | |||||
| JASPER | |||||
| JOHNSON | |||||
| KNOX | |||||
| LAFAYETTE | |||||
| LAWRENCE | |||||
| LEWIS | |||||
| LINCOLN | |||||
| LINN | |||||
| LIVINGSTON | |||||
| MACON | |||||
| MADISON | |||||
| MARION | |||||
| MCDONALD | |||||
| MERCER | |||||
| MILLER | |||||
| MISSISSIPPI | |||||
| MONITEAU | |||||
| MONROE | |||||
| MONTGOMERY | |||||
| MORGAN | |||||
| NEW MADRID | |||||
| NEWTON | |||||
| NODAWAY | |||||
| OREGON | |||||
| OZARK | |||||
| PEMISCOT | |||||
| PERRY | |||||
| PETTIS | |||||
| PHELPS | |||||
| PIKE | |||||
| PLATTE | |||||
| POLK | |||||
| PUTNAM | |||||
| RALLS | |||||
| RANDOLPH | |||||
| RAY | |||||
| REYNOLDS | |||||
| RIPLEY | |||||
| SALINE | |||||
| SCHUYLER | |||||
| SCOTLAND | |||||
| SCOTT | |||||
| SHANNON | |||||
| SHELBY | |||||
| ST. CHARLES | |||||
| ST. CLAIR | |||||
| ST. FRANCOIS | |||||
| STE. GENEVIEVE | |||||
| STODDARD | |||||
| SULLIVAN | |||||
| TEXAS | |||||
| VERNON | |||||
| WARREN | |||||
| WASHINGTON | |||||
| WAYNE | |||||
| WEBSTER | |||||
| WORTH |
References for distribution: 008 , 009 , 010 , 003 , 004
Distribution by Watersheds
Meramec R.
Bourbeuse R.
Big R.
Gasconade R. from Headwaters to Big Piney R.
Gasconade R. from Big Piney R. to Mo. R.
Comments: ""
Distribution by Ecoregions
Ozark Highlands
Comments: ""
Distribution by Potential Natural Vegetation
Oak-Hickory Forest
Distribution by Natural Divisions of Missouri
Ozark Border: Missouri River
Ozark Border: Mississippi River
Ozark: Upper Ozark
Habitat Associations
Species is associated with "Aquatic" habitats.
National Wetlands Inventory Association:
Riverine
Aquatic Associations:
"Riverine, lower perennial", "Unconsolidated bottom, cobble/gravel",
"Riverine, lower perennial", "Unconsolidated bottom, sand",
References for Aquatic Associations: 008 , 009 , 010 , 003
Habitat Types:
Permanent Stream
References for Habitat Types: 008 , 009 , 010 , 003
Terrestrial Natural Communities:
References for Terrestrial Natural Communities:
Food Habits
Trophic Level:
"Omnivore"
Larval Food Habits
Comments for larval food habits:
""
References for larval food habits:
Juvenile Food Habits
Comments for Juvenile Food Habits:
""
References Juvenile Food Habits
Adult Food Habits
Algae; Not Specified
Protozoans; Not Specified
Other Microorganisms; Not Specified
Bacillariophyceae (diatoms); Not Specified
Comments for Adult Food Habits:
""
References Adult Food Habits 011
Niche Requirements
Egg Niche Requirements
References for egg niches requirements:
Feeding Larvae Niche Requirements
References for feeding larvae niche requirements:
Resting Larvae Niche Requirements
References for resting Larvae niche requirements:
Feeding Juvenile Niche Requirements
References for feeding juvenile niche requirements:
Resting Juvenile Niche Requirements
References for resting juvenile niche requirements:
Breeding Adult Niche Requirements
References for feeding Adult niche requirements:
Feeding Adult Niche Requirements
References for feeding adult niche requirements:
Resting Adult Niche Requirements
References for resting adult niche requirements:
Niche Requirement Summary
Current velocity specified in comments(00150)
Elevation specified in comments(00240)
Gradient specified in comments(00140)
Host specified in comments(00680)
Substrate specified in comments(00080)
Water depth specified in comments(00230)
Comments about Life History:
| Code | Comment |
|---|---|
| 007 | Spawns in early to mid-August *09*. |
| 003 | Fish host for glochidia is the freshwater drum *012*. |
| 020 | Eggs are fertilized and develop into glochidia in gills of female *03*. |
| 034 | Limited by availability of suitable habitat and presence of host species *03*. |
| 035 | Regulatory factors include predation *03*. |
| 037 | Depend on host for dispersal *03*. |
Life History Information
Limiting factors specified in comments(034)
