BI 101: Invertebrate Animals
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5/30/2014 BI 101: Invertebrate Animals Hornwort- a bryophyte 1 5/30/2014 Announcements • Lab tomorrow: Invertebrates ( lab worksheet provided) – No prelab • Extra credit: Mycorestoration at Sequoia creek – Friday June 6th, 2014 3-4pm – the street Coffee culture, Corvallis • Extra credit: World Oceans Day- beach cleanup – Sunday June 8th – Nye Beach, Newport Classification The three-domains Bacteria Archaea Eukarya The six-kingdom system Bacteria Archaea Protista Plantae Fungi Animalia The traditional five-kingdom system Monera Protista Plantae Fungi Animalia 2 5/30/2014 (Forams and Radiolarians) Rhizarians Alveolates Rhodophyta Stramenopile CHLOROPHYTA Euglenozoa AMOEBOZOANS What are some characteristics animals share? List as many as you can think of. Discuss this in your groups 3 5/30/2014 Animal Cell Fungus Cell Evidence indicates that animals evolved from choanoflagellates (protists) ~ 570 mya • Single cells • Often clonal • Heterotroph • No specialization or coodination between cells 4 5/30/2014 Animal Classification 1. DNA sequencing 2. Body Symmetry 3. Presence or absence of body cavity 4. Embyonic Development Symmetry 5 5/30/2014 Body Cavity Most bilateral animals have body cavities – Body cavities are fluid-filled cavities between the digestive tube and the outer body wall – Functions: • skeleton, providing support for the body and a framework against which muscles can act • protective buffer between the internal organs and the outside world • They can allow organs to move independently of the body wall Body Cavity? epidermis gut cavity organs packed between A No coelom gut and body wall (acoelomate animal) Fig. 25-4a, p. 405 6 5/30/2014 Body Cavity? epidermis gut cavity B Pseudocoel (pseudocoelomate animal) unlined body cavity around gut Fig. 25-4b, p. 405 Body Cavity? gut epidermis cavity C Coelom body cavity with a lining (dark (coelomate animal) blue) derived from mesoderm Fig. 25-4c, p. 405 7 5/30/2014 Embryonic Development Blastopore forms Protostomes mouth first Deuterostomes Blastopore forms anus first What is the difference between vertebrates and invertebrates? 8 5/30/2014 Porifora - sponges • Sessile (Larva motile) • No true tissues or organs • Exhibit asymmetry or radial symmetry • Filter feeders 9 5/30/2014 (water flow out Sponge Anatomy of the sponge) epithelial cell pore spicules (water flow into the sponge) amoeboid cell pore cell collar cell (water flow) Fig. 23-5 Sponge filtration/feeding Collar Cell Collar Cell http://www.youtube.com/ watch?v=T7E1rq7zHLc&feat ure=player_embedded http://www.youtube.com/watch?v =29W77870BgE&list=PLVN5247pO BYcE1Mn_pWHIL9l0sMIx19TI 10 5/30/2014 Sponges for Breast Cancer Research! • The artificial component called eribulin mesylate imitates an element found in sponges. • It can check cell division, which is a reason of cells to self-damage. • http://www.topnews.com.sg/content/22106-marine- sponge-probable-treatment-breast-cancer 11 5/30/2014 Cnidaria – Sea Anemone • Radial symmetry • Two tissue layers • Filled with water– supports body • Nerve net • Nematocysts -stinging organelles that release toxins Cnidarian Weaponry: The Cnidocyte trigger filament trigger nuclei (b) Cnidocytes Fig. 23-8 12 5/30/2014 Cnidaria: Symbiosis Coral is a mutualism between photosynthetic dinoflagellates (protist) and a cniderian (animal) • Algae in coral called zooxanthelle In many coral species polyps form colonies Cnideria video Colonial polyps secrete a hard external skeleton of calcium carbonate The skeleton remains after the polyp dies New polyps build on the skeletal remnants of earlier generations 13 5/30/2014 Platyhelminthes - flatworms • Bilateral symmetry • 3 tissue layers • Cephalization (nerve mass) • True organs and organ systems • Aceolomate (no body cavity) • Parasitic forms but some free living 14 5/30/2014 Evolved ~500 mya 15 5/30/2014 Fig. 32-8 Nematoda - Round worms Coelom Body covering • Exoskeleton (molts)– 25,000 (fromspecies ectoderm) body coved in a thick Tissue layer cuticle lining coelom Digestive tract and suspending • Psuedocoelom (false (from endoderm) internal organs (from mesoderm) body cavity) • Bilateral worms (a) Coelomate • 3 tissue layers Body covering • Unsegmented (from ectoderm) Pseudocoelom Muscle layer • Parasitic (50%) (from and free-living (50%) mesoderm) Digestive tract (from endoderm) (b) Pseudocoelomate Body covering (from ectoderm) Tissue- filled region (from 16 mesoderm) Wall of digestive cavity (from endoderm) (c) Acoelomate 5/30/2014 A Freshwater Nematode posterior end intestine anterior end ovary vagina eggs mouth cuticle Fig. 23-25 17 5/30/2014 Arthropoda– Earth’s most diverse phylum Billions of species! Major groups: • Crustaceans • Myriopods • Arachnids • Hexapods Arthropoda