Arthro- means jointed Pod – means foot or feet Jointed feet Arthropods Arthro- means jointed Pod – means foot or feet Jointed feet

Number of species Mollusca Chordata Platyhelminthes Nematoda Arthropoda Porifera Annelida Echinodermata Sarcomastigophora Apicomplex Ciliophora

Arthropods Most Successful Animals Number of species Diversity Distribution Longevity

Reasons for Success Versatile exoskeleton Segmentation Oxygen piped directly to cells (terrestrial) Highly developed sensory organs Complex behavior Metamorphosis

1. How many species of arthropods have scientists found? Copy the following questions and answer them from the video “Those Amazing Arthropods.” 1. How many species of arthropods have scientists found? 2. What are the three characteristics all arthropods have? 3. List two functions of the exoskeleton. 4. What is a soft-shelled crab? 5. In what habitat do you find most crustaceans?

6. How many pairs of legs does a spider have? 7. What do scientists guess the ratio is between insects and humans? 8. What is the best thing to remember when deciding if an animal is an insect or not? 9. Name two ways arthropods hurt or harm humans. 10. Name two ways arthropods help humans. Number 1 – 10 and answer Video Quiz questions.

Characteristics of Arthropods Have segmented bodies that are bilaterally symmetrical Have an exoskeleton – hard covering on the outside of their body made of chitin Have many appendages – any structure such as an arm or leg that grows out of the body of an animal Respiratory organs are either gills, tracheal tubes or book lungs

5. Have many sense organs such as antennae that can detect movement, sound or chemicals 6. Well developed nervous systems Most have either simple or compound eyes. Some have both What are some disadvantages of an exoskeleton? (Think what it would be like to have a tough armor on the outside of your body.)

Disadvantages of an exoskeleton Heavy Must be shed for growth to occur. Shedding of an exoskeleton is called molting. Can be easier for predators to attack before new exoskeleton hardens Not flexible (why jointed appendages are so important

5 classes of arthropods Class Insecta – flies, grasshoppers, beetles Class Arachnida – spiders, scorpions and mites (chiggers and mange) Class Crustacea – shrimp, lobsters, crayfish, pill bugs (rolly polly) Class Chilopoda – centipedes Class Diplopoda -- millipedes

Class Insecta Entomology – study of insects Characteristics Largest arthropod group Found in freshwater & terrestrial habitats, especially tropical areas Legs, mouthparts, & antenna jointed Body segmented into three sections --- head, thorax, & abdomen Six legs & up to two pairs of wings located on thorax

Have compound & simple eyes One pair of antennae on head Abdomen has 11 segments Exoskeleton, covering & protecting body, is made of chitin & must be molted to grow Elaborate mouthparts

Compound Eye

Types of metamorphosis Complete – 4 stages Egg  larva  pupa  adult Examples: ants, butterflies, silkworms, ladybugs Incomplete – 3 stages Egg  nymph  adult Examples: stinkbugs, earwigs, crickets, grasshoppers, cockroaches

Monarch Butterfly

Success of Insects Found everywhere except in deep part of ocean Very short life span & rapidly adapt to new environments Small size helps minimize competition in habitats Flight helps escape predators & move into other environments

Environmental Impact Pollinate almost 2/3's of all plants Serve as food for fish, birds, & mammals Help recycle materials (termites recycle wood) Make useful byproducts such as silk & honey Some spread disease Agricultural pests

Class Arachnida 4 pair of legs Have pedipalps – 2nd pair of appendages used in gathering food and other functions 2 body segments called cephalothorax and abdomen Except mites & ticks Most are predators Inject enzymes into prey Suck fluid into pharynx Have 8 eyes -- a combination of simple and compound eyes

Arachnid Body Regions Cephalothorax Abdomen

Orders of Arachnids Scorpions Pseudoscorpions Daddy Long-Legs Mites & Ticks Spiders 23

Order Scorpionida Large pedipalps Abdominal stinger Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Order Scorpionida Large pedipalps Abdominal stinger Photo (a) © SS#11/PhotoDisc

