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Lab report:

Earthworm dissection

Makhmudova Nadira G

Partner: Babamukhamedova Shakhnoza

Earthworm dissection

Introduction:

Earthworms are ideal specimens to use for teaching basic anatomy and investigating simple organ systems. Although these annelids, or segmented worms, are one of the simpler preserved invertebrates, the digestive, circulatory, reproductive and nervous systems are well developed and easy to identify.

Procedure:

● Earthworm ● Pins ● Scalpel ● Forceps ● Alcohol (for euthanasia) ● Magnifying glass Procedures:

1. Find the anterior (front) end of the earthworm by locating the fleshy bump over its mouth, called the prostomium. The posterior (back) end has a small hole where solid waste is expelled, called the anus. The length of the worm is made up of many tiny segments, each separated by a thin wall called a septum.
2. About one-third of the way back from the mouth you should see a thicker and smoother section of the worm. This is called the clitellum, and it is involved in reproduction.
3. Notice that the earthworm has a rounded dorsal (back) surface and a flatter ventral (belly) surface. Usually the dorsal surface is darker than the ventral surface (though sometimes this is obscured in the preservation process). Lightly rub your finger along the ventral side toward the posterior end of the worm. You should feel a roughness caused by tiny bristles called setae.
4. With your magnifying glass look for tiny pores on each segment. Liquid wastes are expelled through these pores. Near the front end of the worm you should see some larger pores that can be easily seen without magnification. These are genital pores and are important in reproduction. Earthworm Dissection: Internal Anatomy
5. Lay the worm with its dorsal side facing up. Start your dissection about an inch posterior to the Go slowly and be sure to cut just the skin—if you go too deep you may damage the internal organs.
6. Using the forceps and dissecting pins, carefully pull apart the two flaps of skin and pin them

animals. We learned the anatomy of earthworms. To sum up, the experiment was conducted successfully