1. Ch. 36 - Arthropods Video Phylum: Arthropoda Means “jointed legs”
75% of all animals belong to this phylum
Insects, lobsters, crabs, spiders, millipedes, & centipedes
Video

2. Characteristics of Arthropods
1. Appendages – legs, antennae
2 appendages per segment
2. Open circulatory system
3. Digestive system
4. Ventral nervous system
5. Exoskeleton – protection & desiccation
Made of chitin
Video

3. What is molting?
Shedding of the exoskeleton
Why do animals molt?
Every time an animal molts it enlarges or grows

4. What are some advantages & disadvantages of molting?
Protection, prevents desiccation
Must molt to grow, vulnerable after it molts

5. Crustacea subphylum Video
Crayfish, lobsters, crab, sow bugs, daphnia.
Mainly aquatic
Crayfish Characteristics
2 main body parts
1. Cephalothorax – head & thorax
2. Abdomen – 7 segments
Last segment is the telson
Video

6. Appendages of the Crayfish
1. Chelipeds – pinchers
2. Antennules – smaller (inside)
3. Antenna – larger (outside)
4. Walking legs – 4 along the thorax
5. Swimmerets – along the abdomen
6. Uropod – outside the telson

7. Digestive & Excretory Systems
First the crayfish tears the food with their maxillae & maxillipeds.
They chew their food with their mandibles
The food passes through the esophagus to the stomach.

8. The digestive glands absorb nutrients, then the undigested material enters the intestine, and then exits the anus.
Green glands are also used in the excretory system to remove waste; much like kidneys.

9. Circulatory & Respiratory Systems
Open Circulatory System
Dorsal heart that pumps blood to the body cavity to bath the organs. It is then pumped to the gills.
What do the gills do?
Large surface area for gas exchange
The gills are attached to each walking leg

10. Nervous System
Ventral nerve cord
Brain
Sense receptors  antennules, antennae, & compound eyes
A compound eye has many lenses
Do you have a compound eye?

11. Usually mate in the fall
Reproductive System
Usually mate in the fall
The male uses its swimmerets to transfer sperm to the female, where she keeps the sperm until spring.
The eggs are then fertilized and kept along the female’s swimmerets until they hatch.

12. Chelicerae - subphylum
Class: Arachnida
Spiders, mites, scorpions
Many use stingers or fangs with poison.
How do spiders catch their prey?
with webs or “trap doors”
Scorpions hunt at night and hide during the day.
Video

13. Only a few scorpions are poisonous enough to kill humans.
Mites and ticks are the most abundant in this class.
Ticks are parasitic and some carry diseases.
Lyme’s disease
Rocky mountain spotted fever.
Spider mites can damage and wipe out fruit trees or other trees.

14. Structure of a spider 2 segments 1. Cephalothorax 2. Abdomen
Chelicerae – hollow fangs
Pedipaps – aid in chewing
8 legs & eyes
Spiracles – openings for respiration

15. Video Book lung – air sacs in the abdomen for respiration.
Malpighian tubules – kidney-like excretory system. Removes wastes.
Spinnerets – spins silk for webs
Can also be used as silk balloons to fly away in young spiders.
Black widow & Brown Recluse
2 poisonous spiders in Kansas
Video

16. Uniramia - subphylum Video 2 classes 1. Diplopoda – millipedes
Means “thousand feet”
2 pair of legs per segment
2. Chilopoda – centipedes
Means “hundred feet”
1 pair of legs per segment
Some are poisonous
Video

17. Insects – 2nd Part of Ch. 39 Video
Most diverse and largest number of species of any class of organism.
They were present on earth before the dinosaurs, over 300 million years ago.
Differences from other arthropods
1. 3 body segments  head, thorax, abdomen
Video

18. 2. Head has 1 pair of antennae
3. Thorax has 3 pairs of legs & 1 or 2 pair of wings.
4. No wings or legs attached to the abdomen.

19. Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta (700,000 + species named)
What makes insect so successful?
Lots of them – adapt very well
Great diversity – several types
Reproduce rapidly
Small size & ability to fly (most)

20. Benefit of insects? Video
1. Pollination – plants can’t reproduce without insects. We need plants to survive.
2. Food – for other animals. Several animals rely on insects as a source of food.
3. Industrial uses – silk & honey
What is the study of insects called? (E.C)
Entomology
Video

21. Grasshopper  External Structures
3 Body Parts:
1. Head
Labium – grasps the food ( bottom lip)
Mandible – chews the food (jaws)
Labrum – holds the food (upper lip)
Maxilla – extra jaws
2. Thorax
3 pairs of legs (6 total)
2 pair of wings usually

22. 3 parts to the thorax
1. Prothorax – pair of walking legs
2. Mesothorax. – pair of walking legs
3. Metathorax – pair of jumping legs
Forewings are attached to the mesothorax
Hindwings are attached to the metathorax

23. 3. Abdomen
Spiracle – for respiration
Tympanum – for hearing (eardrum)
Ovipositors – holds it eggs

24. GrasshopperInternal Structures
Digestive System
What do grasshoppers eat?
What are the mouth parts?
Food passage: esophaguscrop (storage) gizzard (grind) midgut (digested) hindgut (rectum & colon)  out the anus

25. Circulatory System
Open Circulatory System
An aorta is a large vessel that carries the blood on the dorsal side.
2 Hearts along the aorta

26. Respiratory System
No lungs or gills
Use spiracles – openings along the abdomen
The spiracles lead to the trachea
Nervous System
Brain connected to a ventral nerve cord
Has simple and complex eyes

27. Have antennae
Tympanum for sensing sound
Reproductive System
The male deposits sperm into the seminal receptacle, which stores the sperm.
The female uses its ovipositors to deposit her eggs in the ground.

28. Types of Metamorphosis
Incomplete Metamorphosis
1. Egg
2. Nymph – immature form of an adult
3. Adult – able to reproduce (wings)

29. Video Complete Metamorphosis 1. Egg 2. Larvae – catepillar stage
3. Pupa – cocoon protects the pupa
4. Adult – emerges from the pupa (butterfly)
Video

30. Defenses of Insects What ways do insects use defenses?
1. Stinger or bite – bee, wasp, ants
2. Camouflage – blend into their surroundings.
Ex. Grasshopper, praying manthesis
Video
3. Warning coloration – alert other animals that the insect might be poisonous.

31. Insect Behavior Division of Labor among Bees
1. Worker bee – female bees, most abundant. (8,000) - sterile
2. Drone – male bees (100)
3. Queen bee – the only fertile female
CHARACTERISTIS OF EACH BEE
Video

32. The worker bee produces royal jelly to feed the queen bee
The worker also secretes wax to make the hive.
The produces a pheromone called queen factor, which makes the other females sterile.
Round Dance – tells the other bees food is within 50 meters
Waggle Dance – tells the other bees food is greater than 50 meters.