Name Class Date
Ecology Activity: Spider Anatomy
Background Information: Spiders are very successful predators and therefore play a very important role in keeping the balance of an ecosystem in place. Over many years of evolution the spider has evolved to meet the needs of its niche in the environment. Looking closely at the anatomy of a spider helps scientists to identify different species and better understand how spiders fulfill their role in the ecosystem. The spider’s body consists of a cephalothorax, covered by a carapace (shield), and an abdomen (spider size is measured along the body length, not leg span). Four pairs of legs are attached to the cephalothorax and each leg ends in either two or three claws. Spiders have from 2 to eight eyes depending on the species. Spiders also have spinnerets and pedipalps. When looking at anatomy of spiders it is important to look at details of the specimen. (i.e. shape and size of each of the body parts; body color, covering, and markings; size, number, and location of eyes; leg length and color and covering; shape, size and visibility of spinnerets, jaws, and pedipalps.)
Materials: Spider specimens, spider microscope slides, microscope, hand lens, stereoscope, reference books, computer, websites in shared folder under Ecology, pencil.
Procedure: Part 1: Observation with hand lens and/or stereoscope.
1. Choose a spider specimen from the class collection. Referred to as your specimen.
Record specimen name (Genus, species and common name): Genus Species Common name
2. Use the hand lens and the stereoscope to observe your specimen.
3. Use the two spider specimens, along with class reference books, observation tools, and recommended websites (in shared folder), to answer the following questions.
Part 1 Questions
1. Write a detailed description of your spider specimen.
2. What is the function of the cephalothorax?
a. Describe the cephalothorax of your specimen
3. What is the function of the abdomen?
a. Describe the abdomen of your specimen
4. Define and describe the function of the following:
a. Eyes:
i. Describe the eyes of your specimen
b. Legs:
i. Describe the legs of your specimen
c. Jaws:
i. Describe the jaws of your specimen
d. Spinnerets:
i. Describe the spinnerets of your specimen
e. Pedipalps:
i. Describe the pedipalps of your specimen
Procedure Part 2: Observation with a Microscope
1. Select a prepared microscope slide of a spider.
Record slide name (Genus, species and common name): Genus Species Common name
2. Place your spider slide on the microscope.
3. Focus under low power and center the spider in the field of view.
4. Switch to the highest power that allows you to view the entire spider.
5. Record your total magnification here:
6. In the space below, draw a detailed scientific drawing of the spider specimen on your slide. Remember to use your field of view to help with the accuracy of your drawing.
7. If the field of view is 10mm across, what is the approximate size of your spider? Mm
8. Describe any similarities between your spider specimen and the spider slide.
9. Describe any differences between your spider specimen and the spider slide.
Part 3: Review the information you collected in this activity and rewrite a detailed description of your spider specimen (the one in the tube, not the microscope slide).
Conclusion: Look at the first detailed description of your spider specimen and the second detailed description you just wrote above. Discuss how your rewrite is different from your first description. Also discuss how you could improve your work if you were responsible for identifying many different types of spiders.
4