0 an organism shaped like a bag with holes through which water is sucked in and forced out, found attached to surfaces under the sea:
Most sea squirts stay fixed in one spot, eating dead plants and microorganisms that they siphon through their bodies.
Communities of tiny European sea squirts that probably arrived stuck to the hulls of visiting ships are crowding out native organisms.
Researchers are studying a substance excreted by some sea squirt species as a possible treatment for breast cancer.
