Animal Diversity

• Body symmetry (asymmetrical, radial, or bilateral)
• The presence or absence of coelom body cavity
• Whether the blastopore of the embryo develops into the mouth or the anus

• Sponges
• Asymmetrical
• Spongeol
• Filter feeding
• no true tissues

• Jellyfish, hydra
• Radial body symmetry
• Gastrovascular cavity; tissues
• One-opening
• Cnidoblasts (stinging cells)

• Flatworms
• Bilateral
• Gastrovascular cavity; organs
• One-opening
• 1st true organs (pharynx)

• Gastropod
• Bivalves
• Cephalopods

• Bilateral
• Coelom
• Two-opening
• Head-foot & mantle shell

• Snails, slugs
• scraping tongue

• clams, oysters
• filter feeder
• enlarged gills

• octopus, squid
• free-swimming predator
• tentacles, eyes, large brain

• Segmented worms
• Bilateral
• Coelom; segmented
• Two-opening

• Bilateral
• Coelom; some segmentation
• Two-openings
• Segmented

• arachnids
• crustaceans
• insects

• Spiders
• Fang-like mouths

• Crabs, lobsters
• 2 pairs of antennae

• Insects
• 1 pair antennae
• 6 legs, wings

• starfish
• bilateral larvae
• secondarily radial adults
• coelom
• two-opening
• deuterostomes; water vascular system
• "spiny skinned"

• Bilateral
• Coelom; some segmentation
• Two-openings
• Deuterostomes
• no backbone
• dorsal, hollow nerve cord; pharyngeal gill slits; tail; backbone

Dorsal, hollow nerve cord; pharyngeal gill slits; tail; no backbone

• Sharks, bony fish, amphibians, reptiles, birds, and mammals
• Dorsal, hollow nerve cord; pharyngeal gill slits; tail; backbone

excurrent opening in sponges

primitive form of structural support left behind by the bleach

stinging cells all cnidarians have and use for protection and for catching food

stinging devices on the tentacles of cnidarians

Polyp and medusa

a sessile (permanently attached) asexual stage (look like hydra)

sexual stage (look like jellyfish)

They are not true organs, but just clusters of gametes (eggs and sperm)

Asexually (like polyps, by "budding") and sexually (with eggs and sperm, like the medusa form)

dorsal fold of tissue that secretes the shell

• water passes into the mantle cavity through the ventral incurrent siphon and out through the dorsal excurrent siphon
• also directs the jet of water that is forced out of the mantle cavity when the squid contracts its mantle

• Annelids have serially segmented bodies
• This means that the body is composed of repeated similar segments or "metameres".
• This is called metamerism and is also found in arthropods and chordates.

• "second" body cavity that surrounds and is completely separate from the digestive cavity.
• Inside this fluid-filled space of the coelom the internal organs can increase their surface are by bending and coiling (human intestine), can fill, empty, and slide past one another, lubricated with coelomic fluid (human lungs).
• Foudn in annelids, mollusks, & other "higher" phyla
• Not found in porifera and cnidaria

Bristles attached to the outside of the parapodia that help the earthworm move

Parapodia have a large surface are and keep fresh water with a high concentration constantly moving over the respiratory surface.

Bees, butterflies, roaches

crabs, lobsters, crayfish

spiders, ticks, scorpions

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Insects

echinoderms and chordates

anthropods and mollusks

• Head, thorax, and abdomen
• In arachnids and crustaceans the head and thorax are fused into a cephalothorax

• Four foot
• Amphibians, reptiles, birds, mammals

The round structure which leads into the water vascular system on a starfish

The clear-white fleshy protrusions of the coelom that serve as sites of gas exchange