The adults are identified by their symmetry (usually five-point.) This Phylum includes Starfish, Sea Urchins, Sand Dollars, and Sea Cucumbers. Most Echinoderms have the ability to regenerate tissue, limbs, and organs. Sometimes, they are even able to completely restore a single limb.
They primarily use their tube feet, which are like little suction pads that are tip-shaped, to move around. Sea Urchins will use their spines to move as well.
Echinoderms can be found in nearly every area in the world’s oceans, at almost every depth, latitude, and environment. They are at their greatest density in coral reefs.
Sea Urchins feed on algae by scraping off layers of algae from the surfaces of rocks.
Sand Dollars eat algae as well as phytoplankton.
Sea Cucumbers feed on mobile deposits, this means they ingest large amounts of sediment, but they are able to filter out the unwanted minerals, and only digest the organic matter.
Starfish are carnivores or detritivores, meaning they feed on dead organic material or fish.
They, as you can probably imagine, are not very fast moving creatures. Some try to move more often than others, but they are pretty sluggish individuals.
There are over 7000 species of Echinoderms broken down as such:
- Crinoidea (Feather Stars)
- Holothuroidea (Sea Cucumbers)
- Echinoidea (Sea Urchins, Sand Dollars)
- Ophiuroidea (Brittle Stars)
- Asteroidea (Starfish)
They are all marine, and nearly every species is benthic (lives on the seafloor.)