Download d. Arthropods

Introduction to Arthropods
Biology 11
Mrs. Trevelyan
Arthropoda
1. PRESCRIBED LEARNING OUTCOMES
and VOCABULARY
2. VIDEOS:
Introduction to Insects (25 min)
3. TEXTBOOK PGS
Chp 28 pg 740 -761
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Scared of Tattoos?
Bringer of Destruction?
Overview…
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80% of all animals are arthropods…..
76% of those are insects…..
www.onacd.ca
Examples of Members:
1. Unifying Characteristics
 Bilateral symmetry, coelomate (have a true coelem)
 More complex organisms- have 3 layers and organs
 Have an exoskeleton made of CHITIN with jointed appendages
 Have 3 body regions (head, thorax, abdomen)
 Have blood in an open circulatory system with heart(s)
 Separate sexes, fertilization is usually internal
 Extreme diversity in habitat (marine, freshwater, terrestrial and
air), adaptations and food sources
1. Unifying Characteristics
 Sensory organs are well-developed:
 compound eyes
 tympanum (drum-like ear)
 antenna (touch, smell, chemical reception)
 Complete digestive systems with mouth, specialized organs
and anus
 Respiration by body surface, gills, trachea, or book lungs
 Developed nervous system with a brain and double ventral
nerve cords
How to Classify so many members?
ACTIVITY: Insect Flashcards- make 5 groups
ACTIVITY: Identifying Insects Online Lab:
http://www.mhhe.com/biosci/genbio/virtual_labs_2K8/labs/BL_10/index
.html
Five Major Subphylums
Major Classes of Arthropoda
1. Subphylum Myriapoda, Class Chilipoda: includes
the centipedes
2. Subphylum Myriapoda, Class Diplopoda:
includes the millipedes
3. Subphylum Hexapoda, Class Insecta:
includes all 6 legged insects
4. Subphylum Chelicerata Class Arachnida:
includes the spiders, mites and scorpions
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Major Classes of Arthropoda
5. Subphylum Crustacea, Class Malacostraca: includes the
lobsters, crab and shrimp
6. Subphylum Crustacea, Class Maxillopoda: includes the
barnacles
***All the members of the Phylum Trilobites are EXTINCT
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Fare Thee Well, Trilobites!
Class Insecta
 Head with 6 segments, sensory
antennae and compound eyes
 Thorax with attached segmented
legs and possibly wings
 Abdomen with 11 segments which
has most of the digestive,
respiratory, excretory and
reproductive systems
 Insects breathe through small tubes
and sacs that are directly next to the
circulatory system (=SPIRACLES)
 No closed vessels
 Most insects hatch from eggs which
are formed by sexual reproduction
 Insects molt as they grow in size
(slough off exoskeleton to grow).
 Some undergo complete
metamorphosis (change form e.g.
butterflies) or incomplete
metamorphisis (juveniles look like
adults)
Complete and Incomplete
Metamorphosis
Structure of a Wasp:
Head
Thorax
antenna
Abdomen
forewing
tympanum
hindwing
compound eye
ovipositor
air sac
simple
eye
spiracles
labial palps
a.
spiracle tracheae
crop
brain
aorta
Malpighian
tubules
ovary
heart
intestine
rectum
oviduct
vagina
salivary
gland
mouth
stomach
gastric
ceca
ventral
nerve cord
seminal
receptacle
nerve
ganglion
Subphylum Cheliceratae
Members of the Phylum Chelicerata include
spiders, scorpions and horseshoe crabs. These
all have chelicera, or fang-like projections at the
mouth
Class Arachnid
 Spiders are not insects.
 Arachnids include spiders,
scorpions, mites and ticks.
 Arachnids have four pairs of
legs.
 Two main body sections abdomen and
cephalothorax
 This is a joined head and thorax.
 No antennae
 Use book lungs to breath
Subphylum Myriapoda
 Myriapod means having many legs.
 Millipedes and Centipedes belong to this
subphylum of arthropods
 Both centipedes and millipedes care for their eggs
Class Chilipoda - Centipedes
 One pair of legs per body segment.
 Up to 15 to 170 pairs of legs in total
 Wriggle when they walk because the legs on either side
of their body move alternately.
• Centipedes have flat bodies
• Centipedes are carnivores
- they have fangs
- may have venomous claws to
catch their food.
• They can move very quickly.
Class Diplopoda - Millipedes
 Two pairs of legs per body segment.
 Smooth motion because both legs on either side of their
body are moving at the same time.
 They have a round tube shape bodies.
 Millipedes may give off a bad odor when they are
frightened
 Vegetarian
Class Maxillopoda : The Barnacles
The Barnacle Life Cycle
Includes 2 larval stages
1. NAUPILUS
 Floats in the ocean
2. CYPRID
 Settles in a safe place
 Glues itself headfirst to
surface and undergoes
metamorphosis into a
barnacle
Adult Barnacle
 develops 6 hard armor
plates around its body
 feathery legs to capture
food and gametes when
spawning
 Barnacles are
hermaphroditic
Famous Barnacle Fact:
Barnacles have the
largest penis to body
size ratio of any species
in the animal kingdom
Goose barnacles feeding
http://www.youtube.com/watch?v=v1SW-pl2gYs&feature=related
Class Malacostraca
 Cephalothorax
 almost completely covered
by a carapace
 6 abdominal segments
often used for swimming
 Stick out the end in
shrimps and lobsters
 Tucked underneath the
body in crabs
 Compound eyes
 5 pairs of walking legs,
some with modified
pincers
Hermit Crab
Spiny King Crab
 2 chambered stomach
 Centralized nervous
system
The Largest living Arthropod…
…is the Japanese
Spider Crab with a
leg span of 4 meters
and a weight of
20kg.
This crab has a life
expectancy of 100
years.
Male vs. Female crabs
Male or
Female?
Male or
Female?
second walking leg
first walking leg (modified
as a pincerlike claw)
third walking leg
fourth walking leg
fifth walking leg
uropods
swimmerets
carapace
compound
eye
mouth
antennae
claspers
gills opening of
sperm duct
Cephalothorax
anus
telson
Abdomen
brain stomach
heart
dorsal abdominal artery
green
gland
anus
sperm
ventral
duct
nerve cord
mouth
digestive
gland
testis
Ecological Roles of Arthropods
 Pollination
 Production of honey,
wax, and silk
 Recycle biological
materials to help
make topsoil
 Form symbiotic
Burrowing shrimp and Goby fish living
together
relationships with
other organisms
 Part of food chain
http://www.youtube.com/watch?v
=SX4ymCik3iQ
The 3 MOST IMPORTANT
Adaptations, in Summary:
1. Tough exoskeleton made of chitin (protection,
prevents water loss, but must be sloughed off to
grow)
2. Jointed appendages- they can walk/fly!
3. A segmented body which allows for specific
purposes
Don’t try this at home...
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