What are Echinoderms?

Introduction. Echinoderms (scientific name Echinodermata) are a major group of only marine animals. The name comes from the Greek word for "spiny skin". There are about 7,000 species found usually on the sea floor in every marine habitat from the intertidal zone to the ocean depths. They have a wide variety of colours. read more

Echinoderm is the common name given to any member of the phylum Echinodermata (from Ancient Greek, ἐχῖνος, echinos –"hedgehog" and δέρμα, derma –"skin") of marine animals. read more

Echinoderms, or members of the phylum Echinodermata, are some of the most easily-recognized marine invertebrates. This phylum includes sea stars (starfish), sand dollars, and urchins, and they are identified by their radial body structure, often featuring five arms. read more

Echinoderms are characterized by radial symmetry, several arms (5 or more, mostly grouped 2 left - 1 middle - 2 right) radiating from a central body (= pentamerous). The body actually consists of five equal segments, each containing a duplicate set of various internal organs. read more