How do Echinoderms eat and what do they eat?

Question

Hey

I have a school assignment and I need to write about half a page on the echinoderm's eating habits. I need info on echinoderms on a whole not on the individual classes. Please answer if you can. I will take any info and good websites would really help. Thanks in advance for all your help!

Answer 1

Because there are different kinds of echinoderms, I have to give an answer that tells something about classes.  For example, some echinoderms cannot move -- they're stuck on the bottom of the ocean like a plant is.  They eat passively, which means they just wait for bits of dead plants and animals to float down to them and they suck these crumbs in through a hole that they also use to breathe and drink with.  Go to "Wikipedia" to get all the details and then go to the section on "Mode of life" and in that part, the section on "feeding."  Other kinds can move around, like starfish, and they hunt down other creatures and grab them.  Then, they actually squeeze their stomach out through a little hole, which is like a mouth, and ooze out their stomach acids onto the creature they want to eat.  So they are digesting their food on the outside, instead of the inside like we do.  Another good website is "enchantedlearning" at "ucmp.berkeley" where you should go to the section on "life history and ecology."  They have lots of good pictures.

Answer 2

The Echinoderms are a pretty diverse Phylum, including sea stars (aka starfish), crinoids, sea cucumbers and sea urchins - each of which have very different feeding habits and methods of obtaining their food.

Many sea stars are predators, feeding on molluscs like clams by prying apart their shells and actually everting their stomach inside the shell to digest the meat.

Crinoids are filter feeders, using their long arms to capture food particles wafting past in the currents.

Sea urchins have powerful grinding mouthparts that allow them to chew apart rock-hard coral, or scrape algae and kelp from the rocks.

There's no one food or technique that's shared by all Echinoderms.