Earthworms are hermaphrodites since they can generate both sperm and eggs. Mating involves 2 earthworms inseminating each other where sperms are exchanged. The male and female sexual cavities are located near the clitellum. They connect the lower ends of their anteriors with heads positioned in reverse directions. Mucous secreted joins the openings with slime. Sperm is pushed into the longitudinal channels formed by the mucous. They reach the sperm receptacles of their partner, which then break apart. Laying of the eggs and fertilization follows ("Native Australian," 2006)
The circulatory system is constituted of the heart, blood and blood vessels. It is needed to distribute nutrition to different areas in the body and is of two types -- open and closed. An open circulatory system (used by earthworms) is the simpler of the two where the heart drives blood into open spaces. The organs and tissues in the body are soaked in blood which flows at a low pressure. The system lacks any major arteries or veins. A closed circulatory system is used by larger animals. It consists of two...
The pulmonary process passes deoxygenated blood towards the lungs. Systematic circulation transmits oxygenated blood from the lungs into the body. Blood gets distributed via arteries and veins at high pressures (Higgins, 2010).
References
n.a.(n.d.) Earthworm. Retrieved from http://animals.howstuffworks.com/worms/earthworm-info.htm
Sherwood, R. (2010, May 25) How many hearts does an earthworm have?. Retrieved from http://www.ehow.com/about_4597386_many-hearts-earthworm-have_.html
n.a.(2006, Feb 19) Native Australian Earthworms. Retrieved from http://www.wormdigest.org/content/view/209/2/
Higgins, J.(2010, June 6) Difference Between a Closed & Open Circulatory System. Retrieved from http://www.ehow.com/about_6594843_difference-closed-open-circulatory-system.html
n.a. (n.d.) Composting Worms -- FAQ. Retrieved from http://www.planetnatural.com/site/xdpy/kb/worms-faq.html
n.a.(n.d.) Annelida: worms and leeches. Retrieved from http://www.ento.csiro.au/education/allies/annelida.html
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