What animals don't have back bones?

Answer 1

Aside from the common invertebrates we know like insects, cnidarians, molluisks, echinodrms, etc... there are also chordates that do not have vertebrae for example, the tunicates(urochordata) and the lancelets(cephalochoradata)...

Answer 2

Animals without backbones are known as invertebrates. Examples include insects, Spiders, worms, jellyfish, and shellfish like clams and snails. These animals have different types of support structures or exoskeletons instead of a backbone.

Answer 3

an octopus, jelly fish, insects, arachnids (8 legged critters like spiders or lobsters), crabs, the list goes on....

Answer 4

sponges

Answer 5

A lamprey