Hooked Mussel
Ischadium recurvum
Hooked mussels colonize a rock collected from the site of an artificial stone ribbon reef and living shoreline restoration project at Hail Cove, part of a living shoreline designed to slow the rate of erosion at a portion of Eastern Neck National Wildlife Refuge in Kent County, Md., on June 26, 2014. (Photo by Jenna Valente/Chesapeake Bay Program)
The outside of the hooked mussel's shell has distinct ridges and curves, with a dull-colored black or gray color. (Photo courtesy BJ Stacey/iNaturalist CC BY-NC)
The hooked mussel, also called a bent or curved mussel, has a ridged shell with a distinct hook on the front end. Its shell has a shiny purple or rosy brown interior. (Photo courtesy BJ Stacey/iNaturalist CC BY-NC)
Hooked mussels grow on an eastern oyster pulled from the water by researchers abord the R/V Rachel Carson out of the Chesapeake Biological Laboratory (CBL) in Solomons, Md., monitor the dead zone in the mainstem of the Chesapeake Bay on July 16, 2014. CBL is part the University of Maryland Center for Environmental Science (UMCES) Chesapeake Biological Laboratory to monitor the dead zone in the mainstem of the Chesapeake Bay. (Photo courtesy E. Guy Stephens/Southern Maryland Photography)
The hooked mussel is a bivalve whose dark, ridged shell is strongly curved, or “hooked” on one end. It is prolific in oyster reefs—often “wrapping up” oysters—and can outnumber the amount of oysters by several fold.
Appearance
The hooked mussel is small, generally reaching one to two inches long. Its shell surface has distinct ridges and curves, and has a dull-colored black or gray exterior with a shiny purple or rosy brown interior. The front end of its shell is strongly curved, or “hooked.”
Feeding
Hooked mussels are filter feeders that open their shells during high tide, drawing in water and filter food particles over their gills.
Predators
Predators of hooked mussels are primarily seaducks, such as scoters and goldeneye.
Reproduction and Life Cycle
As hooked mussels reach sexual maturity, their mantle will turn either bright yellow or stippled brown in color. Spawning occurs from June to October. Free-swimming larvae drift in the water for a few months, eventually anchoring themselves on hard surfaces as they mature into adults.
Did You Know?
- Research suggests that hooked mussels can more than double the overall filtration capacity of an oyster reef. Hooked mussels also filter picoplankton, the smallest type of marine plankton, twice as effectively as oysters.
- Hooked mussels can actually move by pulling themselves along on their byssus threads—releasing some and reattaching others—although this is a very slow process and they do not move very far.
Sources and Additional Information
- Oysters have sidekick in Chesapeake Bay clean-up – Shorelines: Life and Science at Smithsonian Environmental Research Center
- Ischadium recurvum – National Exotic Marine and Estuarine Species Information System
- Study puts some mussels into Chesapeake Bay restoration – Virginia Institute of Marine Science
- Life in the Chesapeake Bay, Third Edition by Alice Jane Lippson and Robert L. Lippson
Quick Facts
Species
Native
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Size
One to two inches long
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Habitat
Attach to shells, rocks and other hard surfaces using strong, thin threads called byssus threads. They grow prolifically on oyster reefs, often “wrapping up” oysters.
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Range
Found throughout the Chesapeake Bay and its rivers, but reach maximum size and greatest abundance in waters with low salinity
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Diet
Filter feeder; feeds on plankton
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Status
Stable
