Earthworm

Daniela Rojas~ Vu-PAP Bio-1st period

Background Information

Scientific Name: Lumbricus terrestris

Habitat: soil

Predators: insects, birds, etc.

Prey: nematodes, protozoans, etc.

Niche: break down organic matter and improve soil.

Ecological Adaptations: Mucus coating helps oxygen pass through the earthworms skin and its streamlined shape helps it move through the soil.

Objective

The earthworm is a member of of the phylum Annelida. An earthworm is a well-adapted to a life of burrowing through the soil. In this investigation, you will observe the external and internal structure of the earthworm.

Digestive System

Function: Food enters the earthworms mouth which is then swallowed by the pharynx. The food passes through the esophagus then the food moves into the crop where it is stored and and the moves into the gizzard. It uses stones that the earthworm eats to grind the food completely. The food moves into the intestines as gland cells in the intestine release fluids to aid in the digestive process. The intestinal walls contain blood vessels where the digested food is absorbed and transported to the rest of the body.


Organs involved: pharynx, esophagus, crop intestine, and gizzard.


More: The circulatory system works with the digestive system to move nutrients throughout the organism and to all of the cells.

Interesting Facts

  • The earthworm is made out of about 100-150 segments.
  • People use earthworm castings as garden fertilizers.
  • Earthworms are the main contributors to enriching and improving soil for plants, animals, and humans.
  • The largest earthworm ever found was in South Africa and measured 22 feet.