What is an invertebrate?
Q: What is an invertebrate?
A: An invertebrate is an animal that does not have a spinal column or backbone. It contrasts with vertebrate animals, which do have a spine.
Q: What are the main phyla (groups) of invertebrates?
A: The main phyla of invertebrates are Annelida (segmented worms), Arthropods (arachnids, crustaceans, insects and others), Brachiopods (lamp-shells), Bryozoa (sea mats or moss animals), Cnidarians (jellyfish, sea anemones and hydroids), Echinoderms (starfish, sea urchins and sea cucumbers), Molluscs (gastropods, cephalopods, bivalves and others) Nematoda (roundworms), Porifera (sponges) Platyhelminthes (flatworms) and Rotifers ("wheel animals"). There are 18 more minor groups as well.
Q: How do arthropods have a skeleton?
A: Arthropods such as insects have no bones but they do have an exoskeleton on the outside of their bodies. This exoskeleton provides protection for the animal's internal organs.
Q: What type of environment can rotifers be found in?
A: Rotifers are tiny "wheel animals" that live in habitats such as pond water.
