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Atlantic Ribbed Mussel

Geukensia demissa

Clumps of ribbed mussels are usually found half-buried in the mud among marsh grasses. (Sandy Richard/Flickr)
Clumps of ribbed mussels are usually found half-buried in the mud among marsh grasses. (Sandy Richard/Flickr)

The Atlantic ribbed mussel is a bivalve with dark, ribbed shells. It is found in low marshes and mud flats throughout the middle and lower Chesapeake Bay.

Appearance:

  • Glossy, ribbed shells
  • Varies in color from olive or yellowish-brown to black
  • Interior is iridescent blue to silvery white
  • Grows 2-4 inches long

Habitat:

  • Lives in low, regularly flooded marshes and mud flats
  • Clumps of mussels are usually found half-buried in the mud among marsh grasses
  • Attaches itself to marsh grass roots and other surfaces with strong, thread-like strands secreted from the byssus gland

Range:

  • Found throughout the middle and lower Chesapeake Bay

Feeding:

  • Filter feeder
  • Feeds during high tide
  • Opens its shells slightly to draw in water, filtering out algae and other particles

Predators:

  • Has many predators, including blue crabs, mud crabs and shorebirds such as rails and willets

Reproduction and Life Cycle:

  • Spawns once per summer
  • During spawning season, a ribbed mussel’s gender can be determined by the color of its mantle: females tend to be brownish and males are cream or yellowish
  • Larvae eventually settle and develop into juveniles
  • Can live 15 years or longer

Other Facts:

  • A ribbed mussel’s age can be determined by counting the ribs on its shells
  • A large group of ribbed mussels can filter all of the water entering a marsh during each tidal cycle. This helps clean and clarify the water.
  • Although ribbed mussels are edible, they are tough and do not taste as good as the popular blue mussel
  • During low tide, ribbed mussels close their shells, keeping in waste products that can be toxic to humans. For this reason, you should only collect mussels during high tide.

Sources and Additional Information:




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