1. Dissection of a Grasshopper

2. What is a grasshopper? A grasshopper is an arthropod. It has
Jointed appendages
A segmented body
An exoskeleton

3. Grasshopper Facts:
Country: Worldwide Habitat: meadows, fields, and hedges Length: up to 3 in. (8cm) but mostly 5/8 -1 1/8 in. (15-30 mm) Weight: almost nothing Closest relative: katydid and cricket

4. Why dissect a grasshopper?
To identify the external and internal anatomy of the grasshopper
To practice basic dissection skills

5. Explore this site to learn more about grasshoppers.

6. Get ready to learn more as we dissect a grasshopper!

7. Step One Identify the materials you will need for your dissection.
Dissection Tray
Hand lens

8. Materials, continued Ruler Scalpel Scissors Eye dropper
Dissection pins
Forceps (tweezers)

9. Materials, continued
Gloves
Goggles
And a grasshopper!

10. Study the external parts of the grasshopper

12. Step Two: Identify the Head Thorax Abdomen
Notice also the eyes, antennae, legs and wings

13. Skeleton
The grasshopper has a hard exoskeleton. That means its skeleton is located on the outside of its body, not internally like ours. This skeleton is made of chitin, a carbohydrate.

14. The head

15. A Frontal View of the head

16. The compound eye
The grasshopper has two compound eyes that are made up of hundreds of individual eyelets.

17. Observe the antennae
The grasshopper's head has two antennae that are able to feel and smell what is nearby.

18. The mouth
The mouthparts are a set of movable jaws that let the grasshopper chomp its way through grass blades.

19. The mouth Labrum - the broad upper lip Hypopharynx - the tongue
Mandibles - two heavy blackish jaws with teeth along the inner margin. The mandibles move up and down.
Maxillae - two smaller jaws that move side to side
Labium - the lower lip
Palp - maxillary and labial palps are sensory appendages

20. The thorax

21. The legs
Using huge hind legs, the grasshopper makes gigantic leaps into the air.
Long legs are an advantage for jumping, because they increase the distance over which the jumper can push off the ground

22. The legs, continued
When a grasshopper jumps, it first crouches down, there is then a short delay, and then off it goes.
Back leg- knee

23. The leg, continued
The two rear legs are specialized and strengthened for jumping, while the front two pairs are used only for walking on the ground

24. The Wings
The two pairs of grasshopper wings differ in shape, structure, and function. The hind pair are responsible for flight.

25. Close up of the wings
After its spring-assisted takeoff, it can unfurl its two pairs of wings and continue flying with them.

26. The abdomen
The hind region of the grasshopper’s body, the abdomen, consists of 11 segments.

27. The Abdomen
The abdomen is built up of a series of upper plates known as 'tergites' and lower plates known as 'sternites‘. It is held together by a tough yet stretchable membrane

28. Determine the sex of your grasshopper

29. Close up
Female
Male

30. Reproductive organs
Female

31. Reproductive organs
Male

32. Task
Draw a diagram of the external parts of the grasshopper. Label at least the following:
Head
Thorax
Abdomen
Compound eye
Antennae
Wings (forewing and hindwing)
Mouth

33. Step Three: Measure

34. Measure Be sure to record the length of your grasshopper.
Measure the grasshopper from the tip of the head to the end of the abdomen.
We will collect these measurements at the end of the dissection lab and compare!

35. Step Four: The Dissection begins:
Position the grasshopper dorsal side up
Carefully remove the protective sheath from the scalpel.
Hold the grasshopper firmly.

36. Cut along the dorsal surface of the thorax and abdomen

40. Gently pull the exoskeleton aside

43. You may wish to use the dissection pins to make viewing easier.

44. Using a hand lens, identify as many of the internal organs as possible

45. Digestive System These are the parts of the digestive system :
Mouth
Esophagus
Crop
Stomach
Intestine
Chewed food is stored in the crop, digested in the stomach, and absorbed in the intestine.

46. Observe the digestive system

47. A little closer

48. The crop, gizzard and digestive caecae
The digestive caecae produce enzymes which aid in digestion

49. Respiratory System
You will probably NOT be able to see the small holes. on the side of their bodies without your hand lens. These holes are called spiracles, each hole leads to a large tube called a trachea. The large tubes divide into small tubes that branch out to all the cells of the body. This system of tubes carries oxygen to the cells and takes away the carbon dioxide.

50. Respiratory System
Do you see anything in your grasshopper that resembles a lung?

51. Respiratory System
The grasshopper does not have a lung. How then does it breathe?
Air enters the spiracles and as the abdomen expands and contracts, fresh air moves in and used air moves out.
The air enters the cells directly and is not transferred to the blood- that’s why their blood is yellow, not red- it contains no hemoglobin!

52. Circulatory System
The grasshopper’s circulatory system is open- that means that it does have a “heart”, but the heart is more of a muscular tube that collects the blood and forces it to the front of the body. The blood freely flows throughout the grasshopper

53. The Nervous System
The grasshopper's brain is located between its eyes, above the esophagus.

54. Cool fact…
The grasshopper does not use its brain to walk or jump! It does that without a brain.
The brain is used to control the mouth and to send sensory information to the rest of the body.

55. Excretory System
There are a number of tubules between the large intestine and the stomach. The outer end enters into the body cavity and takes in the wastes. The wastes are carried into the large intestine and out through the anus.

56. Task
Draw a diagram of the internal organs you identified. Include at least the following:
Intestines
Crop
Reproductive organs

57. Be sure to: Properly dispose of your grasshopper
Remove the dissection pins.
Pick up the grasshopper and any organs that you may have removed. Discard them into the plastic bag provided.
Be sure to dump the remaining liquid in the jar as this is the last dissection.
Sanitize scalpels and pins, rulers and hand lenses and trays. Return them to the kit.
Wipe down lab tables and discard gloves.

58.
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