1. PHYLUM ARTHROPODA

2. Arthropoda Characteristics
account for over 80% of all living animal species

3. Arthropoda Characteristics
means “jointed foot”
True coelom
exoskeleton made of chitin
show a high degree of cephalization
variety of segmented antennae used for sensing the environment and detecting chemicals
most have compound eyes & other light sensing structures
body plan of repeated segments that attach to an appendage

4. Arthropoda Characteristics
open circulatory system
Heart pumps circulatory fluid thru vessels that empty into spaces in the body
nervous system is ladder-like with brain formed from fused ganglia
Respiratory system varies with each species.

5. Life cycle
Stage 1: Egg – females lay thousands of eggs. Some # survive
Stage 2: juvenile
each has different names to describe this stage (example: lice – nymph)
Stage 3: Molting – shedding or physical change before adulthood
Stage 4: Adulthood – those surviving can reproduce. Most fertilization of eggs inside female then released to hatch.

6. Phylum Arthropoda classes
5 major classes:
Chilopoda – centipedes
Diplopoda – millipedes
Crustacea – crabs, lobster, crayfish,shrimp
Insecta – insects
Arachnida – spiders, scorpions, mites, chiggers

7. Classification of Arhtropoda
Centipedes – 1 pr legs/segment
Millipedes – 2 prs legs/segment
Crustaceans – 5 pairs of legs
Insects – 3 pairs of legs
Arachnids – 4 pairs of legs

8. Class Diplopoda 1000 leggers millipede
Cylindrical worm-like with 2/prs legs/seg. Juveniles may possess only 1 pair per segment
Simple eyes if any present. Many have no eyes
Decomposers or herbivores
Short antenna
Non-toxic

9. Diplopoda Characteristics
Very timid
Protect by rolling themselves up tight and discharge a foul smelling, distasteful substance.
Fertilized eggs are laid in the soil.
They are found in cool, moist environments. Found under rocks and logs.

10. Class Diplopoda

11. Class Chilopoda Centipedes 100 leggers
Flattened worm like w/1 pr legs/seg
Carnivores
Possess a pair of poison claws or legs just behind the head which are used to paralyze their prey
Feed on insects or small animals
Most centipedes are beneficial
Large species found in the tropics (length of up to 18 inches)
Can inflict painful bites

12. More Chilopoda characteristics
Simple eyes
The bite of centipedes can be painful to humans but not deadly.
Life Cycle:
Males spin web where they deposit sperm for females to pick up.
Sometimes there is a courtship of dancing or tapping.
Habitat:
Like millipedes can be found under rocks, logs, or bark of tree.

13. Class Chilopoda

14. Class Insecta Upwards of 3 million species
Outnumber all other plant and animal groups
Found in all environments
Some fly hundreds of KM per week

15. Class Insecta Three body divisions Head Thorax Abdomen
12 Inches—Largest
1MM-Smallest
Rapid growth rate
Most mature < 1 year
Display almost every color

16. Class Insecta
Spiracles (external openings) along abdomen used for breathing
Highly modified mouth parts (mandibles)
Some beetles can chew through lead or zinc
Well developed tube within a tube digestive system
Well developed nervous system
Sight: two types of eyes (Ocelli and compound eyes)
Smell/taste-Use of antennae and feet
Hearing- tympanum (eardrum)

17. Defense Insects use can use a variety of defenses: Hiding Burrowing
Mimicry
Shedding appendages
Chemical defense
Camouflage
Warning colors

18. Insects and the Economy
Insects have direct impact on agricultural food production
Chewing leaves
Sucking out plant juices
Boring into roots
Spreading plant pathogens
Can transmit diseases

19. Benefits Insects play a role in the cycle of nutrients on Earth.
Help aerate soil
Improve soils retention of rainwater
As parasites and predators
help with community stability
prevents over population growth
Insects help pollinate
Other benefits:
Produce honey to eat
Beeswax
Silk from silkworms

20. Insect Reproduction Reproduction is most often sexual
Parthenogenesis is asexual reproduction – species can form from unfertilized eggs. Example bees – unfertilized produce males, fertilized can produce females
Females:
Make eggs
Receive sperm and store it
Able to manipulate sperm from different males
Number of eggs an insect lays can vary
Males:
Reproductive system consists of testis

21. Class Insecta
Pheromones- External hormones used for communication (especially in finding mates)

22. Crustacea Body segmented with hardened Limbs
Limbs generally with two branches
Two pairs of antennae
Two compound eyes (eyes with many lenses)
Body with 7 or more pairs of sometimes very different appendages for feeding, locomotion and sex
Respiration by gills
Nauplius- Distinctive larval stage with three pairs of branched appendages
Although originally aquatic, many crustaceans are adapted to life on land

23. Crustacea Shrimp Lobster Krill Pill bug Crabs Crayfish
Barnacles (sessile)

24. Crustacea

25. Class Arachnida
Spiders
Mites/ticks
Scorpions

26. Class Arachnida Many, but not all spiders web builders Liquid feeders
Most familiar spiders
head (fused to thorax) and abdomen
All toxic
No antennae
Many, but not all spiders web builders
Liquid feeders
Inject digestive enzymes into prey and drink juices
Use powerful jaws to crush exoskeleton- then digest and eat

27. Class Arachnida