Defining "Animals" Multicellular, Eukaryote Ingestive Heterotroph specialized tissues, nervous and muscle sexual reproduction - sperm and egg diploid stage dominate

General comments 35 phyla over 1,000,000 extant species Phylum Chordata is best known (5%) over 95% of described species are invertebrates

Parazoa Little or no tissue organization

Phylum Porifera sponges sessile radial symmetry? "plant-like" 9000 species - mostly marine 100 freshwater species filter feeder No true tissue or loose tissue organization

Eumetazoa True Tissue Layers Endoderm – inside layer Mesoderm – middle layer Ectoderm – outside layer

Phylum Cnidaria made of two layers, Sac Body radial symmetry 10,000 species - mostly marine carnivores – Tentacles with stinging cells Exist in two forms: polyps and medusa Three classes Hydrozoa - hydra, Scyphozoa - jellyfishes Anthozoa - corals

Phylum Ctenophora comb jellies 2 tissue layers marine 100 species two tentacles – no stinging cells bioluminescence

-Acoelomates - Three Layers - No body Cavity

Phylum Platyhelminthes flatworms bilateral symmetry acoelomates triploblastic - endoderm, mesoderm, ectoderm 20,000 species freshwater and marine no respiratory or circulatory system incomplete digestive system - no anus

Phylum Platyhelminthes Examples of Flatworms Turbellaria - free living flat worms, planarians Trematoda - parasitic flukes Cestoda - parasitic tapeworms

Pseudocoelomates Characteristics of Pseudocoelomates eumetazoa bilateral symmetry body cavity other than digestive cavity Body cavity only partially lined with mesoderm

Phylum Rotifera wheel bearers animals 1800 species microscopic mm freshwater, usually high quality water complete digestive tract organs located in pseudocoele

Phylum Nematoda Round Worms 80,000 species freshwater, marine, terrestrial, and parasitic complete digestive tract tough cuticle only longitudinal muscles pseudocoele parasitic hookworms pinworms trichinosis

Coeloemates “True” Body cavity Body cavity lined completely lined with mesoderm.

Phylum Annelida Segmented Worms 15,000 species freshwater, marine and terrestrial earthworms, polychetes, leeches Characteristics of annelids segmentation coelom locomotion all systems complete

Phylum Molluska Mollusks 50, 000 species marine, freshwater, and terrestrial Characteristics of mollusks most have external shells of calcium carbonate, although some have internal shells and some have none three body parts - foot, visceral mass, and mantle mantle cavity - houses gills and other organs no body segmentation

Examples of Molluska chitons, snails, slugs, clams, oysters, octopuses, and squids

Phylum Arthropoda 1-2,000,000 species most diversified group freshwater, marine, and terrestrial Characteristics of arthropods segmentation hard exoskeleton jointed appendages specialized appendages antennae, mouthparts, legs moulting variety of gas exchange or respiratory structures

Examples of Arthropods extinct trilobites

Examples of Arthropods horse shoe crabs, spiders, mites, scorpions

Examples of Arthropods insects, millipeds, centipedes

Examples of Arthropods crabs, lobsters, crayfish, shrimp, barnacles

Phylum Echinodermata Echinoderms 7000 species Sand dollars, sea urchins, sea stars spiny skin marine Characteristics radial symmetry as adults pentagonal, five sides or five arms endoskeleton water vascular system

Examples of Echinodermata starfish or sea stars sea urchins brittle stars sea cucumber sea lilies

Phylum Chordata The Chordates very diversified freshwater, marine, terrestrial Characteristics of chordates notochord dorsal hollow nerve chord pharynx slits muscular postanal tail

Classification of Chordates Subphylum Cephalochordata Amphioxus Subphylum Urochordata sea squirts, tunicates

Classification of Chordates Subphylum Vertebrata Lampreys, sharks, fish, amphibians, reptiles, birds, and mammals

Class Agnatha Jawless Fish – Lamprey and Hagfish Gills 2 chambered heart Cartilage skeleton No jaws – open “sucker” Parasite of Fish

Class Chondrichthyes Cartilaginous Fish – Sharks and Rays 2 chambered heart Skeleton entirely of Cartilage Paired fins Internal fertilization Scales No swim bladder

Class Osteichthyes Bony Fish Skeleton made of bone Swim bladder 2 chambered heart Most fish spawn – some live bearers Scales

Class Amphibia Frogs, Toads, Salamanders, Newts Moist smooth skin Show metamorphosis Ectotherms Non-amniotic egg External reproduction Gills when young, lungs as adults 3 chambered hearts as adults

Class Reptilia Lizards, Snakes, Crocodiles, Alligators Scaly Skin 3 Chambered heart (Croc’s have 4) Amniotic egg, Internal Fertilization Ectothermic

Class Aves Birds Feathers Endotherms, 4 chambered heart Internal Fertilization Amniotic Egg

Class Mammalia Lions, Tigers and Bears Hair Mammary glands Diaphragm – well developed lungs 4 chambered heart, endotherm Internal Fertilization Placental - internal development Marsupial – pouch development Monotremes – egg layers