Download Upper Merion Area High School

Upper Merion Area High School
Biology
Name_____________________________
Lumbrius terrestrius
Background- What is an annelid, describe its specific characteristics
Purpose- Why are we doing this lab?
Materials/Method
1. What tools and materials are needed for this lab?
2. Look at the external features of the earthworm; draw a sketch of the animal. Label the
anterior, posterior, mouth, anus, clitellum, and segments.
3. How do you know which is the anterior?
4. Turn the earthworm over so that the dark, rounded, dorsal side is up. Move your finger over
the ventral side to feel the setae. What are the setae?
5a. Pin the earthworm to tray just posterior to the clitellum.
b. Make a shallow incision longitudinally from the pined point to the mouth. Make your incision
slightly to one side of the dorsal blood vessel. Notice the thin cuticle as you cut.
c. Make two more incisions along the original incision at a transverse angle to cut through the
peritoneum.
d. Pin the body walls back, may need to make further incisions in the peritoneum to release the
body wall.
e. Sketch the mouth, pharynx, esophagus, crop, gizzard, intestine, seminal vesicles (three pairs
of large white structure) and anterior to the vesicles the two pairs of smaller seminal receptacles, dorsal
blood vessel, aortic arches.
6. Observations/Conclusions (all should be in report)
a. What is the route of food through the earthworm?
b. What does the earthworm use for food?
b. Does the earthworm have a respiratory system, how do gases move in/out of the
organism?
c. What is the habitat?
d. What is the niche of the earthworm?
e. What is segmentation?
f. Which are structures of the circulatory system?
g. Which are structures of the digestive system?
h. Which are structures of the reproductive system?