Earthworm Eager
Earthworm Dissection Virtual Lab by: Tina Liu Vu-PAP Bio-4
OBJECTIVES
Lumbricus terrestris - The general information
Where do earthworms live? The general habitat of an earthworm is in the soil. However, depending on which species of earthworm, earthworms also live in decaying plant matter and manue, decaying logs, mud, aquatic and euryhaline habitats, and littoral habitats.
What adaptations do earthworms have that help them survive? Each segment on an earthworm’s body has setae, which are hairs that provide grip to help the earthworm move through the soil. An earthworm also has adapted to have a streamlined body with no antennae, fins, arms, or legs. This shape allows easy passage through narrow burrows underground through soil. The circular muscles around each body segment also work together to help the earthworm move. Many earthworms also secrete a mucus that helps them slide through the soil more easily.
Earthworms: Eat or Enemies?
Predators
Common Food Web
Prey
Evolutionary relationship of an earthworm (cladogram)
External earthworm
Setae - hairs on the body
Clitellum - a thickened portion that produces slime during mating
Anus - place of excretion
Internal Earthworm - part 1
Seminal receptacles - stores and receives the sperm from other worms
Crop - connected to the esophagus
Gizzard - acts as the stomach
Internal Earthworm - part 2
Intestine - digests the food
Dorsal blood vessel - moves the blood forward to the anterior end
Digestion System
Food enters the mouth and is followed by the pharynx, where enzymes and mucus aid the food to pass through the esophagus. The food is then stored in the crop until it can be emulsified in the gizzard with the aid of soil particles. Then follows the long track of intestines through the worm while the nutrients are continued to be absorbed. Finally, the undigested food and unnecessary nutrients leaves through the anus. The digestive system provides the necessary nutrients and energy so the body of the earthworm can continue functioning.
Map of the native earthworms in the United States
FUN FACT
There are over 6,000 species of earthworms worldwide.
Of the 180 species of earthworms in the United States and Canada, 60 are invasive.
Earthworms breath through their skin.
Baby earthworms emerge fully formed.
Human Impact
Human activity spread invasive species when fisherman dump live bait and garderners use living worms near forests as compost. These earthworms eventually lead to huge environmental changes by destroying the understory plants that native species depend on.
Works cited
http://www.fcps.edu/islandcreekes/ecology/earthworm.htm
http://www.sciencelearn.org.nz/Science-Stories/Earthworms/Earthworm-adaptations
http://upload.wikimedia.org/wikipedia/commons/4/49/Turdus_migratorius_with_worms_1.jpg
http://www.field-studies-council.org/breathingplaces/images/minibeasts/FOODWEB.gif
http://www.omafra.gov.on.ca/english/engineer/facts/10-009f1.jpg
http://www.connecticutvalleybiological.com/images/ch7503.jpg
http://crescentok.com/staff/jaskew/isr/biology/eworm1.gif
http://www.smithlifescience.com/comparativeanatomy.htm
http://faculty.southwest.tn.edu/jiwilliams/earthworm1.gif
http://www.biologyjunction.com/images/earthw4.jpg
http://www.bumblebee.org/invertebrates/images/earthworm.jpg
http://www.biologycorner.com/resources/OLIG001B_colored.gif
http://www.wired.com/2014/03/absurd-creature-week-earthworm-backup/
http://ecowatch.com/2014/03/08/10-facts-about-earthworms/