Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos
cnidarian
Table of Contents
References & Edit History Quick Facts & Related Topics
Images & Videos
sea anemone Great Barrier Reef, Queensland Chrysaora sea wasp sea pen sea fan box jellyfish
How do corals reproduce?
Cassiopea common clown fish; sea anemone
For Students
cnidarian summary
Quizzes
Sea otter (Enhydra lutris), also called great sea otter, rare, completely marine otter of the northern Pacific, usually found in kelp beds. Floats on back. Looks like sea otter laughing. saltwater otters
Animal Group Names
Lion (panthera leo)
Deadliest Animals Quiz
Mute swan with cygnet. (birds)
Match the Baby Animal to Its Mama Quiz
vulture. An adult bearded vulture at a raptor recovery center. The Gypaetus barbatus also known as the Lammergeier or Lammergeyer, is a bird of prey and considered an Old World vulture.
Animal Factoids
Read Next
The fierce snake (also known as the inland taipan, western taipan and Oxyuranus microlepidotus) is the most venomous snake in the world.
How Deadly Are Australia’s Animals?
Jellyfish sea nettle cnidarian
Animals That Were Named Totally Wrong
The saprobe Panellus Stipticus displaying bioluminescence Panellus Stipticus Aug 12, 2009. Bioluminescent fungi. aka bitter oyster, astringent panus, luminescent panellus, stiptic fungus. fungus in the family Mycenaceae
Everything’s Illuminated: 6 Bioluminescent Organisms
Discover
Four year old boy with grandfather and father lighting Hanukkah menorah. Photo taken on: December 21st, 2009
Which Is Correct: Hanukkah or Chanukah?
Facsimile of one of William Henry Ireland's forgeries, a primitive self-portrait of William Shakespeare(tinted engraving). Published for Samuel Ireland, Norfolk Street, Strand, December 1, 1795. (W.H. Ireland, forgery)
The Time a Law Clerk Successfully Forged a New Shakespeare Play to Impress His Dad
Ice Sledge Hockey, Hockey Canada Cup, USA (left) vs Canada, 2009. UBC Thunderbird Arena, Vancouver, BC, competition site for Olympic ice hockey and Paralympic ice sledge hockey. Vancouver 2010 Olympic and Paralympic Winter Games, Vancouver Olympics
10 Best Hockey Players of All Time
Stylish light blue jeans on wooden background, closeup of inset pocket
Why Do Jeans Have That Tiny Pocket?
Colorful winter sunset
What's the Difference Between a Solstice and an Equinox?
Watergate scandal. Richard M. Nixon. President Nixon gives a press conference and talks to the press, March 12, 1971.
9 American Political Scandals
Scottish fold cat. A genetic mutation caused (in the original cat-1961) the ears to bend forward and down.
Shorthair Cat Breeds

The exact relationships between the different cnidarian groups are unknown. Among theories proposed on the evolution of the phylum Cnidaria, most treat the radial symmetry and tissue level of organization as evidence that the group is primitive (that is, it evolved before the evolution of bilateral symmetry) and hold that the medusa is the original body form, being the sexually reproductive phase of the life cycle. Another theory is that the original cnidarian was a planula-like organism that preceded both polyp and medusa. In either case, Hydrozoa is considered to be the most ancient of cnidarian classes, and Trachylina is ...(100 of 6114 words)

Access the full article
Help support true facts by becoming a member.