INVERTEBRATES

YOU MUST KNOW… THE TRAITS WHICH ARE USED TO DIVIDE THE ANIMALS INTO GROUPS EXAMPLES AND UNIQUE TRAITS FOR EACH PHYLUM DISCUSSED THE EVOLUTION OF SYSTEMS FOR GAS EXCHANGE, RESPIRATION, EXCRETION, CIRCULATION, AND NERVOUS CONTROL

INVERTEBRATES LACK BACKBONES 95% OF ALL KNOW SPECIES ARE INVERTEBRATES

SUBKINGDOM PARAZOA SPONGES, PHYLA CALCEREA AND SILICEA SESSILE (ANCHORED), LACK TRUE TISSUES DIPLOBLASTIC (2 LAYERS OF CELLS) NO NERVES OR MUSCLES WATER IS DRAWN THROUGH THE PORES INTO THE SPONGOCOEL AND FLOWS OUT THROUGH THE OSCULUM THROUGH THE MOVEMENT OF FLAGELLATED CHOANOCYTES SPICULES COMPRISE A SKELETAL FRAMEWORK

SUBKINGDOM EUMETAZOA ANIMALS WITH TRUE TISSUES RADIALLY SYMMETRICAL ANIMALS PHYLUM CNIDARIA – POLYP (SEA ANEMONE) AND MEDUSA (JELLYFISH) FORM GASTROVASCULAR CAVITY (A CENTRAL DIGESTIVE COMPARTMENT), CNIDOCYTES (CELLS THAT FUNCTION IN DEFENSE AND CAPTURING OF PREY) EX. CNIDARIANS – HYDRAS, JELLYFISH, CORALS

BILATERALLY SYMMETRICAL ANIMALS ACOELOMATES – NO BODY CAVITY PHYLUM PLATYHELMINTHES (FLATWORMS) – TAPEWORMS, FLUKES FLATTENED BODIES WITH CEPHALIZATION, EXCRETION BY FLAME BULBS AND PROTONEPHRIDIA, NO SPECIALIZED ORGANS FOR GAS EXCHANGE OR CIRCULATION, GASTROVASCULAR CAVITY WITH A SINGLE OPENING

PSEUDOCOELOMATES PHYLUM NEMATODA (ROUNDWORMS) – PINWORMS, HOOKWORMS CYLINDRICAL BODIES WITH A TOUGH CUTICLE, COMPLETE ALIMENTARY CANAL, NO CIRCULATORY SYSTEM

COELOMATES PHYLUM MOLLUSCA (SOFT-BODIES ANIMALS) – SLUGS, CLAMS, SNAILS, SQUIDS, AND OCTOPUS MUSCULAR FOOT FOR MOVEMENT, A VISCERAL MASS CONTAINING MOST OF THE ORGANS, AND A MANTLE THAT SECRETES A SHELL OPEN CIRCULATORY SYSTEM, EXCRETION THROUGH NEPHRIDIA

PHYLUM ANNELIDA (SEGMENTED WORMS) – EARTHWORMS, LEECHES INTERNAL AND EXTERNAL SEGMENTATION, EXCRETION BY METANEPHRIDIA IN EACH SEGMENT CLOSED DIGESTIVE SYSTEM WITH SPECIALIZED REGIONS (CROP, GIZZARD, ESOPHAGUS, AND INTESTINE) BRAINLIKE CENTRAL GANGLIA WITH A VENTRAL NERVE CORD, CLOSED CIRCULATORY SYSTEM

PHYLUM ARTHROPODA (JOINT-LEGGED ANIMALS) – INSECTS, ARACHNIDS, MILLI- AND CENTIPEDES, CRUSTACEANS EXOSKELETON OF CHITIN, MOLTS TO GROW JOINTED APPENDAGES, OPEN CIRCULATORY SYSTEM, VARIOUS ORGANS FOR GAS EXCHANGE INCLUDING GILLS, BOOK LUNGS, TRACHEAL SYSTEMS VENTRAL NERVE CORDS UNDERGO METAMORPHOSIS (INCOMPLETE) – EGG, NYMPH, ADULT (GRASSHOPPER) (COMPLETE) – EGG, LARVA, PUPA, ADULT (BUTTERFLY)

DEUTEROSTOMIA CONTAIN A DIVERSE ARRAY OF ORGANISMS FROM SEA STARS TO CHORDATES HAVE RADIAL CLEAVAGE AND SHARE COMMON DEVELOPMENTAL PROCESSES

PHYLUM ECHINODERMATA – SPINY-SKINNED ANIMALS – SEA STARS, SEA URCHINS, SAND DOLLARS, SEA CUCUMBERS LARVAE HAVE BILATERAL SYMMETRY, ADULTS RADIATE FROM THE CENTER HAVE A THIN SKIN COVERING AN EXOSKELETON HAVE A WATER VASCULAR SYSTEM – NETWORK OF INTERNAL CANALS THAT BRANCH INTO TUBE FEET USED FOR MOVING, FEEDING, AND GAS EXCHANGE

B. PHYLUM CHORDATA – INCLUDES 2 INVERTEBRATE SUBPHYLA AS WELL AS ALL VERTEBRATES