1. ARTHROPODS CHAPTER 26
MRS.BENDER’S BIOLOGY

2. CHARACTERISTICS SEGMENTATION
ALLOWS FOR EFFICIENT AND COMPLEX MOVEMENTS
TWO OR THREE BODY PARTS
HEAD: MOUTHPARTS, EYES, ANTENNAE
THORAX: THE LEGS AND WINGS ARE ATTACHED
ABDOMEN: CONTAINS DIGESTIVE AND REPRODUCTIVE ORGANS
CEPHALOTHORAX: FUSED HEAD AND THORAX
EXOSKELETON
PROVIDES FRAMEWORK FOR SUPPORT, PROTECTION SOFT TISSUE, SLOWS WATER LOSS, PLACE FOR MUSCLE ATTACHMENT
MADE OF CHITIN
VARIES IN THICKNESS

3. CHARACTERISTICS JOINTED APPENDAGES STRUCTURES LIKE LEGS AND ANTENNAE
ADAPTED FOR FEEDING, MATING, SENSING, WALKING AND SWIMMING
MOLTING
PROCESSES OF SHEDDING THE EXOSKELETON
MUST SHED AS THEY GROW
SECRETES A FLUID TO SOFTEN THE OLD WHILE FORMING THE NEW

4. BODY STRUCTURES FEEDING MANDIBLES ADAPTED FOR BITING AND CHEWING
MODIFIED: FEATHERY STRAINERS, NEEDLE FOR STABBING, CUTTING SWORDS, SUCKING STRAWS
HERBIVORES, OMNIVORES, PARASITES
DIGESTION
A COMPLETE ONE-WAY SYSTEM WITH A MOUTH, GUT, AND ANUS
GLANDS WHICH PRODUCE ENZYMES

5. BODY STRUCTURES RESPIRATION AQUATIC ARTHROPODS
GILLS TO EXCHANGE GASES THROUGH DIFFUSION
Crayfish, crabs, lobsters
TERRESTRIAL ARTHROPODS
Tracheal tubes
Air enters through the spiracles, openings located on the side of the abdomen, then travel through the tubes until it reaches the muscles.
insects
Book lungs
Highly folded sac like membranes which take in air which is then transferred through the tubes.
spiders

6. Body structures Circulation Not used to carry oxygen
Used to transport nutrients and removes wastes
Blood is pumped by a heart into vessels which carry blood to the tissue, then blood empties into open spaces then is returned to the heart
Known as open circulatory system
Excretion
Cellular wastes removed through Malpighian tubules, also used to preserve water
Malphighian tubules are attached to and empty into the gut and remove undigested wastes
Some have nephridia to remove cellular wastes

7. Respond to stimuli
Ganglia- groups of nerve cell bodies which take in messages and send back signals to responD
Vision
Compound eyes with many facets, helps to analyze quick changing environments
Detect movement of prey, mates, predators
See color
Simple eyes
Three to eight with one lens
Distinguishes light from dark
Hearing
typanum- flattened membrane used for hearing
Chemicals
Pheromones- used to communicate
Signal mates and feeding

8. Body structures Movement Crawl, run, climb, dig, swim, fly
Muscles attach to exoskeleton
Strength of muscle depends on nerve impulses
Reproduction
Sexually
Have specialized structures
Few are hermaphrodites and undergo cross fertilization like barnacles
Brood or incubate but do not care for their young, some do care or young: bees and few spiders

9. crustaceans Crabs, shrimps, lobsters, crayfish, barnacles
Characteristics
Most aquatic
Two pair of antennae
Two compound eyes, often on the tips of slender moveable stalks
Mandibles or chewing, open and close side to side
Free swimming larval stage called a nauplis
Most have five pairs of legs
Chelipads first pair, large claws used to catch and crush food
Four pairs of walking legs used for locomotion
Swimmerets, short legs used for reproduction and during swimming

10. arachnida SPIDERS, TICKS, MITES, SCORPIONS
TWO BODY SECTIONS: CEPHALOTHORAX AND ABDOMEN
FOUR PAIR WALKING LEGS
NO ANTENNAE
CHELICERAE- MODIFIED FANGS OR PINCERS USUALLY ATTACHED TO POISON SACK
ONLY POISONOUS SPIDER U.S. IS BLACK WIDOW AND BROWN RECLUSE
PEDIPALPS-USED FOR SENSING AND HOLDING PREY, REPRODUCTION IN MALE SPIDERS, AND PINCERS IN SCORPIONS

