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University of California
California Aquatic Invasive Species (AIS)
Invasive Seaweeds and Hull Fouling Species
Filograna implexa - Visit ITIS for full scientific classification.
- Occurs in subtidal and low intertidal areas.
- Like other tubeworms it encrusts hard surfaces including: rocks, shells, other marine animals, vessel hulls, piers, etc.
Invasion Pathways and Distribution
- Spread by attaching to vessel hulls, from which larvae swim to settle on surfaces in marinas.
- Found worldwide, including in California.
- Filter-feeder; uses feather-like gill tentacles to capture particles in the water.
- Reproduces asexually by budding or sexually by releasing sperm and eggs into the water, where they unite to form swimming larvae.
- The chalky tubes form crusts on boat hulls.
- This fouling growth roughens the hull’s surface, creating friction or “drag” that slows sailboats and increases fuel consumption for powerboats.
- Tolerant of copper in antifouling paint, and are very difficult to remove.
References and Useful Links
For references by category and links to other useful AIS sites see our LEARN MORE page.
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