Earth Worm Dissection

Phillip Goldman PAP BIO VU period 4


1. Name and describe all of the organs of the earthworm.

Background Information.

The earthworm (also know as Tumbricus Terrestris), is a member of phylum Annelidia and class Clitellata. It has many niches but it is most commonly know to fertilize the soil by breaking down organic matter. One very interesting feature of earthworms are that they have segmented bodies with hairs called setae which help with locomotion (movement) through soil. Another adaption is that earthworms are able to split apart and still be alive to help them get away from predators and bury into the soil. The earthworms predators consist of birds, moles, salamanders and robins. The earthworm doesn't have much competition due to the fact that it feeds on organic matter which is plenty full. The earthworms play a vital role in the ecosystem and in fertilization.

Pictures of Earthworms

Functions of the Circulatory system

Intestine-Breaks down food

Ventral Vessel-blood moves through tubes called aortic arches

Aortic Arches-Tubes that keep blood flowing

Dorsal Vessel-Blood moves through tubes called aortic arches

anus-The opening of the intestine.

Circulatory system

Earth worms have a closed circulatory system; this means that there blood flows through blood vessels. The earthworms circulatory system relates very much to the human circulatory system.One thing that is very interesting about earth worms is that they use their body to absorb oxygen instead of lungs or gills. In order to get oxygen to certain areas of the worm, it uses its blood vessels to transport oxygen to the places in need. Oxygen is drawn in by the dorsal blood vessel. From there the oxygen travels to the aortic arches (aka hearts). Once the blood travels throughout,the aortic arches it than travels to the lower blood vessel called the ventral blood vessel. The ventral blood vessel pump oxygen to all of the extremities of the earthworms body. Finally smaller blood vessels divert blood back to the ventral blood vessel.

Interesting Facts

1-Earthworms can consume up to 1 half to 1 whole times their body weight.

2-Earthworms can regenerate lost parts of their body

3-Even though earth worms don't have eyes they can still sense light.

4-earth worms have been around at least half a billion years.

Human impact on Earthworms

Earth worms are especially useful in the agriculture industry because they loosen up the soil and cause it to be more nutrient rich. Earth worms are decomposes so, they break down all types of foods that can eventually lead to a more nutrient rich soil.
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Kingdom- animalia




genus- lumbricus

species- terrestrus