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Invasive Tunicates

Learn about invasive tunicates, including types of tunicates, location, habitat, impacts and our response.

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Types of invasive tunicates

Tunicates are small marine invertebrates that spend most of their lives attached to an underwater surface. They are named “tunicate” for their thick outer layer resembling a tunic. They are water-filled sacs that filter feed by drawing in and expelling water through tubular siphons. Several invasive species of tunicates threaten our waters. They can be spread by ocean currents but are mainly moved from place to place by human activities.

Tunicates can be either solitary or colonial. Both can reproduce sexually, producing free swimming larvae. Colonial tunicates can also form new colonies when pieces break off and drift to a new area and become attached there. Colonial tunicates form gelatinous mats or hanging lobes that may cover almost anything underwater. The colonies are made up of many individual organisms, called zooids, embedded in a common matrix, whereas, solitary tunicates operate as separate individuals. Though solitary tunicates grow individually they can form very dense groups.

Invasive solitary tunicates in Canada include:

Species of colonial invasive tunicates include:

If you think you have seen an invasive tunicate, report it.

Where is the group invasive?

Invasive tunicates have been found in coastal waters of the Canadian Pacific and Atlantic Oceans.

Distribution

More information on the distribution ranges of each invasive tunicate species can be found following the links to their individual pages above.

Habitat

Tunicates are typically found:

Impacts

The presence of invasive tunicates can lead to several negative impacts on indigenous aquatic communities, the aquaculture industry and many other users of aquatic resources. The following are examples of potential impacts:

Response

We collaborate in on-going efforts to detect and control invasive tunicates with groups including academia, Indigenous Groups, and industry. Monitoring efforts allow for early detection of new invasive species and to determine the spread, establishment and spatial distribution of existing ones.

Clubbed Tunicate

Clubbed Tunicate

European Sea Squirt

European Sea Squirt

Vase Tunicate

Vase Tunicate

Compound Sea Squirt

Compound Sea Squirt

Golden Star Tunicate

Golden Star Tunicate

Violet Tunicate

Violet Tunicate

Pancake Batter Tunicate

Pancake Batter Tunicate

Solitary vs Colonial tunicates

Solitary (left) vs Colonial tunicates (right)

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