Download The Arthropods: Blueprint for Success

The Arthropods: Blueprint for
Success
Taxonomy we will cover in this Phylum:
• Subphylum Crustacea
• Class Malacostraca
• Exp. Lobster
• Class Cirripedia
• Exp. Barnacles
• Subphylum Chelicerata
• Class Merostomata
• Exp. Horseshoe crab
• Class Arachnida
• Exp. Spiders
General Facts
• Over a million species
• Between 70-85% of all named species
on Earth are Arthropods.
•The majority being insects!
• Live on land, oceans, & freshwater.
• Range in size from 12 ft. armspan (King
Crab) to microscopic insects &
crustaceans & range in taste 
King Crab!
Horseshoe Crab
Find mates in
water
Go to beach &
mate (leave sea
briefly) and lay
eggs
Eggs develop on
land
Spotted Cleaner Shrimp
Pumpkin Spider
Giant Weta
Peruvian Giant Centipede
Millipede
6 Key Features to Arthropod
Success:
1.
2.
3.
4.
5.
6.
Metamerism
Exoskeleton
Jointed Appendages
Efficient Respiratory System
Sensory Structures
Complex Behaviors
Arthropod Success- A group of animals
with a proper toolkit to dominate.
Metamerism – segments are grouped into body regions;
allows for specialization.
Tagmata - specialized for feeding and sensory perception,
locomotion, and visceral functions. (segments fused together)
•
Exoskeleton – skeleton outside body. Protection (body
armor), support, H2O retention, muscle attachment
Ecdysis (molting) – emerges with entire new covering (soft at
first..then hardens over 2 days)
•
Jointed appendages – adapted for a variety of functions imagine yourself w/out joints.
Success continued…
Efficient Respiratory System – tracheal system of tubes
throughout the body with tiny openings (spiracles) that
open into the trachea – tubes
• Allows for direct access of oxygen to muscles
More Developed Sensory Structures – allow organisms
to be more aware
• Compound eyes, antennae, etc.
Complex Behaviors – no big development in nervous
system; but migrates every year, social behavior, can learn
• Allows better survival and more generations
• Each leg has tremendous flexibility
• Saltatorial, cursorial, etc.
• Muscles can attach to exoskeleton
• Legs and body segments = potential to
adapt & evolve
Metamorphosis
Physical change over time; one body form to
another
• Complete (holometabolous) (indirect)
• Egg  Larva  Pupa  Adult
• Larva & Pupa do not look like adult
• Incomplete (hemimetabolous) (direct)
• Egg  Nymph (instars)  Adult
• Instars look like mini adults
Incomplete (hemimetabolism) (Direct)
Complete (holometabolism)
(indirect)
EXTINCT ARTHTROPOD 
•
Trilobites!
Dominant form of life
in the oceans during the
Cambrian period.
•
Body oval, flattened &
divided into 3 sections,
had eyes, could walk &
swim, roll in a ball for
protection.
•
Subphylum Crustacea
Crayfish, shrimp, lobster, crabs, copepods,
isopods.
• 2 pairs of antennae, bi-ramous
appendages.
•
Class Malacostraca
Order Decapoda
Shrimp, crayfish, lobster, crabs.
• Have a cephalothorax and abdomen.
• They eat anything!
• Gills are in the carapace between body wall.
• Sensory structures: antennae, compound eyes,
simple eyes, statocysts, chemoreceptors,
proprioceptors, tactile setae.
•
Exoskeleton (molted)
• Draw & label a crayfish –
antennae, antennules,
cephalothorax, abdomen, uropod, telson, swimmerets, walking legs,
cheliped, rostrum, carapace, eye
Order Decapoda
Isopods (pill bugs) are common under
rocks and in leaf litter.
• Copepods are the most abundant.
•
Subphylum Crustacea
Class Cirripedia
Barnacles
• Unique because they are sessile (attached
to a substrate).
•
Barnacle Life Cycle
Direct or Indirect?
Subphylum Chelicerata
Includes the horseshoe crabs, sea spiders,
spiders, mites, & ticks.
Chelicerata Characteristics
2 tagmata - cephalothorax
& abdomen
Mandible – jaw for chewing
Chelicerea - (used for
feeding)
•
Located on cephalothorax
•
Pedipalps - (sensory or
feeding)
•
Located on cephalothorax.
Subphylum Chelicerata
Class Merostomata
Includes horseshoe crabs and the giant water
scorpion (extinct).
•
Horseshoe crabs have remained virtually
unchanged for 200 million years.
•
They have a long tail-like extension (telson) that
helps it flip over.
•
•
Dioecious – lay eggs in intertidal areas.
Subphylum Chelicerata
Class Arachnida
Spiders, ticks, mites, scorpions.
• Most are carnivorous – they use
chelicerae to hold food while injecting it with
digestive enzymes & suck out the tissue.
•
Subphylum Chelicerata
Class Arachnida continued…
Either have book lungs (folds in the body
wall that allow gas exchange) or
• tracheae (tubule system- opens to the
outside through spiracles & allow oxygen
directly into body tissue
•
Arachnid Development
Direct life cycle– young hatch as mini
adults. (Hemimetabolism)
•
Arachnids Impact Humans
Humans have been impacted the most by
Acarines (ticks & mites).
• Can transmit disease and cause irritation.
•
Subphylum Myriapoda
Class Chilopoda vs. Class Diplopoda
• centipedes vs. millipedes
• Fast moving vs. slow moving
Subphylum Hexapoda
Class Insecta
Entomology – study of insects
3 tagmata – head, thorax, & abdomen
• Head region – specialized for feeding and
sensory input
• Thorax – specialized for movement
• Abdomen – specialized for respiration,
digestion, reproduction, etc.
Class Insecta continued..
• Many types of mouths – chewing, piercing,
sucking, etc.
• Silk glands – movement, create nests/webs
• Pheromones – chemical substance released
outside of the body and influences other
organisms
• Exp. sex pheromones (beetles, attack
pheromones (honeybees)
Draw and label an insect:
• Include:
3 segments, compound eye, ocelli (simple eyes),
mandible, labrum, antennae, thorax (pro, meso, meta) abdomen,
tympanum, ovipositor (female only), leg (5 parts), jumping leg, protective
wing, flight wing, spiracles