3 Body Characteristics Body Symmetry: Bilateral symmetry Cell Organization: Cells to tissues to organs to organ systemsReproduction: SexualBody development: Most arthropods go through METAMORPHOSIS
4 Just the facts… Fully developed to life on land No need of a moist environmentOnly invertebrates to fly.Live in salt and fresh water, soil, land, airSize ranges from tiny mites to over 3 feet.Largest phylum in the animal kingdom.
5 Characteristics of Arthropods InvertebrateExternal skeleton-ExoskeletonSegmented bodyJointed attachments called appendagesWings, mouthparts, antennae, legsOpen circulatory systemInternal fertilizationmost reproduce sexuallyThey are EITHER male or female
6 An Arthropod Exoskeleton Waterproof shellUsed for protectionHelps prevent evaporation, keeps them from drying outPlace for muscle attachmentMade out of chitinAs the arthropod grows larger, it can’t expand, so it must shed its exoskeletonProcess called moltingPillbug molting its exoskeleton
7 MoltingThe difference between a soft-shelled crab and a hard-shelled crabA horse-shoe crab.Adult cockroach
8 CRUSTACEANS CEPHLATHORAX and ABDOMEN GILLS FOR BREATHING Fiddler CrabCEPHLATHORAX and ABDOMEN(2 BODY PARTS)GILLS FOR BREATHINGHARD OUTER SHELL
9 Crustacean Body Segments Head and thorax combinedCephlathoraxThen an abdomen
10 ARACHNIDS Head and Abdomen Breathe with organs called book lungs Four pairs of legsBreathe with organs called book lungsSOME BUT NOT ALL BUILD WEBS
12 CENTIPEDES 2 body sections 100 LEGGER ONE PAIR OF LEGS PER SEGMENT Head with antennaeLong segmented abdomen100 LEGGERONE PAIR OF LEGS PER SEGMENTLONG, FLAT BODIESCARNIVORES
13 MILLIPEDES 2 body sections Head with antennae Abdomen with at least 80 segments“1000 Legger”Most of the body segments bear two pairs of legs.Rounder bodiesFeed on decaying vegetable matter and are herbivoresWill curl up to avoid predators.
14 Insects The Importance of Insects: Pollination of flowers Destroy harmful pestsMake silk fibersLarva of the silkworm mothMake food productsBees make honey
15 Insect Impact on Humans Damage to major cropsCan carry diseasesEx. – some mosquito species cause malariaMosquito on Human Skin
16 Why Insects are So Successful Reproduce very quickly (short generation time)Females produce many youngAbility to eat a variety of foods
17 Why Insects are So Successful Different species have become adapted to live in almost ANY environmentAbility to fly (can travel for food and mates)Mosquito in Flight
18 Insect Body Structure Insects have: Three body parts HEAD, THORAX, ABDOMEN3 pairs of legs attached to the thorax1 pair of antennae attached to the head
19 Insect Body Structure Simple and compound eyes Most insects have one or two pairs of wings attached at the thoraxMany have tubes (spiracles) which allow oxygen to travel directly to the insect’s body cells
20 Insect MetamorphosisGradual Metamorphosis: the egg hatches into a young insect that looks like the adult, only smallerEx. Grasshoppers, termites cockroaches and dragonflies3 stages –1.The egg2. hatches into a nymph3. the nymph molts several times growing into a larger nymph4. eventually becoming the adult.
21 Insect Metamorphosis cont’d Complete Metamorphosis: the young insect looks very different from the adult formEx. Butterflies, beetles, houseflies, and ants4 stages –The egg hatches into alarva,the larva forms pupa, andthe pupa turns into an adult.
22 Insect Examples Black Blister Beetle Thistle Caterpillar 17-year Cicada
23 Robber Fly Catching a Bee for Dinner Insect ExamplesMoss MantidWeaver AntsRobber Fly Catching a Bee for DinnerTropical Cockroach
25 TRILOBITESONCE THE LARGEST GROUP OF ARTHROPODSEXTINCT.
26 Comparison of the largest Arthropod Groups CharacteristicCrustaceansArachnidsInsects# of Body Sections2 or 323# of legs5 or more pairs4 pairs3 pairs# of antennae2 pairs1 pairWhere foundWater or damp placesMostly on landExampleLobsterTarantulaPraying mantis