Invertebrates

Simplest invertebrates

Corals sponge's jellyfish

ocean

Earthworms

soil

Echinoderms

sea urchins' sea stars

saltwater have body parts in multiples of live

Arthropods

largest group

crustacean

spiders

insects

antennae, jaws, three body segments

two body segments, eight legs

exterior shell, five pairs of jointed limbs

more complex invertebrates

mollusks

have shells for protection

squid

have internal shell

octopi

do not have shell at all