Earthworms~ Nightcrawlers

Objectives

Observe the external and internal structure of the earthworm

Background Info

The earthworm, Lumbricus terrestris, is a member of the phylum Annelida. It is well-adapted to a life burrowing in the soil(habitat).Earthworms also help by fertilizing the soil. Its streamlined shape helps it move through the soil and the mucus coating on its skin helps oxygen pass through the earthworm's skin while it is in the air or underwater. Birds tend to be an earthworms main predator.

Dissection Pictures

Digestive System

Digestive System

The digestive system of an earthworm consists of a long tube that runs from the mouth all the way to the anus. The food enters through the mouth and the pharynx acts like a suction pump, sucking in the food. The food then moves into the esophagus and next into the crop in gizzard, in which strong muscular contractions grind the food. After the food passes through the gizzard it enters the intestine where it is digested.

Interesting Facts

-There are about 6,000 earthworm species worldwide.

-they breath through the skin as they lack lungs.

-sizes can vary, some can be less than a half inch long and some over 10 feet.

-earthworms are both male and female producing both sperm and eggs.

Credit

Mitcham. Earthworm Dissection Lab.

Earthworm Dissection. N.d. Www.biologyjunction.com. Web.

"Earthworm." Wikipedia. Wikimedia Foundation, 04 Aug. 2014. Web. 09 Apr. 2014.

"10 Interesting Facts About Earthworms." EcoWatch. N.p.