Characteristics 1. Exoskeleton= External skeleton 2. Specialized body segments 3. Jointed appendages 4. Bilateral symmetry 5. True coelom (body cavity) 18 5/30/2014 Arthropoda respiratory system: Trachea Arthropoda respiratory system: Example: Grasshopper • Spiracles: pores in exoskeleton • Trachea: connect to spiracles, carry oxygen to the body cells 19 5/30/2014 Arthropoda respiratory system Arthropod Phylogeny 20 5/30/2014 Chelicerata 8 legs • Arachnids – spiders, – Mites – Ticks – scorpions • Horseshoe crabs • Pseudoscorpians Arthropod Phylogeny 21 5/30/2014 Crustaceans Rolly pollies– Isopods Lobsters Crayfish Crabs Shrimp Krill Baracles Arthropod Phylogeny 22 5/30/2014 Myripoda • Class: Symphyta • Class: Chilopoda (centipedes) • Class: Diplopoda (millipeds) Arthropod Phylogeny Diplura Insecta Protura Collembola Hexapoda: Reduction in body segments to 3 Reduction in legs to 6 23 5/30/2014 Arthropod Phylogeny Thysanaura : Slverfish Archaegnatha Diplura Protura Collembola Wings! Insecta: mouthparts outside head capsule Hexapoda: Reduction in body segments to 3 Reduction in legs to 6 Figure 23-19 Segments are fused and specialized in insects antennae head thorax abdomen compound eye mouth parts wing 24 5/30/2014 Specializations for Feeding Grasshoppers (a) – mouth has numerous manipulating and shearing parts for eating vegetation. Flies (b) – has a labium mouth part that has a sponge like end for absorbing nutrients from moist foods. Butterflies & Moths (c) – mouth part is a tube like maxilla for sucking up nectar from flowers. Mosquitoes (d) – have a stylus for piercing their prey to draw blood like a hypodermic needle. Insect Development 25 5/30/2014 Discussion Why might it be advantageous for insects to have complete metamorphosis? 26 5/30/2014 Annelida - segmented worms Fig. 32-8 Coelom Body covering • Segmented body (from ectoderm) • Bilateral symmetry Tissue layer lining coelom • 3 tissue layers Digestive tract and suspending (from endoderm) internal organs • Coelom (fully enclosed (from mesoderm) body cavity) (a) Coelomate Body covering • Organ systems are more (from ectoderm) fully developed Pseudocoelom Muscle layer (from mesoderm) • Decomposers and Digestive tract (from endoderm) Parasites (b) Pseudocoelomate Body covering (from ectoderm) Tissue- filled region (from mesoderm) Wall of digestive cavity (from endoderm) Annelida - segmented(c) Acoelomate worms • Class: Polychaetes – Each segment with many hairlike chetae – 12,000 species – Mostly marine • Class: Clitellata – Earthworms - Oligochaete 10,000 species Terrestrial Decomposers – Leeches – Hirudinea 700 species Predators or parasites Most freshwater 27 5/30/2014 Discussion questions 1. How do earthworms differ from tapeworms and planarians? Discussion questions 1. How do earthworms differ from tapeworms and planarians? 2. How do earthworms differ from nematodes? 28 5/30/2014 Mollusca Characteristics: • bilateral symmetry • Coelomates- true body cavity • Unsegmented • aquatic & terrestrial • possess all organ systems Mollusca Diversity 2nd most diverse animal group: 93,000 species Gastropods Cephalopods Bivalves 80% of mollusk Most neurologically Aquatic species advanced • Clams • Snails Marine predators • Mussels • Slugs • Octopus • Nudibranchs • Squid • Cuttlefish 29 5/30/2014 Nudibranchs • 3,000 described species • Snails without a shell • Unique lifestyle and defense mechanisms Elysia– the photosynthetic animal (video) Glaucus atlanticus consumes ‘man of war’ jellyfish and puts the nematocytes on its own back! Nudibranchs The Blue Dragon, Pteraeolidia ianthina, has a symbiosis with dinoflagellates. It also steals the armed tentacles of a sea anemone, a Cniderian, for defense and combat! 30 5/30/2014 31 5/30/2014 Phylum Echinodermata 6,000 species Includes sand dollars, sea urchins, sea stars, sea cucumbers, and sea lilies Three tissue layers True coelom Echinodermata characteristics 1. Deuterostomes 32 5/30/2014 Echinodermata characteristics 2. Larvae exhibit bilateral symmetry; adults show radial symmetry Echinodermata characteristics 3. Endoskeleton (internal skeleton) that sends projections through the skin Composed of calcareous plates or ossicles 33 5/30/2014 Echinodermata characteristics 4. Water vascular system: Food and waste transport Respiration Locomotion Discussion question • How do sea urchins and sea stars differ from sea anemones and coral? VS 34 5/30/2014 Phylum Chordata Contains both vertebrates AND invertebrates! All Chordates share four characteristics: 1. Dorsal nerve cord 2. Notochord (Primitive skeleton) 3. Pharyngeal gill slits 4. Post-anal tail 35 5/30/2014 Animal Diversity Ancestral Derived Radial Symmetry Bilateral 0, 2 # of tissue layers 3 1 # gut openings 2 Acoelomate, Type of coelom Eucoelomate Pseudocoelomate Type of development Protostome Deuterostome Animal