Urochordates, also known as tunicates, are marine animals belonging to the phylum Chordata. They are characterized by a gelatinous outer covering called a tunic. Urochordates exhibit a simple body structure and are primarily filter feeders, using their siphons to draw in water and extract food particles. These organisms have a unique life cycle, often starting as free-swimming larvae that possess a notochord and a dorsal nerve cord. As they mature, they undergo a metamorphosis, losing these features and becoming sessile adults. Urochordates include various species, such as sea squirts and salps.