There are two major groups of nonvertebrate chordates: tunicates and lancelets (sometimes called amphioxus).
Lancelets are fishlike animals that have bilateral symmetry and live in salt water. They are filter feeders and have no internal skeleton. Example: Branchiostoma
Two lancelets, Branchiostoma lanceolatum, poking out of sand.
Tunicates are filter feeders that live in salt water. Most adults have a tough outer covering (“tunic”) and no body symmetry; most display chordate features and bilateral symmetry only during larval stages. Many adults are stationary; some are free-swimming. Examples: sea squirts, sea peaches, salps
Pastel Sea Squirt
Sea Squirts