arthropods. what are arthropods? coelomate segmented bilateral symmetry exoskeleton – made of...
TRANSCRIPT
![Page 2: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/2.jpg)
What are ARTHROPODS?
• Coelomate
• Segmented
• Bilateral Symmetry
• Exoskeleton – made of protein and chitin
• Jointed appendages – any structure (leg or antennae) that grows out of the body
![Page 3: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/3.jpg)
• earliest invertebrates to exhibit jointed appendages– Jointed appendages are an advantage
because they allow more flexibility for animals with hard, rigid exoskeletons
– Joints allow powerful movements and allow appendages to be used in many ways
What are Arthropods?
![Page 4: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/4.jpg)
What are Arthropods?
Appendages
Jointed Appendages
![Page 5: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/5.jpg)
• made up of protein and CHITIN
• can be a continuous
covering over most
of body OR made of plates
that are held together by hinges
Exoskeletons Provide Protection
Continuous
Hinged
![Page 6: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/6.jpg)
• Protects, supports internal tissues
• Provides place for muscle attachment
• Aquatic arthropods have exoskeleton reinforced with calcium carbonate
Exoskeleton Advantages
![Page 7: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/7.jpg)
Exoskeleton Disadvantages
• Heavy– the larger the animal, the thicker and
heavier the exoskeleton
• Exoskeletons don’t grow– animals must molt when they get too large
for exoskeleton
![Page 8: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/8.jpg)
Molting• Animal contracts muscles and takes in
air or water
• Body swells and causes exoskeleton to split open, usually along the back
• Most arthropods will molt 4-7 times before becoming an adult.
![Page 9: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/9.jpg)
• increased circulation to all parts of the body cause the animal to puff up and new exoskeleton hardens leaving some “growing room”
• animal can’t protect itself, can’t move
Before the new exoskeleton hardens...
![Page 10: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/10.jpg)
Question 1
Which of the following organisms would be most likely to have an exoskeleton reinforced with calcium carbonate?
A. Spider
B. Beetle
C. Crab
D. Dragonfly
Correct!
![Page 11: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/11.jpg)
Question 2
• Exoskeletons are heavy. Why can aquatic arthropods grow so much larger than terrestrial arthropods?
The buoyancy of the water helps support the weight of the exoskeleton
![Page 12: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/12.jpg)
Question 3
• What is one advantage and one disadvantage of flying arthropods having a thinner, lighter weight exoskeleton?
Disadvantage: less protection
Advantage: greater freedom to fly and jump
![Page 13: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/13.jpg)
Question 4
• What is one advantage and one disadvantage of having a cephalothorax?
Disadvantage: less flexibility, mobility
Advantage: more protection
![Page 14: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/14.jpg)
Segmentation
• 3 segments – abdomen – thorax – head
![Page 15: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/15.jpg)
• Sometimes these segments can be fused together– some have head and fused thorax and
abdomen– some have abdomen
and fused head and
thorax (cephalothorax)
Segmentation
![Page 16: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/16.jpg)
Respiration
• Efficient respiratory systems to meet large O2 demands
• Large O2 demand needed to sustain high metabolism for fast movements
• 3 types of respiratory structures– gills (aquatic arthropods)– tracheal tubes (terrestrial arthropods)– book lungs (terrestrial arthropods)
![Page 17: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/17.jpg)
• Gills– water moves over gills– O2 from water diffuses
into gills and into
bloodstream– CO2 from body diffuses out through gills
into surrounding water
Respiration
![Page 18: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/18.jpg)
• Tracheal tubes– branching network of hollow air passages
that take air throughout the body
Respiration
Muscle movement brings air in/out through SPIRACLES (openings in abdomen and thorax)
![Page 19: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/19.jpg)
• Book lungs– spiders and relatives– air filled chambers with leaf-like plates– stacked plates
are arranged
like pages
of a book
Respiration
![Page 20: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/20.jpg)
Antennae
• Acute sensing by antennae– stalk like structure that can detect changes
in the environment• movement• sound • chemicals
Used for sound and odor communication
![Page 21: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/21.jpg)
Eyes• Compound Eyes
– visual structure with many lenses
• Simple Eyes– visual structure with one lens for detecting
light
one pair of compound eyes and 3-8 simple eyes
![Page 22: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/22.jpg)
Nervous System
• Double ventral nerve cord
• Anterior brain
• Several fused ganglia that control the body section they are located in
![Page 23: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/23.jpg)
Circulatory System
• Open circulatory system– blood flows away from the heart in vessels– blood flows out of vessels into tissues– blood returns to the heart through open
spaces
![Page 24: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/24.jpg)
Digestive System• Complete digestive system with mouth,
intestine, and anus
• Mouth has 1 pair of jaws called MANDIBLES– adapted for holding, chewing, sucking, or
biting
![Page 25: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/25.jpg)
Reproduction – Sexual and Asexual
• Sexual reproduction– separate sexes– internal fertilization for terrestrial species– external fertilization for aquatic species
![Page 26: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/26.jpg)
• Asexual reproduction– PARTHENOGENISIS
• a new individual develops from an unfertilized egg
• seen with ants, aphids and bees
Reproduction – Sexual and Asexual
![Page 27: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/27.jpg)
Arachnids
• spiders (largest group), ticks, mites, and scorpions
• 2 body regions: cephalothorax and abdomen
• 6 pairs of jointed appendages – 12 total appendages!
