Symmetry: Asymmetry (Porifera), Radial (Coelenterata, Echinodermata), Bilateral (most others).
Coelom: Acoelomate (no coelom — Porifera, Platyhelminthes), Pseudocoelomate (false coelom from blastocoel — Aschelminthes), Eucoelomate (true coelom from mesoderm — Annelida, Arthropoda, Mollusca, Echinodermata, Chordata).
Segmentation: Metamerism in Annelida, Arthropoda. Pseudometamerism in Cestoda (tapeworm).
Notochord: Present only in Chordata. Distinguishes from non-chordates.
Porifera: Canal system, choanocytes, spongocoel, hermaphrodite. Sycon, Euspongia, Spongilla. Cellular level of organisation.
Coelenterata/Cnidaria: Cnidoblasts/nematocysts, tissue level, diploblastic, alternation of generation. Hydra, Aurelia (jellyfish), Adamsia (sea anemone).
Platyhelminthes: Flatworms, acoelomate, triploblastic, flame cells for excretion. Tapeworm (Taenia), Liver fluke (Fasciola), Planaria.
Aschelminthes/Nematoda: Roundworms, pseudocoelomate, dioecious. Ascaris, Wuchereria (filarisis), Ancylostoma.
Annelida: True coelom, closed circulatory system, metamerism. Nereis, Earthworm (Pheretima), Leech (Hirudinaria).
Arthropoda: Largest phylum. Jointed appendages, exoskeleton (chitin), open circulatory system. Insects (6 legs), Arachnida (8 legs), Crustaceans. Cockroach, Prawn, Scorpion, Butterfly.
Mollusca: Soft body, mantle, radula (for feeding). Pila (apple snail), Pinctada (pearl oyster), Sepia (cuttlefish), Octopus. Second largest phylum.
Echinodermata: Spiny skin, water vascular system, radial symmetry (adults), deuterostome. Asterias (starfish), Echinus (sea urchin), Ophiura (brittle star).
4 fundamental features: (1) Notochord — at some stage of life, (2) Dorsal hollow nerve cord, (3) Pharyngeal gill slits, (4) Post-anal tail — at some stage.
Sub-phyla: Urochordata (Ascidia — notochord in larva only), Cephalochordata (Branchiostoma/Amphioxus — notochord from head to tail), Vertebrata (notochord replaced by vertebral column).
Agnatha: Cyclostomata — no jaws. Petromyzon (lamprey), Myxine (hagfish). Ectoparasites on fish.
Pisces: Cold-blooded, 2-chambered heart, gills. Cartilaginous (Chondrichthyes — Scoliodon/shark), Bony (Osteichthyes — Labeo/rohu, Hippocampus/seahorse).
Amphibia: 3-chambered heart, first tetrapods, dual life. Frog (Rana), Toad (Bufo), Salamander.
Reptilia: 3-chambered (except crocodile — 4), scales, ectothermic. Lizard, Snake, Turtle, Crocodile. First true terrestrial vertebrates.
Aves: Warm-blooded, 4-chambered heart, feathers, pneumatic bones (hollow, lightweight), 4-chambered. Pigeon, Ostrich (cannot fly, vestigial wings), Neophron (vulture).
Mammalia: Hair, mammary glands, 4-chambered heart, warm-blooded, viviparous (mostly). Monotremes (Platypus — lays eggs), Marsupials (Kangaroo, Opossum), Placental (most).
Amphibia: 3 chambers
Reptiles: 3 (crocodile: 4)
Birds: 4 chambers
Mammals: 4 chambers
2nd largest: Mollusca
Largest animal phylum by species
Insects = 80% of all animal species
Most successful: Arthropoda
Bioluminescent: Firefly (Photinus), some fish
No true tissues: Porifera
No coelom: Porifera, Platyhelminthes
Radial symmetry adult: Echinodermata
Closed: Annelida, Vertebrates
Cephalopods (Octopus, Sepia): closed
Earthworm: closed (5 pairs of aortic arches)
Crocodile is the only reptile with a 4-chambered heart. Frog (Amphibia) = 3 chambers. Lizard (Reptile) = 3 chambers. Shark (Chondrichthyes/Fish) = 2 chambers.
Water vascular system is unique to Echinodermata. It's a hydraulic system of water-filled canals used for locomotion (tube feet), feeding, and gas exchange. Examples: Starfish, Sea urchin, Sea cucumber.
Heart chambers: 1 Q/year
Characteristic features: 1 Q/year
Expected: Match phylum to characteristic
Watch: Exceptions (crocodile, platypus)