Inverterbrates

sponges Simplest invertebrate Live in salt water 2 layers of cells Attach to one spot

jellyfish Live in the ocean Have tentacles with stinging cells Float around trap their food

flatworms Flat bodies Parasites – tapeworm Live inside host bodies

Round worms Parasites – hookworm example Found in soil and water

Segmented worms Have segments in their bodies Earthworm example They burrow through soil bring air to plants Leeches another example – blood sucking – Used in medicine

Spiny skinned animals Starfish, urchins, sand dollars Starfish have tubed feet Can break apart clams for food

Mollusks Octopus, squid, clam and snails Live in both water and land Most have shells and soft bodies

Arthropods Largest group of animals Jointed feet with claws Sectioned bodies Exoskeletons

insects Pair of antennae 3 body parts, head, thorax, abdomen Most have one or two pairs of wings Live everywhere except the ocean

Arachnids Spiders and horseshoe crabs 8 legs Two body parts – head and abdomen

crustaceans Crabs, lobsters, barnacles, shrimp Most live in the ocean or fresh water

centipedes One pair of jointed legs per body section Predators – eat insects

millipedes Two pair of legs per body section Often called 1000 legger Decomposers