Phylum Porifera Example: Sponges Sponges are the simplest of animals that carry out all processes by the movement of water through pores Characteristics: Lack definite symmetry No germ layers or mouth. Reproduce both sexually and asexually All process carried out a few specialized cells

Phylum Cnidarians Examples: Jellyfish, Hydra, Sea Anemones and Corals Characteristics: Two layers – an endoderm and ectoderm, with a layer of jelly-like material between. A single mouth/anus surrounded by stinging tentacles A nerve net to detect stimuli Hydrostatic skeleton allow the animal to move

Phylum Platyhelminthes Example: Flatworms Characteristics: Bilateral symmetry Protostome Digestive system is branched with a single opening (mouth) with a specialized pharynx that pumps food into the digestive system Cephalization – in some the head encloses ganglia – a group of nerve cells Some are parasitic (ex: Flukes and tapeworms) Phylum Platyhelminthes Example: Flatworms

Phylum Nematoda Examples: Roundworms Characteristics: Body cavity, pseudocoelom, located between endoderm and mesoderm Three Germ layers. Have complete, one-way digestive tracts (mouth and anus) Protostome Bilateral symmetry Nematoda contains the most members, most are microscopic, many parasitic

Phylum Annelida Examples: earthworm, leeches, polychaetes, and feather dusters Characteristics: Worms with segmented bodies. Three germ layers and a true coelom Bilateral symmetry Cephalization Protostome

Phylum Mollusca Examples: snails, slugs, clams, squids, octopi Characteristics: Soft-bodied that usually have a shell 4 part body plan Foot – movement Mantle – layer of tissue covering body Shell – created my mantle, lost in some members Visceral mass – internal organs Three germ layers with coelom Bilateral symmetry

Phylum Arthropoda Examples: insects, crabs, centipedes, spiders Characteristics: Arthropods have a segmented body, tough exoskeleton, and jointed appendages. Most successful of all invertebrates Many specialized organs Three Germ Layers with coelom Bilateral symmetry

Phylum Echinodermata Examples: sea stars, sea urchins, sea cucumbers, and sand dollars. Characteristics: Most have spiny skin, an internal skeleton, a water vascular system, and suction-cuplike tube feet. Larva forms have bilateral symmetry and adults have radial symmetry. Adults possess five-part body plan Deuterstome Three germ layers with a coelom