What is an Animal? 1.Animals lack a cell wall 2.Sexual reproduction is normal. 3.Most animals are mobile. 4.Animals are multicellular heterotrophs. 5.Animals store energy as glycogen not starch (plants).

Porifera Examples: Sponges Characteristics: “Pore Bearing”, no nervous system, no circulatory system, no true digestive system, (ameobocytes are a cell that acts to digest material).

Cnidarians Examples: coral, jellyfish, hydra, portuguese-man-of-war Characteristics: The have radial symmetry, tentacles covered with nematocytes, a sac digestive system, nerve net nervous system (no brain), no circulatory system.

Jellyfish Life Cycle

Platyhelimenthes Examples: (flat worms) tapeworm, fluke, planaria Characteristics: They have bilateral symmetry and a primitive nervous system. They have flat bodies, absorb nutrients and O 2 from surrounding, sac digestive system if have one, nerve net and ganglia, few sense organs.

Nematoda Examples: “roundworms”, hookworm, ascaris, pinworm, trichinosis… Characteristics: They have a tube digestive system (mouth, intestine and anus), they have no circulatory, ladder-like nervous with ganglia, few sense organs and all are parasites.

Annelida Examples: “segmented worms”; earthworm, leech, polychete. Characteristics: Closed circulatory system and 5 hearts, complete digestive system, ventral nerve cord and brain (ganglia) Reproduction: hermaphrodites but cannot self fertilize

Mollusca Examples: Snails, clams, octopus, slug… Characteristics of all but octopus/squid: Most have one or two shells, complete digestive system, open circulatory system, breath with gills, ventral nerve cord and a decent “brain” ganglia, some sense organs.

Cephalopods: an exceptional mollusk Octopus and squid are unique. They have excellent eyesight, closed circulatory system and three hearts, complete digestive, use gills to breathe, nervous is the best of everyone including several vertebrates. They can learn, plan, strategize and think. They use chromatophores to change colors for courtship and territoriality. They have separate sexes and internal reproduction. They are so cooooool!!!

Squid Anatomy

Arthropoda Examples: insects, spiders, millipedes, crayfish, crabs, ticks… (75% of invertebrates are Arthropods) Characteristics: They are segmented, contain a hard exoskeleton made from chitin, have jointed appendages, open circulatory, ventral nerve cord and ganglion, one heart, breathe through spiracles, book lungs or gills, complete digestive system, and good sense organs. (antenna, eyes, hairs…) they have internal reproduction and no regeneration.

Echinodermata Examples: starfish, sea urchins, sand dollars Characteristics: They are deuterostomes with penta-radial symmetry, no circulatory, no blood or hearts, simple nerve ring and nerve down each arm, no ganglia, mouth  stomach  anus, WATER VASCULAR SYSTEM. They are unlike any other invertebrate.