ANIMAL KINGDOM CLASSIFICATION

Animals can be grouped into two large categories:Vertebrates and Invertebrates.

Vertebrates have backbones and invertebrates DO NOT.

95% of all animals are invertebrates!

The major phyla of invertebrates are: Phylum Porifera Phylum Cnidaria Phylum Platyhelminthes Phylum Nematoda Phylum Mollusca Phylum Annelida Phylum Arthropoda Phylum Echinodermata

Invertebrates

These are the simplest invertebrates. All sponges are asymmetric They have no tissues, organs or organ

systems. They just have specialized cells. They all live in water.

Porifera

Cnidarians do not have organs or organ systems.

They have radial symmetry. They have a single body opening surrounded

by tentacles. They have simple tissue to carry out body

functions. They have specialized cells to capture food.

Cnidarians

Radial symmetry Hard plates embedded in the skin Live only in oceans Complete digestive systems Tube feet Include sea stars, sea cucumbers and sea

urchins

Echinoderms

They have bilateral symmetry They have nerve, muscle and digestive

tissues They have a simple brain They have soft, flattened bodies Have a mouth Most are parasites.

Platyhelminthes

Roundworms Bilateral symmetry Nerve muscle and digestive tissues Simple brain Round bodies with mouth and anus

Nematoda

Bilateral symmetry Soft bodies Some have hard shells Digestive system with two openings Body cavity with heart, stomach and other

organs. Eyes and a simple brain Must remain wet

Mollusks

Bilateral symmetry Soft bodies Circulatory system Simple brains Includes earthworms, leeches, etc.

Annelids

Arthropods

Includes insects, spiders, shrimp, crab and relatives

Insects, arachnids and crustaceans Bilateral symmetry Exoskeletons Jointed appendages