1. *
07/16/96
ARTHROPODS
BIOLOGY
MR. Quinn …
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2. Animals of Phylum Arthropoda*
07/16/96
Animals of Phylum Arthropoda
Termites, ticks, scorpions, grasshoppers, flies, mosquitoes, lobsters, crabs, bugs,spiders, centipedes, millipedes, daphnia,crayfish,beetles,dragon flies, bees, wasps, daddy-long legs, mites, fleas, trilobites, butterflies, moths, barnacles, ants,……..and many many more!!!!! 1
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3. Characteristics of Arthropods !!*
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Characteristics of Arthropods !!
Invertebrates with an exoskeleton!
Jointed appendages (legs)
Bilaterally symmetrical
Has a true coelom
Segmented body 2
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4. What are the advantages or disadvantages of an exoskeleton??*
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What are the advantages or disadvantages of an exoskeleton??
Protection -made of chitin and protein- hard and thick !!
Supports internal organs
Provides for muscle attachment
Heavy-disadvantage
Can’t grow, so it must be shed by molting periodically! 3
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5. *
Segmentation
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Most arthropods have three body segments! HEAD, THORAX, and ABDOMEN
Sometimes the head and thorax are fused together to form a CEPHALOTHORAX- like in lobsters!
All legs and wings attach to the thorax! 4
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6. How do Arthropods breathe??*
How do Arthropods breathe??
07/16/96
Some land Arthropods breathe through tiny openings on their body called spiracles which lead to tubes within the body called tracheal tubes! - crickets!
Other land arthropods (spiders) breathe using book lungs found just behind the legs on the body!
Aquatic arthropods have gills!! 5
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7. Senses found in Arthropods!- from a brain and ventral nerve chord!!!*
Senses found in Arthropods!- from a brain and ventral nerve chord!!!
07/16/96
Antennae are sensitive to movement, sound and chemicals!
Antennae also are used to communicate between arthropods!
Pheromones are chemical-odor signals given off by arthropods!
EYES - both simple and compound! Simple eyes detect light/dark! Compound eyes have many lenses together forming an image! Excellent for detecting movement! 6
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8. Sight through a Bees Compound Eye*
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Sight through a Bees Compound Eye
Bee
Sight
Human Sight
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9. Circulation and Digestion in Arthropods!*
Circulation and Digestion in Arthropods!
07/16/96
Open circulatory system- blood flows into spaces in the body- not kept in blood vessels!
Dorsal heart !
Complete digestive system-mouth-crop-stomach-intestines-anus!
Digestive enzymes breakdown food!
Chewing mandibles , or sucking mouth parts are strong!
Malphigian Tubules filter wastes into the intestines! 7
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10. Reproduction in Arthropods !*
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Reproduction in Arthropods !
Most arthropods have separate sexes (males/females)
Internal Fertilization- eggs protected inside female.
A few are hermaphrodites
Some show parthenogenesis- young forming from unfertilized eggs!
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11. Arthropods and Humans ?? The Good, the Bad and the Ugly!!!*
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Arthropods and Humans ?? The Good, the Bad and the Ugly!!!
Great pollinators …bees, wasps!
Provide honey, shellac, wax and silk!
Alternative to pesticides - lady bugs, praying mantis
Used in genetic research to make artificial skin, surgical sutures, and anti-fungal medicine from crab shells!
Problems: eating our food!
Spread diseases- malaria, yellow fever!
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12. Diversity - The Arachnids!!- spiders, scorpions, mites, and ticks!*
Diversity - The Arachnids!!- spiders, scorpions, mites, and ticks!
07/16/96
30,000 species of spiders - but only about a dozen are poisonous to humans!
2 body parts - cephalothorax and abdomen!
6 pairs of appendages- 2 Chelicera-fangs, two pedipalps for handling food and used in reproduction, and 8 legs!!
2-6 silk glands in the abdomen-passing the liquid silk to the spinnerets which knit it into thread!
No mandibles - but a sucking stomach!
No antennae, and only simples eyes -usually 8
Ticks and mites have only one body part!! (All fused)
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13. *
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Arachnids
Chelicera
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14. *
Diversity - The Crustaceans - crayfish, shrimp, lobsters, barnacles, crabs!
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Gills for breathing- found underneath the cephalothorax!
Large mandibles for crushing food!- jaws open side to side not up and down!
2-pairs of antennae!
2 stalked compound eyes!
5 or more pairs of walking legs with 2 large chelipeds called pinchers!
Pill bugs are the most common terrestrial land crustacean!- found in damp soils
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15. Crustacean Example - Crayfish*
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Crustacean Example - Crayfish
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16. Diversity-Centipedes and Millipedes*
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Diversity-Centipedes and Millipedes
Class Chilopoda- centipedes with one pair of legs per segment!
Centipedes are carnivorous- eating snails, slugs and worms- They bite!!
Class Diplopoda - millipedes with two pairs of legs per body segment!
Millipedes are herbivorous - eating roots and leaves
Millipedes don’t bite but they can spray a smelly-fluid from their stink glands!
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17. *
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Centipede Millipede
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18. Diversity-The Insects*
Diversity-The Insects
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3-body parts- head-thorax-abdomen
Spiracles-tracheal tubes for breathing
Dorsal heart-open circulatory system
3-pairs of legs- antennae, both simple and compound eyes-
A tympanum for hearing
Sometimes wings- one or two pair
Complete Metamorphosis- (butterflies-moths) egg-larva-pupa-adult !!
Incomplete Metamorphosis-( crickets, grasshoppers) egg- nymph-molt-nymph-molt-nymph-molt-adult
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19. Complete Vs Incomplete Metamorphosis*
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Complete Vs Incomplete Metamorphosis
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