[1][2] The doliolid body is small, typically 1–2 mm long, and barrel-shaped; it features two wide siphons, one at the front and the other at the back end, and eight or nine circular muscle strands reminiscent of barrel bands.

Doliolids can also move by contracting the muscular bands around the body creating a temporary water jet that thrusts them forward or backward quite quickly.

The spoon-shaped zooids supply food for the whole colony via a common blood circulation along two blood-filled sinuses that extend from the nurse along the whole length of the dorsal stalk.

As this first generation grows, the nurse's feeding role is gradually diminished, and at the point where the colony's nutrition is supplied by the stalk zooids the nurse loses most of its organs, becoming a purely generative and propulsive agent, dragging its huge grape-like stalk behind it.

Gonozooids detached from the phorozooid swim free, mate, and produce fertilized eggs - from which spring the next generation of asexual zooid "factories", and the cycle repeats.

The total number of zooids produced by a single nurse colony can reach tens of thousands - explosive growth unusual in the animal kingdom.

The gelatinous doliolid Dolioletta gegenbauri is preyed upon by the copepod Sapphirina nigromaculata that chews through and enters its body cavity and then ingests its internal tissues.