Invertebrates

More complex invertebrates

Echinoderms

Simplest Invertebrates

Arthropods

Corals, sponges, and jellyfish.

Earthworms

Ocean

Soil

sea urchins, sea stars

salt water have body parts in multiples of five

crustaceans

Largest group

exterior shell, five pairs of jointed limbs

spiders

two body segments, eight legs

insects

antennae

mollusk

squid

have shells for protection

octopi

have internal shell

do not have a shell at all