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15-ch18-animals1 - Familiar groups of molluscs include...

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Unformatted text preview: Familiar groups of molluscs include: gastropods, bivalves & cephalopods Our phylum is second only to arthropods in diversity. limpet shell snail-eating snails • snails & slugs are the only molluscs to invade land • most gastropods graze on autotrophic organisms • a few are specialized for drilling into other molluscs oyster drill potential for slug slime • drug delivery systems • pollutant traps • water-based lubricants Bivalve molluscs have shells divided in two scallop eyes razor clams Shellfish are are easily cultured on suspended lines or nets. http://www.youtube.com/watch?v=hyoM_UBI58&feature=channel Cephalopods are active predators with complex behaviors • beak to inject toxin • only mollusks with closed circulatory system nautilus http://www.usatoday.com/tech/science/2006-12-22-squid_x.htm • shell reduced, internal, or absent extinct a ammonites • tentacles for grasping grasping http://www.pbs.org/wgbh/nova/preview/i_3404.html change color with chromatophores cuttlefish giant squid blue-ringed octopus aposematism = warning colors tetrodotoxin Annelids are segmented worms earthworms propel themselves via peristalsis Leach On Me (April 2007) Leeches are experiencing a medical renaissance: the Food and Drug Administration recently approved the use of Hirudo medicinalis, known as the European medicinal leech, as a medical device. Prized for their anti-coagulants, leeches are used after surgery to improve blood flow in places where skin was reattached. Increased blood flow helps tissue survive… http://www.sciencefriday.com/news/041907/news0419071.html Arthropods are named for their “jointed appendages” “arthro" = joint joint "pod" = foot pod foot (extinct) segmentation (repetition of body parts) is pronounced in early arthopods like myriapods & trilobites - body segments & jointed appendages - exoskeleton (cuticle or shell) - open circulatory system circulatory system armor has its down side… ecdysis is the molting of an exoskeleton each time it is outgrown Cheliceriform arthropods have clawlike pinscers or fangs eurypterid (sea spider) Phylum Arthropoda; Cheliceriformes chelicerae – feeding appendages 2 regions: cephalothorax, abdomen http://www.ticktexas.org/ w horseshoe "crabs" Check out my book lungs! Lyme disease is a spiral bacterium transmitted by the deer (a.k.a. black-legged) tick. lack- Mites Mites and ticks are he most abundant and diverse arachnids Spider mites are plant pests. Predatory “Typhs” Typhs are mite-eating mites used mitefor biocontrol. http://insects.ippc.orst.edu/pnw/insects?33MITE05.dat http://www.cdc.gov/ncidod/dvbid/lyme http://www.cdc.gov/scabies scabies feather mites on Kentucky Warbler Cheliceriform arthropods have clawlike pinscers or fangs the “camel spider” - fact or fiction? • move at speeds over 30 MPH (screaming while they run) • as large as a frisbee • jump three feet high up on camels to eat their bellies • sneak up on camels to eat their bellies We have (smaller) members of this family in Texas http://www.solpugid.com/Introduction.htm sun scorpions scorpions a.k.a. wind scorpions family solifugidae You didn’t believe those urban legends, did you?! But we can be 6 inches long... & we do bite in self defense. Myriapods were the 1st animals on land Phylum Arthropoda; Myriapoda mandibles – jaw-like mouthparts Millipedes have chemical defenses (if you eat us)... and we (if you eat us) and we curl up for added protection. "myria" = many Local giant redhead centipede (Possum Kingdom Lake) Centipedes paralyze prey and fend off predators with poison claws! poison claws! "pod" = foot Crustaceans Crustaceans have appendages on their abdomen Phylum Arthropoda; Crustacea - most are marine or freshwater; a few terrestrial - some are very small (zooplankton) - two pairs of antennae pairs of antennae decapod crustaceans crustaceans have calcified shells tiny copepods: big biomass biomass “water flea” isopods & isopods & o o barnacles are barnacles are c c crustaceans, too crustaceans, too e e There’s a fine line between our “mouthparts” & “legs!” Insects are more diverse than all other groups of organisms, combined “Gad, I hate walking through this place at night.” Insects have three body regions (head, thorax, abdomen) beetles flies true bugs ants, bees & wasps Some familiar groups of insects are amazingly diverse… And only 15 of 26 orders are shown in these two pages! butterflies moths & dragonflies & damselflies damselflies grasshoppers & crickets No, you do not need to learn our names! Egyptian Scarab The scarab is a symbol of renewal and rebirth The god Khepera (or and rebirth. The god Khepera (or Khepri; he who came forth from the earth) took the form of this beetle when he rolled the sun across the sky each da Protecti scarab am each day. Protective scarab amulets were often laid to rest with the dead. metamorphosis (common in insects) is illustrated by in insects) is illustrated by the dung beetle life cycle http://www.npr.org/templates/story/story.php?storyId=103775784 male weaponry varies greatly among species (intrasexual selection) Look Up! The Billion-Bug Highway You Can't See If all mankind were to disappear, the world would regenerate regenerate back to the rich state of equilibrium that existed existed ten thousand years ago. If insects were to vanish, the environment would collapse into chaos. — E.O. Wilson Bugs Bugs are not going to inherit the Earth. They own it They now. now. So we might as well make peace with the landlord. — Thomas Eisner developmental developmental similarities bilateral symmetry true tissues animals (= multicellular) Developmental & molecular evidence agree: sea stars are the closest cousins to our own phylum! Adult Adult sea stars & urchins have radial symmetry Phylum Echinodermata “echino” = prickly “derm” = skin Our adult radial symmetry is secondary. We larvae are bilateral, just like you. urchin etymology - a hedgehog - a goblin or elf - an offspring of hell - a hunchback person - a pert or roguish youngster; a brat - an ugly or uncomely woman; a hag Ask me how I use my endoskeleton and elaborate water vascular system! Welcome Welcome to the clade called “fishes” (vertebrates and their close cousins) Hagfishes Hagfishes are jawless fishes who have a head (but no vertebral column) hagfishes Predators beware the slimy defense of the hagfish! http://www.youtube.com/watch?v=Bb2EOP3ohnE o a O • cartilage skull skull • small brain, eyes, ears Lampreys Lampreys are jawless fishes who have a head and a vertebral column and lampreys = oldest living lineage of vertebrates Introduction of lampreys to the Great Lakes ecosystem devastated native fish populations. USGS has reduced lamprey numbers with a chemical “lampricide” called TFM. http://www.glsc.usgs.gov/main.php?content=research_lamprey&title=Invasive%20Fish0&menu=research_invasive_fish Vertebrae Vertebrae serve as anchors for muscles... lateral undulation – how fish move (along with lampreys, salamanders, snakes) I propagate a series of body waves (from front to back) by alternating muscle contractions on the left & right sides of my elongated body. the left right sides of my elongated body Water resistance (friction) pushes me forward. Sharks Sharks & rays have jaws (but their skeletons are their skeletons are mostly cartilage) Even if you swim if at the beach, your odds of (non-fatal) (nonshark attack are 1 in 11.5 million. in Florida Museum of Natural History http://www.flmnh.ufl.edu/fish/sharks/statistics/beachattacks.htm ...
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