Earthworm External Anatomy

Entrance to the digestive tract of an earthworm. Locate the mouth of the worm on the far anterior end of the worm.

Worm Dissection 2014 Warning Stay Focused In This Lab Ppt

They are the common inhabitants of moist soil and feed on organic matter.

Earthworm external anatomy. Part of the digestive tract of an earthworm just after its mouth. They occur worldwide and are commonly found in soil eating live and dead organic matter. Lift up the skin with a pair of forceps and snip an opening with a pair of dissecting scissors.

This is because the worm casting fecal deposit increases the fertility and burrowing help in proper aeration of the soil. Start your dissection about an inch posterior to the clitellum. The very first section of the anterior contains the mouth and prostomium.

Insects sea stars spiders jellyfish and millipedes are other examples of invertebrate animals. The openings near the clitellum are the genital setae. What is the external anatomy of an earthworm.

Locate the clitellum which is on the anterior end of the worm. An earthworm with a well developed clitellum an earthworm is a tubular segmented worm of the phylum annelida. The anterior end is tapering while the posterior end is more or less blunt.

Earthworm anatomy external features. Large band of the earthworm close to anterior end secretes mucus for the cocoon that the eggs are in. An earthworms digestive system runs the length of its body.

The openings toward the anterior of the worm are the sperm ducts. Lay the worm on your dissecting tray with its dorsal side facing up. Internal anatomy of an earthworm lateral section.

Pores to receive sperm from another worm during copulation and later to release that sperm for fertilization of the eggs. Earthworm is elongated long narrow cylindrical or vermiform shaped. The skin of segments fourteenth fifteenth and sixteenth is swollen and pale in mature worms to form a saddle shaped structure called clitellum or cingulum.

The front or head of the worm is called the anterior. External morphology of earthworm. The external body of an earthworm is well adapted for living in the soil similar to the external structure of other insects.

The important external features are as follows. Earthworms are commonly called as farmers friend. Use dissection pins to secure each end on the tray.

Body consists of dorsal and ventral surfaces. Small long cylindrical animal without legs or hard body parts. External anatomy of earthworm.

Examine your earthworm and determine the dorsal and ventral sides. Insert the scissors into the opening and cut in a straight line all the way up through the mouth. The earthworms found in india are pheretima and lumbricus.

Study the illustration of an earthworm shown on the left. Every segment of the body excepting the clitellar and the first and last. That is they do not have a backbone.

You will notice that earthworms have long cylindrical body that is divided into similar segments. Set of nerves in the abdomen of an earthworm. It secretes the material for producing cocoons.

Ll Earthworm Dissection