Earthworms External Anatomy

Locate the mouth of the worm on the far anterior end of the worm the openings toward the anterior of the worm are the sperm ducts the openings near the clitellum are the genital setae. You will notice that earthworms have long cylindrical body that is divided into similar segments.

Earthworm General Characters External Morphology Setae

Place the specimen in the dissecting pan.

Earthworms external anatomy. The light colored tissue above and around the hearts are seminal vesicles. Nitrogenous fertilizers tend to create acidic conditions which are fatal to the worms and dead specimens are often found on the surface following the application of substances such as ddt lime sulphur and lead arsenate. Insects sea stars spiders jellyfish and millipedes are other examples of invertebrate animals.

Be careful not to damage the internal organs. The earthworms found in india are pheretima and lumbricus. The very first section of the anterior contains the mouth and prostomium.

The diagram given below represents the morphological features of an earthworm. The external body of an earthworm is well adapted for living in the soil similar to the external structure of other insects. Locate the dark line that runs down the dorsal side of the worm.

Large band of the earthworm close to anterior end secretes mucus for the cocoon that the eggs are in. Study the illustration of an earthworm shown on the left. All the way up to the head.

As a bonus site members have access to a banner ad free version of the site with print friendly pages. 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. Try to keep the scissors pointed up and only cut through the skin.

Label them on the worm pictured to the right. What is the external anatomy of an earthworm. Earthworms have many internal parasites including protozoa platyhelminthes and nematodes.

Label earthworm external anatomy diagram printout. External anatomy of earthworm. It secretes the material for producing cocoons.

The front or head of the worm is called the anterior. The morphology and anatomy of the earthworm are discussed below. Pores to receive sperm from another worm during copulation and later to release that sperm for fertilization of the eggs.

Other reproductive parts appear as small white organs on the ventral side of the hearts. Earthworms have a tube like arrangement or cylindrical shaped and reddish brown segmented body. That is they do not have a backbone.

Locate the clitellum and insert the tip of the scissors about 3 cm behind the clitellum. They can be found in the worms blood seminal vesicles coelom or intestine or in their cocoons. A fleshy lobe the prostcmium projects over the mouth in front of the first segment.

Earthworm anatomy external features.

Earthworm Dissection Print Out Sheet 1 Earthworm