Transcript Centipedes
Arthropods • Arthropoda - “jointed legs. • Largest animal phylum; includes insects, spiders shrimp, and centipedes. • Jointed appendages include, legs, antennae, claws, & pinchers. • Body Cavity & digestive system; possess mouth & anus. • Open circulatory system w/ a heart • Nervous system is similar to annelids, but with larger brains • Have compound eyes to detect color & motion • Have featherlike gills, book gills or book lungs to respire Skeletal Structure • Have an external structure called an exoskeleton. • Made up a protein & a carbohydrate called chitin. • Sheds its exoskeleton as it grows in a process called molting. • Is vulnerable to predators while new exoskeleton hardens Class Insecta Insects are largest invertebrate class. • Three body regions: head, thorax, & abdomen. • Head contains a pair of antennae, eyes, & a mouth. • Thorax has 3 pair of jointed legs, & 1 or 2 pair of wings in most species. • Abdomen is divided into 11 segments (No wings or legs attached to abdomen). • Only invertebrates capable of flight. - allows them to find food, home, and mates better and it allows them to escape predators. • Possess both simple & compound eyes (detect color and movement). • Antennae are used for touch & smell. • Open circulatory system carries food and waste. • O2 enters and CO2 exits through spiracles (holes) on the abdomen and thorax. Reproduction • Reproduce sexually. • Many undergo metamorphosis series of changes controlled by hormones. • Two types: Complete & Incomplete. Complete Metamorphosis • Most insects such as: butterflies, beetles, ants, bees, moths & flies develop through complete Metamorphosis. • 4 stages: Egg, Larva, Pupa (resting), & Adult. Incomplete Metamorphosis • Grasshoppers, crickets & lice. • Three stages: egg, nymph, adult • Nymph is a wingless version of the adult. • The exoskeleton, jointed appendages, and wings allow them to live on land and fly. • Small size allows them to hide from enemies and live in a wide range of environments. Crustaceans • Crabs, crayfish, lobsters, shrimp, barnacles, water fleas, & pill bugs. - Cephalothorax (fusion of head & thorax) & abdomen - 5 pairs of walking legs, 1st pair are claws. Carapace Tail Abdomen Cephalothorax Swimmerets Mandible First antenna Second antenna Walking legs Cheliped • 4 others are walking legs. 5 pairs of swimmerets on abdomen help in locomotion & reproduction. • Lost appendages can be regenerated. • Telson is a muscular tail possessed by crayfish, shrimp & lobster. • Possess compound eyes. • One or two antennae • Jaws called mandibles are used for crushing food. • they force water over the gills for breathing. • Important food source for humans. Arachnids • Class containing spiders, scorpions, mites, & ticks. • Possess cephalothorax & abdomen. • 4 pairs of legs, but lack antennae. • Poison glands, stingers, or fangs are used to subdue prey. • Some have a pair of modified appendages (pedipalps) used in feeding & prey capture. Pedipalp •Respiration occurs through spiracles & book lungs. Spiders • Poisonous bite paralyzes prey. • Digestive enzymes then liquefy organs, which are drunk later. 2 Poisonous Spiders: 1.Black widow 2.Brown recluse Black Widow • Latrodectus mactrans - Black Widow. • Red hour glass design on abdomen. - Only females bite are dangerous, extremely poisonous. Related species:Australian Brown Widow & Japanese Red Widow Brown Recluse • Loxceles reclusa - Brown Recluse. • Southern Spider/ house spider. • Bite causes massive cell destruction. • Related species are dev. potent venom. Scorpions • Pedipalps are enlarged into claws to hold prey to be stung by poisonous tail stinger. • Chew their prey Ticks, Chiggers, & Mites • Parasites that can cause diseases such as Lyme’s Disease (deer tick) & Rocky Mountain Spotted Fever (wood or dog tick). Centipedes & Millipedes • many segments • antennae • simple eyes • live on land in moist areas • make nests and stay with eggs until they hatch Centipedes • One pair of jointed leg per body segment. Flattened body. • Carnivorous & possess venomous claws. • Quick moving. • 15-181 segments (always odd) Millipedes • Round bodies with 2 pairs of legs per body segment. • Possibly over 100 segments • Feed on dead & decaying plant matter • Roll up in a ball when disturbed. • Some can expel cyanide gas or unpleasant chemicals as a defense mechanism.