The Clubbed tunicate is an invasive solitary tunicate from the Western Pacific. It is one of the worst invasive alien species in the world. It has been reported in the Gulf of St. Lawrence in Prince Edward Island since 1997.
Body firm and wrinkled with little bumps, shaped like a water-filled wineskin. Presence of a solid stalk. Leathery texture;
Measures up to 18 cm, the stalk accounting for one third of its length;
Solitary, but may grow in very dense clumps.
DFO C. Nozères
Among native species, sea potatoes and sea peaches are other tunicates, but they are solitary or found in small groups. The sea potato is shaped like a rattle and has a stalk that can reach 13 cm. The sea peach's body is firm and rounded and its skin is rough.