Marine Invertebrates

What are Marine invertebrates? There are two main groups of animals, vertebrates and invertebrates. A vertebrate has a backbone while an invertebrate has no backbone (no bones at all!).

Marine invertebrates are any animal that lives in the marine environment and have no vertebrae. All animals are are multicellular, eukaryotic and are heterotrophs (heterotrophs that ingest food). Invertebrates have tissues specialized for specific functions (nerve tissue and muscle are unique to the kingdom). Most invertebrates are motile at some time in their lives (like the above jelly fish) through some simple forms are attached to a substrate (sessile). Many lower forms have simple asexual (budding or fragmentation) and sexual reproduction is more common in so called "higher" invertebrates. Within the Invertebrates, symmetry is a very important characteristic.

Please click the links to examine these Invertebrate Phyla. Each selection has images and a basic description of the unique chaacteristics of the selected Phylum.

Porifera - Sponges
Cnidarians - Jelly Fish and Anemones
Platyhelminthes - Flatworms
Nematodes - Round worms
Mollusca - Snails, Bivalves and Cephalopods
Annelida - Segmented worms
Arthropoda - Crustaceans
Echinodermata - Starfish, Sand Dollars and Sea Urchins