nonvertebrate
Lacking a backbone
A nonvertebrate is any animal lacking a backbone—invertebrates such as insects, mollusks, worms, and jellyfish.
The term appears mainly in scientific contexts as a functional grouping: The study examined both vertebrate and nonvertebrate species.
It emphasizes what these animals lack rather than what they share.
Jointed-limb invertebrate phylum
- molluskSoft-bodied invertebrate, often shelled
- cnidarianStinging aquatic invertebrate
- echinodermSpiny-skinned marine invertebrate
- annelidSegmented worm phylum member
nematode · jellyfish · octopus · squid · crustacean · insect · spider · coral
Drifting marine stinger
- octopusEight-limbed sea mollusk
- squidTen-armed marine mollusk
- coralMarine skeletal formation
- spongeAbsorbent cleaning material
anemone · starfish · urchin · nautilus · cuttlefish · sea slug · sea cucumber · barnacle
Single-celled eukaryotic organisms
- amoebaShape-shifting single-celled organism
- parameciumCiliated slipper-shaped protozoan
- planktonDrifting marine microlife
- diatomSingle-celled silica algae
euglena · rotifer · tardigrade · nematode · ciliate · flagellate · microorganism · zooplankton
arthropod
Jointed-limb invertebrate phylum
- molluskSoft-bodied invertebrate, often shelled
- cnidarianStinging aquatic invertebrate
- echinodermSpiny-skinned marine invertebrate
annelid · nematode · jellyfish · octopus · squid · crustacean · insect · spider · coral · worm
jellyfish
Drifting marine stinger
sponge · anemone · starfish · urchin · nautilus · cuttlefish · sea slug · sea cucumber · barnacle · mussel
protozoa
Single-celled eukaryotic organisms
- amoebaShape-shifting single-celled organism
- parameciumCiliated slipper-shaped protozoan
- planktonDrifting marine microlife
diatom · euglena · rotifer · tardigrade · nematode · ciliate · flagellate · microorganism · zooplankton · phytoplankton
insect
Six-legged invertebrate
- spiderWeb-spinning arachnid
- earthwormSegmented soil-dwelling invertebrate
- snailShelled, slow-moving mollusk
slug · centipede · millipede · scorpion · tick · mite · beetle · ant · termite · grasshopper