Earthworms
Pre-AP Biology Period 7 - VU 4/8/2014
Lumbricina
The Earthworm is under the Kingdom Animalia, and the phylum Annelida. An Earthworm spends most of its life burying itself in soil, because of this, the streamlined, tube shaped body with the addition of sensory nerves along the earthworm's body allows the earthworm to live and dig in soil efficiently.
Did you know?
There's around 6,000 species around the world?
Earthworms breathe through their skin?
Earthworms are hermaphrodites?
Objectives
Student's will be investigating the external and internal anatomy of an Earthworm.
Student's will learn the structures, organs, and functions of the circulatory system.
Student's will learn the ecological role and function of the earthworm.
Habitat
The Earthworm, as we all know... lives in the dirt/soil.
Life Cycle
The life cycle of an earthworm is relatively simple with only 3 stages.
Predators
Insects, Rodents, and Birds are only some of the predators of the Earthworm.
Earthworm Dissection
Earthworm Dissection
Internal Anatomy
brain, nephridium, gizzard, seminal vesicles, espohagus, lateral heart, pharynx, seminal receptacle, ventral blood vessel, and mouth cavity.
Circulatory System
dorsal/ventral vessel and heart.
External Anatomy
Segment and Clitellum
Circulatory System Overview
The earthworm has a dual circulatory system in which both the coelomaic fluid and a closed circulatory system carry the food, waste, and respiratory gasses. The dorsal vessel moves the blood forward, while the other four longitudinal vessels carry the blood to the rear. In segments six through eleven, a pair of aortic arches rings the coelom and acts as hearts, pumping the blood to the ventral vessel that acts as the aorta. The second circulatory system derives from the cells of the digestive system that line the coelom.
Evolution of Earthworms
Ecology
Earthworms are decomposers as they aid in the breakdown of dead organisms and helps create soil sustainable for agriculture.
Human Impact
Earthworms do wonders to humans as they make soil sustainable for agriculture, and in result, we are able to eat vegetables that we eat today. However in return, humans have only been killing off earthworms as they plow their fields and spray pesticides.