Interview with the Earthworm
Kiara Staton 2nd period Biology Mrs. Vu
Underground with the Earthworm (Background Information)
The earthworm (also known as Lumbricus terrestris) is a member of the phylum Annelida. The earthworm is well adapted to a life of burrowing through the soil. The shape of the worm helps for it to move through the soil, and its mucus coating aids with letting oxygen pass through the earthworm's skin whether it is in the air or in the water. The earthworm moves through the soil by sucking soil through its mouth with help from its muscular pharynx. The earthworm feeds on live and dead organic matter, making it a decomposer.
The external body characters used in identifying different species of earthworms are: the segmental position of the clitellum on the body, body length, body shape (cylindrical or flattened), number of body segments, type and position of body bristles or setae, the description of the tongue-like lobe, the prostomium, projecting forward above the mouth, type of peristomium or first body segment, external position and morphology of genital apertures or opening and type of glandular swellings on the clitellum. The shape and the relationship of various internal organs are also used to identify some species of worms.
Inside the Worm
This lab consisted of both external and internal examinations. The earthworm is made up of many basic structures. The outside of the worm is an almost slimy consistency, and the inside of the worm has parts that include the prostomium, pharynx, crop, and gizzard. The picture below illustrates the inside of the worm and gives a close look at the overall make up of the earthworm.
The internal anatomy of the earthworm has many important key parts. The most important parts are the seminal vesicles which stores sperm from other worms, the clitellium that produces mucus for the outer membrane that is produced during mating. The sepra is a thin inner walls that divide each segment into a separate compartment. The five pairs of enlarged tubes that function as the heart are the aortic arches.
Frequently Asked Questions
The worm is a very interesting organism. They have the ecological niche of burrowing and eating the soil to move around and survive underground. Although they are relatively safe in their habitat (the soil) they are also at risk because they only have receptors and other types of cells to help them to survive and escape predators, nonetheless, these decomposers are very helpful to the environment.
Fun in the Soil
Earthworms live as long as 6 and a half years. Earthworms don't have eyes, but they are able to visualize light and touch with the receptors cells that they have inside their body. Earthworms breathe through their skin, and have many other receptors within their bodies that help them to grow and live.
Earthworms have a rather large digestive system within their bodies. They use their pharynx (apart of the digestive system) as a way to move and work through the soil, while also gathering nutrients that they use as food for themselves from the soil. The esophagus is used to digest and move the food down and lower into the body. After soil has traveled through the esophagus it goes into the intestine before finally making its way through the rest of the body and out of the anus. This is all made possible because of the mouth and the digestive systems ability to move and contract the body of the worm in order to keep things moving.