EVERYDAY SCIENCE

Detailed explanation-1: -Echinoderms are marine animals and can be found in the depths of the ocean as well as in the intertidal zone. An interesting feature of this phylum is that all animals belonging to Echinodermata are marine. There are no freshwater or terrestrial organisms in this phylum.

Detailed explanation-2: -Echinoderms include starfish, sea urchins, sand dollars, and sea cucumbers, and crinoids (sea lilies). Echinoderms are found at every ocean depth. The phylum contains about 7000 living species. There are no known freshwater or terrestrial species.

Detailed explanation-3: -Echinoderms are the largest phylum with no freshwater or terrestrial forms. Echinoderm environments must be marine, as in saltwater, for the echinoderm to survive.

Detailed explanation-4: -Echinodermata is a phylum of about 7000 living species distributed among five classes: Echinoidea (sea urchins and sand dollars), Holothuroidea (sea cucumbers), Ophiuroidea (brittle stars), Asteroidea (sea stars), and Crinoidea (feather stars and sea lilies).

Detailed explanation-5: -Echinodermata are exclusively marine organisms. Sea stars (Figure 1), sea cucumbers, sea urchins, sand dollars, and brittle stars are all examples of echinoderms. To date, no freshwater or terrestrial echinoderms are known.