An Earthworm Epidemic!
Objectives:
- To explore the functions and locations of structures in earthworms, focusing on the digestive system.
- To understand the roles of earthworms in their environments.
- To exercise the dissection skills of students and their ability with lab equipment.
Taxonomy of the earthworm:
- Kingdom: Animalia
- Phylum: Anelida
- Class: Clitellata
- Subclass: Oligochaeta
- Order: Opisthopora
- Family: Lumbricidae
- Genus: Lumbricus
- Species: Terrestris
Background Information:
The earthworm, or Lumbricus terrestris, is a member of the Annelida phylum, meaning that it is a segmented worm. Earthworms are invertebrates. Earthworms like to live in moist soils containing dead organic matter. Earthworms do not have eyes or ears, however they have adapted to become extremely sensitive to temperature, light, and touch. These adaptations allow the earthworm to survive when the climates change; during winter, when it is cold, the worm tunnels further down into the soil. When it is night, the earthworm comes up to the surface of the soil. As the earthworm tunnels through the soil, it eats the dead matter within it, and releases wastes which replenish the soil and are beneficial to much plant growth. Earthworms play a large role as decomposers in the soil, breaking down all decaying matter. Being an annelid (from phylium Annelida), the earthworm body is made of segments called annuli. Each earthworm can have up to 150 separate annuli stretching its body for up to 35 cm in length. The annuli on an earthworm are covered with small bristles called setae, which are an important adaptation for motion and aid the worm in tunneling through the soil. Earthworms are hermaphrodites. This means they have both the male and female reproductive organs, however the earthworm cannot self-fertilize. Two worms join over the clitellum, in which they deposit their sperm and egg cells in a protective layer, which is buried in the soil, and then hatches a few weeks later. This is another example of an adaptation. By storing the sperm and egg in a protective layer, the worms decrease the chance that the egg will be damaged or hurt.
Earthworms feed on decaying matter, and are fed on my many different animals, such as birds, rats, toads, and many more.
Earthworms are native to Europe, however they have found themselves all over the planet, primarily because of their essential adaptations.
The earthworm, or Lumbricus terrestris, is a member of the Annelida phylum, meaning that it is a segmented worm. Earthworms are invertebrates. Earthworms like to live in moist soils containing dead organic matter. Earthworms do not have eyes or ears, however they have adapted to become extremely sensitive to temperature, light, and touch. These adaptations allow the earthworm to survive when the climates change; during winter, when it is cold, the worm tunnels further down into the soil. When it is night, the earthworm comes up to the surface of the soil. As the earthworm tunnels through the soil, it eats the dead matter within it, and releases wastes which replenish the soil and are beneficial to much plant growth. Earthworms play a large role as decomposers in the soil, breaking down all decaying matter. Being an annelid (from phylium Annelida), the earthworm body is made of segments called annuli. Each earthworm can have up to 150 separate annuli stretching its body for up to 35 cm in length. The annuli on an earthworm are covered with small bristles called setae, which are an important adaptation for motion and aid the worm in tunneling through the soil. Earthworms are hermaphrodites. This means they have both the male and female reproductive organs, however the earthworm cannot self-fertilize. Two worms join over the clitellum, in which they deposit their sperm and egg cells in a protective layer, which is buried in the soil, and then hatches a few weeks later. This is another example of an adaptation. By storing the sperm and egg in a protective layer, the worms decrease the chance that the egg will be damaged or hurt.
Earthworms feed on decaying matter, and are fed on my many different animals, such as birds, rats, toads, and many more.
Earthworms are native to Europe, however they have found themselves all over the planet, primarily because of their essential adaptations.
Human Impacts:
Throughout the years, humans have been using earthworms as a means of decomposing garden material in compost bins. They place garden trash or dead plants into the bin, place in the worms, and as the worms replenish and decompose the soil, the once dead leaves and plants will be transformed into rich healthy soil, perfect for the garden again. Another use of worms by humans is for fishing. Fishers hook worms to their hooks as bait for fish. |
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The Digestive System:
First off, the digestive system in the earthworm is responsible for taking in soil and other dead matter, digesting it so that the worm absorbs its needed nutrients, and then transporting it to the anus where it is released. The digestive system consists of the following organs:
First off, the digestive system in the earthworm is responsible for taking in soil and other dead matter, digesting it so that the worm absorbs its needed nutrients, and then transporting it to the anus where it is released. The digestive system consists of the following organs:
- The Mouth
- The Pharynx
- The Esophagus
- The Crop
- The Gizzard
- The Intestine
- The Anus
Fun Facts!
- There are about 2700 different kinds of earthworms.
- In one acre of land, there can be more than 1 MILLION earthworms.
- The largest earthworm was found in South Africa and measure 22 feet from tip to tail.
- Charles Darwin spent 39 years studying worms.
- Worms are cold blooded.
- Earthworms have the ability to replace or replicate lost segments.
- If a worm's skin dries out, it will die.
- Worms eat their own weight each day!
Works Cited:
http://www.naturephoto-cz.com/photos/others/common-earthworm-77003.jpg
http://powerman486.tripod.com/info.html
http://animals.nationalgeographic.com/animals/invertebrates/earthworm/
http://www.edupic.net/Images/Science/earthworm01.JPG
http://www.ecoyardfarming.com/wp-content/uploads/2008/01/wormbintop2.jpg
http://www.sas.upenn.edu/~jbryson/webpics/SBPfoodwebWords.jpg
http://www.enchantedlearning.com/subjects/invertebrates/earthworm/Earthwormcoloring.shtml
http://media1.shmoop.com/images/biology/biobook_taxonomy_graphik_14.png
http://www.buzzle.com/articles/earthworm-digestive-system.html
http://www.sas.upenn.edu/~rlenet/digestion.gif
http://www.biologycorner.com/resources/OLIG001B_colored.gif
http://urbanext.illinois.edu/worms/facts/
http://www.naturephoto-cz.com/photos/others/common-earthworm-77003.jpg
http://powerman486.tripod.com/info.html
http://animals.nationalgeographic.com/animals/invertebrates/earthworm/
http://www.edupic.net/Images/Science/earthworm01.JPG
http://www.ecoyardfarming.com/wp-content/uploads/2008/01/wormbintop2.jpg
http://www.sas.upenn.edu/~jbryson/webpics/SBPfoodwebWords.jpg
http://www.enchantedlearning.com/subjects/invertebrates/earthworm/Earthwormcoloring.shtml
http://media1.shmoop.com/images/biology/biobook_taxonomy_graphik_14.png
http://www.buzzle.com/articles/earthworm-digestive-system.html
http://www.sas.upenn.edu/~rlenet/digestion.gif
http://www.biologycorner.com/resources/OLIG001B_colored.gif
http://urbanext.illinois.edu/worms/facts/