Story of an Earthworm
Jennifer Dong Earthworm Dissection April 1, 2014 GUZMAN-P7
This Lesson’s Objectives:
An Earthworm’s Daily Environment
The earthworm’s scientific name is the Lumbricus terrestris. Earthworm habitats are much more complicated than just being the soil. Earthworms’ prefer places that are not too dry or too cold, and they are usually found in fertile soil. For instance most earthworms are found in lawns, gardens, and pastures. Earthworms that live in the soil can be epigeic, which means the live on the soil’s surface; endogeic, which means they live in the topsoil; or anecic, which means they live deep under the soil. The most unusual habitats earthworms are found in would be underwater and on the branches of trees.
Who Consumes Earthworms?
The Important Ecological Niche of the Earthworm
Earthworms provide the soil with natural means of aeration. The burrows they create in the soil act similar to irrigation tunnels for both oxygen and water. Plants are benefitted by these tunnels since this allows their roots to access vital resources. Moreover, earthworms decompose organic plant and animal matter, which releases nitrogen that is essential for plant growth. Earthworms are a popular meal among a wide variety of predators but the earthworms itself does not prey on animals. They only break down animal remains once they are no longer living.
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
Earthworm Specimen
Dissecting Earthworm
Finished Dissection of 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
KINGDOM: Animal
PHYLUM: Annelid
CLASS: Oligochaeta
ORDER: Opisthopora
FAMILY: Lumbricidae
GENUS: Lumbricus
SPECIES: terrestris or rubella
Bonus Fun Facts
*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.
Human Impact
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.
Citations:
Barrows, Preston. "How Chemical Fertilizers and Pesticides Affect Earthworm and Soil Health." Yahoo Contributor Network. N.p., 11 Aug. 2011. Web. 07 Apr. 2014. <http://voices.yahoo.com/how-chemical-fertilizers-pesticides-affect-earthworm-8894083.html?cat=32>.
Baxamusa, Batul Nafisa. "Earthworm Digestive System." Buzzle.com. Buzzle.com, 23 Sept. 2011. Web. 07 Apr. 2014.
<http://www.buzzle.com/articles/earthworm-digestive-system.html>.
Bove, Fred. "How To Build a Worm Farm - Modern Farmer." Modern Farmer. N.p., 23 May 2013. Web. 07 Apr. 2014.
<http://modernfarmer.com/2013/05/how-to-build-a-worm-farm/>.
Holcomb, Karen. "Niche of an Earthworm." EHow. Demand Media, 14 Apr. 2010. Web. 07 Apr. 2014.
<http://www.ehow.com/about_6321468_niche-earthworm.html>.
Painter, Theresa. "Earthworm." Earthworm. FCPS, n.d. Web. 07 Apr. 2014. <http://www.fcps.edu/islandcreekes/ecology/earthworm.htm>.
Palmer, G.D. "Predators of the Earthworm." EHow. Demand Media, 05 Aug. 2010. Web. 07 Apr. 2014.
<http://www.ehow.com/list_6820604_predators-earthworm.html>.
Shmoop Editorial Team. "Genetics - Shmoop Biology." Shmoop.com. Shmoop University, Inc., 11 Nov. 2008. Web. 07 Apr. 2014.
<http://www.shmoop.com/taxonomy/genetics.html>.
Steffan, Rachel. "Environmental Adaptations in Earthworms." EHow. Demand Media, 22 Apr. 2011. Web. 07 Apr. 2014.
<http://www.ehow.com/info_8281134_environmental-adaptations-earthworms.html>.
The University of Waikato. "Niches within Earthworms' Habitat." Science Learning Hub RSS. N.p., 31 May 2012. Web. 07 Apr. 2014.
<http://www.sciencelearn.org.nz/Science-Stories/Earthworms/Niches-within-earthworms-habitat>.
http://ecowatch.com/2014/03/08/10-facts-about-earthworms/
http://bio1152.nicerweb.com/Locked/media/ch41/digestive_systems.html
http://www.keywordpicture.com/keyword/lumbricus%20terrestris%20anatomy/
https://www.youtube.com/watch?v=8p-GAX4Xb2A
http://www.worm-farming.com/save-the-planet.html
https://www.naturewatch.ca/english/wormwatch/virtual_worm/Digestion.htm
http://www.sciencelearn.org.nz/Science-Stories/Earthworms/Earthworm-adaptations