Animal Diversity Lecture 8 Winter 2014

Transcription

1 Animal Phylogeny 1 Animal Diversity Lecture 8 Winter 2014 Fig Phylum Porifera (sponges) 2 Phylum Cnidaria (corals, jellies, hydras, sea anemones) 3a ~5,500 species Primarily marine Suspension feeders No true tissues No plane of symmetry Sessile (attached) ~ 10,000 species Primarily marine Feed by using tentacles with stinging cells (cnidocytes) to capture prey s Radial symmetry Gastrovascular cavity Diploblast See Fig Fig Fig Phylum Cnidaria (corals, jellies, hydras, sea anemones) Fig b Phylum Platyhelminthes (flatworms) ~ 20,000 species Marine, freshwater & moist terrestrial Free-living & parasitic Feeds by sucking food into mouth with muscular tube Fig Gastrovascular cavity Acoelomate Fig

2 Phylum Mollusca (molluscs) ~93,000 species e.g., slugs, snails, squid, octopus, oysters Most marine, some freshwater and terrestrial Use radula (scraping tongue) to feed Soft body with hard Some have reduced or lost Fig Phylum Annelida (segmented worms) ~ 16,500 species Earthworms, polychaetes, leeches Marine, freshwater & damp terrestrial Segmented body plan Earthworms eat by swallowing soil Polychaetes & leeches eat small invertebrates (few suck blood) 6 Phylum Nematoda (Roundworms) (Clade Ecdysozoa) ~25,000 species Also called nematodes Soil and aquatic habitats Pseudocoelom Tough cuticle coating body Fig Decomposers Also parasites Pinworm, hookworm Agricultural pests 7 Phylum Arthropoda (Arthropods) (Clade Ecdysozoa) > 1 million species Widespread Huge population numbers Often reduced in adults Segmented body plan Tagmatization Jointed appendages Exoskeleton chitin (polysaccharide) 8 Class Arachnida (spiders, mites, ticks, scorpions) & Class Merostomata (horseshoe crabs) 9 (Subphylum Cheliceriformes) Body having one or two main parts (cephalothorax, abdomen) 4 pairs of walking legs Lacks mandibles Has pincers or fangs (chelicerae) No antennae Simple eyes (most) Fig Fig Class Insecta (insects) (Subphylum Hexapoda ) Species rich & abundant! Over ½ of named species on earth Flight Metamorphosis Diverse habitats (rarely marine) Body divided into head, thorax, abdomen 1 pair of antennae Uniramous appendages Mouthparts adapted for many uses 3 pair of walking legs ~ 2 pair of wings Compound eyes 10 2

3 Class Chilopoda (centipedes) & Class Diplopoda (millipedes) (Subphylum Myriapoda) 1 pair of antennae Mandibles Uniramous appendages Terrestrial Class Chilopoda (centipedes) One set of legs per body segment Poison claws on first body segment Carnivorous Class Diplopoda (milipedes) Two sets of legs per body segment Herbivorous Fig Centipede Fig Millipede 11 Class Malacostraca (crabs, lobsters, shrimps) & 12 Class Maxillopoda (barnacles, copopods) (Subphylum Crustacea) Marine & freshwater Body of two or three parts ~Highly specialized appendages Biramous appendages Mandibles Two pair of antennae Three or more pairs of legs Pair of compound eyes Fig Phylum Echinodermata (Echinoderms) ~7,000 species Sea stars, sea urchins, sea cucumbers, sand dollars Apparent radial symmetry (as adults) (larval form) Deuterostome No body segmentation Endoskeleton Water vascular system Network of water filled canals, for gas exchange, waste disposal, and movement 13 Marine Sessile or slow moving Named for spiny surfaces Most closely related phylum to the chordates Phylum Chordata (Chordates) ~ 52,000 species present in embryo (sometime in adult) can be greatly reduced or not present in adults Dorsal, hollow nerve cord Notochord Flexible rod located between nerve cord and digestive tract Pharyngeal pouches (slits) Gill structures Post-anal tail Tail is to rear of anus Fig Other traits Body segmentation Deuterostome 14 Phylum Chordata (Chordates) Three subphylum Cephalochordata Lancelets Urochordata tunicates Vertebrata Vetebrata Trait Vertebrae Fig Subphylum Cephalochordata (Lancelets) Marine environment Dorsal, hollow nerve cord Notochord Extends to front of head Pharyngeal slits Post-anal tail 16 Fig

4 Subphylum Urochordata (tunicates) Marine Filter feeder Chordate characteristics present in larval stage, most lost as adult 17 Subphylum Vertebrata Class Cephalaspidomorphi (Petromyzontida) Lampreys ~25 species Marine & Freshwater No jaws Parasitic (most) Skeleton of cartilage Made of protein matrix (not collagen) External gill slits Fig Fig Class Chondrichthyes Sharks, skates & rays ~750 species Skeleton of cartilage Derived condition Mostly collegen matrix Some with calcium Jaws External gill slits No swim bladder Fig Class Actinopterygii Superclass Osteichthyes Ray-finned fish ~27,000 species Ossified (bony) skeleton skeletons reinforced with calcium phosphate Operculum Protective flap over gill slits Swim bladder Buoyancy evolved from early lungs Fins supported by bony rays 20 Fig Class Sarcopterygii Superclass Osteichthyes Lobe-finned fish Coelacanth, lungfish Ossified (bony) skeleton Lungs or lung derivatives Operculum Swim bladder Pectoral & pelvic fins have rod-shaped bones surrounded by thick layer of muscle walk underwater Fig : Coelacanth Lungfish 21 Class Amphibia ~6150 species Frogs, salamanders Moist environments Egg has no, needs to be kept from drying out Skin acts in gas exchange, needs to be moist Many undergo metamorphosis (four limbs) Adults have lungs See Fig

5 Class Reptilia ~17,900 species of snakes, lizards, turtles, crocodiles, alligators, and birds Ectotherms (except birds!) Keratin also in feathers, fingernails 24 See figure See figure Class Reptilia (Superorder Lepidosauria) Lizards, Snakes and Tuataras ~7,900 species of snakes, lizards, turtles Ecototherms Do not generate their own heat, use heat from their environment See Fig Class Reptilia (Superorder Archosauria) Birds, Crocodiles, and Alligators ~10,000 species birds 23 species alligators and crocodiles Birds descended from lineage of dinosaurs that had feathers Crocodiles and Alligators are closest living relatives to birds : Wings - Feathers of keratin Bird Adaptations for flight Hollow bones No teeth Large sternum and strong pectoral muscles Reduced organs or missing organs Endotherms Birds only! High metabolic rate use heat produced to maintain constant body temperatures! 26 See figure Class Reptilia (Order Testudines) Turtles 307 known species of species of turtles Vertebral column fused to Terrestrial or aquatic (both marine and fresh water) Ecototherms Do not generate their own heat, use heat from their environment 27 Class Mammalia ~5,300 species Rapid diversification ~ 65 myo (end of age of the reptiles ) Amniotic egg (most w/o ) Hair Mammary glands Endotherms Three main group Monotremes (egg laying mammals) Only 2 species (duck-billed platypus, echidna) Marsupials ( pouched mammals) Offspring complete their development in pouches Primarily Australia & South America Eutherians (placental mammals) Offspring remain in womb 28 5