Regulatory factors specified in comments(035)
Dispersal specified in comments(037)
Origin in state: native
Seasonal distribution in state: all seasons
Closely associated plant or animal species specified in comments(003)
Foraging strategy: filtering
Foraging sites: water
Breeding season specified in comments(007)
Duration of pair bond: no pair bond formed
Development of young at birth/hatching specified in comments(020)
Comments about Life History:
| Code | Comment |
|---|---|
| 007 | Spawns in early to mid-August *09*. |
| 003 | Fish host for glochidia is the freshwater drum *012*. |
| 020 | Eggs are fertilized and develop into glochidia in gills of female *03*. |
| 034 | Limited by availability of suitable habitat and presence of host species *03*. |
| 035 | Regulatory factors include predation *03*. |
| 037 | Depend on host for dispersal *03*. |
References for life history: 009 , 003 , 005 , 006 , 007
Management
Beneficial Management Practices:
Water - control sedimentation
Water - control pollution (thermal, physical, chemical)
Water - stabilize streambanks
Grassland - maintain stream banks
Grassland - maintain streamside vegetation
Beneficial Management References: 009
Adverse Managment Practices:
Water - dredging and filling
Adverse Management References: 009
Comments on Management:
No work should be allowed below the high bank of the stream between May 1 and August 15, to allow for successful reproduction and recruitment. Take precautions to prevent spread of zebra mussels *009*.
References for Management Comments: 009
References
| Reference Code | Citation |
|---|---|
| 001 | Williams, J.D., A.E. Bogan, R.S. Butler, K.S. Cummings, J.T. Garner, J.L. Harris, N.A. Johnson and G.T. Watters. 2017. A revised list of the freshwater mussels (Mollusca: Bivalvia: Unionida) of the United States and Canada. Freshwater Mollusk Biology and Conservation 20:33-58. |
| 002 | Missouri Natural Heritage Program. 2007. Missouri Species and Communities of Conservation Concern Checklist. Missouri Department Of Conservation. Jefferson City, Missouri. 51 Pp. |
| 003 | Oesch, R.D. 1995. Missouri Naiades. A Guide To The Mussels Of Missouri. Second Edition. Missouri Dept. Of Conservation. Jefferson City, Missouri. 271 Pp. |
| 004 | Unpb Missouri Department of Conservation Heritage Database. P.O. Box 180, Jefferson City, Mo 65102. |
| 005 | Baker, F.C. 1928. The fresh-water mollusca of Wisconsin. Part II. Pelecypoda. Bull. Univ. Wisconsin, Bull. 70, II. WI Geol. and Nat. Hist. Surv. Gen. Ser. 1301, 495 pp. (cited in ref. 001) |
| 006 | Fuller, S.L.H. 1978. Fresh-water mussels (Mollusca: Bivalvia: Unionidae) of the Upper Mississippi River: Observations at selected sites within the 9-foot channel navigation project on behalf of the Unites States Army Corps of Engineers. Acad. Nat. Sciences. Philadelphia, PA. 401 pp. (cited in ref. 003). |
| 007 | Brynildson, I. 1985. Freshwater mussels of the Upper Mississippi River. Wisc. Dept. Nat. Resources. 63 pp. |
| 008 | Buchanan, A. C. 1980. Mussels (naiades) of the Meramec River Basin. Missouri Dept. of Conservation Aquatic Ser. No. 17. Jefferson City, MO. 76 pp. |
| 009 | Missouri Department of Conservation. Best Management Practices: Scaleshell mussel. Missouri Dept. of Conservation. Jefferson City, MO. |
| 010 | Unpb Bruenderman, S. Mussel Occurrence Database. Missouri Dept. Of Conservation, 1110 S. College Ave., Columbia, Mo 65201 (573-882-9880). |
| 011 | Allen, W.R. 1914. The Food And Feeding Habits Of Freshwater Mussels. Biol. Bull. 27(3):127-139. |
| 012 | Unpb Faiman, S. Missouri Department of Conservation, 1110 S. Collge Ave., Columbia, MO 65201, 573-882-9909. |
| 013 | Freshwater Mollusk Conservation Society (FMCS). 2021. The 2021 checklist of freshwater mussels. https://molluskconservation.org/Library/Committees/Names/Appendix_1_Bivalves_Revised_Names_List_20210825.pdf |