Echinoderms

Echinoderms

KNOWN SPECIES

11,579

0.49% of our world's living things are echinoderms

CHARACTERISTICS

animals without a backbone (invertebrates), that also have no head, eyes, or brain
they can be divided into matching sections branching from a central point
usually with five arms

SIZE RANGE

less than 0.39 inch to 6.5 feet (1 centimeter to 2 meters)

WHERE THEY LIVE

in oceans

Here are just SOME of the world’s echinoderms:

chocolate chip sea cucumber
SCIENTIFIC NAME:
Isostichopus badionotus

sand dollar
SCIENTIFIC NAME:
Dendraster excentricus

bat star
SCIENTIFIC NAME:
Asterina miniata

blood star
SCIENTIFIC NAME:
Henricia leviuscula

sunflower sea star
SCIENTIFIC NAME:
Pycnopodia helianthoides

slate pencil urchin
SCIENTIFIC NAME:
Eucidaris tribuloides

Guess what?

When stressed, sea cucumbers may spit out all of their internal organs, but they can usually grow them back!

Image credits

Find out what lives in the deep sea, coral reef, and continental shelf.

What adaptations help these creatures survive?

How is the ocean like a layer cake? What creatures live there? And how important is the ocean? Take a dive and find out!