2007 2008 Kingdom Animalia Domain Eukarya INVERTEBRATES Domain

2007 -2008 Kingdom: Animalia Domain: Eukarya INVERTEBRATES!!!! Domain Bacteria Domain Archaea Common ancestor Domain Eukarya

ANIMAL CHARACTERISTICS Heterotrophs must ingest others for nutrients Multicellular complex No bodies cell walls allows Sexual no active movement reproduction alternation of generations no haploid gametophyte

ANIMAL EVOLUTION Cnidaria Porifera sponges jellyfish Nematoda Platyhelminthes Annelida Mollusca Echinodermata Arthropoda flatworms roundworms mollusks segmented worms redundancy, segmentation specialization, mobility insects spiders starfish Chordata vertebrates body & brain backbone size, mobility body size endoskeleton coelom digestive sys radial body cavity body complexity digestive & repro sys bilateral symmetry tissues multicellularity Ancestral Protist distinct body plan; cephalization specialized structure & function, muscle & nerve tissue specialization & body complexity bilateral

BODY CAVITY Space for organ system development increase digestive & reproductive systems increase food capacity & digestion increase gamete production Coelem & endoderm interact during development allows complex structures to develop in digestive system acoelomate ectoderm mesoderm endoderm pseudocoel mesoderm ex. stomach coelomate ectoderm mesoderm coelom cavity endoderm

INVERTEBRATE: PORIFERA Sponges no distinct tissues or organs do have specialized cells (amoebocytes and choanocytes) no symmetry sessile (as adults) food taken into each cell by endocytosis

INVERTEBRATE: PORIFERA Sponges Diffusion is the method used for circulation, gas exchange and excretion of wastes Reproduction Asexual – Fragmentation Sexual – Hermaphrodites: release egg and sperm; produce flagellated, swimming larvae

INVERTEBRATE: CNIDARIA Jellyfish, hydra, sea anemone, coral tissues, but no organs Polyp = two cell layers sessile predators tentacles surround gut opening extracellular digestion release enzymes into gastrovascular cavity absorption by cells of gastrodermis Medusa = motile

CNIDOCYTES OF CNIDARIANS mouth tentacles sensory cell stinging cell hydra trigger Cnidocyte (stinging cell) with nematocyst discharged nematocyst undischarged nematocyst

INVERTEBRATE: CNIDARIA Nerve Net: not centralized, can respond equally on all sides Use diffusion for circulation, gas exchange and excretion of wastes Reproduction Asexual – Budding (polyp) Sexual – External fertilization/development (medusa)

INVERTEBRATE: PLATYHELMINTHES Flatworms tapeworm, planaria mostly parasitic bilaterally symmetrical cephalization = concentration of nervouse system in anterior end concentration of sense organs in head Eye spots Animals now face the world Lateral flaps(smell) head on! increase specialization in body plan ectoderm acoelomate mesoderm endoderm

INVERTEBRATE: PLATYHELMINTHES Gastrovascular Cavity – one opening for mouth and anus Use diffusion for transport and gas exchange Protonephridia Network to excrete ammonia Flame bulbs Nephrostomes Locomotion Cilia used to move along mucus Muscles used to undulate (swim)

INVERTEBRATE: NEMATODA Roundworms bilaterally symmetrical many are parasitic Hookworm Nerve ring Exhibits cephalization Longitudinal muscles = thrashing motion C. elegans

INVERTEBRATE: NEMATODA Complete digestive system tube running through length of body (mouth, esophagus, midgut, rectum, anus) Midgut secretes enzymes and absorbs nutrients Material circulate body in fluid of pseudocoelom Gas exchange occurs by diffusion Wastes collected by simple structures leading to excretory pores in body wall Nitrogenous waste usually ammonia, but sometimes urea Reproduction = sexual Internal fertilization/external development Zygote = resistant cell – can survive harsh environment Rigid cuticle shed periodically

INVERTEBRATE: MOLLUSCA slugs, snails, clams, squid soft bodies, mostly protected by hard shells General body plan: Muscular foot (movement) Visceral mass (contains internal organs) Mantle (fold of tissue over visceral mass creating mantle cavity) Nerve ring & nerve cords – exhibit cephalization Locomotion via muscular foot, or jet propulsion

INVERTEBRATE: MOLLUSCA Differentiated digestive tract Open circulatory System: 3 -chambered heart pumps hemolymph Gas exchange via gills in mantle cavity Use countercurrent exchange Nitrogenous waste removed by metanephridia Radula: belt of curved teeth for scraping up food Nephridiopore discharge into mantle cavity Reproduction: most gonochoristic (separate sexes) Many snails hermaphroditic Ciliated larvae = trochophore

INVERTEBRATE: ANNELIDA Segmented worms earthworms, leeches segments increase mobility redundancy in body sections Setae (Bristles) = traction for burrowing Longitudinal + Circular muscles = peristaltic or slinky type movement fan worm leech

INVERTEBRATE: ANNELIDA Complete Digestive tract (mouth, pharynx, esophagus, crop, gizzard, intestine, anus) Closed cirulatory system Separted body fluids (blood and interstitial) hemoglobin as repiratory pigment Moist skin = respiratory surface (gas exchange)

INVERTEBRATE: ANNELIDA Excretory system = metanephridia in each segment Nephrostome Nephridiopore Waste usually ammonia Reproduction Some asexual – regeneration Sexual – hermaphrodites that cross fertilize

INVERTEBRATE: ARTHROPODA Spiders, insects, crustaceans most successful animal phylum (most abundant on Earth) segmented specialized segments (head, thorax, abdomen) allows jointed appendages specialized for swimming, walking or flying exoskeleton chitin + protein Molting – shed exoskeleton periodically

INVERTEBRATE: ARTHROPODA Extensive cephalization Well developed sense organs (eyes, olfactory, antennae) Complete digestive tract (foregut, midgut, hindgut) Excretory System Malpighian tubules Waste = uric acid (terrestrial) Waste = ammonia/urea (aquatic)

INVERTEBRATE: ARTHROPODA Open circulatory system (hearts and body movement circulate hemolymph) Gas exchange: Gills (aquatic) Book lungs (terrestrial) Tracheal system (terrestrial) Spiracles Tracheae Reproduction – Sexual Internal fertilization/external development Metamorphosis

ARTHROPOD GROUPS arachnids 8 legs, 2 body parts spiders, ticks, scorpions crustaceans gills, 2 pairs antennae crab, lobster, barnacles, shrmp insects 6 legs, 3 body parts

INVERTEBRATE: ECHINODERMATA Starfish, sea urchins, sea cucumber Bilateral larvae; radially symmetrical as adults spiny endoskeleton Nerve Ring with radial nerves Short Digestive tract Gills for gas exchange Excretion: Coelomocytes Phagocytize wastes and Carry to discharge sites

INVERTEBRATE: ECHINODERMATA Circulation Water Vascular system: madreporites take in water from environment; water flows through tubes terminating in tube feet (used for locomotion) Hemal System: fluid moves through tubes due to peristalsis and cilia Reproduction Asexual – Regeneration Sexual – external fertilization and development

INVERTEBRATE QUICK CHECK… Invertebrates: Porifera, Cnidaria, Platyhelminthes, Nematoda, Annelida, Mollusca, Arthropoda, Echinodermata Which group includes snails, clams, and squid? Which group is the sponges? Which are the flatworms? …segmented worms? …roundworms? Which group has jointed appendages & an exoskeleton? Which two groups have radial symmetry? What is the adaptive advantage of bilateral symmetry? Which group has no symmetry?

2007 -2008 That’s the buzz! Any Questions?