Invertebrates

Aquatic, terrestrial, or parasitic animals with long, slim bodies and very simple brains. Earthworms are members of this group.

• Insects

• Worms

• Cnidarians

• Gastropods

Aquatic animals that have tentacles with stinging cells and go through 2 life phases – polyp and medusa. Jellyfish are members of this group.

• Gastropods

• Mollusks

• Cnidarians

• Arthropods

Aquatic animals that have an endoskeleton that gives their body spines, and a water vascular system. Sea stars are members of this group.

• Cnidarian

• Gastropod

• Worms

• Echinoderms

The simplest of all animals, they are aquatic, let water in through pores, and are able to regenerate

• Worms

• Sponges

• Cnidarians

• Insects

Aquatic or terrestrial animals with soft, unsegmented bodies, they use a foot for movement and have a mantle to protect their organs

• Mollusks

• Arthropods

• Echinoderms

• Sponges

Aquatic or terrestrial animals with segmented bodies, and exoskeleton, and jointed appendages

• Cnidarians

• Worms

• Arthropods

• Mollusks

Mollusks with 2 shells connected at a hinge and held together with strong muscles. Clams are members of this group

• Cnidarians

• Bivalves

• Gastropods

• Cephalopods

Mollusks whose foot is arranged into tentacles around their mouth – they have the most complex brain of all invertebrates. Octopus and squid are members of this group.

• Cephalopods

• Gastropods

• Bivalves

• Cnidarians

Mollusks with a single external shell or no shell at all. Snails are members of this group.

• Cnidarians

• Bivalves

• Cephalopods

• Gastropods

Arthropods with 2 or 3 segments with appendages on each, most are aquatic and have gills to get oxygen. Lobsters are members of this group.

• Crustaceans

• Arachnids

• Insects

• Arthropods