Story of an Earthworm

Jennifer Dong Earthworm Dissection April 1, 2014 GUZMAN-P7

This Lesson’s Objectives:

Students will be familiarized with the internal and external structure of an earthworm. Students will gain in depth knowledge about the structures and function of each organ in the digestive and circulatory systems. Furthermore, students will gain insight into the ecological aspects surrounding the unique earthworm.

Unique Ecological Adaptations

The earthworm has a prostomium on the anterior end that helps the earthworm push through the soil. A coating of mucus allows oxygen to enter the earthworm’s skin. Another adaptation that helps the movement of the organism includes its thin, streamlined shape. The muscular pharynx and gizzard are necessary adaptations that assist the earthworm in consuming the contents in soil. Moreover, earthworms breathe by diffusing oxygen and carbon dioxide across their skin. Since this process only takes place under moist conditions, earthworms have developed the behavioral adaptation to come to the top of the soil at night or when it rains to take advantage of the damp air.

Evolutionary Relationships of an Earthworm

The Soil-Friendly Digestive System

First, soil, plant material, and animal remains enter the earthworm’s mouth with the help of the pharynx. Then, the contraction of the muscular gizzard crushes the food, which travels to the intestines. After the intestine properly digests and absorbs the essential nutrients, the excretory system is responsible for excreting the waste.

Taxonomy Breakdown


PHYLUM: Annelid

CLASS: Oligochaeta

ORDER: Opisthopora

FAMILY: Lumbricidae

GENUS: Lumbricus

SPECIES: terrestris or rubella

Bonus Fun Facts

Did you know...

*There are more than 6,000 species of earthworms.

*Earthworms lack respiratory organs, so they breathe through their skin.

*60 of the 180 species in U.S. an Canada are invasive species brought from Europe.

*The earthworm commonly found in gardens is known as the night crawler.

*Earth worms produce both eggs and sperm but still mate with each other.

Earthworm Dissection

Human Impact

The natural habitat of earthworms are becoming more and more unsuitable for these creature as farmers treat the soil with synthetic chemical fertilizers. Moreover, when farmers plow the fields, earthworms are being killed in the process. Furthermore, pesticides intended to kill other organisms eradicate earthworms as well. This results in the reduction of the quality of the soil since earthworms are no longer available to aerate and provide nitrogen for the soil.

On a more positive note, others have taken to earthworm farming--the raising of earthworms. The earthworm provides the owners with rich fertile soil, therefore both the earthworm and the farmer benefits.


Barrows, Preston. "How Chemical Fertilizers and Pesticides Affect Earthworm and Soil Health." Yahoo Contributor Network. N.p., 11 Aug. 2011. Web. 07 Apr. 2014. <>.

Baxamusa, Batul Nafisa. "Earthworm Digestive System.", 23 Sept. 2011. Web. 07 Apr. 2014.


Bove, Fred. "How To Build a Worm Farm - Modern Farmer." Modern Farmer. N.p., 23 May 2013. Web. 07 Apr. 2014.


Holcomb, Karen. "Niche of an Earthworm." EHow. Demand Media, 14 Apr. 2010. Web. 07 Apr. 2014.


Painter, Theresa. "Earthworm." Earthworm. FCPS, n.d. Web. 07 Apr. 2014. <>.

Palmer, G.D. "Predators of the Earthworm." EHow. Demand Media, 05 Aug. 2010. Web. 07 Apr. 2014.


Shmoop Editorial Team. "Genetics - Shmoop Biology." Shmoop University, Inc., 11 Nov. 2008. Web. 07 Apr. 2014.


Steffan, Rachel. "Environmental Adaptations in Earthworms." EHow. Demand Media, 22 Apr. 2011. Web. 07 Apr. 2014.


The University of Waikato. "Niches within Earthworms' Habitat." Science Learning Hub RSS. N.p., 31 May 2012. Web. 07 Apr. 2014.