How to Dissect a Worm
Put the worm in a bowl of 50% alcohol., Feel for bristles on the body., Attach a pin to each end of the worm., Look for the clitellum., Poke a hole above the wide band on the shorter end of the body., Cut through the skin from one end to another...
Step-by-Step Guide
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Step 1: Put the worm in a bowl of 50% alcohol.
The alcohol causes the body and the muscles to relax.
Without that, the worm will most likely be stiff and not as long as you'd like, making for a harder time dissecting.If the worm is already dead, make sure the body is still soft and flexible.
Immediately place it in alcohol to preserve the body.
Earthworm bodies begin to dry and shrivel quickly after death.For this reason, you should have a container of rubbing alcohol with you when you search for the worm.
After a few minutes, remove the worm and lightly pat it dry with a paper towel. -
Step 2: Feel for bristles on the body.
Turn that side of the body down, facing the surface of the tray.
The smoother side should face upward, towards you. , This way, you'll avoid accidentally moving it around during the process.
Put in the pin as close as to the end as you can without tearing the worm.
Then stretch the worm taut and put a pin in the other end., This is the large band that runs around the body of the worm.
Place the end of your knife closer to the clitellum in the direction that you plan to begin cutting.
This end contains many of the organs you will have to identify first., This is a good starting point, since that's where the most important organs are. , Do this carefully, keeping your cut shallow.
If you go too deep, you could damage the organs. , Do this for both sides of the worm.
Pull back the skin until you can easily see the insides.
Make sure to do so slowly and carefully to avoid tearing the skin. , This is to keep the skin from receding back into the body when you're examining it.
Make sure not to stretch the skin out too much in order to avoid tearing it. , Focus on the upper end of the body first.
Gently place the organs to the side so as to not obstruct your examination of the other parts of the body. , Compare them to a diagram of an earthworm.
You will likely be required to recognize the parts of the digestive system, which can be identified as a series of small and large bulges separated by narrow indentations., The mouth is located at the end of the worm closer to the clitellum.
It is the beginning of the digestive system, where food enters the body. , This is a collection of muscles that suck in food.
Below the thin tube that extends from the mouth is a noticeable bulge.
This is the pharynx. , The esophagus is the tube where the food passes through from the mouth to the crop.
This organ is the tapered area located immediately below the pharynx. , After food leaves the esophagus, it is temporarily stored in the crop.
The crop is another bulge, wider than the pharynx, located directly below the esophagus. , This organ grinds the food down completely.
It is the next large bulge of the digestive system.
You can find it directly below the crop. , The intestine, the bulge directly below the gizzard, performs much of the digestion.
In this organ, nutrients are absorbed into the blood stream, while waste products are pushed downward toward the anus. , This is the end of the digestive system where excrement leaves the worm.
It is located at the other end of the worm's body. , Each pin should be removed carefully one at a time.
Place the pins in a cup or tray.
Move them to a location where they will not be knocked over. , Do this when you have finished inspecting the organs and taking notes.
Because dissected bodies are not considered hazardous waste, they may be placed in the regular landfill trash., Disinfect your tools with rubbing alcohol.
Wash your hands with soap and warm water.
Thoroughly remove any blood or other remnants of the body from your workspace. -
Step 3: Attach a pin to each end of the worm.
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Step 4: Look for the clitellum.
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Step 5: Poke a hole above the wide band on the shorter end of the body.
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Step 6: Cut through the skin from one end to another.
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Step 7: Pull the skin back gently with the forceps.
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Step 8: Pin the dissecting needles in the skin.
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Step 9: Remove the organs with the forceps.
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Step 10: Examine the organs with the magnifying glass.
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Step 11: Identify the mouth.
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Step 12: Identify the pharynx.
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Step 13: Identify the esophagus.
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Step 14: Identify the crop.
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Step 15: Identify the gizzard.
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Step 16: Identify the intestine.
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Step 17: Identify the anus.
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Step 18: Remove the pins.
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Step 19: Dispose of the worm.
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Step 20: Clean up.
Detailed Guide
The alcohol causes the body and the muscles to relax.
Without that, the worm will most likely be stiff and not as long as you'd like, making for a harder time dissecting.If the worm is already dead, make sure the body is still soft and flexible.
Immediately place it in alcohol to preserve the body.
Earthworm bodies begin to dry and shrivel quickly after death.For this reason, you should have a container of rubbing alcohol with you when you search for the worm.
After a few minutes, remove the worm and lightly pat it dry with a paper towel.
Turn that side of the body down, facing the surface of the tray.
The smoother side should face upward, towards you. , This way, you'll avoid accidentally moving it around during the process.
Put in the pin as close as to the end as you can without tearing the worm.
Then stretch the worm taut and put a pin in the other end., This is the large band that runs around the body of the worm.
Place the end of your knife closer to the clitellum in the direction that you plan to begin cutting.
This end contains many of the organs you will have to identify first., This is a good starting point, since that's where the most important organs are. , Do this carefully, keeping your cut shallow.
If you go too deep, you could damage the organs. , Do this for both sides of the worm.
Pull back the skin until you can easily see the insides.
Make sure to do so slowly and carefully to avoid tearing the skin. , This is to keep the skin from receding back into the body when you're examining it.
Make sure not to stretch the skin out too much in order to avoid tearing it. , Focus on the upper end of the body first.
Gently place the organs to the side so as to not obstruct your examination of the other parts of the body. , Compare them to a diagram of an earthworm.
You will likely be required to recognize the parts of the digestive system, which can be identified as a series of small and large bulges separated by narrow indentations., The mouth is located at the end of the worm closer to the clitellum.
It is the beginning of the digestive system, where food enters the body. , This is a collection of muscles that suck in food.
Below the thin tube that extends from the mouth is a noticeable bulge.
This is the pharynx. , The esophagus is the tube where the food passes through from the mouth to the crop.
This organ is the tapered area located immediately below the pharynx. , After food leaves the esophagus, it is temporarily stored in the crop.
The crop is another bulge, wider than the pharynx, located directly below the esophagus. , This organ grinds the food down completely.
It is the next large bulge of the digestive system.
You can find it directly below the crop. , The intestine, the bulge directly below the gizzard, performs much of the digestion.
In this organ, nutrients are absorbed into the blood stream, while waste products are pushed downward toward the anus. , This is the end of the digestive system where excrement leaves the worm.
It is located at the other end of the worm's body. , Each pin should be removed carefully one at a time.
Place the pins in a cup or tray.
Move them to a location where they will not be knocked over. , Do this when you have finished inspecting the organs and taking notes.
Because dissected bodies are not considered hazardous waste, they may be placed in the regular landfill trash., Disinfect your tools with rubbing alcohol.
Wash your hands with soap and warm water.
Thoroughly remove any blood or other remnants of the body from your workspace.
About the Author
Janet Sanchez
Professional writer focused on creating easy-to-follow hobbies tutorials.
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