The Worms of the Earth

Earthworm Dissection

Going Underground.

An earthworm is a tube-shaped, segmented animal commonly found living in soil, that feeds on live and dead organic matter. It conducts respiration through its skin. Earthworms carry both male and female sex organs. The scientific name of the earthworm is the lumbricina. Worms are often used as fish bait, but other than fish they are eaten by moles, birds, some ants, birds, raccoon's, chipmunks, monkeys, and groundhogs. The earthworm lacks a skeleton, making it a invertebrate. Earthworms are very important for the soil. Investigations in the United States show that fresh earthworm casts are five times richer in available nitrogen, seven times richer in available phosphates and 11 times richer in available potassium than the surrounding upper 6 inches of soil.

Fossil evidence show that earthworm-like creatures have been around for at least half a billion years, surviving the mass extinction about 65 million years ago.

Digging Deeper

~Earthworms are able to regenerate most lost segments of their bodies.

~Earthworms can process about 10 pounds of organic material a year.

~Some earthworms can grow as long as 22 inches.

~Earthworms do not have eyes, but can sense light.

~Earthworms have been found 2 miles under the earths surface.

Taxonomy and Ecology

Kingdom: Animalia

Phylum: Annelida

Class: Oligochaeta

Order: Megadrilacea


Earthworms form the base of many food chains. Earthworms are classified into three main ecophysiological categories: leaf litter- or compost-dwelling worms that are non burrowing, topsoil- or subsoil-dwelling worms that feed on the soil, burrow and cast within soil, and worms that construct permanent deep vertical burrows which they use to visit the surface to obtain plant material for food, such as leaves. Earthworm populations depend on both physical and chemical properties of the soil, such as temperature, moisture, pH, salts, aeration, and texture, as well as available food, and the ability of the species to reproduce and disperse.

Objective

The purpose of this dissection was to see the inside of the earthworm, and learn about it more in depth. On this day we used dissection scissors and cut from the head to clitellum and opened up the worm.
Earthworm Anatomy

Digestive System

We focused on the digestive system for the earthworm, The digestive system is important because it allows the worm to eat and take in food and keep it alive. Even though the earthworm is a decomposer, it still needs to eat the products it needs to decompose,
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