Brought to you by: Kate Lee, Beth Reinert, Christie Currie, and Maggie Gorski

 Segmented animals  Five subphylums: Trilobita, Cehelicerata, Crustacea, Myriapoda, and Hexapoda  Arthropods include insects, spiders, trilobites, shrimp, lobsters, crabs, etc.  Evolved around 545 million years ago around the same time as chordates evolved

 Bilateral symmetry  Coeloms  Uses exoskeletons for structure and support  Exoskeleton has three layers and the tough covering is called the carapace.  Most arthropods shed their exoskeleton through a process called molting. Macrocheira kaempferi (Japanese Spider Crab)

 Reproduce sexually through internal fertilization  Aquatic crustaceans use swimmerets that transfer sperm to egg.  The eggs then hatch into a free-swimming larva called a nauplius  Through many series of molting, the nauplius eventually develops into the adult form

 Food passes through a one way digestive tract (mouth to anus).  Uses a digestive gland to mix food with enzymes  Excess water and wastes are eliminated using green glands.

 Open circulatory system  uses hearts and vessels to transport circulatory fluid throughout the crustacean  Uses gills to exchange oxygen and carbon dioxide for respiration Nervous System  has clusters of ganglia in the brain that controls the body (cephalized)  Ganglias throughout the body are connected by a ventral nerve cord Circulation and Respiration

Tissues include heart tissues, nerve tissues, and gill tissues.

 Crustaceans use sensory hairs that sense vibrations and chemicals  Can be terrestrial or aquatic  Some crustaceans are up to 4 meters long The goose barnacle (Lepas anatifera) is an aquatic crustacean.

Insecta

 Order Hemiptera (“half wing”); true bugs  Order Homoptera (“like wing”); aphids, mealy bugs, cicadas  Order Isoptera (“equal wing”); termites  Order Odonata (“toothed”); dragonflies, damselflies  Order Orthoptera (“straight wing”); grasshoppers, crickets, katydids  Order Coleoptera (“sheathed wing”); weevils, ladybugs, beetles  Order Diptera (“two wing”); mosquitoes, flies, gnats  Order Hymenoptera (“membrane wing”); bees, wasps, and ants  Order Lepidoptera (“scaled wing”); butterflies, moths

 Bilateral Symmetry

 The body of an insect is divided into three tagmata: the head, thorax, and abdomen.

 Brain, Crop, Aorta, Gastric Ceca, Ovary, Heart, Tracheae, Anus, Oviduct, Seminal Receptacle, Hindgut, Malphigian tubules, midgut, Ganglion, Ventral Nerve cord, gizzard, salivary glands, and the esophagus.

 Characteristics of most insects: a body consisting of a head, thorax, and abdomen; a pair of unbranched antennae; three pairs of jointed legs; and two pairs of wings.

 One way digestive tract  Malphigian tubules which collect water and cellular wastes from the hemolymph and produce a very concentrated mixture of wastes that is deposited in the hindgut and leaves the body with the feces.

 Open circulatory system  Insects exchanges oxygen and carbon dioxide with the environment through a complex network of air tubes called trachea.

 All insects have separate sexes and reproduce through internal fertilization  Develop either through incomplete metamorphosis

 Or incomplete metamorphosis

 Consists of a brain and a ventral nerve cord with ganglia located in each body segment.  Antennae contain sensory structures that respond to touch and smell.  Three simple eyes function to sense the intensity of light  Two bulging compound eyes provide a wide field of view and can detect movement and form images.  The tympanum detects sounds  Sensory hairs detect touch or movement by vibration

 Insect defense: warning coloration, Müllerian mimicry, Batesian mimicry, venomous stingers, spraying noxious chemicals

 Insects communicate through pheromone, sound, and light.

 The Round Dance  The Waggle Dance Bee Dances