Marine invertebrates

Marine invertebrates are all multicellular animals that inhabit a marine environment apart from the vertebrate members of the chordate phylum; invertebrates, lack a vertebral column. Some have evolved a shell or a hard exoskeleton.

As on land and in the air, invertebrates make up a great majority of all macroscopic life, as the vertebrates makes up a subphylum of one of over 30 known animal phyla, making the term almost meaningless for taxonomic purpose. Invertebrate sea life includes the following groups, some of which are phyla: