Inside of an Earthworm
A small body with many parts
Objective
A poster that will show you the many parts inside of an earthworm. Know interesting facts of the earthworms, how their bodies function and what they are capable of. You can find out what really goes on inside a simple looking body and figure out its complex forms.
Lumbricus terrestri
Lumbricus terrestri is a member of the phylum Annelida, is in the kingdom Animalia, in the class of Oligochaeta, in the order Opisthopora, in the family Lumbricidae and has a genus Lumbricus. An earthworm has a well adapted life digging through soil.Its wiry shape helps it move through its habitat. Earthworms bodies are soft and long with a cylinder shape. Their coloration is red and brown, and can grow up to 8 in. long. The earth worm is important to our environment because they help move the nutrients around the soil. The used to be known as "the intestines of the earth" by Aristotle in ancient Greece.
Habitat
An earthworm's habitat is buried inside the soil. They live in a soil that is dark, cool and slightly damp however, the climate and vegetation also determines where they live. They tend to live in dank or cold places. The reason why they live in dank places is because the dampness helps respire through their skin which helps prevent them from drying out. They are mostly found in New Zealand and indigenous forests due to the climate and vegetation.
Predator & Diet
One of earthworm's largest predators are birds such as the Red Robin. Red Robins mostly catch their meal when they see their opportunity is open. For example in a rainstorm or puddle earthworms rise to the surface to get moist and are left wide open and stranded to any predators. Then the predators come and snatch their meal. Other predators are bullfrogs, crayfish, Largemouth Bass etc... Earthworms sustain themselves by eating anything organic such as dead organisms, manure, and living plants (including bacteria).
Niche
The niche of an earthworm is either in an epigeic area (top soil dwellers), Endogeic (top 20cm of soil) or Anecic (3m below ground). They improve soil wherever they need to and as they move through the soil, they create tunnels in which air and water pass through to the roots of the plants.
Ecological Adaptations
The front section of an earthworm's segmented body contains the wedge like proscenium, which allows the worm to push into tiny cracks in the soil widening it as it goes. The earthworm also has hair around its body to help it maneuver through the soil more easily.Another adaptation they have developed is a slime that helps them move along different types of surfaces.
Digestive System
Food such as soil enters the earthworm's mouth where it is swallowed by the pharynx. Then the soil passes through the esophagus, which has calciferous glands that release calcium carbonate to rid the earthworm's body of excess calcium. After it passes through the esophagus, the food moves into the gizzard. The gizzard uses stones that the earthworms 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 wall contains blood vessels where the digested food is absorbed and transported to the rest of the body.
External System
Anterior (head) End, Mouth, Seminal Recepcle Openings,Female Openings, Clitellum, Setae, Dorsal Pores, Anus, Posterior (tail) end
Digestive System
Mouth, Buccal cavity, Brain, Pharynx, Pseudohearts, Esophagus, Crop, Gizzard, Nephiridia, Intestine, Dorsal Blood Vessel, Ventral Blood Vessel. Seminal Receptacles, Testes, Seminal Vesicles, Ovary, Oviduct, Sperm Duct, Typhlosole, Central Nerve Cord, Septum
Evolutionary relationships and Cladogram
How Earthworms Work in our Ecosystem
Earthworms are like garden helpers. They break down dead matter into the soil which allow new plant and animals to grow. In the soil they move around allowing air inside, mixing minerals around and allowing water through.
Life Cycle of an Earthworm
Earthworms are hermaphroditic meaning that they both have female and male organs. In order to reproduce, they have to line up their clitellums and exchange sperm packets. There are four steps to a life cycle of an earthworm. Earthworms begin as fertilized eggs then they move on to the juvenile stage, followed by the mature stage and finally the mating stage.
Interesting Facts about an Earthworm
- Of the more 180 species found in the U.S. and Canada, 60 are invasive species brought over from the Old World, also known as Night Crawlers.
- Earthworms breathe through their skin because of lack of respiratory organs
- in terms of biomass and over all activity, earthworms dominate the world of soil invertebrates, including arthropods
- can detect the motion of a robin (that can hear the earthworm in its burow)
- earthworms can turn over the top six inches of soil in ten to twenty years