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Club tunicate (Styela clava)
Credit: N. Balcom, CT Sea Grant
club tunicate
Styela clava

• First observed in Long Island Sound in 1973; by 1988, its range expanded northward to Maine and southward to Connecticut

• Yellowish-gray to reddish-brown
• Club-shaped with two siphons
• Tough, leathery, bumpy exterior; often covered with other organisms
• Up to 8 in (20 cm) tall with stalk approximately 1/3 of its total length
• Fast-growing, prolific breeder

• Grows on hard surfaces such as pilings
• Shallow water below low-tide line

Known Distribution:
• Prince Edward Island, and Maine to New Jersey
• Native to Sea of Okhotsk south to Shanghai

• Aggressive competitor for living space and food
• Can replace native species of invertebrates
• Occurs by the tens of thousands in areas previously occupied by the blue mussel, Mytilus edulis, in parts of southern New England

Common Vector(s):
AquacultureShipping: Ballast waterShipping: Fouling

Club tunicate (Styela clava)
Credit: MIT Sea Grant College Program