Tunicates, also known as sea squirts, are marine animals belonging to the phylum Chordata. They are characterized by their sac-like bodies and are often found attached to rocks, shells, or other surfaces in shallow waters. Tunicates filter feed by drawing in water through an incurrent siphon, trapping food particles, and expelling the filtered water through an excurrent siphon. These creatures have a simple body structure and can be solitary or colonial. Tunicates exhibit two main life stages: a free-swimming larval stage and a sessile adult stage. They play a vital role in marine ecosystems by filtering water and providing habitat for other organisms.