Show Summary Details

Quick Reference

A phylum that comprises the sea anemones, jellyfish, and corals, and which is known from the late Precambrian. Cnidarians are basically radially symmetrical and have tentacles. The body contains a gastrovascular cavity and the body wall is diploblastic. Cnidarians occur as two distinct types: polyps and medusae, which in many taxa constitute alternating generations. All are aquatic and most are marine. There are about 9000 extant species.

Subjects: Biological Sciences.

Reference entries

See all related reference entries in Oxford Index »

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.