Slippery And Slimy Dissection

Earthworm Dissection Lab

Michael Flora

Pap Bio

Period 2

Mitcham

Objectives

1. Name the organs of an Earthworm.

2. Describe the appearance of various organs in the Earthworm.

Background Information

The earthworm, Lumbricus Terrestris, is a member of the phylum Annelida. The predators of an Earthworm are birds, robins, and moles. The niche of an earthworm is to break down dead organic matter to fertilize the soil. An earthworm have segments on their bodies that have hairs called setae which provide grip to move through the soil. Another adaptation is being sensitive to vibrations and touch to stay away from predators. An earthworm is well-adapted to a life of burrowing through the soil. Here is a picture of an earthworm in its habitat below.
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Circulatory System

The circulatory system of an earthworm is much like the circulatory system of most mammals. Earthworms have a closed circulatory system. This means that their blood flows through blood vessels. Earthworms use their bodies to absorb oxygen through their skin. They get this oxygen from the soil in which they live. Their blood vessels actually help to process oxygen for them. How does this work? Oxygen is drawn in by the dorsal blood vessel. From there it travels to the five different hearts that the earthworm has. These five hearts are called aortic arches. Once it passes through the aortic arches it travels to the lower blood vessel, called the ventral blood vessel. This blood vessel pumps oxygen all over the earthworms' body. In each portion of the earthworm there are smaller blood vessesls that help to divert blood flow back to the dorsal blood vessel. This final process completes the circulatory loop of the earthworm.
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Functions Of Circulatory Organs

Intestine: Breaks down food and blood circulating absorbs it.

Anus: The opening of the intestine.

Aortic Arches: Tubes that keep blood flowing.

Ventral Vessel: blood moves through to tubes called aortic arches.

Dorsal Vessel: Blood moves through to tubes called aortic arches.

Interesting facts!!!

1. There are around 6,000 species of earthworms.

2. Earthworms breathe through their skin.

3. There is a disease called Guinea Worm disease or also called Dracunculiasis; There is a link below to more information on this disease.

4. The largest worm in the world can grow up to 3 meters in length that lives in Australia.

5. Charles darwin thought of worms as "The intenstines of the Earth."