Pyrosoma

Pyrosoma is a genus of pyrosomes, marine colonial tunicates in the class Thaliacea. It contains four pelagic species found in temperate waters worldwide. Pyrosomes are filter feeders that uniquely use a type of continuous jet propulsion, generated by individual zooids, to slowly move forward while grazing; the species P. atlanticum has the highest known food clearance rate among zooplankton grazers. Colonies can reach lengths of up to 20 m (66 ft).