Pseudoscorpion Tick (a mite) Scorpion Wolf Spider Daddy-long-legs 25

Scorpion Anatomy 26

27

chelicerae eyes pedipalp 28

Pseudoscorpion 29

Mite and Tick Body Regions pedipalps & chelicerae cephalothorax abdomen 30

Blacklegged (deer) tick female American dog tick male Blacklegged (deer) tick female 31

American dog tick female laying egg mass (1000-2000 eggs!). 32

Twospotted spider mites Clover mites Twospotted spider mites Predatory mite 33

daddy long-legs cephalothorax abdomen 34

Respiratory structures Arachnid respiratory structure is Book lung or Spiracles – tiny holes on the abdomen that open and close allowing air to come in and flow over a series of tubes called trachae.

Copyright © The McGraw-Hill Companies, Inc Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Spider Anatomy pedipalp chelicera (fang) cephalothorax narrow waist abdomen 37

The Incredible World of Spiders

Jumping Spider Abdomen Cephalothorax Chelicera (fang) Pedipalp 39

Wolf spider with egg case Spitting spider Orb-weaving spider Tarantula 40

Black widow with egg case Brown recluse 41

Order Araneae Spiders Fangs with poison glands Silk glands

Silk glands and Spinnerets – all spiders have glands that produce and structures that either spin it or lay it down in a line. All spiders produce draglines (used as a safety net).

DO NOT COPY!!! Gland Silk Use Ampullate (Major) Dragline silk - used for the web’s outer rim and spokes and the lifeline. Ampullate (Minor) Used for temporary scaffolding during web construction. Flagelliform Capture-spiral silk - used for the capturing lines of the web. Tubuliform Egg cocoon silk - used for protective egg sacs. Aciniform Used to wrap and secure freshly captured prey; used in the male sperm webs Aggregate A silk glue of sticky globules Piriform Used to form bonds between separate threads for attachment points

Read BUT DO NOT COPY! Due to the difficulties in extracting and processing substantial amounts of spider silk, there is currently only one known piece of cloth made of spider silk, an 11-by-4-foot (3.4 by 1.2 m) textile with a golden tint made in Madagascar in 2009. Eighty-two people worked for four years to collect over one million golden orb spiders and extract silk from them.[85]

Fig. 18.4

Fig. 18.5

World’s most poisonous spider – Brazilian Wandering Spider

Dugesiella Tarantula

Latrodectus mactans Black widow spider Neurotoxin

Loxosceles reclusa Fiddle back spider Necrotoxin Brown recluse Brown Violin Necrotoxin

Loxosceles reclusa Necrosis of tissue

Day 3

Day 4

Day 5

Day 6

Day 9

Day 10

Order Acari Ticks Mites Body segments fused

Rocky Mountain Spotted Fever Ticks are vector High fever Headache Muscle pain Rash BEGINS ON EXTREMETIES 25% fatal without antibiotics

Dermacentor variabilis Dog tick Dermacentor andersoni Wood tick

Fig. 18.16

Dermatophagoides Dust mite Allergies to fecal products 1 gram of dust holds 250,000 droppings

Trombicula Chigger mite Larva feed on skin Dermatitis

Class Crustacea mostly marine, fresh water, a few terrestrial all have two pair of antennae, some have antennules that are used for balance five or more pairs of legs segmented abdominal appendages head & trunk fused into a cephalothorax & abdomen body arrangement have gills 67

Sowbugs or pillbugs (rolly polly) only terrestrial crustacean Sand fleas Barnacles Crabs, lobster, shrimp

Crayfish cephalothorax (Decapoda) Sowbug (Isopoda), a terrestrial crustacean 69

Two pair of antennae Biramous appendages

Fig. 19.3

Fig. 19.1

Crayfish

Fig. 19.2a

Fig. 19.2b

Fig. 19.5 Fig. 19.5

Fig. 19.6

Fig. 19.7 Fig. 19.7

Lobster

Shrimp

Crab

Pill Bug

Fig. 19.15c

Fig. 19.16c

Class Chilopoda Centipedes One pair of legs per body segment Poison fang and claws Flattened bodies Carnivores

Class Diplopoda milliipedes Two pair of appendages per body segment Cylindrical body Herbivores Have stink glands for protection