![Page 28: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/28.jpg)
• 1st pair - chelicerae, are near the mouth
• modified into pincers (hold food) or fangs (inject poison)
Arachnids
chelicerae
![Page 29: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/29.jpg)
• 2nd pair – pedipalps, for handling food and sensing
Arachnids
pedipalps
![Page 30: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/30.jpg)
• Silk, for webs, is secreted by silk glands in the abdomen
• as it is secreted, it is spun into thread by SPINNERETTES
• spiders are predatory and feed almost exclusively on other animals
Arachnids
![Page 31: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/31.jpg)
• Ticks and mites have only 1 body section
• Head, thorax and abdomen are completely fused• Ticks feed on blood of other animals
Arachnids
![Page 32: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/32.jpg)
• Mites feed on fungi, plants, and animals
• small – not usually visible
• can transmit diseases
Arachnids
Dust mites
![Page 33: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/33.jpg)
• Scorpions have many abdominal body segments
• Enlarged pincers
• Long tail with
venomous stinger
at the tip
Arachnids
![Page 34: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/34.jpg)
Crustaceans• crabs, lobster, shrimp, crayfish,
barnacles
• Only arthropods with 2 pairs of antennae
• mandibles – move
from side to side
• 2 compound
eyes
![Page 35: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/35.jpg)
• 5 pairs of walking legs
• 1st pair are claws for defense
Crustaceans
claw legs
![Page 36: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/36.jpg)
• Most are aquatic and use gills
• pill bugs (roly-polies) live on land, but must have moisture to aid in gas exchange
Crustaceans
Yes! This is a crustacean!
![Page 37: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/37.jpg)
• Centipedes are carnivorous – eat soil arthropods, snails, slugs, and worms
• Bites can be painful• Millipedes – eats plants and dead
material on damp forest floors• Does not bite, but does
spray foul-smelling fluid
Centipedes and Millipedes
![Page 38: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/38.jpg)
Horseshoe Crabs
• Class Merostomata
• “Living Fossils”- unchanged for 220 million years (Triassic period)
• Extensive exoskeleton
• Live in deep coastal waters
• forage bottoms for algae,
annelids and molluscs
![Page 39: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/39.jpg)
Insecta
• Flies, grasshoppers, lice, butterflies, beetles
• 3 body segments
• 6 legs
• Very diverse - more insects than all other classes of animals combined
![Page 40: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/40.jpg)
• mate once in lifetime
• internal fertilization
• some exhibit
parthenogenesis
• large number of eggs
to increase survival rate
Insecta
![Page 41: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/41.jpg)
• insect embryos develop inside eggs, eggs hatch
• some look like miniature adults– will molt
several times until adult size
Insecta
EggsNymph
Molt
Nymph
Molt
Adult
![Page 42: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/42.jpg)
• INCOMPLETE METAMORPHOSIS– 3 stages: egg, nymph, adult
Insecta
• Nymphs can’t reproduce
• Nymph gradually becomes an adult
![Page 43: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/43.jpg)
• Some undergo COMPLETE METAMORPHOSIS– 4 stages: egg, larva,
pupa, adult
• Metamorphosis is controlled by chemical substances in the insect
Insecta
Egg
Larva
Pupa
Adult
![Page 44: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/44.jpg)
Insecta
• Incomplete metamorphosis: grasshoppers and cockroaches
• Complete metamorphosis: ants, beetles, flies, wasps
![Page 45: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/45.jpg)
Origins of Arthropods
• Successful because of
– varied life styles
– high reproductive output
– structural adaptations
– hard exoskeletons
– jointed appendages
![Page 46: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/46.jpg)
• Hard exoskeletons fossilize – a lot is known about evolutionary history
• Evolved from ANNELIDS (segmented worms)
• Arthropods have more complex segments, more developed nervous systems
• circular muscles in annelids do not exist in arthropods
Origins of Arthropods
![Page 47: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/47.jpg)
Question 5
Spiders are:
a. predators
b. scavengers
c. decomposers
d. parasites
Predators!
![Page 48: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/48.jpg)
Question 6
Having 2 pairs of antennae distinguish _________ from other arthropods.
a. centipedes
b. millipedes
c. crustaceans
d. horseshoe crabs
Crustaceans!
![Page 49: Arthropods. What are ARTHROPODS? Coelomate Segmented Bilateral Symmetry Exoskeleton – made of protein and chitin Jointed appendages – any structure (leg](https://reader036.vdocuments.mx/reader036/viewer/2022081421/56649ce15503460f949aca04/html5/thumbnails/49.jpg)
Question 7• Why are horseshoe crabs called “living
fossils?”
They remain unchanged after 220 million years!