New York Metropolitan Region and New Jersey
Freshwater Mussel Identification Handbook

Family Unionidae
Genus Ligumia
 

    
Status: Two species of Ligumia occur in New York state. Only L. nasuta
 reaches the metro area, occuring in scattered locations in the Hudson, 
Delaware, and Housatonic rivers. It is more common in western New York state.
 Although considered by some researchers to be a species of special concern, 
L. nasuta is not legally protected in the metro area.



    
Species Summary

    
 Ligumia nasuta (Say, 1817) eastern pondmussel
Features:
  size: 100mm
  beak: umbos extended only slightly above the hinge line
  color patterns: black, rarely with fine color rays over the posterior half of the shell; periostracum
  dark brown; nacre bluish-white but may be purple   
  shape: elongate, and pointed posteriorly
  shell features: distinct posterior ridge
  teeth: one to two pseudocardinals in each valve; laterals long and straight

Status:
  abundance: uncommon
  status: US, NY: not legally protected; NJ: threatened; CT: special concern 

Distribution:
  N.A. distribution: Nova Scotia (Canada) to South Carolina and west to the northern 
  Interior Basin
  present metro distribution: NY: upper Delaware River watershed; NJ: Swartswood
  Lake (upper Delaware River watershed), Delaware River, Cohansey Creek, Mantua Creek, 
  Pennsauken Creek tributary and Raccoon Creek in Gloucester County, Pompeston Creek in  
  Riverton (lower Delaware River watershed), Raritan River; CT: not present in metro area   MAP
  other regional localities: NY: Allegheny River watershed, eastern Lake Erie watershed,
  Lake Ontario watershed, southwestern Lake Ontario watershed, St. Lawrence River
  watershed, Webatuck Creek (Housatonic River watershed), Oswego River watershed,
  upper Hudson River watershed; NJ: none known; CT: All watersheds except Hudson 
  River watershed
  historical localities: NY: Lake Erie watershed; NJ: Stony Brook (lower Hudson River 
  watershed); CT: South central coast watershed

Life History:
  habitat: quiet standing water of estuaries, lakes and canals, and slow streams;
  substrate: silt and sand (varies)  Habitat Photo
  host: not known


    
Key Features Refresher
Anterior and Posterior
   Beak and Beak Sculpture   Color Ray
 Hinge Teeth   Length, Width, Height, Profile, Silhouette
Growth Line  Posterior Ridge and Slope
Shell Shape 

Plates
L. nasuta

     
 

     
 

    
 left view

    
right view

     
 

     
 

     
 

     
 

    
dorsal view

    
profile view


     
 

     
 

    

 

    

 

    
posterior end drawn to a point 

    
beak sculpture double-looped


     
 

     
 

     
 

     
 

    
laterals thin and sharp

    
pseudocardinals delicate



    
View other genera
Alasmidonta  Anodonta  Corbicula   Dreissena
 Elliptio  Lampsilis  Lasmigona  Leptodea   Ligumia
  Margaritifera  Pyganodon  Strophitus  Utterbackia