GENERAL HISTOLOGY

Detailed explanation-1: -Echinoderms are exclusively found in sea water.

Detailed explanation-2: -Most echinoderms have a complete digestive system and a large coelom. They have separate sexes, usually with gonads in sets of five, showing internal pentaradial symmetry. All echinoderm species live in the ocean; there are no freshwater or terrestrial echinoderms.

Detailed explanation-3: -Echinoderm Environment: 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: -There are no freshwater or terrestrial (land) echinoderms. Almost all echinoids (>99%) live strictly in areas of normal marine salinity. This means that echinoids cannot survive in waters with an above average area of dissolved salts, like lagoons and brine marshes. Echinoids vary in tactics when obtaining food.

Detailed explanation-5: -Echinoderms live in every ocean, even off the coast of Antarctica. Well known as coastal dwellers, they can be found at depths over three miles deep (5, 000 meters).