Animal Diversity Animal Diversity Exploring the Categorization of Animal Species Exploring the Categorization of Animal Species

The Tree of Life The three domains of life represent the earliest branches in evolutionary history

Characteristics of Animals EukaryoticEukaryotic MulticellularMulticellular HeterotrophicHeterotrophic Most are capable of sexual reproduction.Most are capable of sexual reproduction. Animal cells lack a cell wall.Animal cells lack a cell wall. Motile during some stage of their lifeMotile during some stage of their life Respond to external stimuli as a result of nerve and/or muscle actionRespond to external stimuli as a result of nerve and/or muscle action

Classification Scheme Kingdom Phylum Class Order Family Genus Species Animalia Chordata Mammalia Felidae Carnivora Felis sylvestris Primates Hominidae Homo sapiens Animalia Chordata Mammalia

Ways to Distinguish Between Animal Groups Body Symmetry Body Cavities Development Patterns Segmentation Skeleton Surface Features or Appendages

Body symmetry

 Asymmetrical  Loosely structured collection of cells  Cell specialization  Lack tissues  Non-motile as adults  Filter feeders Phylum Porifera Sponges

 Radial symmetry  Cells organized into two tissue layers  Lack true organs  Nerve network and contractile tissue  Body plans Polyp- attached Medusa- motile  Mouth and anus are same opening  Asexual and sexual reproduction Phylum Cnidaria Coral, Hydra, Anemones and Jellyfish

Body Cavities Coelom: body cavity lined on all sides by a layer of mesodermal cells

 Bilateral symmetry  Acoelomate  Three tissue layers  Excretory and Reproductive Organs  Move by use of nerve cells, ganglia  Many are free-living; some are parasitic some are parasitic Phylum Platyhelminthes Tapeworms, Flukes, Flatworms

 Bilateral symmetry  Pseudocoelomate  Three tissue layers  Tubular gastrovascular cavity; two openings  “ Ganglionic Brain ”  Gas exchange by diffusion  A few species are parasitic Phylum Nematoda Roundworms

 Bilateral symmetry  Coelomate, fluid filled cavity allows movement  Three tissue layers  Segmented body  Closed circulatory system: 5 pairs of hearts  Excretory organs: nephridia  Digestive system with specialized areas  Segmented muscles for movement Phylum Annelida: Segmented Worms

 Bilateral symmetry  Coelomate  Three tissue layers  Soft body in a calcium containing shell  3-chambered heart, blood vessels  Ciliated digestive tract  Excretory organs: nephridia  Head-foot has sensory and motor organs  Gills for oxygen absorption  Tooth-bearing strap: radula Phylum Mollusca

 Class Bivalvia  clams, mussels, oysters, scallops  Class Gastropoda  snails, slugs  Class Cephalopoda  squid, octopus  Class Polyplacophora  chitons (ancestral)  eight plates on back Classes of Phylum Mollusca

 Bilateral symmetry  Coelomate  Three tissue layers  Distinct body regions: head, thorax, abdomen  “ joint-footed ”  Exoskeleton, moved at joints by muscles  Open circulatory system  Complex nervous system, compound eye  Efficient gas exchange system Phylum Arthropoda

 Class Arachnida  spiders, ticks, scorpions  Class Crustacea  crabs, lobsters, shrimp  Class Insecta  insects  Class Diplopoda  millipedes 2 pairs of legs/segment  Class Chilopoda  centipedes 1 pair of legs/segment  Class Meristomata  horseshoe crabs Classes of Phylum Arthropoda

Protostome: mouth forms first during embryonic development Deuterostome: anus forms first and then mouth forms

 Radial symmetry, 5-part body plan  Coelomate  Deuterostome  Three tissue layers  “ Spiny Skin ”  Modified coelom forms a water vascular system to move tube feet  Nervous system: central nerve ring with branches Phylum Echinodermata

 Class Asteroidea  sea stars  Class Echinoidea  sea urchins, sand dollars  Class Holothuroidea  sea cucumbers  Class Ophiuroidea  brittle stars Classes of Phylum Echinodermata

 Bilateral symmetry  Coelomate  Deuterostome  Three tissue layers  Four common features  Notochord  Dorsal, hollow nerve cord  Pharyngeal gill slits  Post-anal tail Phylum Chordata

 Notochord replaced by vertebral column  Endoskeleton  Development of brain  Closed circulatory system, heart with 2 or more chambers  Use of gills, skin or lungs to obtain oxygen  waste removal by kidneys  Separate sexes, internal or external fertilization Sub-Phylum Vertebrata

 Class Agnatha  jawless fishes  Class Condrichhthyes  cartilaginous fish  Class Osteichthyes  bony fish Classes of Sub-Phylum Vertebrata

 Class Amphibia  frogs, toads, salamanders  Class Aves  birds  Class Reptilia  lizards, snakes, turtles, alligators Classes of Sub-Phylum Vertebrata

 Class Mammalia  most bear live young  milk from mammary glands  hair  endotherms  monotremes: egg laying  platypus  marsupials  kangaroo  placentals  bat, rabbit, dog, cattle, whale, human Classes of Sub-Phylum Vertebrata

Worksheet Complete pages from lab manualComplete pages from lab manual –Record your answer and reasoning for any 8 specimens, making sure to write the answer on the line that matches the specimen number Be sure your instructor checks your completed worksheet before you leave the lab.Be sure your instructor checks your completed worksheet before you leave the lab.

CLEAN UP! Leave animal specimens and their skeletons in orderly arraysLeave animal specimens and their skeletons in orderly arrays Thank you!