Salps and doliolids have a transparent barrel-shaped body through which they pump water, propelling them through the sea, and from which they extract food.

Water enters the pharynx through the large buccal siphon at the front end of the animal, and is forced through a number of slits in the pharyngeal wall into an atrium lying just behind it.

The pharynx is both a respiratory organ and a digestive one, filtering food from the water with the aid of a net of mucus slowly pulled across the slits by cilia.

This then develops into an oozoid, which reproduces asexually by budding to produce a number of blastozoids, which form long chains (see image).

The dorsal, hollow nerve cord and notochord found in Chordata has been lost, except for a rudimentary one in some doliolid larvae.