Hydroides spp. (H. elegans, & H. gracilis) - Visit ITIS for full scientific classification.
- Occur in subtidal and low intertidal areas.
- Abundant in marinas, docks, and rocky environments with many hard surfaces.
- Found on a variety of natural and man-made surfaces including: woody debris, shells of other animals, oyster reefs, rocky reefs, pier pilings, vessel hulls, intake lines, canals, etc.
Invasion Pathways and Distribution
- Spread by attaching to vessel hulls, from which larvae swim to settle on surfaces in marinas.
- One species, Hydroides elegans, is originally described from Sydney, Australia.
- The exact native origin is assumed to be somewhere in the Indo-Pacific.
- The origin of a close relative, H. gracilis, is Pacific Grove, California.
- Both are found worldwide, including all along the California coast.
- See NEMESIS for a distribution map.
- Filter-feeders; use feather-like gill tentacles to capture particles in the water.
- Reproduce sexually by releasing sperm and eggs into the water, where they unite to form swimming larvae
- Hydroides elegans is a well-known, dominant fouling species with the potential to outcompete native species for space and food.
- The chalky tubes form heavy 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
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