Earthworm - Dissection

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WILLIE's FINAL HOURS

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Patient #001883: Wiggle, Willie

Specimen: Earthworm

Height: 11 in

Eye color: N/A

Weight: 1.4 oz

Ethnicity: Lumbricina

Biography: Earthworms are found on nearly every continent on Earth. They live in the soil, and a lot of species are actually invasive. They breathe through the pores in their skin. Since earthworms are decomposers, they eat decomposing materials in their environment. This could be rotting leaves or even other animals. They can also eat fungi and bacteria. They are a very important part of the environment they live in. In south America, they can stretch up to 10 feet long!

REFER TO THE INFORMATIONAL DISSECTION VIDEO AT THE BOTTOM IF KNOWING HOW TO DISSECT THIS ORGANISM IS DESIRED. THE VIDEO CONTAINS A DETAILED VISUAL AND VOICEOVER.

DISSECTION INSTRUCTIONS

Place the earthworm on the tray so that the flatter side (ventral) is facing up. Carefully, using a scalpel, cut down the middle of the earthworm. As you cut, pin down the skin of the earthworm so you can see the internal parts of it. Make sure you don't press down too hard with the scalpel or you will destroy all of the internal organs of the earthworm.

INFORMATIONAL DISSECTION VIDEO ABOVE 

EXTERNAL PARTS

Mouth: a muscular part of the body used to eat -  no teeth

Segmented body: acts as a barrier to the outside world

Clitellum: is involved in reproduction of the organism 

Anus: excretes waste 

 

 

INTERNAL ORGANS

 

Pharynx: muscle to suck in food

Esophagus: place where food passes through muscular contractions

Heart: pumps blood through the body

Gizzard: food is ground here to smaller bits by muscular contractions that rubs the food together

Dorsal Blood Vessel: blood is carried through the body in this tube

Intestine: food is chemically broken down by enzymes here

 

www.learner.org/jnorth/tm/worm/WormLife.html