Marine Nuisance Species
This project is complete and the website is archived and no longer updated.
This archived website assembles and communicates information on the distribution, ecology, and marine habitat impacts of the invasive colonial ascidian invader Didemnum vexillum
Colonies of Didemnum vexillum exhibit a wide variety of morphological variants. Where current velocity is low, they form long, ropey or beard-like colonies that commonly hang from hard substrates such as docks, lines, and ship hulls. Where current velocity is high, they form low, undulating mats with short surficial appendages that encrust and drape rocky seabeds (pebbles, cobbles, boulders, and rock outcrops).
Didemnum vexillum colonies alter marine habitats and threaten to interfere with fishing, aquaculture, and other coastal and offshore activities. The colonies shown here are found on hard substrates that include dock structures and floats, wood and metal pilings, moorings and ropes, steel chain, automobile tires, polythene plastic, rock outcrops, gravel seabed (pebbles, cobbles, boulders), and ship hulls. They overgrow organisms such as tunicates, sponges, macroalgae, hydroids, anemones, bryozoans, scallops, mussels, and oysters. Where these colonies occur on the seabed, they likely cover the siphons of infaunal bivalves and also serve as a barrier between demersal fish and benthic prey. The colonies have been found at water depths ranging from intertidal to continental shelf depths of 65m (213 ft).
This project is complete and the website is archived and no longer updated.
This archived website assembles and communicates information on the distribution, ecology, and marine habitat impacts of the invasive colonial ascidian invader Didemnum vexillum
Colonies of Didemnum vexillum exhibit a wide variety of morphological variants. Where current velocity is low, they form long, ropey or beard-like colonies that commonly hang from hard substrates such as docks, lines, and ship hulls. Where current velocity is high, they form low, undulating mats with short surficial appendages that encrust and drape rocky seabeds (pebbles, cobbles, boulders, and rock outcrops).
Didemnum vexillum colonies alter marine habitats and threaten to interfere with fishing, aquaculture, and other coastal and offshore activities. The colonies shown here are found on hard substrates that include dock structures and floats, wood and metal pilings, moorings and ropes, steel chain, automobile tires, polythene plastic, rock outcrops, gravel seabed (pebbles, cobbles, boulders), and ship hulls. They overgrow organisms such as tunicates, sponges, macroalgae, hydroids, anemones, bryozoans, scallops, mussels, and oysters. Where these colonies occur on the seabed, they likely cover the siphons of infaunal bivalves and also serve as a barrier between demersal fish and benthic prey. The colonies have been found at water depths ranging from intertidal to continental shelf depths of 65m (213 ft).