The phylum Echinodermata , which contains about 6000 species, gets its name from the Greek, literally meaning "spiny skin." Many echinoderms actually do have "spiny" skin, but others do not. This phylum exists exclusively in the sea, and cannot be found on land or in fresh water.
Answer:
These organisms should be adapted to live in this enviroment, i.e., they need to have adaptations to breathe, to swim (fins), streamlined bodies to move through the water, to eat the food found in the region, etc. Moreover, in this environment, the diversity tends to be high because marine regions are often characterized by their richness.
Execration in man
transport and gutation in plant
