Sticky and Slimy Earthworms

Earthworm Dissection Lab

Jamie Lu

Mitcham-Pap Bio-6th period

4/6/14

Objectives

  1. Name the organs of the earthworm
  2. One will observe the external and internal structures of the earthworms

Background information

The earthworm also known as the Lumbricus terresrtis. Their habitats are located almost everywhere, tree bark, under rocks, around meadows, and of course in soil. However some can live in small ponds or puddles. They live around cool moist areas. Their predators are numerous, but the main predators are the snake, bird, large rodents and even other worms. Earthworms will eat almost anything from dead animal matter, leaf remains, fungi, bacteria, protozoa's, and DIRT!! An earthworm's niche in it's ecosystem is to become a food source for birds and small animals and also increase soil fertility for the plants. The adaptations made by the earthworm are quite amazing, they create a mucus which covers their body allowing them to move through the soil with ease. Another adaptation would be that when it gets to hot or too cold they move lower into the soil and go through aestivation and lower the metabolic rate to save energy and water.

Dissection Photos

HIGHLIGHT Circulatory System

The circulatory system of an earthworm is closley related to our own human circulatory system and mammals in general. Earthworms have a closed circulatory system meaning all of their blood is encolsed by veins, cappilaries, etc. Earthworms use their skin to absorb oxygen. They come up to the surface for air during storms or rain because the soil is too damp for them to absorb oxygen. Their blood vessels help "process the oxygen" just like a fish does with his gills. Oxygen is taken in from the dorsal blood vessel. It travels through 5 hearts which is it's processing center, and yes earthworms have 5 hearts, it's amazing. These are also known as the aortic arches. After the processing of the aortic arches, it then travels to the lower blood vessel or better known as the ventral blood vessel. This blood vessel, takes the blood carrying oxygen which is then pumped throughout the earthworm's body. There are smaller blood vessels as the blood moves farther away from the heart, the thck vessels are longer needed to distribute the blood.
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Organs of the Circulatory System

Intestine: Absorbs the nutrients from food such as algae.

Aortic Arches: This organ uses oxygen absorbed by the skin and pumps the oxygenated blood throughout the earthworm's body

Anus: The opening of the Intestine.

Ventral Blood Vessel:This blood vessel is where unoxygenated blood comes back.

Dorsal Blood Vessel: This blood vessel delivers the oxygenated blood.

Excretory Organ: The excretory organ is responsible for excreting any wastes wether it be from cellular respiration or eating.

Interesting Facts

  1. There are over 6,000 species of earthworms.
  2. If you put earthworms in a compost bin and put several earthworms inside, it will fertilize the compost.
  3. The "Night Crawler" was an invasive species brought over during America's colonization.
  4. The earthworm is both male and female. They produce eggs and sperm.
  5. A glacier that swept over the northern contiguous United States nearly wiped out all earthworm species in that area.

Classification


Kingdom: Animalia

Phylum: Annelids

Class:oligocheta

Order:opisthopora

Family:lumbriadae

Genus: lumbricus

species: terrestrus

Cladogram

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Human Impact/ Influence

The Lumbricus Terrestris originated in Europe and have been taken over to the United States and anywhere European colonization has been. They have been taken some by accident and others by the necessity of fertilizing soil. Today in modern society humans use earthworms as a source of fertilization and to rid any decaying animal matter