Type of fouling organism: Bivalve
Bivalves are molluscs and include species of oyster, scallop, mussel, cockle and clam. All are aquatic and most are marine. Their body is laterally compressed between two halves of a hinged shell. Many bivalves are sedentary with a foot that secretes a number of byssus threads that enables them to attach to the substratum. Feeding is by way of two main ciliary tracts located on enlarged gill surfaces within the mantle which is contained in the shell. Hair-like structures (cilia) produce water currents and trap food particles beating them towards labial palps allowing small particles to be conveyed to the mouth.
The shell is rectangular but can also be irregular, reaching sizes up to 40 mm. Usually one end is rounded and the other truncated or cut shorter. Two ridges run towards the truncated end on both valves, which are dull white to yellow brown in colour.
Environment and Habitat
- Subtidal to depths of 50 m.
- Reproductive type: Separate sexes.
- Found on other biofouling organisms.
Effects and Impacts
- Problematic for stock species as can compete for space and resources.
Control/ Strategies and Management
Principles of Management
C Combat Settlement
- From Arctic waters to at least the Mediterranean and north west Africa.
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