Invertebrates are animals without backbones.
Invertebrates inhabit pelagic, benthic, and terrestrial environments. The majority of animal species that inhabit benthic environments are invertebrates. These organisms feed on other benthic organism (plants and animals), pelagic organisms (small fish and plankton forms), and decaying matter. These animals are, in turn, eaten by a host of pelagic animals (secondary and tertiary tropic feeders).
|Protozoa||Single-celled animals (microbes): single-celled zooplankton, ciliates, flagellates, amoebas|
|Porifera||Sponges – filter feeders|
|Coelenterada||Coral, Jellyfish, Anemones|
|Mollusca||Bivalves, squid, octopus, nautilus, gastropods (things with shells or large cavities),
(extinct varieties: cephalopods, belemnites, ammonites)
|Brachiopoda||Have two valves, but valves are on top and bottom|
|Arthropoda||Crabs, shrimp, scorpions, and spiders (trilobites, eurypterids)|
|Echinodermata||Sea Stars, urchins and sea cucumbers (spiny skin)|