Species Information

Sheath tunicate on rockweed Sheath tunicate on rockweed
A. Pappal
Sheath tunicate on rockweed
A. Pappal
Sheath tunicate
Botrylloides violaceus

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Characteristics
  • Usually orange, sometimes red or dull purple
  • Individual animals (zooids) arranged in loose circles, rows, or dense colonies
  • Dense colonies can be extensive, creating firm, gelatinous coating on submerged structures; colony sometimes forms lobes

Habitat
  • Grows on rocks, shells, pilings, seaweeds, ship hulls, and other submerged surfaces
  • Usually below low-tide line

Known Distribution in the Northeast
  • Newfoundland to Florida
  • Native to northwestern Pacific Ocean

Impacts
  • Competition with native species (invertebrates and algae)  for living space
  • Grows over other organisms, interfering with their feeding and other behaviors

Sheath tunicate (Botrylloides violaceus)
Dann Blackwood (USGS)
Sheath tunicate with other species
A. Pappal