Invasive SpeciesOrange sheath tunicate

Botrylloides violaceus
FOUND by D Swag i
ID Confirmed
Quality checked by Ms. H
Peer reviewed by
Field Notes
The weather was brisk and dense to begin with, but it warmed up a bit later. The shore was muddier than I remember, (I have visited Town Landing many times) and there was much more seaweed. Crabs were everywhere; under rocks, wrapped in seaweed, and in tide pools. The water was very still, boats lined the bay and seagulls dotted the sky. There was a small breeze. Anyways, the species we are looking at is the Orange sheath tunicate. The Orange sheath tunicate is invasive, and we found it in a tide pool. The tunicate was attached to shell that looked a bit like an oyster shell. The Orange sheath tunicate seemed to be taking over the shell. We didn't think it was impacting the environment in a really big way, though.
A sketch of our study site.
Supporting Evidence
Photo of my evidence.
First off, I'm going to ask--what exactly is Orange sheath tunicate? Orange sheath tunicate is a species that is invasive to Maine. This species, introduced in 1981, comes from the coast of Siberia through the coast of China and Japan. Orange sheath tunicate grows in small groups called colonies. These colonies can be found in the sub-tidal zone, occasionally attached to stones, rocks, boats, buoys, and even floating docks. It can also be found taking over plants an animals such as: seaweeds; eelgrass; and shellfish. This is orange sheath tunicate because it looks like a sponge covering this shell.
Photo of my evidence.
If you look closely at this picture, you can notice the small colonies mentioned before. These small colonies are known as zooids. A zooid is a dark, rounded animal that growing in a colony.
Photo of my evidence.
These zooids are maroon colored.The group is all one color. This group of zooids grow in a rounded manner. They feel gelatinous, but not as soft as a sponge.
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Botrylloides violaceus
Common name:
Orange sheath tunicate
Is it alive?: 
All alive
Count of individuals: 
Less than 1/4 covered
How big is it?: 
5 - 10 cm
Is it male or female?: 
Can't tell
Sampling method: 
Just looking around
Photo of our sampling method.
Place Studied
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Map this species
N 43.731520 °
W -70.205280 °
Observation Site Information
A photo of our study site.
Coastal - Beach or dune
Trip Information
Falmouth Town Landing
Trip date: 
Wed, 2014-10-15 10:00
Town or city: 
Type of investigation: 
Species and Habitat Survey
Time of low tide: 
Wed, 2014-10-15 11:06
Habitat Observations
Species diversity: 
5 different species
Evidence of vectors: 
Boat ramp
Paved road
Water temperature: 
Dissolved oxygen: 
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