11. ARACHNIDIA SPIDERS CARNIVORES BY HUNTING OR CATCHING PREY
SPINNERETS- STRUCTURE IN WHICH SILK IS SECRETED FOR SPINNING WEBS, LOCATED ON ABDOMEN
WRAP FOOD IN SILKEN COCOON UNTIL READY TO EAT
DIGESTION BEGINS EXTERNALLY BY SECRETING DIGESTIVE ENZYMES INTO PREY
AFTER LIQUIDIFICATION, SOFTEN FOOD IS INGESTED
REPRODUCTION
MALE DEPOSITS SPERM AND STORED IT IN THE CAVITY ON HIS PEDIPALPS

12. ARACHNIDIA
SCORPIONS
CARNIVORES, FEED ON INSECTS, SPIDERS AND SMALL VERTEBRATES
CAPTURE WITH THE PEDIPALPS AND TEAR APART WITH CHELICERAE
NOCTURNAL
MOST IN U.S. NOT POISONOUS TO HUMANS BUT STING IS PAINFUL
TICKS
PARASITES
CARRY DISEASE CAUSING ORGANISMS
MITES
PREDATORS OR PARASITES
HORSHOE CRAB
ANCESTORS WHICH ARE MARINE

13. INSECTA 30 MILLION SPECIES 80% ARTHROPODS ARE INSECTS
TERRESTRIAL LIVING IN ALL ENVIRONMENTS
HARD EXOSKELETON PROTECTS THEM FROM PREDATORS AND DRYING OUT
REPRODUCTION LARGE NUMBERS

14. INSECTA EXTERNAL FEATURES
THREE BODY PARTS
HEAD
CONTAINS ANTENNAE, COMPOUND EYES, SIMPLE EYES, MOUTHPARTS
THORAX
THREE PAIRS OF LEGS
GENERALLY TWO PAIR OF WINGS
ABDOMEN
CONTAINS DIGESTION ORGANS
CONTAINS REPRODUCTIVE ORGANS

15. INSECTA ADAPTATIONS LEGS CLAWS FOR DIGGING
STICKY PADS TO WALK UPSIDE DOWN
COLLECTION OF POLLEN
JUMPING
SKIMMING OVER WATER
MOUTHPARTS
SIPHONING; FEEDING TUBE UNCOILS AND EXTENDED TO SUCK : BUTTERFLIES AND MOTHS
SPONGING; FLESHY END OF MOUTH ACTS LIKE A SPONGE; HOUSE FLIES
PIERCING/SUCKING; NEEDLE LIKE TUBE PIERCE AND SUCKS: MOSQUITOES, FLEAS, LEAFHOPPERS
CHEWING; MANDIBLE PIERCES OR CUTS, OTHER PARTS BRING FOOD TO MOUTH: BEETLES, ANTS,BEES, GRASSHOPPERS

16. INSECTA ADAPTATIONS ONLY INVERTEBRATES THAT CAN FLY WINGS
FORMED FROM THIN MEMBRANE OF CHITIN
RIGID VEIN THAT GIVE STRENGTH
BUTTERFLY AND MOTH WINGS COVERED WITH SCALES
ROTATE IN FIGURE 8 TO FLY
SENSE ORGANS
ANTENNAE AND EYES
HAIRLIKE STRUCTURES SENSITIVE TO TOUCH, PRESSURE, VIBRATION AND ODOR
CHEMICAL RECEPTORS FOR TASTE AND SMELL LOCATED ON MOUTH PARTS

17. metamorphosis Series of changes Complete metamorphosis 4 stages
Egg…..larva…..pupa…..adult
Wormlike larva is called a caterpillar
Pupa is a non feeding stage
Incomplete metamorphosis
3 stages
Egg….nymph……adult
Nymph is the immature form of adult without wings

18. Insect societies
Caste is a group of individuals within a society that perform a specific task
Bees
Workers: females that do not reproduce…gather nectar and pollen…build honeycomb…care for young…guard the hive
Drones: reproductive males, die after mating
Queen: only reproductive female

19. Insects and humans Needs for pollination Produce honey and silk
Serve as food for animals
Prey on plant pests
Harmful as parasites and carry disease