Pyura is a large genus of sessile ascidians that live in coastal waters at depths of up to 80 m (260 feet). Like all ascidians, Pyura are filter feeders. A few species, including Pyura chilensis are commercially fished.

Pyura chilensis, called piure in Spanish and piür or piwü in Mapudungun, is a tunicate of the family Pyuridae. It was described in 1782 by Juan Ignacio Molina.