Animal Diversity Figure 32.4 A traditional view of animal diversity based on body-plan grades Figure 32.8 Animal phylogeny based on sequencing of SSU-rRNA The diversification of animals through evolution helps us to understand what an animal is. • “All models are false, but some are useful” George Box, Professor of Statistics, University of Wisconsin Figure 32.13x Burgess Shale fossils Burgess shale • http://www.youtube.com/watch?v=O8UXlc gzcEA • Anomalocaris 1 meter long predator • http://www.youtube.com/watch?v=iEh6ufo p6tE Opabinia • five stalked eyes; a backward-facing mouth under the head; and a long, flexible, hose-like proboscis which extended from under the front of the head and ended in a "claw" fringed with spines. Figure 32.13 A sample of some of the animals that evolved during the Cambrian explosion Figure 33.1 Review of animal phylogeny Choanoflagellate colony Phylum Porifera • Sponges • “colony” of flagellated cells (choanocytes) • Porocytes on surface • individual cells can potentially regenerate into a new individual • No true tissues, no symmetry • Spicules, spongin Figure 33.3 Anatomy of a sponge Radial Figure 32.5 Body symmetry Phylum Cnidaria • Hydras, jellyfish, sea anemones, corals • True tissues, nervous system, muscles, sensory organs, digestive system • generally two tissue layers: gastrodermis, epidermis • gastrovascular cavity • stinging cells • Radiata Figure 33.4 Polyp and medusa forms of cnidarians Figure 33.5 A cnidocyte of a hydra Discharged cnidocyte • http://www.youtube.com/watch?v=KHBhW VKOXt0 Cnidarians - Medusa forms The Irukandji (Carukua barnesi) • 1 inch diameter • Australia • Can kill human in a few days • Microscopic video footage of jellyfish nematocysts firing. The video was created by the TASRU (Tropical Australian Stinger Research Unit) of James Cook University. The video shows nematocysts along a section of tentacle from Carukia barnesi (Irukandji jellyfish) discharging after artificial stimulation. The image has been filmed through a microscope and is magnified about 400 times. • http://www.youtube.com/watch?v=6zJiBc_N1Zk • http://www.youtube.com/watch?v=GTXinF8ZJellyfish lake Palau VCo • The golden jellyfish Mastigias cf. papua etpisoni Giant jellyfish • http://www.youtube.com/watch?v=HqfCm5 8SB6Y Cnidarians – Polyp forms Sea anemone – Anthopleura tidepools Pacific Coast Corals – see also “google street view” Cnidaria • Stomphia didemon • Orange swimming anemone • 80-160 m depth • Usually attached to horse mussels around sandy substrates • http://www.youtube.co m/watch?v=Dm98n39 08QM Phylum Ctenophora • Comb jellies • comblike ciliary plates for propulsion, no stinging cells (sticky tentacles instead) • True tissues, nervous system, muscles, sensory organs, digestive system • 2-3 tissue layers; gastrovascular cavity • Radiata Diverse body shapes despite being a relatively small phylum Bilateral Figure 32.6 Body plans of the bilateria Phylum Platyhelminthes • Flatworms • dorsoventrally flattened • no segmentation • gastrovascular cavity • bilateral, no coelom, protostome Figure 33.10 Anatomy of a planarian Figure 33.12 Anatomy of a tapeworm http://www.youtube.com/watch? v=HOaZCkA8Zvk Phylum Nematoda • Roundworms • unsegmented • no circulatory system • bilateral, pseudocoelomate, protostome Figure 33.25a Free-living nematode Lophophorates - several phyla • Bryozoans, lampshells (brachiopods) • bilateral, coelomate, protostome Figure 33.14 Lophophorates: Bryozoan (left), brachiopod (right) Phylum Mollusca • Clams, snails, squids • foot, visceral mass, mantle • bilateral, coelomate, protostome Table 33.3 Major Classes of Phylum Mollusca Phylum Mollusca Class Gastropoda Figure 33.16 Basic body plan of mollusks Mollusca • Euspira lewisii • Moon snail • one of the largest to be found intertidally in the Northwest • It does not usually stay inside the shell long because it cannot breathe. • It crawls across sandflats and mudflats with its huge foot partly extended in front of the shell like a snowplow, pushing through the sediments in search of clams. Figure 33.18 The results of torsion in a gastropod Phylum Mollusca Class Bivalvia Figure 33.21 Anatomy of a clam Freshwater mussel: Lampsilis reeveiana http://unionid.missouristate.edu/gallery/L_reeveiana/Reeviana.htm http://www.unionid.missouristate.edu/gallery/Epioblasma/default.htm Snuffbox mussel (Epioblasma triquetra) and logperch host Phylum Mollusca Class Cephalopoda Humboldt squid Architeuthis dux Vampyroteuthis infernalis • Vampire squid from “hell” http://www.youtube.com/watc h?v=S3CJIKKSUpg • No ink production, produces bioluminescent mucus cloud • Black surface • Lives in the oxygen minimum zone Hawaiian bobtail squid • Houses bioluminescent Vibrio bacteria in a “crypt”. Uses the light for counterillumination when they hunt at night • There is a reflector and lens as part of the light organ Phylum Annelida • Segmented worms • bilateral, coelomate, protostome Figure 33.23 Anatomy of an earthworm Giant palouse earthworm Driloleirus americanus • The white, lily- scented denizen of the region’s fertile, deep soils reportedly can grow to 3 feet long • Thought to be extinct • Specimen found by UI researcher in 2006 Table 33.4 Classes of Phylum Annelida Phylum Arthropoda • Crustaceans, insects, spiders • segmented body, jointed appendages, exoskeleton • bilateral, coelomate, protostome Figure 33.26 External anatomy of an arthropod Interesting arthropods • Pistol shrimp http://www.youtube.com/watch?v=eKPrGx B1Kzc Isopods • Look like pillbugs, normally small • http://www.youtube.com/watch?v=xeOSXt BCY30 Mantis shrimp - Stomatopods • Second leg is a spear or club, special hard chitin • http://www.youtube.com/watch?v=pgvsQ6o NZyo Figure 33.30b Spider anatomy Figure 33.33 Anatomy of a grasshopper, an insect Bilateral Deuterostomes Figure 32.7 A comparison of early development in protostomes and deuterostomes Phylum Echinodermata • Starfish, sea urchins • Endoskeleton, water vascular system, tube feet, pedicellaria, spines, regeneration capability • bilateral, coelomate, deuterostome Figure 33.38 Anatomy of a sea star Echinodermata - starfish • Pycnopodia helianthoides • Sunflower star • Voracious predator • http://www.youtu be.com/watch?v= Tys0w3CgApQ • http://www.youtu be.com/watch?v= ALaMoS_vvNE Echinodermata - urchin • Strongylocentrotus franciscanus • Red sea urchin – eats kelps, jaw like structure • these urchins live over 100 years, and found some near Vancouver Island that may be 200 years old • A prime food for sea otters. • http://www.youtube.com/watch?v=MXQF7dhVDSY&feature=related • http://www.youtube.com/watch?v=b44_-bxr07w Echinoderms • Sea cucumber – radial symmetry, forms cylinder shape Phylum Chordata • Lancelets, tunicates, vertebrates • notochord, nerve cord • bilateral, coelomate, deuterostome Figure 34.2 Chordate characteristics Figure 34.4a Subphylum Cephalochordata: lancelet anatomy Figure 34.3 Subphylum Urochordata: a tunicate Table 33.7 Animal phyla .