Invertebrate is a kind of animal that does not have a spinal column or backbone. It is the opposite of vertebrate, that means if an animal is not a vertebrate (fish, reptile, amphibian, bird, or mammal), it is an invertebrate.
The main phyla (groups) of invertebrate animals are:
- Annelida: segmented worms
- Arthropods: (arachnids, crustaceans, insects, and others);
- Brachiopods: the lamp-shells.
- Bryozoa: sea mats or moss animals (sometimes they look like corals)
- Cnidarians: jellyfish, sea anemones, hydroids.
- Echinoderms: starfish, sea urchins, sea cucumbers
- Molluscs: (gastropods, cephalopods, bivalves and others);
- Nematoda: roundworms
- Porifera: sponges
- Platyhelminthes: flatworms
- Rotifers: tiny "wheel animals", which live in habitats such as pond water.
There are 18 more groups of invertebrates, mostly minor: see List of animal phyla.
Images for kids
The common fruit fly, Drosophila melanogaster, has been used extensively for research.
Tracheal system of dissected cockroach. The largest tracheae run across the width of the body of the cockroach and are horizontal in this image. Scale bar, 2 mm.
The tracheal system branches into progressively smaller tubes, here supplying the crop of the cockroach. Scale bar, 2.0 mm.
Invertebrate Facts for Kids. Kiddle Encyclopedia.