Echinoderms (Phylum Echinodermata, from the Greek for spiny skin) are a phylum of marine animals found at all depths. This phylum appeared in the early Cambrian Period and contains about 7,000 living species and 13,000 extinct ones. Five or six classes (six counting Concentricycloidea) are alive today:

• Asteroidea (asteroids, starfish, or sea stars): about 1,500 species that capture prey for their own food.
• Concentricycloidea (sea daisies), notable for their unique water vascular system; two species; recently merged into Asteroidea.
• Crinoidea (crinoids, feather stars or sea lilies): about 600 species that are suspension feeders.
• Echinoidea (echinoids, sea urchins and sand dollars): notable for their movable spines; about 1,000 species.
• Holothuroidea (sea cucumbers): elongated animals resembling slugs; about 1,000 species.
• Ophiuroidea (brittle stars and basket stars), the physically largest of echinoderms; about 1,500 species.

Extinct forms known from fossils include blastoids, edrioasteroids, and several early Cambrian animals such as Helicoplacus, carpoids, Homalozoa, and possibly machaerids.

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MarineBio Blog

You can love the ocean and seafood too…
Joni Tue, 26 Aug 2008 00:25:27 -0000
Ocean and seafood lovers unite and spread the word. There is such a thing as sustainable seafood. And organizations such as SeaWeb’s Seafood Choices Alliance and Charting Nature are here to tell you all about it. Charting Nature donated 100 copies of their informative and beautiful Seafood Guide posters. The posters are available in fish or [...]
I can’t bear the ignorance any longer. Spread the facts: SHARK FIN SOUP IS BAD
Joni Wed, 20 Aug 2008 15:10:22 -0000
Because travel is one of life’s greatest pleasures, I often watch the Travel Channel to travel vicariously when I’m not traveling myself. There’s a show that I find interesting for its glimpse into off-the-beaten-path cultures, but not so much for its main focus - the consumption of “bizarre” food. Unfortunately, a recent episode featured the [...]
My favorite recent headline: First Do More Harm
Joni Thu, 14 Aug 2008 19:43:11 -0000
Once again, I’m abandoning MarineBio’s policy of striving to remain politically neutral. What is with the Bush administration? First it’s “hey! let’s drill offshore to trick people into thinking it will lower gas prices - it won’t do any good, but my buddies in the oil industry will give me another atta boy!” Now it’s [...]
Good news and great advice about the plight of corals
Joni Wed, 06 Aug 2008 21:31:18 -0000
I just came across this quote in an interview with International Society for Reef Studies President Richard Aronson on SeaWeb and was immediately inspired to share it with you: The main thing that I would advise scientists, conservationists and the public to do is to take heart, be courageous and don’t give up on coral [...]
Tuna: A Love Story
Joni Thu, 31 Jul 2008 19:50:32 -0000
Richard Ellis’ new book Tuna: A Love Story is now in bookstores. In his latest book, Ellis focuses on the bluefin tuna - an amazing species that is being loved to death in sushi bars worldwide. We’re fans of Ellis’ The Empty Ocean, which paints a grim but accurate view of the exploitation of the ocean [...]
Why corals need urgent protection
Joni Thu, 24 Jul 2008 22:11:30 -0000
Time Magazine published this great article earlier this month. Read: You don’t have to be a marine biologist to understand the importance of corals — just ask any diver. The tiny underwater creatures are the architects of the beautiful, electric-colored coral reefs that lie in shallow tropical waters around the world. Divers swarm to them not [...]

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