Story: Corals, anemones and jellyfish

Polyp and medusa body shapes

Polyp and medusa body shapes

Corals, sea anemones and jellyfish belong to a group of animals called cnidarians. They have a simple body consisting of a central gut cavity surrounded by tentacles. A jelly-like substance called mesoglea lies between the outer and inner layers of the body. There are two basic cnidarian body shapes: a polyp form, which is attached to a surface; and an upside-down free-floating form called a medusa. Some cnidarians change form at different phases of their life cycle, while others remain in one form for their entire life.

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How to cite this page:

Dennis Gordon, 'Corals, anemones and jellyfish - Cnidaria – the nettle animals', Te Ara - the Encyclopedia of New Zealand, http://www.TeAra.govt.nz/en/diagram/4721/polyp-and-medusa-body-shapes (accessed 30 March 2024)

Story by Dennis Gordon, published 12 Jun 2006, updated 26 Sep 2016